75 files changed, 2808 insertions, 3804 deletions

diff --git a/advanced_opengl/1.depth/depth b/advanced_opengl/1.depth/depth
index 68f04d6..80da145 100755
--- a/advanced_opengl/1.depth/depth
+++ b/advanced_opengl/1.depth/depth
diff --git a/advanced_opengl/1.depth/depth.c b/advanced_opengl/1.depth/depth.c
index eb79c1c..03092df 100644
--- a/advanced_opengl/1.depth/depth.c
+++ b/advanced_opengl/1.depth/depth.c
@@ -2,273 +2,184 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	State state;
+	S32 width, height;
+	Input input;
 
-#define WIDTH 1280
-#define HEIGHT 720
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-static V3F camera_pos;
-static F32 dt;
-static Input input;
+	width = 1024;
+	height = 768;
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "Depth testing.", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_RESIZABLE, 0);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(WIDTH, HEIGHT, "depth testing", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetKeyCallback(window, key_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glEnable(GL_DEPTH_TEST);
-    glDepthFunc(GL_LESS);
-    
-    U32 shader = create_shader_program("shaders/depth.vs", "shaders/depth.fs");
-    U32 marble_texture = load_texture("../../data/textures/marble.jpg");
-    U32 metal_texture = load_texture("../../data/textures/metal.png");
-    
-    F32 a = 0.5f;
-    F32 vertices[] = {
-        -a, -a, -a, 0.0f,  0.0f,
-        a, -a, -a, 1.0f,  0.0f,
-        a,  a, -a, 1.0f,  1.0f,
-        a,  a, -a, 1.0f,  1.0f,
-        -a,  a, -a, 0.0f,  1.0f,
-        -a, -a, -a, 0.0f,  0.0f,
-        
-        -a, -a,  a, 0.0f,  0.0f,
-        a, -a,  a, 1.0f,  0.0f,
-        a,  a,  a, 1.0f,  1.0f,
-        a,  a,  a, 1.0f,  1.0f,
-        -a,  a,  a, 0.0f,  1.0f,
-        -a, -a,  a, 0.0f,  0.0f,
-        
-        -a,  a,  a, 1.0f,  0.0f,
-        -a,  a, -a, 1.0f,  1.0f,
-        -a, -a, -a, 0.0f,  1.0f,
-        -a, -a, -a, 0.0f,  1.0f,
-        -a, -a,  a, 0.0f,  0.0f,
-        -a,  a,  a, 1.0f,  0.0f,
-        
-        a,  a,  a, 1.0f,  0.0f,
-        a,  a, -a, 1.0f,  1.0f,
-        a, -a, -a, 0.0f,  1.0f,
-        a, -a, -a, 0.0f,  1.0f,
-        a, -a,  a, 0.0f,  0.0f,
-        a,  a,  a, 1.0f,  0.0f,
-        
-        -a, -a, -a, 0.0f,  1.0f,
-        a, -a, -a, 1.0f,  1.0f,
-        a, -a,  a, 1.0f,  0.0f,
-        a, -a,  a, 1.0f,  0.0f,
-        -a, -a,  a, 0.0f,  0.0f,
-        -a, -a, -a, 0.0f,  1.0f,
-        
-        -a,  a, -a, 0.0f,  1.0f,
-        a,  a, -a, 1.0f,  1.0f,
-        a,  a,  a, 1.0f,  0.0f,
-        a,  a,  a, 1.0f,  0.0f,
-        -a,  a,  a, 0.0f,  0.0f,
-        -a,  a, -a,  0.0f,  1.0f
-    };
-    
-    Transform cube_positions[] = {
-        transform_default(),
-        transform_make_translate(v3f(a, 0.0f, -4*a))
-    };
-    
-    Transform platform_position =
-        transform_make_scale_translate(v3f(10.0f, 0.2f, 10.0f),
-                                       v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f));
-    
-    U32 VAO, VBO;
-    glGenVertexArrays(1, &VAO);
-    glBindVertexArray(VAO);
-    
-    glGenBuffers(1, &VBO);
-    glBindBuffer(GL_ARRAY_BUFFER, VBO);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-    
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    
-    glBindVertexArray(0);
-    
-    F32 target_fps = 60.0f;
-    F32 target_spf = 1.0f/target_fps;
-    camera_pos = v3f(0.0f, 0.0f, 3.0f);
-    
-    /* glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); */
-    
-    F32 last_time = glfwGetTime();
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* INFO(pryazha): update */
-        V3F left, up, forward;
-        V3F world_up = v3f(0.0f, 1.0f, 0.0f);
-        
-        forward = v3f_norm(v3f_sub(v3f(0.0f, 0.0f, 0.0f), camera_pos));
-        left = v3f_norm(v3f_cross(world_up, forward));
-        up = v3f_cross(forward, left);
-        
-        V3F dp = v3f_zero();
-        
-        F32 speed = 2.0f;
-        if (key_is_pressed(input.move_right))
-            dp = v3f_add(dp, v3f_scalef(left, -speed*dt));
-        if (key_is_pressed(input.move_forward))
-            dp = v3f_add(dp, v3f_scalef(forward, speed*dt));
-        if (key_is_pressed(input.move_left))
-            dp = v3f_add(dp, v3f_scalef(left, speed*dt));
-        if (key_is_pressed(input.move_backward))
-            dp = v3f_add(dp, v3f_scalef(forward, -speed*dt));
-        if (key_is_pressed(input.move_up))
-            dp = v3f_add(dp, v3f_scalef(up, speed*dt));
-        if (key_is_pressed(input.move_down))
-            dp = v3f_add(dp, v3f_scalef(up, -speed*dt));
-        
-        input_update_last_state(&input);
-        
-        camera_pos = v3f_add(camera_pos, dp);
-        
-        /* INFO(pryazha): render */
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        
-        glUseProgram(shader);
-        MAT4 model, view, projection;
-        
-        view = look_at(camera_pos, v3f(0.0f, 0.0f, 0.0f), v3f(0.0f, 1.0f, 0.0f));
-        shader_set_mat4fv(shader, "view", view);
-        
-        /* projection = ortho(-5.0f, 5.0f, -5.0f, 5.0f, 0.1f, 100.0f); */
-        F32 fovx = 90.0f;
-        F32 near = 0.1f;
-        F32 far = 100.0f;
-        projection = perspective(fovx, (F32)WIDTH/(F32)HEIGHT, near, far);
-        
-        shader_set_mat4fv(shader, "projection", projection);
-        
-        glBindTexture(GL_TEXTURE_2D, marble_texture);
-        glBindVertexArray(VAO);
-        for (S32 transform_index = 0;
-             transform_index < (S32)ArrayCount(cube_positions);
-             ++transform_index)
-        {
-            model = transform_apply(cube_positions[transform_index]);
-            shader_set_mat4fv(shader, "model", model);
-            glDrawArrays(GL_TRIANGLES, 0, 36);
-        }
-        
-        glBindTexture(GL_TEXTURE_2D, metal_texture);
-        model = transform_apply(platform_position);
-        shader_set_mat4fv(shader, "model", model);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf) {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0) {
-                sleep(sleep_time);
-            }
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        last_time = current_time;
-    }
-    
-    glfwTerminate();
-    return(0);
+	glfwMakeContextCurrent(window);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glEnable(GL_DEPTH_TEST);
+	glDepthFunc(GL_LESS);
+
+	U32 shader = create_shader_program("shaders/depth.vert", "shaders/depth.frag");
+	U32 marble_texture = load_texture("../../data/textures/marble.jpg");
+	U32 metal_texture = load_texture("../../data/textures/metal.png");
+
+	F32 a = 0.5f;
+	F32 vertices[] = {
+		-a, -a, -a,  0.0f, 0.0f,
+		 a, -a, -a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		-a,  a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 0.0f,
+
+		-a, -a,  a,  0.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		-a,  a,  a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+
+		-a,  a,  a,  1.0f, 0.0f,
+		-a,  a, -a,  1.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a,  a,  a,  1.0f, 0.0f,
+
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a,  a,  0.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+
+		-a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  1.0f, 1.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+
+		-a,  a, -a,  0.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		-a,  a,  a,  0.0f, 0.0f,
+		-a,  a, -a,  0.0f, 1.0f
+	};
+
+	Transform cube_positions[] = {
+		transform_default(),
+		transform_make_translate(v3f(a, 0.0f, -4*a))
+	};
+
+	V3F platform_pos = v3f(10.0f, 0.2f, 10.0f);
+	V3F platform_scale = v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f);
+	Transform platform_transform = transform_make_scale_translate(platform_pos, platform_scale);
+
+	U32 VAO, VBO;
+	glGenVertexArrays(1, &VAO);
+	glBindVertexArray(VAO);
+	glGenBuffers(1, &VBO);
+	glBindBuffer(GL_ARRAY_BUFFER, VBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	state.camera = (Camera) {
+		v3f(0.0f, 0.0f, 3.0f),
+		90.0f, 0.1f, 100.0f,
+		0.0f, 0.0f
+	};
+
+	F32 target_fps = 60.0f;
+	F32 target_spf = 1.0f/target_fps;
+	F32 last_time = glfwGetTime();
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		process_glfw_keyboard(window, &input);
+		glfwGetFramebufferSize(window, &width, &height);
+
+		/* INFO(pryazha): Update */
+		V3F target = v3f_zero();
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		V3F dv = get_dv_camera_orbital(&input, state.camera.pos,
+					       target, state.dt, 3.0f);
+		state.camera.pos = v3f_add(state.camera.pos, dv);
+
+		input_update_last_state(&input);
+
+		/* INFO(pryazha): Render */
+		MAT4 model, view, proj;
+		view = look_at(state.camera.pos, target, v3f(0.0f, 1.0f, 0.0f));
+		/* proj = ortho(-5.0f, 5.0f, -5.0f, 5.0f, 0.1f, 100.0f); */
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+
+		glViewport(0, 0, width, height);
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		glUseProgram(shader);
+		shader_set_mat4fv(shader, "view", view);
+		shader_set_mat4fv(shader, "proj", proj);
+		glBindTexture(GL_TEXTURE_2D, marble_texture);
+		glBindVertexArray(VAO);
+		for (S32 i = 0; i < (S32)ArrayCount(cube_positions); ++i) {
+			model = transform_apply(cube_positions[i]);
+			shader_set_mat4fv(shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+		}
+		glBindTexture(GL_TEXTURE_2D, metal_texture);
+		model = transform_apply(platform_transform);
+		shader_set_mat4fv(shader, "model", model);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindVertexArray(0);
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		last_time = current_time;
+	}
+
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/1.depth/shaders/depth.fs b/advanced_opengl/1.depth/shaders/depth.frag
index a515c15..710b0d2 100644
--- a/advanced_opengl/1.depth/shaders/depth.fs
+++ b/advanced_opengl/1.depth/shaders/depth.frag
@@ -9,19 +9,15 @@ uniform sampler2D our_texture;
 float near = 0.1;
 float far = 100.0;
 
-float
-linearize_depth(float depth)
+float linearize_depth(float depth)
 {
     float ndc_z = 2.0*depth-1.0;
     return((2.0*near*far)/(far+near-ndc_z*(far-near)));
 }
 
-void
-main(void)
+void main(void)
 {
-    /* 
-    frag_color = texture(our_texture, tex_coords);
-    */
+    /* frag_color = texture(our_texture, tex_coords); */
     float depth = linearize_depth(gl_FragCoord.z)/far;
     frag_color = vec4(vec3(depth), 1.0);
 }
diff --git a/advanced_opengl/2.stencil/shaders/stencil.vs b/advanced_opengl/1.depth/shaders/depth.vert
index 62e71a2..68b8fe2 100644
--- a/advanced_opengl/2.stencil/shaders/stencil.vs
+++ b/advanced_opengl/1.depth/shaders/depth.vert
@@ -4,13 +4,12 @@ layout(location = 1) in vec2 atex_coords;
 
 uniform mat4 model;
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
 out vec2 tex_coords;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
     tex_coords = atex_coords;
 }
diff --git a/advanced_opengl/10.antialiasing/anti_aliasing_msaa b/advanced_opengl/10.antialiasing/anti_aliasing_msaa
index 36811f7..694aa7d 100755
--- a/advanced_opengl/10.antialiasing/anti_aliasing_msaa
+++ b/advanced_opengl/10.antialiasing/anti_aliasing_msaa
diff --git a/advanced_opengl/10.antialiasing/anti_aliasing_msaa.c b/advanced_opengl/10.antialiasing/anti_aliasing_msaa.c
index 65a5b01..250ab97 100644
--- a/advanced_opengl/10.antialiasing/anti_aliasing_msaa.c
+++ b/advanced_opengl/10.antialiasing/anti_aliasing_msaa.c
@@ -2,207 +2,126 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	Arena *arena = 0;
+	Mesh *cube;
+	Input input;
+	F32 target_fps, target_spf, last_time;
+	MAT4 proj, view, model;
+	State state;
+	S32 width, height;
+	U32 color_shader;
 
-static S32 global_width = 1024, global_height = 768;
-static Input global_input;
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    global_input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    global_input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    global_input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    global_input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    global_input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    global_input.move_down.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_SPACE: {
-                    global_input.jump.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_RIGHT: {
-                    global_input.action_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_LEFT: {
-                    global_input.action_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_ESCAPE: {
-                    global_input.exit.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    global_input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    global_input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    global_input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    global_input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    global_input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    global_input.move_down.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_SPACE: {
-                    global_input.jump.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_RIGHT: {
-                    global_input.action_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_LEFT: {
-                    global_input.action_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_ESCAPE: {
-                    global_input.exit.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	width = 1024;
+	height = 768;
 
-void
-window_resize_callback(GLFWwindow* window, int width, int height)
-{
-    global_width = width;
-    global_height = height;
-    glViewport(0, 0, global_width, global_height);
-}
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	glfwWindowHint(GLFW_SAMPLES, 4);
+	window = glfwCreateWindow(width, height, "Anti Aliasing (MSAA)", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    Arena *arena = 0;
-    F32 target_fps, target_spf,
-    last_time, dt;
-    MAT4 projection, view, model;
-    V3F camera_pos;
-    F32 camera_speed, fovx, near, far;
-    U32 color_shader;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    glfwWindowHint(GLFW_SAMPLES, 4);
-    window = glfwCreateWindow(global_width, global_height, "Anti Aliasing (MSAA)", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetKeyCallback(window, key_callback);
-    glfwSetWindowSizeCallback(window, window_resize_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glEnable(GL_DEPTH_TEST);
-    glEnable(GL_MULTISAMPLE);
-    
-    arena = arena_alloc(Megabytes(64));
-    
-    Mesh *cube_mesh = mesh_load_obj(arena, "../../data/models/cube.obj");
-    color_shader = create_shader_program("shaders/color.vs",
-                                         "shaders/color.fs");
-    
-    target_fps = 60.0f;
-    target_spf = 1.0f/target_fps;
-    
-    camera_pos = v3f(0.0f, 0.0f, 3.0f);
-    camera_speed = 2.0f;
-    fovx = 90.0f;
-    near = 0.1f;
-    far = 1000.0f;
-    
-    last_time = glfwGetTime();
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* NOTE(pryazha): Update */
-        if (key_is_pressed(global_input.exit))
-            glfwSetWindowShouldClose(window, GLFW_TRUE);
-        
-        V3F camera_dv = get_dv_camera_orbital(&global_input, camera_pos,
-                                              v3f_zero(), dt, camera_speed);
-        camera_pos = v3f_add(camera_pos, camera_dv);
-        
-        projection = perspective(fovx, (F32)global_width/(F32)global_height, near, far);
-        view = look_at(camera_pos, v3f_zero(), v3f(0.0f, 1.0f, 0.0f));
-        model = mat4_identity();
-        
-        input_update_last_state(&global_input);
-        
-        /* NOTE(pryazha): Render */
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        glUseProgram(color_shader);
-        shader_set_mat4fv(color_shader, "projection", projection);
-        shader_set_mat4fv(color_shader, "view", view);
-        shader_set_mat4fv(color_shader, "model", model);
-        mesh_draw(cube_mesh);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf)
-        {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0)
-                sleep(sleep_time);
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        last_time = current_time;
-    }
-    
-    arena_release(arena);
-    glfwTerminate();
-    return(0);
+	glfwMakeContextCurrent(window);
+
+	glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glEnable(GL_DEPTH_TEST);
+	glEnable(GL_MULTISAMPLE);
+
+	arena = arena_alloc(Kilobytes(4));
+
+	cube = mesh_load_obj(arena, "../../data/models/cube.obj");
+	color_shader = create_shader_program("shaders/color.vert",
+					     "shaders/color.frag");
+
+	state.camera = (Camera) {
+		v3f(0.0f, 0.0f, 3.0f),
+			90.0f, 0.1f, 1000.0f,
+			0.0f, 0.0f
+	};
+	input = input_init();
+
+	target_fps = 60.0f;
+	target_spf = 1.0f/target_fps;
+	last_time = glfwGetTime();
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		/* NOTE(pryazha): Update */
+		glfwGetFramebufferSize(window, &width, &height);
+		process_glfw_keyboard(window, &input);
+		process_glfw_mouse_pos(window, &input);
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		V3F dv = get_dv_camera_first_person(&input, &state.camera,
+						    4.0f, state.dt);
+		state.camera.pos = v3f_add(state.camera.pos, dv);
+
+		F32 sensitivity = 0.1f;
+		input.mouse_offset = v2f_scalef(input.mouse_offset, sensitivity);
+		state.camera.yaw += input.mouse_offset.x;
+		state.camera.pitch += input.mouse_offset.y;
+		if (state.camera.pitch > 89.0f)
+			state.camera.pitch = 89.0f;
+		if (state.camera.pitch < -89.0f)
+			state.camera.pitch = -89.0f;
+
+		input_update_last_state(&input);
+
+		view = get_view_matrix(&state.camera);
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+		model = mat4_identity();
+
+		/* NOTE(pryazha): Render */
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		glUseProgram(color_shader);
+		shader_set_mat4fv(color_shader, "proj", proj);
+		shader_set_mat4fv(color_shader, "view", view);
+		shader_set_mat4fv(color_shader, "model", model);
+		mesh_draw(cube);
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		last_time = current_time;
+	}
+
+	arena_release(arena);
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/10.antialiasing/anti_aliasing_offscreen b/advanced_opengl/10.antialiasing/anti_aliasing_offscreen
index c8a241c..db7f6ec 100755
--- a/advanced_opengl/10.antialiasing/anti_aliasing_offscreen
+++ b/advanced_opengl/10.antialiasing/anti_aliasing_offscreen
diff --git a/advanced_opengl/10.antialiasing/anti_aliasing_offscreen.c b/advanced_opengl/10.antialiasing/anti_aliasing_offscreen.c
index 5c6debb..31f3cae 100644
--- a/advanced_opengl/10.antialiasing/anti_aliasing_offscreen.c
+++ b/advanced_opengl/10.antialiasing/anti_aliasing_offscreen.c
@@ -2,275 +2,200 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	Arena *arena = 0;
+	Mesh *cube;
+	F32 target_fps, target_spf, last_time;
+	MAT4 proj, view, model;
+	U32 fbo, intermediate_fbo, color_tex,
+	    screen_texture, rbo,
+	    quad_vao, vbo, color_shader,
+	    screen_shader;
+	S32 width, height;
+	State state;
+	Input input;
 
-#define WIDTH 1024
-#define HEIGHT 768
-static Input global_input;
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    global_input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    global_input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    global_input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    global_input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    global_input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    global_input.move_down.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_SPACE: {
-                    global_input.jump.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_RIGHT: {
-                    global_input.action_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_LEFT: {
-                    global_input.action_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_ESCAPE: {
-                    global_input.exit.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    global_input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    global_input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    global_input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    global_input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    global_input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    global_input.move_down.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_SPACE: {
-                    global_input.jump.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_RIGHT: {
-                    global_input.action_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_LEFT: {
-                    global_input.action_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_ESCAPE: {
-                    global_input.exit.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	width = 1024;
+	height = 768;
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    Arena *arena = 0;
-    F32 target_fps, target_spf,
-    last_time, dt;
-    MAT4 projection, view, model;
-    V3F camera_pos;
-    F32 camera_speed, fovx, near, far;
-    U32 fbo, intermediate_fbo, color_tex,
-    screen_texture, rbo,
-    quad_vao, vbo,
-    color_shader, screen_shader;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(WIDTH, HEIGHT, "Anti Aliasing (Off-screen)", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetKeyCallback(window, key_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    arena = arena_alloc(Megabytes(64));
-    
-    Mesh *cube_mesh = mesh_load_obj(arena, "../../data/models/cube.obj");
-    color_shader = create_shader_program("shaders/color.vs",
-                                         "shaders/color.fs");
-    screen_shader = create_shader_program("shaders/screen.vs",
-                                          "shaders/screen.fs");
-    glGenFramebuffers(1, &fbo);
-    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
-    glGenTextures(1, &color_tex);
-    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, color_tex);
-    glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGB,
-                            WIDTH, HEIGHT, GL_TRUE);
-    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
-                           GL_TEXTURE_2D_MULTISAMPLE, color_tex, 0);
-    glGenRenderbuffers(1, &rbo);
-    glBindRenderbuffer(GL_RENDERBUFFER, rbo);
-    glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_DEPTH24_STENCIL8,
-                                     WIDTH, HEIGHT);
-    glBindRenderbuffer(GL_RENDERBUFFER, 0);
-    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
-                              GL_RENDERBUFFER, rbo);
-    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
-        fprintf(stderr, "[ERROR]: Framebuffer is not complete.\n");
-    fprintf(stdout, "[INFO]: Multisample fbo complete.\n");
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
-    
-    glGenFramebuffers(1, &intermediate_fbo);
-    glBindFramebuffer(GL_FRAMEBUFFER, intermediate_fbo);
-    glGenTextures(1, &screen_texture);
-    glBindTexture(GL_TEXTURE_2D, screen_texture);
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, WIDTH, HEIGHT,
-                 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
-                           GL_TEXTURE_2D, screen_texture, 0);
-    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
-        fprintf(stderr, "[ERROR]: Framebuffer is not complete.\n");
-    fprintf(stdout, "[INFO]: Intermediate fbo complete.\n");
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
-    
-    F32 quad_vertices[] = {
-        -1.0f, -1.0f, 0.0f,  0.0f, 0.0f,
-        1.0f, -1.0f, 0.0f,  1.0f, 0.0f,
-        1.0f,  1.0f, 0.0f,  1.0f, 1.0f,
-        -1.0f, -1.0f, 0.0f,  0.0f, 0.0f,
-        1.0f,  1.0f, 0.0f,  1.0f, 1.0f,
-        -1.0f,  1.0f, 0.0f,  0.0f, 1.0f
-    };
-    
-    glGenVertexArrays(1, &quad_vao);
-    glBindVertexArray(quad_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(quad_vertices), quad_vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    target_fps = 60.0f;
-    target_spf = 1.0f/target_fps;
-    
-    camera_pos = v3f(0.0f, 0.0f, 3.0f);
-    camera_speed = 2.0f;
-    fovx = 90.0f;
-    near = 0.1f;
-    far = 1000.0f;
-    
-    last_time = glfwGetTime();
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* NOTE(pryazha): Update */
-        if (key_is_pressed(global_input.exit))
-            glfwSetWindowShouldClose(window, GLFW_TRUE);
-        
-        V3F camera_dv = get_dv_camera_orbital(&global_input, camera_pos,
-                                              v3f_zero(), dt, camera_speed);
-        camera_pos = v3f_add(camera_pos, camera_dv);
-        
-        projection = perspective(fovx, (F32)WIDTH/(F32)HEIGHT, near, far);
-        view = look_at(camera_pos, v3f_zero(), v3f(0.0f, 1.0f, 0.0f));
-        model = mat4_identity();
-        
-        input_update_last_state(&global_input);
-        
-        /* NOTE(pryazha): Render */
-        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        glEnable(GL_DEPTH_TEST);
-        glUseProgram(color_shader);
-        shader_set_mat4fv(color_shader, "projection", projection);
-        shader_set_mat4fv(color_shader, "view", view);
-        shader_set_mat4fv(color_shader, "model", model);
-        mesh_draw(cube_mesh);
-        
-        glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
-        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, intermediate_fbo);
-        /* TODO(pryazha): Update width and height */
-        glBlitFramebuffer(0, 0, WIDTH, HEIGHT,
-                          0, 0, WIDTH, HEIGHT,
-                          GL_COLOR_BUFFER_BIT, GL_NEAREST);
-        
-        glBindFramebuffer(GL_FRAMEBUFFER, 0);
-        glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT);
-        glUseProgram(screen_shader);
-        glDisable(GL_DEPTH_TEST);
-        glBindTexture(GL_TEXTURE_2D, screen_texture);
-        glBindVertexArray(quad_vao);
-        glDrawArrays(GL_TRIANGLES, 0, 6);
-        glBindVertexArray(0);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf)
-        {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0)
-                sleep(sleep_time);
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        last_time = current_time;
-    }
-    
-    arena_release(arena);
-    glfwTerminate();
-    return(0);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "Anti Aliasing (Off-screen)", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glfwMakeContextCurrent(window);
+
+	glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	arena = arena_alloc(Kilobytes(4));
+
+	cube = mesh_load_obj(arena, "../../data/models/cube.obj");
+	color_shader = create_shader_program("shaders/color.vert",
+					     "shaders/color.frag");
+	screen_shader = create_shader_program("shaders/screen.vert",
+					      "shaders/screen.frag");
+	glGenFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+	glGenTextures(1, &color_tex);
+	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, color_tex);
+	glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGB,
+				width, height, GL_TRUE);
+	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+			       GL_TEXTURE_2D_MULTISAMPLE, color_tex, 0);
+	glGenRenderbuffers(1, &rbo);
+	glBindRenderbuffer(GL_RENDERBUFFER, rbo);
+	glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_DEPTH24_STENCIL8,
+					 width, height);
+	glBindRenderbuffer(GL_RENDERBUFFER, 0);
+	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
+				  GL_RENDERBUFFER, rbo);
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
+		fprintf(stderr, "[ERROR]: Framebuffer is not complete.\n");
+	fprintf(stdout, "[INFO]: Multisample fbo complete.\n");
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+	glGenFramebuffers(1, &intermediate_fbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, intermediate_fbo);
+	glGenTextures(1, &screen_texture);
+	glBindTexture(GL_TEXTURE_2D, screen_texture);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height,
+		     0, GL_RGB, GL_UNSIGNED_BYTE, 0);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+			       GL_TEXTURE_2D, screen_texture, 0);
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
+		fprintf(stderr, "[ERROR]: Framebuffer is not complete.\n");
+	fprintf(stdout, "[INFO]: Intermediate fbo complete.\n");
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+	F32 quad_vertices[] = {
+		-1.0f, -1.0f, 0.0f,  0.0f, 0.0f,
+		 1.0f, -1.0f, 0.0f,  1.0f, 0.0f,
+		 1.0f,  1.0f, 0.0f,  1.0f, 1.0f,
+		-1.0f, -1.0f, 0.0f,  0.0f, 0.0f,
+		 1.0f,  1.0f, 0.0f,  1.0f, 1.0f,
+		-1.0f,  1.0f, 0.0f,  0.0f, 1.0f
+	};
+
+	glGenVertexArrays(1, &quad_vao);
+	glBindVertexArray(quad_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(quad_vertices), quad_vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	state.camera = (Camera) {
+		v3f(0.0f, 0.0f, 3.0f),
+			90.0f, 0.1f, 1000.0f,
+			0.0f, 0.0f
+	};
+	input = input_init();
+
+	target_fps = 60.0f;
+	target_spf = 1.0f/target_fps;
+	last_time = glfwGetTime();
+
+	while (!glfwWindowShouldClose(window))
+	{
+		glfwPollEvents();
+
+		/* NOTE(pryazha): Update */
+		glfwGetFramebufferSize(window, &width, &height);
+		process_glfw_keyboard(window, &input);
+		process_glfw_mouse_pos(window, &input);
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		V3F dv = get_dv_camera_first_person(&input, &state.camera,
+						    4.0f, state.dt);
+		state.camera.pos = v3f_add(state.camera.pos, dv);
+
+		F32 sensitivity = 0.1f;
+		input.mouse_offset = v2f_scalef(input.mouse_offset, sensitivity);
+		state.camera.yaw += input.mouse_offset.x;
+		state.camera.pitch += input.mouse_offset.y;
+		if (state.camera.pitch > 89.0f)
+			state.camera.pitch = 89.0f;
+		if (state.camera.pitch < -89.0f)
+			state.camera.pitch = -89.0f;
+
+		input_update_last_state(&input);
+
+		view = get_view_matrix(&state.camera);
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+		model = mat4_identity();
+
+		/* NOTE(pryazha): Render */
+		glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		glEnable(GL_DEPTH_TEST);
+		glUseProgram(color_shader);
+		shader_set_mat4fv(color_shader, "proj", proj);
+		shader_set_mat4fv(color_shader, "view", view);
+		shader_set_mat4fv(color_shader, "model", model);
+		mesh_draw(cube);
+
+		glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
+		glBindFramebuffer(GL_DRAW_FRAMEBUFFER, intermediate_fbo);
+		glBlitFramebuffer(0, 0, width, height,
+				  0, 0, width, height,
+				  GL_COLOR_BUFFER_BIT, GL_NEAREST);
+
+		glBindFramebuffer(GL_FRAMEBUFFER, 0);
+		glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT);
+		glUseProgram(screen_shader);
+		glDisable(GL_DEPTH_TEST);
+		glBindTexture(GL_TEXTURE_2D, screen_texture);
+		glBindVertexArray(quad_vao);
+		glDrawArrays(GL_TRIANGLES, 0, 6);
+		glBindVertexArray(0);
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		last_time = current_time;
+	}
+
+	arena_release(arena);
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/2.stencil/shaders/outline.fs b/advanced_opengl/10.antialiasing/shaders/color.frag
index 542143e..b4a31df 100644
--- a/advanced_opengl/2.stencil/shaders/outline.fs
+++ b/advanced_opengl/10.antialiasing/shaders/color.frag
@@ -2,8 +2,7 @@
 
 out vec4 frag_color;
 
-void
-main(void)
+void main(void)
 {
     frag_color = vec4(0.76, 0.47, 0.84, 1.0);
 }
diff --git a/advanced_opengl/10.antialiasing/shaders/color.vs b/advanced_opengl/10.antialiasing/shaders/color.vert
index ade669b..a8b1247 100644
--- a/advanced_opengl/10.antialiasing/shaders/color.vs
+++ b/advanced_opengl/10.antialiasing/shaders/color.vert
@@ -1,12 +1,11 @@
 #version 330 core
 layout(location = 0) in vec3 apos;
 
-uniform mat4 projection;
+uniform mat4 proj;
 uniform mat4 view;
 uniform mat4 model;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
 }
diff --git a/advanced_opengl/10.antialiasing/shaders/screen.fs b/advanced_opengl/10.antialiasing/shaders/screen.frag
index 183d490..5ccc843 100644
--- a/advanced_opengl/10.antialiasing/shaders/screen.fs
+++ b/advanced_opengl/10.antialiasing/shaders/screen.frag
@@ -6,15 +6,13 @@ in vec2 tex_coords;
 
 uniform sampler2D texture1;
 
-vec4
-inversion()
+vec4 inversion()
 {
     vec4 result = vec4(1.0-vec3(texture(texture1, tex_coords)), 1.0);
     return(result);
 }
 
-vec4
-grayscale_average()
+vec4 grayscale_average()
 {
     vec4 tex_color = texture(texture1, tex_coords);
     float average = (tex_color.r+tex_color.g+tex_color.b)/3.0;
@@ -22,8 +20,7 @@ grayscale_average()
     return(result);
 }
 
-vec4
-grayscale_weights()
+vec4 grayscale_weights()
 {
     vec4 tex_color = texture(texture1, tex_coords);
     float average = 0.2126*tex_color.r+0.7152*tex_color.g+0.0722*tex_color.b;
@@ -33,8 +30,7 @@ grayscale_weights()
 
 const float offset = 1.0/300.0;
 
-vec4
-kernel_effect(float[9] kernel)
+vec4 kernel_effect(float[9] kernel)
 {
     vec2 offsets[9] = vec2[](
         vec2(-offset, offset), /* top-left */
@@ -49,13 +45,8 @@ kernel_effect(float[9] kernel)
     );
 
     vec3 sample_texture[9];
-    for (int offset_index = 0;
-         offset_index < 9;
-         ++offset_index)
-    {
-        sample_texture[offset_index] =
-            vec3(texture(texture1, tex_coords+offsets[offset_index]));
-    }
+    for (int i = 0; i < 9; ++i)
+        sample_texture[i] = vec3(texture(texture1, tex_coords+offsets[i]));
 
     vec3 color = vec3(0.0);
     for (int i = 0; i < 9; ++i)
diff --git a/advanced_opengl/10.antialiasing/shaders/screen.vs b/advanced_opengl/10.antialiasing/shaders/screen.vert
index 1f233ee..e473ddd 100644
--- a/advanced_opengl/10.antialiasing/shaders/screen.vs
+++ b/advanced_opengl/10.antialiasing/shaders/screen.vert
@@ -4,8 +4,7 @@ layout(location = 1) in vec2 atex_coords;
 
 out vec2 tex_coords;
 
-void
-main(void)
+void main(void)
 {
     gl_Position = vec4(apos, 1.0);
     tex_coords = atex_coords;
diff --git a/advanced_opengl/10.antialiasing/shaders/color.fs b/advanced_opengl/2.stencil/shaders/outline.frag
index 542143e..b4a31df 100644
--- a/advanced_opengl/10.antialiasing/shaders/color.fs
+++ b/advanced_opengl/2.stencil/shaders/outline.frag
@@ -2,8 +2,7 @@
 
 out vec4 frag_color;
 
-void
-main(void)
+void main(void)
 {
     frag_color = vec4(0.76, 0.47, 0.84, 1.0);
 }
diff --git a/advanced_opengl/2.stencil/shaders/stencil.fs b/advanced_opengl/2.stencil/shaders/stencil.frag
index ff7dd9b..ff7dd9b 100644
--- a/advanced_opengl/2.stencil/shaders/stencil.fs
+++ b/advanced_opengl/2.stencil/shaders/stencil.frag
diff --git a/advanced_opengl/1.depth/shaders/depth.vs b/advanced_opengl/2.stencil/shaders/stencil.vert
index 62e71a2..68b8fe2 100644
--- a/advanced_opengl/1.depth/shaders/depth.vs
+++ b/advanced_opengl/2.stencil/shaders/stencil.vert
@@ -4,13 +4,12 @@ layout(location = 1) in vec2 atex_coords;
 
 uniform mat4 model;
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
 out vec2 tex_coords;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
     tex_coords = atex_coords;
 }
diff --git a/advanced_opengl/2.stencil/stencil b/advanced_opengl/2.stencil/stencil
index eb4eac5..a20d0bb 100755
--- a/advanced_opengl/2.stencil/stencil
+++ b/advanced_opengl/2.stencil/stencil
diff --git a/advanced_opengl/2.stencil/stencil.c b/advanced_opengl/2.stencil/stencil.c
index 9f45048..3b01f5b 100644
--- a/advanced_opengl/2.stencil/stencil.c
+++ b/advanced_opengl/2.stencil/stencil.c
@@ -2,298 +2,212 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	State state;
+	S32 width, height;
+	Input input;
 
-#define WIDTH 1280
-#define HEIGHT 720
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-static V3F camera_pos;
-static F32 dt;
-static Input input;
+	width = 1024;
+	height = 768;
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "Stencil testing", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_RESIZABLE, 0);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(WIDTH, HEIGHT, "Stencil testing", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetKeyCallback(window, key_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glEnable(GL_DEPTH_TEST);
-    
-    glEnable(GL_STENCIL_TEST);
-    glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
-    
-    U32 shader = create_shader_program("shaders/stencil.vs", "shaders/stencil.fs");
-    U32 outline_shader = create_shader_program("shaders/stencil.vs", "shaders/outline.fs");
-    U32 marble_texture = load_texture("../../data/textures/marble.jpg");
-    U32 metal_texture = load_texture("../../data/textures/metal.png");
-    
-    F32 a = 0.5f;
-    F32 vertices[] = {
-        -a, -a, -a, 0.0f,  0.0f,
-        a, -a, -a, 1.0f,  0.0f,
-        a,  a, -a, 1.0f,  1.0f,
-        a,  a, -a, 1.0f,  1.0f,
-        -a,  a, -a, 0.0f,  1.0f,
-        -a, -a, -a, 0.0f,  0.0f,
-        
-        -a, -a,  a, 0.0f,  0.0f,
-        a, -a,  a, 1.0f,  0.0f,
-        a,  a,  a, 1.0f,  1.0f,
-        a,  a,  a, 1.0f,  1.0f,
-        -a,  a,  a, 0.0f,  1.0f,
-        -a, -a,  a, 0.0f,  0.0f,
-        
-        -a,  a,  a, 1.0f,  0.0f,
-        -a,  a, -a, 1.0f,  1.0f,
-        -a, -a, -a, 0.0f,  1.0f,
-        -a, -a, -a, 0.0f,  1.0f,
-        -a, -a,  a, 0.0f,  0.0f,
-        -a,  a,  a, 1.0f,  0.0f,
-        
-        a,  a,  a, 1.0f,  0.0f,
-        a,  a, -a, 1.0f,  1.0f,
-        a, -a, -a, 0.0f,  1.0f,
-        a, -a, -a, 0.0f,  1.0f,
-        a, -a,  a, 0.0f,  0.0f,
-        a,  a,  a, 1.0f,  0.0f,
-        
-        -a, -a, -a, 0.0f,  1.0f,
-        a, -a, -a, 1.0f,  1.0f,
-        a, -a,  a, 1.0f,  0.0f,
-        a, -a,  a, 1.0f,  0.0f,
-        -a, -a,  a, 0.0f,  0.0f,
-        -a, -a, -a, 0.0f,  1.0f,
-        
-        -a,  a, -a, 0.0f,  1.0f,
-        a,  a, -a, 1.0f,  1.0f,
-        a,  a,  a, 1.0f,  0.0f,
-        a,  a,  a, 1.0f,  0.0f,
-        -a,  a,  a, 0.0f,  0.0f,
-        -a,  a, -a,  0.0f,  1.0f
-    };
-    
-    Transform cube_positions[] = {
-        transform_default(),
-        transform_make_translate(v3f(a, 0.0f, -4*a))
-    };
-    
-    Transform platform_position =
-        transform_make_scale_translate(v3f(10.0f, 0.2f, 10.0f),
-                                       v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f));
-    
-    U32 VAO, VBO;
-    glGenVertexArrays(1, &VAO);
-    glBindVertexArray(VAO);
-    
-    glGenBuffers(1, &VBO);
-    glBindBuffer(GL_ARRAY_BUFFER, VBO);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-    
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    
-    glBindVertexArray(0);
-    
-    F32 target_fps = 60.0f;
-    F32 target_spf = 1.0f/target_fps;
-    camera_pos = v3f(0.0f, 0.0f, 3.0f);
-    
-    /* glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); */
-    
-    F32 last_time = glfwGetTime();
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* INFO(pryazha): update */
-        V3F left, up, forward;
-        V3F world_up = v3f(0.0f, 1.0f, 0.0f);
-        
-        forward = v3f_norm(v3f_sub(v3f(0.0f, 0.0f, 0.0f), camera_pos));
-        left = v3f_norm(v3f_cross(world_up, forward));
-        up = v3f_cross(forward, left);
-        
-        V3F dp = v3f_zero();
-        
-        F32 speed = 2.0f;
-        if (key_is_pressed(input.move_right))
-            dp = v3f_add(dp, v3f_scalef(left, -speed*dt));
-        if (key_is_pressed(input.move_forward))
-            dp = v3f_add(dp, v3f_scalef(forward, speed*dt));
-        if (key_is_pressed(input.move_left))
-            dp = v3f_add(dp, v3f_scalef(left, speed*dt));
-        if (key_is_pressed(input.move_backward))
-            dp = v3f_add(dp, v3f_scalef(forward, -speed*dt));
-        if (key_is_pressed(input.move_up))
-            dp = v3f_add(dp, v3f_scalef(up, speed*dt));
-        if (key_is_pressed(input.move_down))
-            dp = v3f_add(dp, v3f_scalef(up, -speed*dt));
-        input_update_last_state(&input);
-        
-        camera_pos = v3f_add(camera_pos, dp);
-        
-        /* INFO(pryazha): Render */
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
-        
-        /* NOTE(pryazha): Update stencil buffer with ones while drawing the cubes */
-        glStencilFunc(GL_ALWAYS, 1, 0xFF);
-        glStencilMask(0xFF);
-        
-        MAT4 model, view, projection;
-        view = look_at(camera_pos, v3f(0.0f, 0.0f, 0.0f), v3f(0.0f, 1.0f, 0.0f));
-        projection = perspective(90.0f, (F32)WIDTH/(F32)HEIGHT, 0.1f, 100.0f);
-        
-        glUseProgram(shader);
-        shader_set_mat4fv(shader, "view", view);
-        shader_set_mat4fv(shader, "projection", projection);
-        
-        glBindTexture(GL_TEXTURE_2D, marble_texture);
-        glBindVertexArray(VAO);
-        for (S32 transform_index = 0;
-             transform_index < (S32)ArrayCount(cube_positions);
-             ++transform_index)
-        {
-            model = transform_apply(cube_positions[transform_index]);
-            shader_set_mat4fv(shader, "model", model);
-            glDrawArrays(GL_TRIANGLES, 0, 36);
-        }
-        
-        /* NOTE(pryazha): Don't update stencil buffer while drawing the floor */
-        glStencilMask(0x00);
-        
-        glBindTexture(GL_TEXTURE_2D, metal_texture);
-        model = transform_apply(platform_position);
-        shader_set_mat4fv(shader, "model", model);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        
-        glStencilFunc(GL_NOTEQUAL, 1, 0xFF);
-        glStencilMask(0x00);
-        glDisable(GL_DEPTH_TEST);
-        
-        glUseProgram(outline_shader);
-        shader_set_mat4fv(outline_shader, "view", view);
-        shader_set_mat4fv(outline_shader, "projection", projection);
-        
-        for (S32 transform_index = 0;
-             transform_index < (S32)ArrayCount(cube_positions);
-             ++transform_index)
-        {
-            Transform transform = cube_positions[transform_index];
-            transform = transform_scale(transform, v3f(1.1f, 1.1f, 1.1f));
-            shader_set_mat4fv(outline_shader, "model", transform_apply(transform));
-            glDrawArrays(GL_TRIANGLES, 0, 36);
-        }
-        
-        glStencilMask(0xFF);
-        glStencilFunc(GL_ALWAYS, 1, 0xFF);
-        glEnable(GL_DEPTH_TEST);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf) {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0) {
-                sleep(sleep_time);
-            }
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        last_time = current_time;
-    }
-    
-    glfwTerminate();
-    return(0);
+	glfwMakeContextCurrent(window);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glEnable(GL_DEPTH_TEST);
+	glEnable(GL_STENCIL_TEST);
+	glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
+
+	U32 shader = create_shader_program("shaders/stencil.vert", "shaders/stencil.frag");
+	U32 outline_shader = create_shader_program("shaders/stencil.vert", "shaders/outline.frag");
+	U32 marble_texture = load_texture("../../data/textures/marble.jpg");
+	U32 metal_texture = load_texture("../../data/textures/metal.png");
+
+	F32 a = 0.5f;
+	F32 vertices[] = {
+		-a, -a, -a,  0.0f, 0.0f,
+		 a, -a, -a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		-a,  a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 0.0f,
+
+		-a, -a,  a,  0.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		-a,  a,  a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+
+		-a,  a,  a,  1.0f, 0.0f,
+		-a,  a, -a,  1.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a,  a,  a,  1.0f, 0.0f,
+
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a,  a,  0.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+
+		-a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  1.0f, 1.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+
+		-a,  a, -a,  0.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		-a,  a,  a,  0.0f, 0.0f,
+		-a,  a, -a,  0.0f, 1.0f
+	};
+
+	Transform cube_positions[] = {
+		transform_default(),
+		transform_make_translate(v3f(a, 0.0f, -4*a))
+	};
+
+	V3F platform_pos = v3f(10.0f, 0.2f, 10.0f);
+	V3F platform_scale = v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f);
+	Transform platform_transform = transform_make_scale_translate(platform_pos,
+								      platform_scale);
+
+	U32 VAO, VBO;
+	glGenVertexArrays(1, &VAO);
+	glBindVertexArray(VAO);
+	glGenBuffers(1, &VBO);
+	glBindBuffer(GL_ARRAY_BUFFER, VBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	state.camera = (Camera) {
+		v3f(0.0f, 0.0f, 3.0f),
+		90.0f, 0.1f, 100.0f,
+		0.0f, 0.0f
+	};
+
+	F32 target_fps = 60.0f;
+	F32 target_spf = 1.0f/target_fps;
+	F32 last_time = glfwGetTime();
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		process_glfw_keyboard(window, &input);
+		glfwGetFramebufferSize(window, &width, &height);
+
+		/* INFO(pryazha): Update */
+		V3F target = v3f_zero();
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		V3F dv = get_dv_camera_orbital(&input, state.camera.pos,
+					       target, state.dt, 3.0f);
+		state.camera.pos = v3f_add(state.camera.pos, dv);
+
+		input_update_last_state(&input);
+
+		/* INFO(pryazha): Render */
+		MAT4 model, view, proj;
+		view = look_at(state.camera.pos, target, v3f(0.0f, 1.0f, 0.0f));
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+
+		glViewport(0, 0, width, height);
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+		/* NOTE(pryazha): Update stencil buffer with ones while drawing the cubes */
+		glStencilFunc(GL_ALWAYS, 1, 0xFF);
+		glStencilMask(0xFF);
+
+		glUseProgram(shader);
+		shader_set_mat4fv(shader, "view", view);
+		shader_set_mat4fv(shader, "proj", proj);
+		glBindTexture(GL_TEXTURE_2D, marble_texture);
+		glBindVertexArray(VAO);
+		for (S32 i = 0; i < (S32)ArrayCount(cube_positions); ++i) {
+			model = transform_apply(cube_positions[i]);
+			shader_set_mat4fv(shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+		}
+
+		/* NOTE(pryazha): Don't update stencil buffer while drawing the floor */
+		glStencilMask(0x00);
+
+		glBindTexture(GL_TEXTURE_2D, metal_texture);
+		model = transform_apply(platform_transform);
+		shader_set_mat4fv(shader, "model", model);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+
+		glStencilFunc(GL_NOTEQUAL, 1, 0xFF);
+		glStencilMask(0x00);
+		glDisable(GL_DEPTH_TEST);
+
+		glUseProgram(outline_shader);
+		shader_set_mat4fv(outline_shader, "view", view);
+		shader_set_mat4fv(outline_shader, "proj", proj);
+		for (S32 i = 0; i < (S32)ArrayCount(cube_positions); ++i) {
+			Transform transform = cube_positions[i];
+			transform = transform_scale(transform, v3f(1.1f, 1.1f, 1.1f));
+			model = transform_apply(transform);
+			shader_set_mat4fv(outline_shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+		}
+
+		glStencilMask(0xFF);
+		glStencilFunc(GL_ALWAYS, 1, 0xFF);
+		glEnable(GL_DEPTH_TEST);
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		last_time = current_time;
+	}
+
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/3.blending/blending b/advanced_opengl/3.blending/blending
index 40fe12a..c7a5ea0 100755
--- a/advanced_opengl/3.blending/blending
+++ b/advanced_opengl/3.blending/blending
diff --git a/advanced_opengl/3.blending/blending.c b/advanced_opengl/3.blending/blending.c
index 9ac92ea..8142ab3 100644
--- a/advanced_opengl/3.blending/blending.c
+++ b/advanced_opengl/3.blending/blending.c
@@ -2,372 +2,277 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	State state;
+	S32 width, height;
+	Input input;
 
-#define WIDTH 1280
-#define HEIGHT 720
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-static V3F camera_pos;
-static F32 dt;
-static Input input;
+	width = 1024;
+	height = 768;
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "Stencil testing", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_RESIZABLE, 0);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(WIDTH, HEIGHT, "Blending", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetKeyCallback(window, key_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glEnable(GL_DEPTH_TEST);
-    glEnable(GL_BLEND);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-    
-    U32 shader = create_shader_program("shaders/blending.vs", "shaders/blending.fs");
-    U32 grass_shader = create_shader_program("shaders/blending.vs", "shaders/grass.fs");
-    U32 marble_texture = load_texture("../../data/textures/marble.jpg");
-    U32 metal_texture = load_texture("../../data/textures/metal.png");
-    U32 grass_texture = load_texture("../../data/textures/grass.png");
-    U32 window_texture = load_texture("../../data/textures/window.png");
-    
-    F32 a = 0.5f;
-    F32 vertices[] = {
-        -a, -a, -a,  0.0f, 0.0f,
-        a, -a, -a,  1.0f, 0.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        -a,  a, -a,  0.0f, 1.0f,
-        -a, -a, -a,  0.0f, 0.0f,
-        
-        -a, -a,  a,  0.0f, 0.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        a,  a,  a,  1.0f, 1.0f,
-        a,  a,  a,  1.0f, 1.0f,
-        -a,  a,  a,  0.0f, 1.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        
-        -a,  a,  a,  1.0f, 0.0f,
-        -a,  a, -a,  1.0f, 1.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        -a,  a,  a,  1.0f, 0.0f,
-        
-        a,  a,  a,  1.0f, 0.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a, -a, -a,  0.0f, 1.0f,
-        a, -a, -a,  0.0f, 1.0f,
-        a, -a,  a,  0.0f, 0.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        
-        -a, -a, -a,  0.0f, 1.0f,
-        a, -a, -a,  1.0f, 1.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        
-        -a,  a, -a,  0.0f, 1.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        -a,  a,  a,  0.0f, 0.0f,
-        -a,  a, -a,  0.0f, 1.0f
-    };
-    
-    Transform cube_positions[] = {
-        transform_default(),
-        transform_make_translate(v3f(a, 0.0f, -4.0f*a))
-    };
-    
-    Transform platform_position =
-        transform_make_scale_translate(v3f(10.0f, 0.2f, 10.0f),
-                                       v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f));
-    
-    U32 cube_vao, quad_vao, vbo;
-    
-    glGenVertexArrays(1, &cube_vao);
-    glBindVertexArray(cube_vao);
-    
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-    
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    F32 quad_side = 1.0f;
-    F32 quad_vertices[] = {
-        /* NOTE(pryazha): left top triangle */
-        -quad_side/2.0f, 0.0f,      0.0f,  0.0f, 0.0f,
-        -quad_side/2.0f, quad_side, 0.0f,  0.0f, 1.0f,
-        quad_side/2.0f, quad_side, 0.0f,  1.0f, 1.0f,
-        
-        /* NOTE(pryazha): right bottom triangle */
-        -quad_side/2.0f, 0.0f,      0.0f,  0.0f, 0.0f,
-        quad_side/2.0f, quad_side, 0.0f,  1.0f, 1.0f,
-        quad_side/2.0f, 0.0f,      0.0f,  1.0f, 0.0f
-    };
-    
-    glGenVertexArrays(1, &quad_vao);
-    glBindVertexArray(quad_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(quad_vertices), quad_vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    Transform grass_positions[] = {
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(1.0f, -0.5f, 0.0f)),
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(-1.5f, -0.5f, 2.0f)),
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(0.0f, -0.5f, -1.0f)),
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(3.0f, -0.5f, 1.0f)),
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(-2.0f, -0.5f, -3.0f))
-    };
-    
-    Transform window_transforms[] = {
-        transform_make_translate(v3f(0.0f, -0.5f, a+0.1f)),
-        transform_make_translate(v3f(0.0f, -0.5f, 2.0f)),
-        transform_make_translate(v3f(1.0f, -0.5f, -1.0f)),
-        transform_make_translate(v3f(-2.0f, -0.5f, 0.5f)),
-        transform_make_translate(v3f(-3.0f, -0.5f, -3.0f)),
-        transform_make_translate(v3f(3.0f, -0.5f, 0.2)),
-    };
-    
-    F32 angle = 0.0f;
-    for (S32 window_index = 0;
-         window_index < (S32)ArrayCount(window_transforms);
-         ++window_index)
-    {
-        Transform *transform = window_transforms+window_index;
-        *transform = transform_rotate(*transform, v3f(0.0f, angle, 0.0f));
-        angle += 30.0f;
-    }
-    
-    F32 target_fps = 60.0f;
-    F32 target_spf = 1.0f/target_fps;
-    camera_pos = v3f(0.0f, 0.0f, 3.0f);
-    
-    /* glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); */
-    
-    F32 last_time = glfwGetTime();
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* INFO(pryazha): update */
-        V3F left, up, forward;
-        V3F world_up = v3f(0.0f, 1.0f, 0.0f);
-        
-        forward = v3f_norm(v3f_sub(v3f(0.0f, 0.0f, 0.0f), camera_pos));
-        left = v3f_norm(v3f_cross(world_up, forward));
-        up = v3f_cross(forward, left);
-        
-        V3F dp = v3f_zero();
-        
-        F32 speed = 2.0f;
-        if (key_is_pressed(input.move_right))
-            dp = v3f_add(dp, v3f_scalef(left, -speed*dt));
-        if (key_is_pressed(input.move_forward))
-            dp = v3f_add(dp, v3f_scalef(forward, speed*dt));
-        if (key_is_pressed(input.move_left))
-            dp = v3f_add(dp, v3f_scalef(left, speed*dt));
-        if (key_is_pressed(input.move_backward))
-            dp = v3f_add(dp, v3f_scalef(forward, -speed*dt));
-        if (key_is_pressed(input.move_up))
-            dp = v3f_add(dp, v3f_scalef(up, speed*dt));
-        if (key_is_pressed(input.move_down))
-            dp = v3f_add(dp, v3f_scalef(up, -speed*dt));
-        
-        input_update_last_state(&input);
-        
-        camera_pos = v3f_add(camera_pos, dp);
-        
-        Transform sorted_window_transforms[ArrayCount(window_transforms)];
-        MemoryCopyArray(sorted_window_transforms, window_transforms);
-        for (S32 i = 0; i < (S32)ArrayCount(sorted_window_transforms); ++i) {
-            for (S32 pos_index = 1;
-                 pos_index < (S32)ArrayCount(sorted_window_transforms);
-                 ++pos_index)
-            {
-                F32 distance_left = v3f_length(v3f_sub(sorted_window_transforms[pos_index-1].translate, camera_pos));
-                F32 distance_right = v3f_length(v3f_sub(sorted_window_transforms[pos_index].translate, camera_pos));
-                if (distance_left < distance_right) {
-                    Transform temp = sorted_window_transforms[pos_index];
-                    sorted_window_transforms[pos_index] = sorted_window_transforms[pos_index-1];
-                    sorted_window_transforms[pos_index-1] = temp;
-                }
-            }
-        }
-        
-        /* INFO(pryazha): Render */
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        
-        MAT4 model, view, projection;
-        view = look_at(camera_pos, v3f(0.0f, 0.0f, 0.0f), v3f(0.0f, 1.0f, 0.0f));
-        projection = perspective(90.0f, (F32)WIDTH/(F32)HEIGHT, 0.1f, 100.0f);
-        
-        glUseProgram(shader);
-        shader_set_mat4fv(shader, "view", view);
-        shader_set_mat4fv(shader, "projection", projection);
-        
-        glBindTexture(GL_TEXTURE_2D, marble_texture);
-        glBindVertexArray(cube_vao);
-        for (S32 transform_index = 0;
-             transform_index < (S32)ArrayCount(cube_positions);
-             ++transform_index)
-        {
-            model = transform_apply(cube_positions[transform_index]);
-            shader_set_mat4fv(shader, "model", model);
-            glDrawArrays(GL_TRIANGLES, 0, 36);
-        }
-        
-        glBindTexture(GL_TEXTURE_2D, metal_texture);
-        model = transform_apply(platform_position);
-        shader_set_mat4fv(shader, "model", model);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        
-        glUseProgram(grass_shader);
-        glBindTexture(GL_TEXTURE_2D, grass_texture);
-        shader_set_mat4fv(shader, "view", view);
-        shader_set_mat4fv(shader, "projection", projection);
-        glBindVertexArray(quad_vao);
-        
-        F32 angle = 0.0f;
-        for (S32 transform_index = 0;
-             transform_index < (S32)ArrayCount(grass_positions);
-             ++transform_index)
-        {
-            Transform *transform = grass_positions+transform_index;
-            Transform new_transform = transform_rotate(*transform, v3f(0.0f, angle, 0.0f));
-            shader_set_mat4fv(shader, "model", transform_apply(new_transform));
-            glDrawArrays(GL_TRIANGLES, 0, 6);
-            angle += 30.0f;
-        }
-        
-        glUseProgram(shader);
-        glBindTexture(GL_TEXTURE_2D, window_texture);
-        shader_set_mat4fv(shader, "view", view);
-        shader_set_mat4fv(shader, "projection", projection);
-        for (S32 window_index = 0;
-             window_index < (S32)ArrayCount(sorted_window_transforms);
-             ++window_index)
-        {
-            MAT4 model = transform_apply(sorted_window_transforms[window_index]);
-            shader_set_mat4fv(shader, "model", model);
-            glDrawArrays(GL_TRIANGLES, 0, 6);
-        }
-        
-        glBindVertexArray(0);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf) {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0) {
-                sleep(sleep_time);
-            }
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        last_time = current_time;
-    }
-    
-    glfwTerminate();
-    return(0);
+	glfwMakeContextCurrent(window);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glEnable(GL_DEPTH_TEST);
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+	U32 shader = create_shader_program("shaders/blending.vert", "shaders/blending.frag");
+	U32 grass_shader = create_shader_program("shaders/blending.vert", "shaders/grass.frag");
+	U32 marble_texture = load_texture("../../data/textures/marble.jpg");
+	U32 metal_texture = load_texture("../../data/textures/metal.png");
+	U32 grass_texture = load_texture("../../data/textures/grass.png");
+	U32 window_texture = load_texture("../../data/textures/window.png");
+
+	F32 a = 0.5f;
+	F32 vertices[] = {
+		-a, -a, -a,  0.0f, 0.0f,
+		 a, -a, -a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		-a,  a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 0.0f,
+
+		-a, -a,  a,  0.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		-a,  a,  a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+
+		-a,  a,  a,  1.0f, 0.0f,
+		-a,  a, -a,  1.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a,  a,  a,  1.0f, 0.0f,
+
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a,  a,  0.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+
+		-a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  1.0f, 1.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+
+		-a,  a, -a,  0.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		-a,  a,  a,  0.0f, 0.0f,
+		-a,  a, -a,  0.0f, 1.0f
+	};
+
+	Transform cube_positions[] = {
+		transform_default(),
+		transform_make_translate(v3f(a, 0.0f, -4.0f*a))
+	};
+
+	V3F platform_pos = v3f(10.0f, 0.2f, 10.0f);
+	V3F platform_scale = v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f);
+	Transform platform_transform = transform_make_scale_translate(platform_pos,
+								      platform_scale);
+
+	U32 cube_vao, quad_vao, vbo;
+	glGenVertexArrays(1, &cube_vao);
+	glBindVertexArray(cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	F32 quad_side = 1.0f;
+	F32 quad_vertices[] = {
+		/* NOTE(pryazha): left top triangle */
+		-quad_side/2.0f, 0.0f,      0.0f,  0.0f, 0.0f,
+		-quad_side/2.0f, quad_side, 0.0f,  0.0f, 1.0f,
+		quad_side/2.0f, quad_side, 0.0f,  1.0f, 1.0f,
+
+		/* NOTE(pryazha): right bottom triangle */
+		-quad_side/2.0f, 0.0f,      0.0f,  0.0f, 0.0f,
+		quad_side/2.0f, quad_side, 0.0f,  1.0f, 1.0f,
+		quad_side/2.0f, 0.0f,      0.0f,  1.0f, 0.0f
+	};
+
+	glGenVertexArrays(1, &quad_vao);
+	glBindVertexArray(quad_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(quad_vertices), quad_vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	Transform grass_positions[] = {
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(1.0f, -0.5f, 0.0f)),
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(-1.5f, -0.5f, 2.0f)),
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(0.0f, -0.5f, -1.0f)),
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(3.0f, -0.5f, 1.0f)),
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(-2.0f, -0.5f, -3.0f))
+	};
+
+	Transform window_transforms[] = {
+		transform_make_translate(v3f(0.0f, -0.5f, a+0.1f)),
+		transform_make_translate(v3f(0.0f, -0.5f, 2.0f)),
+		transform_make_translate(v3f(1.0f, -0.5f, -1.0f)),
+		transform_make_translate(v3f(-2.0f, -0.5f, 0.5f)),
+		transform_make_translate(v3f(-3.0f, -0.5f, -3.0f)),
+		transform_make_translate(v3f(3.0f, -0.5f, 0.2)),
+	};
+
+	F32 angle = 0.0f;
+	for (S32 i = 0; i < (S32)ArrayCount(window_transforms); ++i) {
+		Transform *transform = window_transforms+i;
+		*transform = transform_rotate(*transform, v3f(0.0f, angle, 0.0f));
+		angle += 30.0f;
+	}
+
+	state.camera = (Camera) {
+		v3f(0.0f, 0.0f, 3.0f),
+		90.0f, 0.1f, 100.0f,
+		0.0f, 0.0f
+	};
+
+	F32 target_fps = 60.0f;
+	F32 target_spf = 1.0f/target_fps;
+	F32 last_time = glfwGetTime();
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		process_glfw_keyboard(window, &input);
+		glfwGetFramebufferSize(window, &width, &height);
+
+		/* INFO(pryazha): Update */
+		V3F target = v3f_zero();
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		V3F dv = get_dv_camera_orbital(&input, state.camera.pos,
+					       target, state.dt, 3.0f);
+		state.camera.pos = v3f_add(state.camera.pos, dv);
+
+		input_update_last_state(&input);
+
+		Transform sorted[ArrayCount(window_transforms)];
+		MemoryCopyArray(sorted, window_transforms);
+		for (S32 i = 0; i < (S32)ArrayCount(sorted); ++i) {
+			for (S32 j = 1; j < (S32)ArrayCount(sorted); ++j) {
+				F32 dist_left = v3f_length(v3f_sub(sorted[j-1].translate, state.camera.pos));
+				F32 dist_right = v3f_length(v3f_sub(sorted[j].translate, state.camera.pos));
+				if (dist_left < dist_right) {
+					Transform temp = sorted[j];
+					sorted[j] = sorted[j-1];
+					sorted[j-1] = temp;
+				}
+			}
+		}
+
+		/* INFO(pryazha): Render */
+		MAT4 model, view, proj;
+		view = look_at(state.camera.pos, target, v3f(0.0f, 1.0f, 0.0f));
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+
+		glViewport(0, 0, width, height);
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		glUseProgram(shader);
+		shader_set_mat4fv(shader, "view", view);
+		shader_set_mat4fv(shader, "proj", proj);
+		glBindTexture(GL_TEXTURE_2D, marble_texture);
+		glBindVertexArray(cube_vao);
+		for (S32 i = 0; i < (S32)ArrayCount(cube_positions); ++i) {
+			model = transform_apply(cube_positions[i]);
+			shader_set_mat4fv(shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+		}
+
+		glBindTexture(GL_TEXTURE_2D, metal_texture);
+		model = transform_apply(platform_transform);
+		shader_set_mat4fv(shader, "model", model);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindVertexArray(0);
+
+		glUseProgram(grass_shader);
+		glBindTexture(GL_TEXTURE_2D, grass_texture);
+		shader_set_mat4fv(shader, "view", view);
+		shader_set_mat4fv(shader, "proj", proj);
+		glBindVertexArray(quad_vao);
+		F32 angle = 0.0f;
+		for (S32 i = 0; i < (S32)ArrayCount(grass_positions); ++i) {
+			Transform *transform = grass_positions+i;
+			Transform new_transform = transform_rotate(*transform, v3f(0.0f, angle, 0.0f));
+			model = transform_apply(new_transform);
+			shader_set_mat4fv(shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 6);
+			angle += 30.0f;
+		}
+
+		glUseProgram(shader);
+		glBindTexture(GL_TEXTURE_2D, window_texture);
+		shader_set_mat4fv(shader, "view", view);
+		shader_set_mat4fv(shader, "proj", proj);
+		for (S32 i = 0; i < (S32)ArrayCount(sorted); ++i) {
+			MAT4 model = transform_apply(sorted[i]);
+			shader_set_mat4fv(shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 6);
+		}
+		glBindVertexArray(0);
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		last_time = current_time;
+	}
+
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/6.cubemaps/shaders/cube.fs b/advanced_opengl/3.blending/shaders/blending.frag
index f58c5d3..71892a7 100644
--- a/advanced_opengl/6.cubemaps/shaders/cube.fs
+++ b/advanced_opengl/3.blending/shaders/blending.frag
@@ -6,8 +6,7 @@ in vec2 tex_coords;
 
 uniform sampler2D texture1;
 
-void
-main(void)
+void main(void)
 {
     frag_color = texture(texture1, tex_coords);
 }
diff --git a/advanced_opengl/4.face_culling/shaders/face_culling.vs b/advanced_opengl/3.blending/shaders/blending.vert
index 62e71a2..68b8fe2 100644
--- a/advanced_opengl/4.face_culling/shaders/face_culling.vs
+++ b/advanced_opengl/3.blending/shaders/blending.vert
@@ -4,13 +4,12 @@ layout(location = 1) in vec2 atex_coords;
 
 uniform mat4 model;
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
 out vec2 tex_coords;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
     tex_coords = atex_coords;
 }
diff --git a/advanced_opengl/3.blending/shaders/grass.fs b/advanced_opengl/3.blending/shaders/grass.frag
index cecb0ce..85c806f 100644
--- a/advanced_opengl/3.blending/shaders/grass.fs
+++ b/advanced_opengl/3.blending/shaders/grass.frag
@@ -6,12 +6,10 @@ in vec2 tex_coords;
 
 uniform sampler2D texture1;
 
-void
-main(void)
+void main(void)
 {
     vec4 tex_color = texture(texture1, tex_coords);
-    if (tex_color.a <= 0.2) {
+    if (tex_color.a <= 0.2)
         discard;
-    }
     frag_color = tex_color;
 }
diff --git a/advanced_opengl/4.face_culling/face_culling b/advanced_opengl/4.face_culling/face_culling
index eb6e3e9..c00eeaa 100755
--- a/advanced_opengl/4.face_culling/face_culling
+++ b/advanced_opengl/4.face_culling/face_culling
diff --git a/advanced_opengl/4.face_culling/face_culling.c b/advanced_opengl/4.face_culling/face_culling.c
index 9769b53..c3a31c0 100644
--- a/advanced_opengl/4.face_culling/face_culling.c
+++ b/advanced_opengl/4.face_culling/face_culling.c
@@ -2,305 +2,234 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	State state;
+	S32 width, height;
+	Input input;
 
-#define WIDTH 1280
-#define HEIGHT 720
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-static V3F camera_pos;
-static F32 dt;
-static Input input;
+	width = 1024;
+	height = 768;
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "Face culling", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_RESIZABLE, 0);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(WIDTH, HEIGHT, "Face culling", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetKeyCallback(window, key_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glEnable(GL_DEPTH_TEST);
-    glEnable(GL_CULL_FACE);
-    glFrontFace(GL_CW);
-    glCullFace(GL_BACK);
-    
-    U32 shader = create_shader_program("shaders/face_culling.vs", "shaders/face_culling.fs");
-    
-    U32 grid_texture = load_texture("../../data/textures/grid.png");
-    
-    F32 a = 0.5f;
-    /* NOTE(pryazha): Counter-clockwise order */
-    F32 cube_vertices_ccw[] = {
-        /* NOTE(pryazha): Back face */
-        a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a,  a, -a,  1.0f, 1.0f, /* top-right */
-        a,  a, -a,  0.0f, 1.0f, /* top-left */
-        a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a, -a, -a,  1.0f, 0.0f, /* bottom-right */
-        -a,  a, -a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Front face */
-        -a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a,  a,  1.0f, 1.0f, /* top-right */
-        -a,  a,  a,  0.0f, 1.0f, /* top-left */
-        -a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a, -a,  a,  1.0f, 0.0f, /* bottom-right */
-        a,  a,  a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Left face */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a,  a,  a,  1.0f, 1.0f, /* top-right */
-        -a,  a, -a,  0.0f, 1.0f, /* top-left */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a, -a,  a,  1.0f, 0.0f, /* bottom-right */
-        -a,  a,  a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Right face */
-        a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        a,  a,  a,  0.0f, 1.0f, /* top-left */
-        a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a, -a, -a,  1.0f, 0.0f, /* bottom-right */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Top face */
-        -a,  a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        -a,  a, -a,  0.0f, 1.0f, /* top-left */
-        -a,  a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a,  a,  1.0f, 0.0f, /* bottom-right */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Bottom face */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        a, -a,  a,  1.0f, 1.0f, /* top-right */
-        -a, -a,  a,  0.0f, 1.0f, /* top-left */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        a, -a, -a,  1.0f, 0.0f, /* bottom-right */
-        a, -a,  a,  1.0f, 1.0f, /* top-right */
-    };
-    
-    F32 cube_vertices_cw[] = {
-        /* NOTE(pryazha): Back face */
-        a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a,  a, -a,  1.0f, 1.0f, /* top-right */
-        -a, -a, -a,  1.0f, 0.0f, /* bottom-right */
-        a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        a,  a, -a,  0.0f, 1.0f, /* top-left */
-        -a,  a, -a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Front face */
-        -a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a,  a,  1.0f, 1.0f, /* top-right */
-        a, -a,  a,  1.0f, 0.0f, /* bottom-right */
-        -a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        -a,  a,  a,  0.0f, 1.0f, /* top-left */
-        a,  a,  a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Left face */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a,  a,  a,  1.0f, 1.0f, /* top-right */
-        -a, -a,  a,  1.0f, 0.0f, /* bottom-right */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a,  a, -a,  0.0f, 1.0f, /* top-left */
-        -a,  a,  a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Right face */
-        a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        a, -a, -a,  1.0f, 0.0f, /* bottom-right */
-        a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a,  a,  0.0f, 1.0f, /* top-left */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Top face */
-        -a,  a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        a,  a,  a,  1.0f, 0.0f, /* bottom-right */
-        -a,  a,  a,  0.0f, 0.0f, /* bottom-left */
-        -a,  a, -a,  0.0f, 1.0f, /* top-left */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Bottom face */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        a, -a,  a,  1.0f, 1.0f, /* top-right */
-        a, -a, -a,  1.0f, 0.0f, /* bottom-right */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a, -a,  a,  0.0f, 1.0f, /* top-left */
-        a, -a,  a,  1.0f, 1.0f, /* top-right */
-    };
-    
-    U32 cube_vao, vbo;
-    glGenVertexArrays(1, &cube_vao);
-    glBindVertexArray(cube_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(cube_vertices_cw), cube_vertices_cw, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    Transform cube_transform = transform_default();
-    
-    F32 target_fps = 60.0f;
-    F32 target_spf = 1.0f/target_fps;
-    camera_pos = v3f(0.0f, 1.0f, 3.0f);
-    
-    F32 last_time = glfwGetTime();
-    
-    F32 d_angle = 45.0f;
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* INFO(pryazha): update */
-        V3F left, up, forward;
-        V3F world_up = v3f(0.0f, 1.0f, 0.0f);
-        
-        forward = v3f_norm(v3f_sub(v3f(0.0f, 0.0f, 0.0f), camera_pos));
-        left = v3f_norm(v3f_cross(world_up, forward));
-        up = v3f_cross(forward, left);
-        
-        V3F dp = v3f_zero();
-        F32 speed = 2.0f;
-        if (key_is_pressed(input.move_right))
-            dp = v3f_add(dp, v3f_scalef(left, -speed*dt));
-        if (key_is_pressed(input.move_forward))
-            dp = v3f_add(dp, v3f_scalef(forward, speed*dt));
-        if (key_is_pressed(input.move_left))
-            dp = v3f_add(dp, v3f_scalef(left, speed*dt));
-        if (key_is_pressed(input.move_backward))
-            dp = v3f_add(dp, v3f_scalef(forward, -speed*dt));
-        if (key_is_pressed(input.move_up))
-            dp = v3f_add(dp, v3f_scalef(up, speed*dt));
-        if (key_is_pressed(input.move_down))
-            dp = v3f_add(dp, v3f_scalef(up, -speed*dt));
-        
-        input_update_last_state(&input);
-        
-        camera_pos = v3f_add(camera_pos, dp);
-        
-        /* INFO(pryazha): Render */
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        
-        MAT4 model, view, projection;
-        cube_transform = transform_rotate(cube_transform, v3f(0.0f, d_angle*dt, 0.0f));
-        model = transform_apply(cube_transform);
-        view = look_at(camera_pos, v3f(0.0f, 0.0f, 0.0f), v3f(0.0f, 1.0f, 0.0f));
-        projection = perspective(90.0f, (F32)WIDTH/(F32)HEIGHT, 0.1f, 100.0f);
-        
-        glUseProgram(shader);
-        glBindTexture(GL_TEXTURE_2D, grid_texture);
-        shader_set_mat4fv(shader, "model", model);
-        shader_set_mat4fv(shader, "view", view);
-        shader_set_mat4fv(shader, "projection", projection);
-        glBindVertexArray(cube_vao);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf) {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0) {
-                sleep(sleep_time);
-            }
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        last_time = current_time;
-    }
-    
-    glfwTerminate();
-    return(0);
+	glfwMakeContextCurrent(window);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glEnable(GL_DEPTH_TEST);
+	glEnable(GL_CULL_FACE);
+	glFrontFace(GL_CW);
+	glCullFace(GL_BACK);
+
+	U32 shader = create_shader_program("shaders/face_culling.vert",
+					   "shaders/face_culling.frag");
+
+	U32 grid_texture = load_texture("../../data/textures/grid.png");
+
+	F32 a = 0.5f;
+	/* NOTE(pryazha): Counter-clockwise order */
+	F32 cube_vertices_ccw[] = {
+		/* NOTE(pryazha): Back face */
+		 a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a,  a, -a,  1.0f, 1.0f, /* top-right */
+		 a,  a, -a,  0.0f, 1.0f, /* top-left */
+		 a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a, -a, -a,  1.0f, 0.0f, /* bottom-right */
+		-a,  a, -a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Front face */
+		-a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a,  a,  1.0f, 1.0f, /* top-right */
+		-a,  a,  a,  0.0f, 1.0f, /* top-left */
+		-a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a, -a,  a,  1.0f, 0.0f, /* bottom-right */
+		 a,  a,  a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Left face */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a,  a,  a,  1.0f, 1.0f, /* top-right */
+		-a,  a, -a,  0.0f, 1.0f, /* top-left */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a, -a,  a,  1.0f, 0.0f, /* bottom-right */
+		-a,  a,  a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Right face */
+		 a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+		 a,  a,  a,  0.0f, 1.0f, /* top-left */
+		 a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a, -a, -a,  1.0f, 0.0f, /* bottom-right */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Top face */
+		-a,  a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+		-a,  a, -a,  0.0f, 1.0f, /* top-left */
+		-a,  a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a,  a,  1.0f, 0.0f, /* bottom-right */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Bottom face */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		 a, -a,  a,  1.0f, 1.0f, /* top-right */
+		-a, -a,  a,  0.0f, 1.0f, /* top-left */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		 a, -a, -a,  1.0f, 0.0f, /* bottom-right */
+		 a, -a,  a,  1.0f, 1.0f, /* top-right */
+	};
+
+	F32 cube_vertices_cw[] = {
+		/* NOTE(pryazha): Back face */
+		 a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a,  a, -a,  1.0f, 1.0f, /* top-right */
+		-a, -a, -a,  1.0f, 0.0f, /* bottom-right */
+		 a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a, -a,  0.0f, 1.0f, /* top-left */
+		-a,  a, -a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Front face */
+		-a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a,  a,  1.0f, 1.0f, /* top-right */
+		 a, -a,  a,  1.0f, 0.0f, /* bottom-right */
+		-a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		-a,  a,  a,  0.0f, 1.0f, /* top-left */
+		 a,  a,  a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Left face */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a,  a,  a,  1.0f, 1.0f, /* top-right */
+		-a, -a,  a,  1.0f, 0.0f, /* bottom-right */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a,  a, -a,  0.0f, 1.0f, /* top-left */
+		-a,  a,  a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Right face */
+		 a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+		 a, -a, -a,  1.0f, 0.0f, /* bottom-right */
+		 a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a,  a,  0.0f, 1.0f, /* top-left */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Top face */
+		-a,  a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+		 a,  a,  a,  1.0f, 0.0f, /* bottom-right */
+		-a,  a,  a,  0.0f, 0.0f, /* bottom-left */
+		-a,  a, -a,  0.0f, 1.0f, /* top-left */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Bottom face */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		 a, -a,  a,  1.0f, 1.0f, /* top-right */
+		 a, -a, -a,  1.0f, 0.0f, /* bottom-right */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a, -a,  a,  0.0f, 1.0f, /* top-left */
+		 a, -a,  a,  1.0f, 1.0f, /* top-right */
+	};
+
+	U32 cube_vao, vbo;
+	glGenVertexArrays(1, &cube_vao);
+	glBindVertexArray(cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(cube_vertices_cw), cube_vertices_cw, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	Transform cube_transform = transform_default();
+
+	state.camera = (Camera) {
+		v3f(0.0f, 0.0f, 3.0f),
+		90.0f, 0.1f, 100.0f,
+		0.0f, 0.0f
+	};
+
+	F32 target_fps = 60.0f;
+	F32 target_spf = 1.0f/target_fps;
+	F32 last_time = glfwGetTime();
+
+	F32 d_angle = 45.0f;
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		process_glfw_keyboard(window, &input);
+		glfwGetFramebufferSize(window, &width, &height);
+
+		/* INFO(pryazha): update */
+		V3F target = v3f_zero();
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		V3F dv = get_dv_camera_orbital(&input, state.camera.pos,
+					       target, state.dt, 3.0f);
+		state.camera.pos = v3f_add(state.camera.pos, dv);
+
+		input_update_last_state(&input);
+
+		/* INFO(pryazha): Render */
+		MAT4 model, view, proj;
+		view = look_at(state.camera.pos, target, v3f(0.0f, 1.0f, 0.0f));
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+		cube_transform = transform_rotate(cube_transform,
+						  v3f(0.0f, d_angle*state.dt, 0.0f));
+		model = transform_apply(cube_transform);
+
+		glViewport(0, 0, width, height);
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		glUseProgram(shader);
+		glBindTexture(GL_TEXTURE_2D, grid_texture);
+		shader_set_mat4fv(shader, "model", model);
+		shader_set_mat4fv(shader, "view", view);
+		shader_set_mat4fv(shader, "proj", proj);
+		glBindVertexArray(cube_vao);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindVertexArray(0);
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		last_time = current_time;
+	}
+
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/5.framebuffers/shaders/cube.fs b/advanced_opengl/4.face_culling/shaders/face_culling.frag
index f58c5d3..71892a7 100644
--- a/advanced_opengl/5.framebuffers/shaders/cube.fs
+++ b/advanced_opengl/4.face_culling/shaders/face_culling.frag
@@ -6,8 +6,7 @@ in vec2 tex_coords;
 
 uniform sampler2D texture1;
 
-void
-main(void)
+void main(void)
 {
     frag_color = texture(texture1, tex_coords);
 }
diff --git a/advanced_opengl/3.blending/shaders/blending.vs b/advanced_opengl/4.face_culling/shaders/face_culling.vert
index 62e71a2..68b8fe2 100644
--- a/advanced_opengl/3.blending/shaders/blending.vs
+++ b/advanced_opengl/4.face_culling/shaders/face_culling.vert
@@ -4,13 +4,12 @@ layout(location = 1) in vec2 atex_coords;
 
 uniform mat4 model;
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
 out vec2 tex_coords;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
     tex_coords = atex_coords;
 }
diff --git a/advanced_opengl/5.framebuffers/framebuffers b/advanced_opengl/5.framebuffers/framebuffers
index a1f7170..4a3d49e 100755
--- a/advanced_opengl/5.framebuffers/framebuffers
+++ b/advanced_opengl/5.framebuffers/framebuffers
diff --git a/advanced_opengl/5.framebuffers/framebuffers.c b/advanced_opengl/5.framebuffers/framebuffers.c
index a0523cc..7948a61 100644
--- a/advanced_opengl/5.framebuffers/framebuffers.c
+++ b/advanced_opengl/5.framebuffers/framebuffers.c
@@ -2,423 +2,336 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	State state;
+	S32 width, height;
+	Input input;
 
-#define WIDTH 1024
-#define HEIGHT 768
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-static V3F camera_pos;
-static F32 dt;
-static Input input;
+	width = 1024;
+	height = 768;
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "Framebuffers", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_RESIZABLE, 0);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(WIDTH, HEIGHT, "Framebuffers", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetKeyCallback(window, key_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    U32 screen_shader = create_shader_program("shaders/screen.vs", "shaders/screen.fs");
-    U32 cube_shader = create_shader_program("shaders/cube.vs", "shaders/cube.fs");
-    U32 marble_texture = load_texture("../../data/textures/marble.jpg");
-    U32 metal_texture = load_texture("../../data/textures/metal.png");
-    U32 window_texture = load_texture("../../data/textures/window.png");
-    
-    U32 fbo;
-    glGenFramebuffers(1, &fbo);
-    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
-    
-    U32 texture_colorbuffer;
-    glGenTextures(1, &texture_colorbuffer);
-    glBindTexture(GL_TEXTURE_2D, texture_colorbuffer);
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, WIDTH, HEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-    glBindTexture(GL_TEXTURE_2D, 0);
-    
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
-                           texture_colorbuffer, 0);
-    
-    U32 rbo;
-    glGenRenderbuffers(1, &rbo);
-    glBindRenderbuffer(GL_RENDERBUFFER, rbo);
-    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, WIDTH, HEIGHT);
-    glBindRenderbuffer(GL_RENDERBUFFER, 0);
-    
-    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
-                              GL_RENDERBUFFER, rbo);
-    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
-        fprintf(stderr, "[ERROR]: Framebuffer is not complete.\n");
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
-    
-    F32 a = 0.5f;
-    F32 vertices[] = {
-        -a, -a, -a,  0.0f, 0.0f,
-        a, -a, -a,  1.0f, 0.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        -a,  a, -a,  0.0f, 1.0f,
-        -a, -a, -a,  0.0f, 0.0f,
-        
-        -a, -a,  a,  0.0f, 0.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        a,  a,  a,  1.0f, 1.0f,
-        a,  a,  a,  1.0f, 1.0f,
-        -a,  a,  a,  0.0f, 1.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        
-        -a,  a,  a,  1.0f, 0.0f,
-        -a,  a, -a,  1.0f, 1.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        -a,  a,  a,  1.0f, 0.0f,
-        
-        a,  a,  a,  1.0f, 0.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a, -a, -a,  0.0f, 1.0f,
-        a, -a, -a,  0.0f, 1.0f,
-        a, -a,  a,  0.0f, 0.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        
-        -a, -a, -a,  0.0f, 1.0f,
-        a, -a, -a,  1.0f, 1.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        
-        -a,  a, -a,  0.0f, 1.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        -a,  a,  a,  0.0f, 0.0f,
-        -a,  a, -a,  0.0f, 1.0f
-    };
-    
-    Transform cube_positions[] = {
-        transform_default(),
-        transform_make_translate(v3f(a, 0.0f, -4.0f*a))
-    };
-    
-    Transform platform_position =
-        transform_make_scale_translate(v3f(10.0f, 0.2f, 10.0f),
-                                       v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f));
-    
-    U32 cube_vao, quad_vao, vbo;
-    
-    glGenVertexArrays(1, &cube_vao);
-    glBindVertexArray(cube_vao);
-    
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-    
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    F32 quad_vertices[] = {
-        -1.0f, -1.0f, 0.0f,  0.0f, 0.0f,
-        1.0f, -1.0f, 0.0f,  1.0f, 0.0f,
-        1.0f,  1.0f, 0.0f,  1.0f, 1.0f,
-        -1.0f, -1.0f, 0.0f,  0.0f, 0.0f,
-        1.0f,  1.0f, 0.0f,  1.0f, 1.0f,
-        -1.0f,  1.0f, 0.0f,  0.0f, 1.0f
-    };
-    
-    glGenVertexArrays(1, &quad_vao);
-    glBindVertexArray(quad_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(quad_vertices), quad_vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    Transform window_transforms[] = {
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(0.0f, 0.0f, a+0.1f)),
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(0.0f, 0.0f, 2.0f)),
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(1.0f, 0.0f, -1.0f)),
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(-2.0f, 0.0f, 0.5f)),
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(-3.0f, 0.0f, -3.0f)),
-        transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(3.0f, 0.0f, 0.2)),
-    };
-    
-    F32 angle = 0.0f;
-    for (S32 window_index = 0;
-         window_index < (S32)ArrayCount(window_transforms);
-         ++window_index)
-    {
-        Transform *transform = window_transforms+window_index;
-        *transform = transform_rotate(*transform, v3f(0.0f, angle, 0.0f));
-        angle += 30.0f;
-    }
-    
-    F32 target_fps = 60.0f;
-    F32 target_spf = 1.0f/target_fps;
-    camera_pos = v3f(0.0f, 1.0f, 3.0f);
-    
-    F32 last_time = glfwGetTime();
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* INFO(pryazha): update */
-        V3F left, up, forward;
-        V3F world_up = v3f(0.0f, 1.0f, 0.0f);
-        
-        forward = v3f_norm(v3f_sub(v3f(0.0f, 0.0f, 0.0f), camera_pos));
-        left = v3f_norm(v3f_cross(world_up, forward));
-        up = v3f_cross(forward, left);
-        
-        V3F dp = v3f_zero();
-        F32 speed = 2.0f;
-        if (key_is_pressed(input.move_right))
-            dp = v3f_add(dp, v3f_scalef(left, -speed*dt));
-        if (key_is_pressed(input.move_forward))
-            dp = v3f_add(dp, v3f_scalef(forward, speed*dt));
-        if (key_is_pressed(input.move_left))
-            dp = v3f_add(dp, v3f_scalef(left, speed*dt));
-        if (key_is_pressed(input.move_backward))
-            dp = v3f_add(dp, v3f_scalef(forward, -speed*dt));
-        if (key_is_pressed(input.move_up))
-            dp = v3f_add(dp, v3f_scalef(up, speed*dt));
-        if (key_is_pressed(input.move_down))
-            dp = v3f_add(dp, v3f_scalef(up, -speed*dt));
-        
-        input_update_last_state(&input);
-        
-        camera_pos = v3f_add(camera_pos, dp);
-        
-        Transform sorted_window_transforms[ArrayCount(window_transforms)];
-        MemoryCopyArray(sorted_window_transforms, window_transforms);
-        for (S32 i = 0; i < (S32)ArrayCount(sorted_window_transforms); ++i) {
-            for (S32 pos_index = 1;
-                 pos_index < (S32)ArrayCount(sorted_window_transforms);
-                 ++pos_index)
-            {
-                F32 distance_left = v3f_length(v3f_sub(sorted_window_transforms[pos_index-1].translate, camera_pos));
-                F32 distance_right = v3f_length(v3f_sub(sorted_window_transforms[pos_index].translate, camera_pos));
-                if (distance_left < distance_right) {
-                    Transform temp = sorted_window_transforms[pos_index];
-                    sorted_window_transforms[pos_index] = sorted_window_transforms[pos_index-1];
-                    sorted_window_transforms[pos_index-1] = temp;
-                }
-            }
-        }
-        
-        /* INFO(pryazha): Render */
-        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        glEnable(GL_DEPTH_TEST);
-        MAT4 view, projection;
-        view = look_at(camera_pos, v3f(0.0f, 0.0f, 0.0f), v3f(0.0f, 1.0f, 0.0f));
-        projection = perspective(90.0f, (F32)WIDTH/(F32)HEIGHT, 0.1f, 100.0f);
-        glUseProgram(cube_shader);
-        shader_set_mat4fv(cube_shader, "view", view);
-        shader_set_mat4fv(cube_shader, "projection", projection);
-        glBindTexture(GL_TEXTURE_2D, marble_texture);
-        glBindVertexArray(cube_vao);
-        for (S32 transform_index = 0;
-             transform_index < (S32)ArrayCount(cube_positions);
-             ++transform_index)
-        {
-            shader_set_mat4fv(cube_shader, "model", transform_apply(cube_positions[transform_index]));
-            glDrawArrays(GL_TRIANGLES, 0, 36);
-        }
-        
-        glBindTexture(GL_TEXTURE_2D, metal_texture);
-        shader_set_mat4fv(cube_shader, "model", transform_apply(platform_position));
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindVertexArray(0);
-        
-        glEnable(GL_BLEND);
-        glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
-        glUseProgram(cube_shader);
-        glBindTexture(GL_TEXTURE_2D, window_texture);
-        shader_set_mat4fv(cube_shader, "view", view);
-        shader_set_mat4fv(cube_shader, "projection", projection);
-        glBindVertexArray(quad_vao);
-        for (S32 window_index = 0;
-             window_index < (S32)ArrayCount(sorted_window_transforms);
-             ++window_index)
-        {
-            shader_set_mat4fv(cube_shader, "model", transform_apply(sorted_window_transforms[window_index]));
-            glDrawArrays(GL_TRIANGLES, 0, 6);
-        }
-        glBindVertexArray(0);
-        glDisable(GL_BLEND);
-        
-        glBindFramebuffer(GL_FRAMEBUFFER, 0);
-        glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT);
-        glUseProgram(screen_shader);
-        glDisable(GL_DEPTH_TEST);
-        glBindTexture(GL_TEXTURE_2D, texture_colorbuffer);
-        glBindVertexArray(quad_vao);
-        shader_set_mat4fv(screen_shader, "model", mat4_identity());
-        glDrawArrays(GL_TRIANGLES, 0, 6);
-        glBindVertexArray(0);
-        
-        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        glEnable(GL_DEPTH_TEST);
-        V3F target = v3f_add(camera_pos, v3f_negate(forward));
-        view = look_at(camera_pos, target, v3f(0.0f, 1.0f, 0.0f));
-        glUseProgram(cube_shader);
-        shader_set_mat4fv(cube_shader, "view", view);
-        shader_set_mat4fv(cube_shader, "projection", projection);
-        glBindTexture(GL_TEXTURE_2D, marble_texture);
-        glBindVertexArray(cube_vao);
-        for (S32 transform_index = 0;
-             transform_index < (S32)ArrayCount(cube_positions);
-             ++transform_index)
-        {
-            shader_set_mat4fv(cube_shader, "model", transform_apply(cube_positions[transform_index]));
-            glDrawArrays(GL_TRIANGLES, 0, 36);
-        }
-        
-        glBindTexture(GL_TEXTURE_2D, metal_texture);
-        shader_set_mat4fv(cube_shader, "model", transform_apply(platform_position));
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindVertexArray(0);
-        
-        glEnable(GL_BLEND);
-        glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
-        glUseProgram(cube_shader);
-        glBindTexture(GL_TEXTURE_2D, window_texture);
-        shader_set_mat4fv(cube_shader, "view", view);
-        shader_set_mat4fv(cube_shader, "projection", projection);
-        glBindVertexArray(quad_vao);
-        for (S32 window_index = 0;
-             window_index < (S32)ArrayCount(sorted_window_transforms);
-             ++window_index)
-        {
-            shader_set_mat4fv(cube_shader, "model", transform_apply(sorted_window_transforms[window_index]));
-            glDrawArrays(GL_TRIANGLES, 0, 6);
-        }
-        glBindVertexArray(0);
-        glDisable(GL_BLEND);
-        
-        glBindFramebuffer(GL_FRAMEBUFFER, 0);
-        glUseProgram(screen_shader);
-        glDisable(GL_DEPTH_TEST);
-        glBindTexture(GL_TEXTURE_2D, texture_colorbuffer);
-        glBindVertexArray(quad_vao);
-        MAT4 model = transform_apply(transform_make_scale_translate(v3f(0.3f, 0.3f, 0.3f), v3f(-0.7f, 0.7f, 0.0f)));
-        shader_set_mat4fv(screen_shader, "model", model);
-        glDrawArrays(GL_TRIANGLES, 0, 6);
-        glBindVertexArray(0);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf)
-        {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0)
-                sleep(sleep_time);
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        last_time = current_time;
-    }
-    
-    glfwTerminate();
-    return(0);
+	glfwMakeContextCurrent(window);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	U32 screen_shader = create_shader_program("shaders/screen.vert",
+						  "shaders/screen.frag");
+	U32 cube_shader = create_shader_program("shaders/cube.vert",
+					       	"shaders/cube.frag");
+	U32 marble_texture = load_texture("../../data/textures/marble.jpg");
+	U32 metal_texture = load_texture("../../data/textures/metal.png");
+	U32 window_texture = load_texture("../../data/textures/window.png");
+
+	U32 fbo, texture_colorbuffer, rbo;
+	glGenFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+	glGenTextures(1, &texture_colorbuffer);
+	glBindTexture(GL_TEXTURE_2D, texture_colorbuffer);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glBindTexture(GL_TEXTURE_2D, 0);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+			       GL_TEXTURE_2D, texture_colorbuffer, 0);
+	glGenRenderbuffers(1, &rbo);
+	glBindRenderbuffer(GL_RENDERBUFFER, rbo);
+	glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);
+	glBindRenderbuffer(GL_RENDERBUFFER, 0);
+	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
+				  GL_RENDERBUFFER, rbo);
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
+		fprintf(stderr, "[ERROR]: Framebuffer is not complete.\n");
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+	F32 a = 0.5f;
+	F32 vertices[] = {
+		-a, -a, -a,  0.0f, 0.0f,
+		 a, -a, -a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		-a,  a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 0.0f,
+
+		-a, -a,  a,  0.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		-a,  a,  a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+
+		-a,  a,  a,  1.0f, 0.0f,
+		-a,  a, -a,  1.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a,  a,  a,  1.0f, 0.0f,
+
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a,  a,  0.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+
+		-a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  1.0f, 1.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+
+		-a,  a, -a,  0.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		-a,  a,  a,  0.0f, 0.0f,
+		-a,  a, -a,  0.0f, 1.0f
+	};
+
+	Transform cube_positions[] = {
+		transform_default(),
+		transform_make_translate(v3f(a, 0.0f, -4.0f*a))
+	};
+
+	V3F platform_pos = v3f(10.0f, 0.2f, 10.0f);
+	V3F platform_scale = v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f);
+	Transform platform_transform = transform_make_scale_translate(platform_pos,
+								      platform_scale);
+	U32 cube_vao, quad_vao, vbo;
+	glGenVertexArrays(1, &cube_vao);
+	glBindVertexArray(cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	F32 quad_vertices[] = {
+		-1.0f, -1.0f, 0.0f,  0.0f, 0.0f,
+		 1.0f, -1.0f, 0.0f,  1.0f, 0.0f,
+		 1.0f,  1.0f, 0.0f,  1.0f, 1.0f,
+		-1.0f, -1.0f, 0.0f,  0.0f, 0.0f,
+		 1.0f,  1.0f, 0.0f,  1.0f, 1.0f,
+		-1.0f,  1.0f, 0.0f,  0.0f, 1.0f
+	};
+
+	glGenVertexArrays(1, &quad_vao);
+	glBindVertexArray(quad_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(quad_vertices), quad_vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	Transform window_transforms[] = {
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(0.0f, 0.0f, a+0.1f)),
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(0.0f, 0.0f, 2.0f)),
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(1.0f, 0.0f, -1.0f)),
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(-2.0f, 0.0f, 0.5f)),
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(-3.0f, 0.0f, -3.0f)),
+		transform_make_scale_translate(v3f(0.5f, 0.5f, 0.5f), v3f(3.0f, 0.0f, 0.2)),
+	};
+
+	F32 angle = 0.0f;
+	for (S32 i = 0; i < (S32)ArrayCount(window_transforms); ++i) {
+		Transform *transform = window_transforms+i;
+		*transform = transform_rotate(*transform, v3f(0.0f, angle, 0.0f));
+		angle += 30.0f;
+	}
+
+	state.camera = (Camera) {
+		v3f(0.0f, 0.0f, 3.0f),
+		90.0f, 0.1f, 100.0f,
+		0.0f, 0.0f
+	};
+
+	F32 target_fps = 60.0f;
+	F32 target_spf = 1.0f/target_fps;
+	F32 last_time = glfwGetTime();
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		process_glfw_keyboard(window, &input);
+		glfwGetFramebufferSize(window, &width, &height);
+
+		/* INFO(pryazha): Update */
+		V3F target = v3f_zero();
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		V3F dv = get_dv_camera_orbital(&input, state.camera.pos,
+					       target, state.dt, 3.0f);
+		state.camera.pos = v3f_add(state.camera.pos, dv);
+
+		input_update_last_state(&input);
+
+		Transform sorted[ArrayCount(window_transforms)];
+		MemoryCopyArray(sorted, window_transforms);
+		for (S32 i = 0; i < (S32)ArrayCount(sorted); ++i) {
+			for (S32 j = 1; j < (S32)ArrayCount(sorted); ++j) {
+				F32 dist_left = v3f_length(v3f_sub(sorted[j-1].translate, state.camera.pos));
+				F32 dist_right = v3f_length(v3f_sub(sorted[j].translate, state.camera.pos));
+				if (dist_left < dist_right) {
+					Transform temp = sorted[j];
+					sorted[j] = sorted[j-1];
+					sorted[j-1] = temp;
+				}
+			}
+		}
+
+		/* INFO(pryazha): Render */
+		MAT4 model, view, proj;
+
+		view = look_at(state.camera.pos, target, v3f(0.0f, 1.0f, 0.0f));
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+
+		glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+		glViewport(0, 0, width, height);
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		glEnable(GL_DEPTH_TEST);
+		glUseProgram(cube_shader);
+		shader_set_mat4fv(cube_shader, "view", view);
+		shader_set_mat4fv(cube_shader, "proj", proj);
+		glBindTexture(GL_TEXTURE_2D, marble_texture);
+		glBindVertexArray(cube_vao);
+		for (S32 i = 0; i < (S32)ArrayCount(cube_positions); ++i) {
+			model = transform_apply(cube_positions[i]);
+			shader_set_mat4fv(cube_shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+		}
+
+		glBindTexture(GL_TEXTURE_2D, metal_texture);
+		model = transform_apply(platform_transform);
+		shader_set_mat4fv(cube_shader, "model", model);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindVertexArray(0);
+
+		glEnable(GL_BLEND);
+		glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+		glUseProgram(cube_shader);
+		glBindTexture(GL_TEXTURE_2D, window_texture);
+		shader_set_mat4fv(cube_shader, "view", view);
+		shader_set_mat4fv(cube_shader, "proj", proj);
+		glBindVertexArray(quad_vao);
+		for (S32 i = 0; i < (S32)ArrayCount(sorted); ++i) {
+			model = transform_apply(sorted[i]);
+			shader_set_mat4fv(cube_shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 6);
+		}
+		glBindVertexArray(0);
+		glDisable(GL_BLEND);
+
+		glBindFramebuffer(GL_FRAMEBUFFER, 0);
+		glViewport(0, 0, width, height);
+		glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT);
+		glUseProgram(screen_shader);
+		glDisable(GL_DEPTH_TEST);
+		glBindTexture(GL_TEXTURE_2D, texture_colorbuffer);
+		glBindVertexArray(quad_vao);
+		shader_set_mat4fv(screen_shader, "model", mat4_identity());
+		glDrawArrays(GL_TRIANGLES, 0, 6);
+		glBindVertexArray(0);
+
+		glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+		glViewport(0, 0, width, height);
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		glEnable(GL_DEPTH_TEST);
+		V3F f = v3f(view.m2.x, view.m2.y, view.m2.z);
+		target = v3f_add(state.camera.pos, v3f_negate(f));
+		view = look_at(state.camera.pos, target, v3f(0.0f, 1.0f, 0.0f));
+		glUseProgram(cube_shader);
+		shader_set_mat4fv(cube_shader, "view", view);
+		shader_set_mat4fv(cube_shader, "proj", proj);
+		glBindTexture(GL_TEXTURE_2D, marble_texture);
+		glBindVertexArray(cube_vao);
+		for (S32 i = 0; i < (S32)ArrayCount(cube_positions); ++i) {
+			model = transform_apply(cube_positions[i]);
+			shader_set_mat4fv(cube_shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+		}
+
+		glBindTexture(GL_TEXTURE_2D, metal_texture);
+		model = transform_apply(platform_transform);
+		shader_set_mat4fv(cube_shader, "model", model);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindVertexArray(0);
+
+		glEnable(GL_BLEND);
+		glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+		glUseProgram(cube_shader);
+		glBindTexture(GL_TEXTURE_2D, window_texture);
+		shader_set_mat4fv(cube_shader, "view", view);
+		shader_set_mat4fv(cube_shader, "proj", proj);
+		glBindVertexArray(quad_vao);
+		for (S32 i = 0; i < (S32)ArrayCount(sorted); ++i) {
+			model = transform_apply(sorted[i]);
+			shader_set_mat4fv(cube_shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 6);
+		}
+		glBindVertexArray(0);
+		glDisable(GL_BLEND);
+
+		glBindFramebuffer(GL_FRAMEBUFFER, 0);
+		glViewport(0, 0, width, height);
+		glUseProgram(screen_shader);
+		glDisable(GL_DEPTH_TEST);
+		glBindTexture(GL_TEXTURE_2D, texture_colorbuffer);
+		glBindVertexArray(quad_vao);
+		model = transform_apply(transform_make_scale_translate(v3f(0.3f, 0.3f, 0.3f), v3f(-0.7f, 0.7f, 0.0f)));
+		shader_set_mat4fv(screen_shader, "model", model);
+		glDrawArrays(GL_TRIANGLES, 0, 6);
+		glBindVertexArray(0);
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		last_time = current_time;
+	}
+
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/4.face_culling/shaders/face_culling.fs b/advanced_opengl/5.framebuffers/shaders/cube.frag
index f58c5d3..71892a7 100644
--- a/advanced_opengl/4.face_culling/shaders/face_culling.fs
+++ b/advanced_opengl/5.framebuffers/shaders/cube.frag
@@ -6,8 +6,7 @@ in vec2 tex_coords;
 
 uniform sampler2D texture1;
 
-void
-main(void)
+void main(void)
 {
     frag_color = texture(texture1, tex_coords);
 }
diff --git a/advanced_opengl/5.framebuffers/shaders/cube.vs b/advanced_opengl/5.framebuffers/shaders/cube.vert
index aea5c2c..2436f35 100644
--- a/advanced_opengl/5.framebuffers/shaders/cube.vs
+++ b/advanced_opengl/5.framebuffers/shaders/cube.vert
@@ -5,13 +5,12 @@ layout(location = 1) in vec2 atex_coords;
 
 uniform mat4 model;
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
 out vec2 tex_coords;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
     tex_coords = atex_coords;
 }
diff --git a/advanced_opengl/5.framebuffers/shaders/screen.fs b/advanced_opengl/5.framebuffers/shaders/screen.frag
index 183d490..234b3fc 100644
--- a/advanced_opengl/5.framebuffers/shaders/screen.fs
+++ b/advanced_opengl/5.framebuffers/shaders/screen.frag
@@ -6,15 +6,13 @@ in vec2 tex_coords;
 
 uniform sampler2D texture1;
 
-vec4
-inversion()
+vec4 inversion()
 {
     vec4 result = vec4(1.0-vec3(texture(texture1, tex_coords)), 1.0);
     return(result);
 }
 
-vec4
-grayscale_average()
+vec4 grayscale_average()
 {
     vec4 tex_color = texture(texture1, tex_coords);
     float average = (tex_color.r+tex_color.g+tex_color.b)/3.0;
@@ -22,8 +20,7 @@ grayscale_average()
     return(result);
 }
 
-vec4
-grayscale_weights()
+vec4 grayscale_weights()
 {
     vec4 tex_color = texture(texture1, tex_coords);
     float average = 0.2126*tex_color.r+0.7152*tex_color.g+0.0722*tex_color.b;
@@ -33,8 +30,7 @@ grayscale_weights()
 
 const float offset = 1.0/300.0;
 
-vec4
-kernel_effect(float[9] kernel)
+vec4 kernel_effect(float[9] kernel)
 {
     vec2 offsets[9] = vec2[](
         vec2(-offset, offset), /* top-left */
@@ -49,13 +45,8 @@ kernel_effect(float[9] kernel)
     );
 
     vec3 sample_texture[9];
-    for (int offset_index = 0;
-         offset_index < 9;
-         ++offset_index)
-    {
-        sample_texture[offset_index] =
-            vec3(texture(texture1, tex_coords+offsets[offset_index]));
-    }
+    for (int i = 0; i < 9; ++i)
+        sample_texture[i] = vec3(texture(texture1, tex_coords+offsets[i]));
 
     vec3 color = vec3(0.0);
     for (int i = 0; i < 9; ++i)
@@ -64,8 +55,7 @@ kernel_effect(float[9] kernel)
     return(vec4(color, 1.0));
 }
 
-void
-main(void)
+void main(void)
 {
     float strange_kernel[9] = float[](
         -1, -1, -1,
diff --git a/advanced_opengl/5.framebuffers/shaders/screen.vs b/advanced_opengl/5.framebuffers/shaders/screen.vert
index 8fdea55..92bc378 100644
--- a/advanced_opengl/5.framebuffers/shaders/screen.vs
+++ b/advanced_opengl/5.framebuffers/shaders/screen.vert
@@ -6,8 +6,7 @@ out vec2 tex_coords;
 
 uniform mat4 model;
 
-void
-main(void)
+void main(void)
 {
     gl_Position = model*vec4(apos, 1.0);
     tex_coords = atex_coords;
diff --git a/advanced_opengl/6.cubemaps/cubemaps b/advanced_opengl/6.cubemaps/cubemaps
index bdf54f5..bc274ea 100755
--- a/advanced_opengl/6.cubemaps/cubemaps
+++ b/advanced_opengl/6.cubemaps/cubemaps
diff --git a/advanced_opengl/6.cubemaps/cubemaps.c b/advanced_opengl/6.cubemaps/cubemaps.c
index 5ea5300..32a53d1 100644
--- a/advanced_opengl/6.cubemaps/cubemaps.c
+++ b/advanced_opengl/6.cubemaps/cubemaps.c
@@ -2,450 +2,350 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	State state;
+	S32 width, height;
+	Input input;
 
-#define WIDTH 1024
-#define HEIGHT 768
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-static V3F camera_pos;
-static F32 dt;
-static Input input;
-static B32 first_mouse = 1;
+	width = 1024;
+	height = 768;
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "Cubemaps", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
 
-void
-cursor_pos_callback(GLFWwindow* window, double xpos, double ypos)
-{
-    if (first_mouse)
-    {
-        input.last_mouse_pos = v2f(xpos, ypos);
-        first_mouse = 0;
-    }
-    input.mouse_offset = v2f(input.mouse_offset.x+((F32)xpos-input.last_mouse_pos.x),
-                             input.mouse_offset.y+((F32)ypos-input.last_mouse_pos.y));
-    input.last_mouse_pos = v2f((F32)xpos, (F32)ypos);
-}
+	glfwMakeContextCurrent(window);
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_RESIZABLE, 0);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(WIDTH, HEIGHT, "Cubemaps", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
-    
-    glfwSetKeyCallback(window, key_callback);
-    glfwSetCursorPosCallback(window, cursor_pos_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    U32 skybox_shader = create_shader_program("shaders/skybox.vs", "shaders/skybox.fs");
-    U32 reflection_shader = create_shader_program("shaders/reflection.vs", "shaders/reflection.fs");
-    U32 refraction_shader = create_shader_program("shaders/refraction.vs", "shaders/refraction.fs");
-    U32 cube_shader = create_shader_program("shaders/cube.vs", "shaders/cube.fs");
-    U32 grid_texture = load_texture("../../data/textures/grid.png");
-    
-    const char *cube_texture_filenames[6] = {
-        "../../data/textures/skybox/right.jpg",
-        "../../data/textures/skybox/left.jpg",
-        "../../data/textures/skybox/top.jpg",
-        "../../data/textures/skybox/bottom.jpg",
-        "../../data/textures/skybox/front.jpg",
-        "../../data/textures/skybox/back.jpg"
-    };
-    U32 skybox_texture = load_cubemap(cube_texture_filenames);
-    
-    F32 a = 0.5f;
-    F32 vertices[] = {
-        -a, -a, -a,  0.0f, 0.0f,
-        a, -a, -a,  1.0f, 0.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        -a,  a, -a,  0.0f, 1.0f,
-        -a, -a, -a,  0.0f, 0.0f,
-        
-        -a, -a,  a,  0.0f, 0.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        a,  a,  a,  1.0f, 1.0f,
-        a,  a,  a,  1.0f, 1.0f,
-        -a,  a,  a,  0.0f, 1.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        
-        -a,  a,  a,  1.0f, 0.0f,
-        -a,  a, -a,  1.0f, 1.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        -a,  a,  a,  1.0f, 0.0f,
-        
-        a,  a,  a,  1.0f, 0.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a, -a, -a,  0.0f, 1.0f,
-        a, -a, -a,  0.0f, 1.0f,
-        a, -a,  a,  0.0f, 0.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        
-        -a, -a, -a,  0.0f, 1.0f,
-        a, -a, -a,  1.0f, 1.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        
-        -a,  a, -a,  0.0f, 1.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        -a,  a,  a,  0.0f, 0.0f,
-        -a,  a, -a,  0.0f, 1.0f
-    };
-    
-    Transform cube_positions[] = {
-        transform_default(),
-        transform_make_translate(v3f(a, 0.0f, -4.0f*a))
-    };
-    
-    Transform platform_position =
-        transform_make_scale_translate(v3f(10.0f, 0.2f, 10.0f),
-                                       v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f));
-    
-    U32 cube_vao, vbo;
-    
-    glGenVertexArrays(1, &cube_vao);
-    glBindVertexArray(cube_vao);
-    
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-    
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    a = 1.0f;
-    F32 skybox_cube_vertices[] = {
-        -a, -a, -a,
-        a, -a, -a,
-        a,  a, -a,
-        a,  a, -a,
-        -a,  a, -a,
-        -a, -a, -a,
-        
-        -a, -a,  a,
-        a, -a,  a,
-        a,  a,  a,
-        a,  a,  a,
-        -a,  a,  a,
-        -a, -a,  a,
-        
-        -a,  a,  a,
-        -a,  a, -a,
-        -a, -a, -a,
-        -a, -a, -a,
-        -a, -a,  a,
-        -a,  a,  a,
-        
-        a,  a,  a,
-        a,  a, -a,
-        a, -a, -a,
-        a, -a, -a,
-        a, -a,  a,
-        a,  a,  a,
-        
-        -a, -a, -a,
-        a, -a, -a,
-        a, -a,  a,
-        a, -a,  a,
-        -a, -a,  a,
-        -a, -a, -a,
-        
-        -a,  a, -a,
-        a,  a, -a,
-        a,  a,  a,
-        a,  a,  a,
-        -a,  a,  a,
-        -a,  a, -a,
-    };
-    
-    U32 skybox_cube_vao;
-    glGenVertexArrays(1, &skybox_cube_vao);
-    glBindVertexArray(skybox_cube_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(skybox_cube_vertices), skybox_cube_vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(F32), (void *)0);
-    glBindVertexArray(0);
-    
-    F32 normals_cube_vertices[] = {
-        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
-        0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
-        0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
-        0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
-        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
-        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,
-        
-        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f, 1.0f,
-        0.5f, -0.5f,  0.5f,  0.0f,  0.0f, 1.0f,
-        0.5f,  0.5f,  0.5f,  0.0f,  0.0f, 1.0f,
-        0.5f,  0.5f,  0.5f,  0.0f,  0.0f, 1.0f,
-        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f, 1.0f,
-        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f, 1.0f,
-        
-        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,
-        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,
-        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,
-        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,
-        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,
-        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,
-        
-        0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,
-        0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,
-        0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,
-        0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,
-        0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,
-        0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,
-        
-        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,
-        0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,
-        0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,
-        0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,
-        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,
-        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,
-        
-        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,
-        0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,
-        0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,
-        0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,
-        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,
-        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f
-    };
-    U32 normals_cube_vao;
-    glGenVertexArrays(1, &normals_cube_vao);
-    glBindVertexArray(normals_cube_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(normals_cube_vertices), normals_cube_vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    F32 target_fps = 60.0f;
-    F32 target_spf = 1.0f/target_fps;
-    camera_pos = v3f(0.0f, 1.0f, 3.0f);
-    F32 yaw = 0.0f, pitch = 0.0f;
-    
-    F32 last_time = glfwGetTime();
-    
-    glEnable(GL_DEPTH_TEST);
-    glDepthFunc(GL_LEQUAL);
-    
-    MAT4 view, projection;
-    view = mat4_make_translate(v3f_negate(camera_pos));
-    view = mat4_rotate_angles(view, v3f(pitch, yaw, 0.0f));
-    projection = perspective(90.0f, (F32)WIDTH/(F32)HEIGHT, 0.1f, 100.0f);
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* INFO(pryazha): update */
-        
-        V3F left, up, forward;
-        
-        left = v3f(-view.m0.x, -view.m1.x, -view.m2.x);
-        up = v3f(view.m0.y, view.m1.y, view.m2.y);
-        forward = v3f(-view.m0.z, -view.m1.z, -view.m2.z);
-        
-        V3F dp = v3f_zero();
-        F32 speed = 2.0f;
-        if (key_is_pressed(input.move_right))
-            dp = v3f_add(dp, v3f_scalef(left, -speed*dt));
-        if (key_is_pressed(input.move_forward))
-            dp = v3f_add(dp, v3f_scalef(forward, speed*dt));
-        if (key_is_pressed(input.move_left))
-            dp = v3f_add(dp, v3f_scalef(left, speed*dt));
-        if (key_is_pressed(input.move_backward))
-            dp = v3f_add(dp, v3f_scalef(forward, -speed*dt));
-        if (key_is_pressed(input.move_up))
-            dp = v3f_add(dp, v3f_scalef(up, speed*dt));
-        if (key_is_pressed(input.move_down))
-            dp = v3f_add(dp, v3f_scalef(up, -speed*dt));
-        
-        camera_pos = v3f_add(camera_pos, dp);
-        
-        /* NOTE(pryazha): Mouse handling */
-        F32 sensitivity = 0.1f;
-        input.mouse_offset = v2f_scalef(input.mouse_offset, sensitivity);
-        yaw += input.mouse_offset.x;
-        pitch += input.mouse_offset.y;
-        if (pitch > 89.0f)
-            pitch = 89.0f;
-        if (pitch < -89.0f)
-            pitch = -89.0f;
-        
-        view = mat4_make_translate(v3f_negate(camera_pos));
-        view = mat4_rotate_angles(view, v3f(pitch, yaw, 0.0f));
-        
-        input_update_last_state(&input);
-        
-        /* NOTE(pryazha): Render */
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        
-        glUseProgram(cube_shader);
-        shader_set_mat4fv(cube_shader, "view", view);
-        shader_set_mat4fv(cube_shader, "projection", projection);
-        glBindTexture(GL_TEXTURE_2D, grid_texture);
-        
-        glBindVertexArray(cube_vao);
-        for (S32 transform_index = 0;
-             transform_index < (S32)ArrayCount(cube_positions);
-             ++transform_index)
-        {
-            shader_set_mat4fv(cube_shader, "model", transform_apply(cube_positions[transform_index]));
-            glDrawArrays(GL_TRIANGLES, 0, 36);
-        }
-        
-        shader_set_mat4fv(cube_shader, "model", transform_apply(platform_position));
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindVertexArray(0);
-        
-        glUseProgram(reflection_shader);
-        shader_set_mat4fv(reflection_shader, "model", mat4_make_translate(v3f(0.0f, 2.0f, 0.0f)));
-        shader_set_mat4fv(reflection_shader, "view", view);
-        shader_set_mat4fv(reflection_shader, "projection", projection);
-        shader_set_3fv(reflection_shader, "camera_pos", camera_pos);
-        glBindVertexArray(normals_cube_vao);
-        glBindTexture(GL_TEXTURE_CUBE_MAP, skybox_texture);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
-        glBindVertexArray(0);
-        
-        glUseProgram(refraction_shader);
-        shader_set_mat4fv(refraction_shader, "model", mat4_make_translate(v3f(2.0f, 2.0f, 0.0f)));
-        shader_set_mat4fv(refraction_shader, "view", view);
-        shader_set_mat4fv(refraction_shader, "projection", projection);
-        shader_set_3fv(refraction_shader, "camera_pos", camera_pos);
-        glBindVertexArray(normals_cube_vao);
-        glBindTexture(GL_TEXTURE_CUBE_MAP, skybox_texture);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
-        glBindVertexArray(0);
-        
-        glUseProgram(skybox_shader);
-        MAT4 rotate_view = mat4_identity();
-        rotate_view.m0 = v4f(view.m0.x, view.m0.y, view.m0.z, 0.0f);
-        rotate_view.m1 = v4f(view.m1.x, view.m1.y, view.m1.z, 0.0f);
-        rotate_view.m2 = v4f(view.m2.x, view.m2.y, view.m2.z, 0.0f);
-        shader_set_mat4fv(skybox_shader, "view", rotate_view);
-        shader_set_mat4fv(skybox_shader, "projection", projection);
-        glBindVertexArray(skybox_cube_vao);
-        glBindTexture(GL_TEXTURE_CUBE_MAP, skybox_texture);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindVertexArray(0);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf)
-        {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0)
-                sleep(sleep_time);
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        last_time = current_time;
-    }
-    
-    glfwTerminate();
-    return(0);
+	glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glEnable(GL_DEPTH_TEST);
+	glDepthFunc(GL_LEQUAL);
+
+	U32 skybox_shader = create_shader_program("shaders/skybox.vert", "shaders/skybox.frag");
+	U32 reflection_shader = create_shader_program("shaders/reflection.vert", "shaders/reflection.frag");
+	U32 refraction_shader = create_shader_program("shaders/refraction.vert", "shaders/refraction.frag");
+	U32 cube_shader = create_shader_program("shaders/cube.vert", "shaders/cube.frag");
+	U32 grid_texture = load_texture("../../data/textures/grid.png");
+
+	const char *cube_texture_filenames[6] = {
+		"../../data/textures/skybox/right.jpg",
+		"../../data/textures/skybox/left.jpg",
+		"../../data/textures/skybox/top.jpg",
+		"../../data/textures/skybox/bottom.jpg",
+		"../../data/textures/skybox/front.jpg",
+		"../../data/textures/skybox/back.jpg"
+	};
+	U32 skybox_texture = load_cubemap(cube_texture_filenames);
+
+	F32 a = 0.5f;
+	F32 vertices[] = {
+		-a, -a, -a,  0.0f, 0.0f,
+		 a, -a, -a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		-a,  a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 0.0f,
+
+		-a, -a,  a,  0.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		-a,  a,  a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+
+		-a,  a,  a,  1.0f, 0.0f,
+		-a,  a, -a,  1.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a,  a,  a,  1.0f, 0.0f,
+
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a,  a,  0.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+
+		-a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  1.0f, 1.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+
+		-a,  a, -a,  0.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		-a,  a,  a,  0.0f, 0.0f,
+		-a,  a, -a,  0.0f, 1.0f
+	};
+
+	Transform cube_positions[] = {
+		transform_default(),
+		transform_make_translate(v3f(a, 0.0f, -4.0f*a))
+	};
+
+	V3F platform_pos = v3f(10.0f, 0.2f, 10.0f);
+	V3F platform_scale = v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f);
+	Transform platform_transform = transform_make_scale_translate(platform_pos, platform_scale);
+
+	U32 cube_vao, vbo;
+	glGenVertexArrays(1, &cube_vao);
+	glBindVertexArray(cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	a = 1.0f;
+	F32 skybox_cube_vertices[] = {
+		-a, -a, -a,
+		 a, -a, -a,
+		 a,  a, -a,
+		 a,  a, -a,
+		-a,  a, -a,
+		-a, -a, -a,
+
+		-a, -a,  a,
+		 a, -a,  a,
+		 a,  a,  a,
+		 a,  a,  a,
+		-a,  a,  a,
+		-a, -a,  a,
+
+		-a,  a,  a,
+		-a,  a, -a,
+		-a, -a, -a,
+		-a, -a, -a,
+		-a, -a,  a,
+		-a,  a,  a,
+
+		 a,  a,  a,
+		 a,  a, -a,
+		 a, -a, -a,
+		 a, -a, -a,
+		 a, -a,  a,
+		 a,  a,  a,
+
+		-a, -a, -a,
+		 a, -a, -a,
+		 a, -a,  a,
+		 a, -a,  a,
+		-a, -a,  a,
+		-a, -a, -a,
+
+		-a,  a, -a,
+		 a,  a, -a,
+		 a,  a,  a,
+		 a,  a,  a,
+		-a,  a,  a,
+		-a,  a, -a,
+	};
+
+	U32 skybox_cube_vao;
+	glGenVertexArrays(1, &skybox_cube_vao);
+	glBindVertexArray(skybox_cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(skybox_cube_vertices), skybox_cube_vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(F32), (void *)0);
+	glBindVertexArray(0);
+
+	F32 normals_cube_vertices[] = {
+		-0.5f, -0.5f, -0.5f,   0.0f,  0.0f, -1.0f,
+		 0.5f, -0.5f, -0.5f,   0.0f,  0.0f, -1.0f,
+		 0.5f,  0.5f, -0.5f,   0.0f,  0.0f, -1.0f,
+		 0.5f,  0.5f, -0.5f,   0.0f,  0.0f, -1.0f,
+		-0.5f,  0.5f, -0.5f,   0.0f,  0.0f, -1.0f,
+		-0.5f, -0.5f, -0.5f,   0.0f,  0.0f, -1.0f,
+
+		-0.5f, -0.5f,  0.5f,   0.0f,  0.0f, 1.0f,
+		 0.5f, -0.5f,  0.5f,   0.0f,  0.0f, 1.0f,
+		 0.5f,  0.5f,  0.5f,   0.0f,  0.0f, 1.0f,
+		 0.5f,  0.5f,  0.5f,   0.0f,  0.0f, 1.0f,
+		-0.5f,  0.5f,  0.5f,   0.0f,  0.0f, 1.0f,
+		-0.5f, -0.5f,  0.5f,   0.0f,  0.0f, 1.0f,
+
+		-0.5f,  0.5f,  0.5f,  -1.0f,  0.0f,  0.0f,
+		-0.5f,  0.5f, -0.5f,  -1.0f,  0.0f,  0.0f,
+		-0.5f, -0.5f, -0.5f,  -1.0f,  0.0f,  0.0f,
+		-0.5f, -0.5f, -0.5f,  -1.0f,  0.0f,  0.0f,
+		-0.5f, -0.5f,  0.5f,  -1.0f,  0.0f,  0.0f,
+		-0.5f,  0.5f,  0.5f,  -1.0f,  0.0f,  0.0f,
+
+		 0.5f,  0.5f,  0.5f,   1.0f,  0.0f,  0.0f,
+		 0.5f,  0.5f, -0.5f,   1.0f,  0.0f,  0.0f,
+		 0.5f, -0.5f, -0.5f,   1.0f,  0.0f,  0.0f,
+		 0.5f, -0.5f, -0.5f,   1.0f,  0.0f,  0.0f,
+		 0.5f, -0.5f,  0.5f,   1.0f,  0.0f,  0.0f,
+		 0.5f,  0.5f,  0.5f,   1.0f,  0.0f,  0.0f,
+
+		-0.5f, -0.5f, -0.5f,   0.0f, -1.0f,  0.0f,
+		 0.5f, -0.5f, -0.5f,   0.0f, -1.0f,  0.0f,
+		 0.5f, -0.5f,  0.5f,   0.0f, -1.0f,  0.0f,
+		 0.5f, -0.5f,  0.5f,   0.0f, -1.0f,  0.0f,
+		-0.5f, -0.5f,  0.5f,   0.0f, -1.0f,  0.0f,
+		-0.5f, -0.5f, -0.5f,   0.0f, -1.0f,  0.0f,
+
+		-0.5f,  0.5f, -0.5f,   0.0f,  1.0f,  0.0f,
+		 0.5f,  0.5f, -0.5f,   0.0f,  1.0f,  0.0f,
+		 0.5f,  0.5f,  0.5f,   0.0f,  1.0f,  0.0f,
+		 0.5f,  0.5f,  0.5f,   0.0f,  1.0f,  0.0f,
+		-0.5f,  0.5f,  0.5f,   0.0f,  1.0f,  0.0f,
+		-0.5f,  0.5f, -0.5f,   0.0f,  1.0f,  0.0f
+	};
+	U32 normals_cube_vao;
+	glGenVertexArrays(1, &normals_cube_vao);
+	glBindVertexArray(normals_cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(normals_cube_vertices), normals_cube_vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	state.camera = (Camera) {
+		v3f(0.0f, 1.0f, 3.0f), 100.0f,
+		0.1f, 100.0f, 0.0f, 0.0f
+	};
+	input = input_init();
+
+	F32 target_fps = 60.0f;
+	F32 target_spf = 1.0f/target_fps;
+	F32 last_time = glfwGetTime();
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		/* INFO(pryazha): update */
+		glfwGetFramebufferSize(window, &width, &height);
+		process_glfw_keyboard(window, &input);
+		process_glfw_mouse_pos(window, &input);
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		V3F dv = get_dv_camera_first_person(&input, &state.camera,
+						    4.0f, state.dt);
+		state.camera.pos = v3f_add(state.camera.pos, dv);
+
+		F32 sensitivity = 0.1f;
+		input.mouse_offset = v2f_scalef(input.mouse_offset, sensitivity);
+		state.camera.yaw += input.mouse_offset.x;
+		state.camera.pitch += input.mouse_offset.y;
+		if (state.camera.pitch > 89.0f)
+			state.camera.pitch = 89.0f;
+		if (state.camera.pitch < -89.0f)
+			state.camera.pitch = -89.0f;
+
+		input_update_last_state(&input);
+
+		/* NOTE(pryazha): Render */
+		MAT4 view, proj, model;
+		view = get_view_matrix(&state.camera);
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		glUseProgram(cube_shader);
+		shader_set_mat4fv(cube_shader, "view", view);
+		shader_set_mat4fv(cube_shader, "proj", proj);
+		glBindTexture(GL_TEXTURE_2D, grid_texture);
+		glBindVertexArray(cube_vao);
+		for (S32 i = 0; i < (S32)ArrayCount(cube_positions); ++i) {
+			model = transform_apply(cube_positions[i]);
+			shader_set_mat4fv(cube_shader, "model", model);
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+		}
+
+		model = transform_apply(platform_transform);
+		shader_set_mat4fv(cube_shader, "model", model);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindVertexArray(0);
+
+		glUseProgram(reflection_shader);
+		model = mat4_make_translate(v3f(0.0f, 2.0f, 0.0f));
+		shader_set_mat4fv(reflection_shader, "model", model);
+		shader_set_mat4fv(reflection_shader, "view", view);
+		shader_set_mat4fv(reflection_shader, "proj", proj);
+		shader_set_3fv(reflection_shader, "camera_pos", state.camera.pos);
+		glBindVertexArray(normals_cube_vao);
+		glBindTexture(GL_TEXTURE_CUBE_MAP, skybox_texture);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
+		glBindVertexArray(0);
+
+		glUseProgram(refraction_shader);
+		model = mat4_make_translate(v3f(2.0f, 2.0f, 0.0f));
+		shader_set_mat4fv(refraction_shader, "model", model);
+		shader_set_mat4fv(refraction_shader, "view", view);
+		shader_set_mat4fv(refraction_shader, "proj", proj);
+		shader_set_3fv(refraction_shader, "camera_pos", state.camera.pos);
+		glBindVertexArray(normals_cube_vao);
+		glBindTexture(GL_TEXTURE_CUBE_MAP, skybox_texture);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
+		glBindVertexArray(0);
+
+		glUseProgram(skybox_shader);
+		MAT4 rotate_view = mat4_identity();
+		rotate_view.m0 = v4f(view.m0.x, view.m0.y, view.m0.z, 0.0f);
+		rotate_view.m1 = v4f(view.m1.x, view.m1.y, view.m1.z, 0.0f);
+		rotate_view.m2 = v4f(view.m2.x, view.m2.y, view.m2.z, 0.0f);
+		shader_set_mat4fv(skybox_shader, "view", rotate_view);
+		shader_set_mat4fv(skybox_shader, "proj", proj);
+		glBindVertexArray(skybox_cube_vao);
+		glBindTexture(GL_TEXTURE_CUBE_MAP, skybox_texture);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindVertexArray(0);
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		last_time = current_time;
+	}
+
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/3.blending/shaders/blending.fs b/advanced_opengl/6.cubemaps/shaders/cube.frag
index f58c5d3..71892a7 100644
--- a/advanced_opengl/3.blending/shaders/blending.fs
+++ b/advanced_opengl/6.cubemaps/shaders/cube.frag
@@ -6,8 +6,7 @@ in vec2 tex_coords;
 
 uniform sampler2D texture1;
 
-void
-main(void)
+void main(void)
 {
     frag_color = texture(texture1, tex_coords);
 }
diff --git a/advanced_opengl/6.cubemaps/shaders/cube.vs b/advanced_opengl/6.cubemaps/shaders/cube.vert
index aea5c2c..2436f35 100644
--- a/advanced_opengl/6.cubemaps/shaders/cube.vs
+++ b/advanced_opengl/6.cubemaps/shaders/cube.vert
@@ -5,13 +5,12 @@ layout(location = 1) in vec2 atex_coords;
 
 uniform mat4 model;
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
 out vec2 tex_coords;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
     tex_coords = atex_coords;
 }
diff --git a/advanced_opengl/6.cubemaps/shaders/reflection.fs b/advanced_opengl/6.cubemaps/shaders/reflection.frag
index 3723ea9..72b1c0d 100644
--- a/advanced_opengl/6.cubemaps/shaders/reflection.fs
+++ b/advanced_opengl/6.cubemaps/shaders/reflection.frag
@@ -8,8 +8,7 @@ out vec4 frag_color;
 uniform vec3 camera_pos;
 uniform samplerCube skybox;
 
-void
-main(void)
+void main(void)
 {
     vec3 i = pos-camera_pos;
     vec3 r = reflect(i, normalize(normal));
diff --git a/advanced_opengl/6.cubemaps/shaders/reflection.vs b/advanced_opengl/6.cubemaps/shaders/reflection.vert
index c9a0698..d7070f2 100644
--- a/advanced_opengl/6.cubemaps/shaders/reflection.vs
+++ b/advanced_opengl/6.cubemaps/shaders/reflection.vert
@@ -8,12 +8,11 @@ out vec3 normal;
 
 uniform mat4 model;
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
-void
-main(void)
+void main(void)
 {
     pos = vec3(model*vec4(apos, 1.0));
     normal = mat3(transpose(inverse(model)))*anormal;
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
 }
diff --git a/advanced_opengl/6.cubemaps/shaders/refraction.fs b/advanced_opengl/6.cubemaps/shaders/refraction.frag
index ef8c415..fa01b2c 100644
--- a/advanced_opengl/6.cubemaps/shaders/refraction.fs
+++ b/advanced_opengl/6.cubemaps/shaders/refraction.frag
@@ -8,8 +8,7 @@ out vec4 frag_color;
 uniform vec3 camera_pos;
 uniform samplerCube skybox;
 
-void
-main(void)
+void main(void)
 {
     float ratio = 1.0/1.52;
     vec3 i = pos-camera_pos;
diff --git a/advanced_opengl/6.cubemaps/shaders/refraction.vs b/advanced_opengl/6.cubemaps/shaders/refraction.vert
index c9a0698..d7070f2 100644
--- a/advanced_opengl/6.cubemaps/shaders/refraction.vs
+++ b/advanced_opengl/6.cubemaps/shaders/refraction.vert
@@ -8,12 +8,11 @@ out vec3 normal;
 
 uniform mat4 model;
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
-void
-main(void)
+void main(void)
 {
     pos = vec3(model*vec4(apos, 1.0));
     normal = mat3(transpose(inverse(model)))*anormal;
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
 }
diff --git a/advanced_opengl/6.cubemaps/shaders/skybox.fs b/advanced_opengl/6.cubemaps/shaders/skybox.frag
index bf69c8b..22be301 100644
--- a/advanced_opengl/6.cubemaps/shaders/skybox.fs
+++ b/advanced_opengl/6.cubemaps/shaders/skybox.frag
@@ -6,8 +6,7 @@ out vec4 frag_color;
 
 uniform samplerCube skybox;
 
-void
-main(void)
+void main(void)
 {
     frag_color = texture(skybox, tex_coords);
 }
diff --git a/advanced_opengl/6.cubemaps/shaders/skybox.vs b/advanced_opengl/6.cubemaps/shaders/skybox.vert
index c790148..c7d91c9 100644
--- a/advanced_opengl/6.cubemaps/shaders/skybox.vs
+++ b/advanced_opengl/6.cubemaps/shaders/skybox.vert
@@ -5,12 +5,11 @@ layout(location = 0) in vec3 apos;
 out vec3 tex_coords;
 
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
-void
-main(void)
+void main(void)
 {
     tex_coords = apos;
-    vec4 pos = projection*view*vec4(apos, 1.0);
+    vec4 pos = proj*view*vec4(apos, 1.0);
     gl_Position = pos.xyww;
 }
diff --git a/advanced_opengl/8.geometry_shader/shaders/normals.fs b/advanced_opengl/7.uniform_buffer/shaders/color_cube.frag
index fbbafbf..d40d866 100644
--- a/advanced_opengl/8.geometry_shader/shaders/normals.fs
+++ b/advanced_opengl/7.uniform_buffer/shaders/color_cube.frag
@@ -2,8 +2,7 @@
 
 out vec4 frag_color;
 
-void
-main(void)
+void main(void)
 {
     frag_color = vec4(1.0, 0.0, 0.0, 1.0);
 }
diff --git a/advanced_opengl/7.uniform_buffer/shaders/color_cube.vs b/advanced_opengl/7.uniform_buffer/shaders/color_cube.vert
index 17a3448..67226f8 100644
--- a/advanced_opengl/7.uniform_buffer/shaders/color_cube.vs
+++ b/advanced_opengl/7.uniform_buffer/shaders/color_cube.vert
@@ -3,14 +3,13 @@ layout(location = 0) in vec3 apos;
 
 layout(std140) uniform Matrices
 {
-    mat4 projection;
+    mat4 proj;
     mat4 view;
 };
 
 uniform mat4 model;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
 }
diff --git a/advanced_opengl/7.uniform_buffer/shaders/cube.frag b/advanced_opengl/7.uniform_buffer/shaders/cube.frag
new file mode 100644
index 0000000..71892a7
--- /dev/null
+++ b/advanced_opengl/7.uniform_buffer/shaders/cube.frag
@@ -0,0 +1,12 @@
+#version 330 core
+
+out vec4 frag_color;
+
+in vec2 tex_coords;
+
+uniform sampler2D texture1;
+
+void main(void)
+{
+    frag_color = texture(texture1, tex_coords);
+}
diff --git a/advanced_opengl/7.uniform_buffer/shaders/cube.fs b/advanced_opengl/7.uniform_buffer/shaders/cube.fs
deleted file mode 100644
index f58c5d3..0000000
--- a/advanced_opengl/7.uniform_buffer/shaders/cube.fs
+++ /dev/null
@@ -1,13 +0,0 @@
-#version 330 core
-
-out vec4 frag_color;
-
-in vec2 tex_coords;
-
-uniform sampler2D texture1;
-
-void
-main(void)
-{
-    frag_color = texture(texture1, tex_coords);
-}
diff --git a/advanced_opengl/7.uniform_buffer/shaders/cube.vs b/advanced_opengl/7.uniform_buffer/shaders/cube.vert
index 054164d..ec90f37 100644
--- a/advanced_opengl/7.uniform_buffer/shaders/cube.vs
+++ b/advanced_opengl/7.uniform_buffer/shaders/cube.vert
@@ -5,7 +5,7 @@ layout(location = 1) in vec2 atex_coords;
 
 layout(std140) uniform Matrices
 {
-    uniform mat4 projection;
+    uniform mat4 proj;
     uniform mat4 view;
 };
 
@@ -13,9 +13,8 @@ uniform mat4 model;
 
 out vec2 tex_coords;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
     tex_coords = atex_coords;
 }
diff --git a/advanced_opengl/7.uniform_buffer/shaders/skybox.fs b/advanced_opengl/7.uniform_buffer/shaders/skybox.frag
index bf69c8b..22be301 100644
--- a/advanced_opengl/7.uniform_buffer/shaders/skybox.fs
+++ b/advanced_opengl/7.uniform_buffer/shaders/skybox.frag
@@ -6,8 +6,7 @@ out vec4 frag_color;
 
 uniform samplerCube skybox;
 
-void
-main(void)
+void main(void)
 {
     frag_color = texture(skybox, tex_coords);
 }
diff --git a/advanced_opengl/7.uniform_buffer/shaders/skybox.vs b/advanced_opengl/7.uniform_buffer/shaders/skybox.vert
index 03b2171..ddbeb21 100644
--- a/advanced_opengl/7.uniform_buffer/shaders/skybox.vs
+++ b/advanced_opengl/7.uniform_buffer/shaders/skybox.vert
@@ -6,14 +6,13 @@ out vec3 tex_coords;
 
 layout(std140) uniform Matrices
 {
-    uniform mat4 projection;
+    uniform mat4 proj;
     uniform mat4 view;
 };
 
-void
-main(void)
+void main(void)
 {
     tex_coords = apos;
-    vec4 pos = projection*view*vec4(apos, 1.0);
+    vec4 pos = proj*view*vec4(apos, 1.0);
     gl_Position = pos.xyww;
 }
diff --git a/advanced_opengl/7.uniform_buffer/uniform_buffer b/advanced_opengl/7.uniform_buffer/uniform_buffer
index 57aa64d..154fb08 100755
--- a/advanced_opengl/7.uniform_buffer/uniform_buffer
+++ b/advanced_opengl/7.uniform_buffer/uniform_buffer
diff --git a/advanced_opengl/7.uniform_buffer/uniform_buffer.c b/advanced_opengl/7.uniform_buffer/uniform_buffer.c
index e67b5c9..a27c115 100644
--- a/advanced_opengl/7.uniform_buffer/uniform_buffer.c
+++ b/advanced_opengl/7.uniform_buffer/uniform_buffer.c
@@ -2,391 +2,302 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	State state;
+	S32 width, height;
+	Input input;
 
-#define WIDTH 1024
-#define HEIGHT 768
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-static V3F camera_pos;
-static F32 dt;
-static Input input;
-static B32 first_mouse = 1;
+	width = 1024;
+	height = 768;
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    input.move_down.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "Advanced data (uniform buffer)", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
 
-void
-cursor_pos_callback(GLFWwindow* window, double xpos, double ypos)
-{
-    if (first_mouse)
-    {
-        input.last_mouse_pos = v2f(xpos, ypos);
-        first_mouse = 0;
-    }
-    input.mouse_offset = v2f(input.mouse_offset.x+((F32)xpos-input.last_mouse_pos.x),
-                             input.mouse_offset.y+((F32)ypos-input.last_mouse_pos.y));
-    input.last_mouse_pos = v2f((F32)xpos, (F32)ypos);
-}
+	glfwMakeContextCurrent(window);
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_RESIZABLE, 0);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(WIDTH, HEIGHT, "Advanced data (uniform buffer)", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
-    
-    glfwSetKeyCallback(window, key_callback);
-    glfwSetCursorPosCallback(window, cursor_pos_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    U32 skybox_shader = create_shader_program("shaders/skybox.vs", "shaders/skybox.fs");
-    U32 cube_shader = create_shader_program("shaders/cube.vs", "shaders/cube.fs");
-    U32 color_cube_shader = create_shader_program("shaders/color_cube.vs",
-                                                  "shaders/color_cube.fs");
-    
-    U32 skybox_matrices = glGetUniformBlockIndex(skybox_shader, "Matrices");
-    U32 cube_matrices = glGetUniformBlockIndex(cube_shader, "Matrices");
-    U32 color_cube_matrices = glGetUniformBlockIndex(color_cube_shader, "Matrices");
-    
-    glUniformBlockBinding(skybox_shader, skybox_matrices, 0);
-    glUniformBlockBinding(cube_shader, cube_matrices, 0);
-    glUniformBlockBinding(color_cube_shader, color_cube_matrices, 0);
-    
-    U32 matrices_ubo;
-    glGenBuffers(1, &matrices_ubo);
-    glBindBuffer(GL_UNIFORM_BUFFER, matrices_ubo);
-    glBufferData(GL_UNIFORM_BUFFER, 2*sizeof(MAT4), 0, GL_STATIC_DRAW);
-    glBindBuffer(GL_UNIFORM_BUFFER, 0);
-    glBindBufferRange(GL_UNIFORM_BUFFER, 0, matrices_ubo, 0, 2*sizeof(MAT4));
-    
-    U32 grid_texture = load_texture("../../data/textures/grid.png");
-    
-    const char *cube_texture_filenames[6] = {
-        "../../data/textures/skybox/right.jpg",
-        "../../data/textures/skybox/left.jpg",
-        "../../data/textures/skybox/top.jpg",
-        "../../data/textures/skybox/bottom.jpg",
-        "../../data/textures/skybox/front.jpg",
-        "../../data/textures/skybox/back.jpg"
-    };
-    U32 skybox_texture = load_cubemap(cube_texture_filenames);
-    
-    F32 a = 0.5f;
-    F32 vertices[] = {
-        -a, -a, -a,  0.0f, 0.0f,
-        a, -a, -a,  1.0f, 0.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        -a,  a, -a,  0.0f, 1.0f,
-        -a, -a, -a,  0.0f, 0.0f,
-        
-        -a, -a,  a,  0.0f, 0.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        a,  a,  a,  1.0f, 1.0f,
-        a,  a,  a,  1.0f, 1.0f,
-        -a,  a,  a,  0.0f, 1.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        
-        -a,  a,  a,  1.0f, 0.0f,
-        -a,  a, -a,  1.0f, 1.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        -a,  a,  a,  1.0f, 0.0f,
-        
-        a,  a,  a,  1.0f, 0.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a, -a, -a,  0.0f, 1.0f,
-        a, -a, -a,  0.0f, 1.0f,
-        a, -a,  a,  0.0f, 0.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        
-        -a, -a, -a,  0.0f, 1.0f,
-        a, -a, -a,  1.0f, 1.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        a, -a,  a,  1.0f, 0.0f,
-        -a, -a,  a,  0.0f, 0.0f,
-        -a, -a, -a,  0.0f, 1.0f,
-        
-        -a,  a, -a,  0.0f, 1.0f,
-        a,  a, -a,  1.0f, 1.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        a,  a,  a,  1.0f, 0.0f,
-        -a,  a,  a,  0.0f, 0.0f,
-        -a,  a, -a,  0.0f, 1.0f
-    };
-    
-    Transform platform_position =
-        transform_make_scale_translate(v3f(10.0f, 0.2f, 10.0f),
-                                       v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f));
-    
-    U32 cube_vao, vbo;
-    glGenVertexArrays(1, &cube_vao);
-    glBindVertexArray(cube_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    a = 1.0f;
-    F32 skybox_cube_vertices[] = {
-        -a, -a, -a,
-        a, -a, -a,
-        a,  a, -a,
-        a,  a, -a,
-        -a,  a, -a,
-        -a, -a, -a,
-        
-        -a, -a,  a,
-        a, -a,  a,
-        a,  a,  a,
-        a,  a,  a,
-        -a,  a,  a,
-        -a, -a,  a,
-        
-        -a,  a,  a,
-        -a,  a, -a,
-        -a, -a, -a,
-        -a, -a, -a,
-        -a, -a,  a,
-        -a,  a,  a,
-        
-        a,  a,  a,
-        a,  a, -a,
-        a, -a, -a,
-        a, -a, -a,
-        a, -a,  a,
-        a,  a,  a,
-        
-        -a, -a, -a,
-        a, -a, -a,
-        a, -a,  a,
-        a, -a,  a,
-        -a, -a,  a,
-        -a, -a, -a,
-        
-        -a,  a, -a,
-        a,  a, -a,
-        a,  a,  a,
-        a,  a,  a,
-        -a,  a,  a,
-        -a,  a, -a,
-    };
-    
-    U32 skybox_cube_vao;
-    glGenVertexArrays(1, &skybox_cube_vao);
-    glBindVertexArray(skybox_cube_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(skybox_cube_vertices), skybox_cube_vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(F32), (void *)0);
-    glBindVertexArray(0);
-    
-    F32 target_fps = 60.0f;
-    F32 target_spf = 1.0f/target_fps;
-    camera_pos = v3f(0.0f, 1.0f, 3.0f);
-    F32 yaw = 0.0f, pitch = 0.0f;
-    
-    F32 last_time = glfwGetTime();
-    
-    glEnable(GL_DEPTH_TEST);
-    glDepthFunc(GL_LEQUAL);
-    
-    MAT4 view, projection;
-    projection = perspective(90.0f, (F32)WIDTH/(F32)HEIGHT, 0.1f, 100.0f);
-    glBindBuffer(GL_UNIFORM_BUFFER, matrices_ubo);
-    glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(MAT4), (const void *)&projection);
-    glBindBuffer(GL_UNIFORM_BUFFER, 0);
-    view = mat4_make_translate(v3f_negate(camera_pos));
-    view = mat4_rotate_angles(view, v3f(pitch, yaw, 0.0f));
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* INFO(pryazha): update */
-        
-        V3F left, up, forward;
-        
-        left = v3f(-view.m0.x, -view.m1.x, -view.m2.x);
-        up = v3f(view.m0.y, view.m1.y, view.m2.y);
-        forward = v3f(-view.m0.z, -view.m1.z, -view.m2.z);
-        
-        V3F dp = v3f_zero();
-        F32 speed = 2.0f;
-        if (key_is_pressed(input.move_right))
-            dp = v3f_add(dp, v3f_scalef(left, -speed*dt));
-        if (key_is_pressed(input.move_forward))
-            dp = v3f_add(dp, v3f_scalef(forward, speed*dt));
-        if (key_is_pressed(input.move_left))
-            dp = v3f_add(dp, v3f_scalef(left, speed*dt));
-        if (key_is_pressed(input.move_backward))
-            dp = v3f_add(dp, v3f_scalef(forward, -speed*dt));
-        if (key_is_pressed(input.move_up))
-            dp = v3f_add(dp, v3f_scalef(up, speed*dt));
-        if (key_is_pressed(input.move_down))
-            dp = v3f_add(dp, v3f_scalef(up, -speed*dt));
-        input_update_last_state(&input);
-        camera_pos = v3f_add(camera_pos, dp);
-        
-        /* NOTE(pryazha): Mouse handling */
-        F32 sensitivity = 0.1f;
-        input.mouse_offset = v2f_scalef(input.mouse_offset, sensitivity);
-        yaw += input.mouse_offset.x;
-        pitch += input.mouse_offset.y;
-        if (pitch > 89.0f)
-            pitch = 89.0f;
-        if (pitch < -89.0f)
-            pitch = -89.0f;
-        input.mouse_offset = v2f_zero();
-        
-        view = mat4_make_translate(v3f_negate(camera_pos));
-        view = mat4_rotate_angles(view, v3f(pitch, yaw, 0.0f));
-        glBindBuffer(GL_UNIFORM_BUFFER, matrices_ubo);
-        glBufferSubData(GL_UNIFORM_BUFFER, sizeof(MAT4), sizeof(MAT4), (const void *)&view);
-        glBindBuffer(GL_UNIFORM_BUFFER, 0);
-        
-        /* NOTE(pryazha): Render */
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        
-        glUseProgram(cube_shader);
-        shader_set_mat4fv(cube_shader, "model", mat4_make_translate(v3f(-2.0f, 0.0f, 0.0f)));
-        glBindTexture(GL_TEXTURE_2D, grid_texture);
-        glBindVertexArray(cube_vao);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindTexture(GL_TEXTURE_2D, 0);
-        glBindVertexArray(0);
-        
-        glUseProgram(cube_shader);
-        shader_set_mat4fv(cube_shader, "model", transform_apply(platform_position));
-        glBindTexture(GL_TEXTURE_2D, grid_texture);
-        glBindVertexArray(cube_vao);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindTexture(GL_TEXTURE_2D, 0);
-        glBindVertexArray(0);
-        
-        glUseProgram(color_cube_shader);
-        shader_set_mat4fv(cube_shader, "model", mat4_make_translate(v3f(2.0f, 0.0f, 0.0f)));
-        glBindVertexArray(cube_vao);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindVertexArray(0);
-        
-        glUseProgram(skybox_shader);
-        MAT4 rotate_view = mat4_identity();
-        rotate_view.m0 = v4f(view.m0.x, view.m0.y, view.m0.z, 0.0f);
-        rotate_view.m1 = v4f(view.m1.x, view.m1.y, view.m1.z, 0.0f);
-        rotate_view.m2 = v4f(view.m2.x, view.m2.y, view.m2.z, 0.0f);
-        glBindBuffer(GL_UNIFORM_BUFFER, matrices_ubo);
-        glBufferSubData(GL_UNIFORM_BUFFER, sizeof(MAT4), sizeof(MAT4), (const void *)&rotate_view);
-        glBindBuffer(GL_UNIFORM_BUFFER, 0);
-        glBindVertexArray(skybox_cube_vao);
-        glBindTexture(GL_TEXTURE_CUBE_MAP, skybox_texture);
-        glDrawArrays(GL_TRIANGLES, 0, 36);
-        glBindVertexArray(0);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf)
-        {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0)
-                sleep(sleep_time);
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        last_time = current_time;
-    }
-    
-    glfwTerminate();
-    return(0);
+	glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glEnable(GL_DEPTH_TEST);
+	glDepthFunc(GL_LEQUAL);
+
+	U32 skybox_shader = create_shader_program("shaders/skybox.vert", "shaders/skybox.frag");
+	U32 cube_shader = create_shader_program("shaders/cube.vert", "shaders/cube.frag");
+	U32 color_cube_shader = create_shader_program("shaders/color_cube.vert", "shaders/color_cube.frag");
+
+	U32 skybox_matrices = glGetUniformBlockIndex(skybox_shader, "Matrices");
+	U32 cube_matrices = glGetUniformBlockIndex(cube_shader, "Matrices");
+	U32 color_cube_matrices = glGetUniformBlockIndex(color_cube_shader, "Matrices");
+
+	glUniformBlockBinding(skybox_shader, skybox_matrices, 0);
+	glUniformBlockBinding(cube_shader, cube_matrices, 0);
+	glUniformBlockBinding(color_cube_shader, color_cube_matrices, 0);
+
+	U32 matrices_ubo;
+	glGenBuffers(1, &matrices_ubo);
+	glBindBuffer(GL_UNIFORM_BUFFER, matrices_ubo);
+	glBufferData(GL_UNIFORM_BUFFER, 2*sizeof(MAT4), 0, GL_STATIC_DRAW);
+	glBindBuffer(GL_UNIFORM_BUFFER, 0);
+	glBindBufferRange(GL_UNIFORM_BUFFER, 0, matrices_ubo, 0, 2*sizeof(MAT4));
+
+	U32 grid_texture = load_texture("../../data/textures/grid.png");
+
+	const char *cube_texture_filenames[6] = {
+		"../../data/textures/skybox/right.jpg",
+		"../../data/textures/skybox/left.jpg",
+		"../../data/textures/skybox/top.jpg",
+		"../../data/textures/skybox/bottom.jpg",
+		"../../data/textures/skybox/front.jpg",
+		"../../data/textures/skybox/back.jpg"
+	};
+
+	U32 skybox_texture = load_cubemap(cube_texture_filenames);
+
+	F32 a = 0.5f;
+	F32 vertices[] = {
+		-a, -a, -a,  0.0f, 0.0f,
+		 a, -a, -a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		-a,  a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 0.0f,
+
+		-a, -a,  a,  0.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 1.0f,
+		-a,  a,  a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+
+		-a,  a,  a,  1.0f, 0.0f,
+		-a,  a, -a,  1.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a,  a,  a,  1.0f, 0.0f,
+
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  0.0f, 1.0f,
+		 a, -a,  a,  0.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+
+		-a, -a, -a,  0.0f, 1.0f,
+		 a, -a, -a,  1.0f, 1.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		 a, -a,  a,  1.0f, 0.0f,
+		-a, -a,  a,  0.0f, 0.0f,
+		-a, -a, -a,  0.0f, 1.0f,
+
+		-a,  a, -a,  0.0f, 1.0f,
+		 a,  a, -a,  1.0f, 1.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		 a,  a,  a,  1.0f, 0.0f,
+		-a,  a,  a,  0.0f, 0.0f,
+		-a,  a, -a,  0.0f, 1.0f
+	};
+
+	V3F platform_pos = v3f(10.0f, 0.2f, 10.0f);
+	V3F platform_scale = v3f(0.0f, -(a+(a*0.2f)+0.01f), 0.0f);
+	Transform platform_transform = transform_make_scale_translate(platform_pos, platform_scale);
+
+	U32 cube_vao, vbo;
+	glGenVertexArrays(1, &cube_vao);
+	glBindVertexArray(cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	a = 1.0f;
+	F32 skybox_cube_vertices[] = {
+		-a, -a, -a,
+		 a, -a, -a,
+		 a,  a, -a,
+		 a,  a, -a,
+		-a,  a, -a,
+		-a, -a, -a,
+
+		-a, -a,  a,
+		 a, -a,  a,
+		 a,  a,  a,
+		 a,  a,  a,
+		-a,  a,  a,
+		-a, -a,  a,
+
+		-a,  a,  a,
+		-a,  a, -a,
+		-a, -a, -a,
+		-a, -a, -a,
+		-a, -a,  a,
+		-a,  a,  a,
+
+		 a,  a,  a,
+		 a,  a, -a,
+		 a, -a, -a,
+		 a, -a, -a,
+		 a, -a,  a,
+		 a,  a,  a,
+
+		-a, -a, -a,
+		 a, -a, -a,
+		 a, -a,  a,
+		 a, -a,  a,
+		-a, -a,  a,
+		-a, -a, -a,
+
+		-a,  a, -a,
+		 a,  a, -a,
+		 a,  a,  a,
+		 a,  a,  a,
+		-a,  a,  a,
+		-a,  a, -a,
+	};
+
+	U32 skybox_cube_vao;
+	glGenVertexArrays(1, &skybox_cube_vao);
+	glBindVertexArray(skybox_cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(skybox_cube_vertices), skybox_cube_vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(F32), (void *)0);
+	glBindVertexArray(0);
+
+	state.camera = (Camera) {
+		v3f(0.0f, 1.0f, 3.0f), 100.0f,
+		0.1f, 100.0f, 0.0f, 0.0f
+	};
+	input = input_init();
+
+	F32 target_fps = 60.0f;
+	F32 target_spf = 1.0f/target_fps;
+	F32 last_time = glfwGetTime();
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		/* INFO(pryazha): Update */
+		glfwGetFramebufferSize(window, &width, &height);
+		process_glfw_keyboard(window, &input);
+		process_glfw_mouse_pos(window, &input);
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		V3F dv = get_dv_camera_first_person(&input, &state.camera,
+						    4.0f, state.dt);
+		state.camera.pos = v3f_add(state.camera.pos, dv);
+
+		F32 sensitivity = 0.1f;
+		input.mouse_offset = v2f_scalef(input.mouse_offset, sensitivity);
+		state.camera.yaw += input.mouse_offset.x;
+		state.camera.pitch += input.mouse_offset.y;
+		if (state.camera.pitch > 89.0f)
+			state.camera.pitch = 89.0f;
+		if (state.camera.pitch < -89.0f)
+			state.camera.pitch = -89.0f;
+
+		input_update_last_state(&input);
+
+		/* NOTE(pryazha): Render */
+		MAT4 view, proj, model;
+		view = get_view_matrix(&state.camera);
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+
+		glBindBuffer(GL_UNIFORM_BUFFER, matrices_ubo);
+		glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(MAT4),
+			       	(const void *)&proj);
+		glBindBuffer(GL_UNIFORM_BUFFER, 0);
+		glBindBuffer(GL_UNIFORM_BUFFER, matrices_ubo);
+		glBufferSubData(GL_UNIFORM_BUFFER, sizeof(MAT4),
+			       	sizeof(MAT4), (const void *)&view);
+		glBindBuffer(GL_UNIFORM_BUFFER, 0);
+
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		glUseProgram(cube_shader);
+		model = mat4_make_translate(v3f(-2.0f, 0.0f, 0.0f));
+		shader_set_mat4fv(cube_shader, "model", model);
+		glBindTexture(GL_TEXTURE_2D, grid_texture);
+		glBindVertexArray(cube_vao);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindTexture(GL_TEXTURE_2D, 0);
+		glBindVertexArray(0);
+
+		glUseProgram(cube_shader);
+		model = transform_apply(platform_transform);
+		shader_set_mat4fv(cube_shader, "model", model);
+		glBindTexture(GL_TEXTURE_2D, grid_texture);
+		glBindVertexArray(cube_vao);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindTexture(GL_TEXTURE_2D, 0);
+		glBindVertexArray(0);
+
+		glUseProgram(color_cube_shader);
+		model = mat4_make_translate(v3f(2.0f, 0.0f, 0.0f));
+		shader_set_mat4fv(cube_shader, "model", model);
+		glBindVertexArray(cube_vao);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindVertexArray(0);
+
+		glUseProgram(skybox_shader);
+		MAT4 rotate_view = mat4_identity();
+		rotate_view.m0 = v4f(view.m0.x, view.m0.y, view.m0.z, 0.0f);
+		rotate_view.m1 = v4f(view.m1.x, view.m1.y, view.m1.z, 0.0f);
+		rotate_view.m2 = v4f(view.m2.x, view.m2.y, view.m2.z, 0.0f);
+		glBindBuffer(GL_UNIFORM_BUFFER, matrices_ubo);
+		glBufferSubData(GL_UNIFORM_BUFFER, sizeof(MAT4), sizeof(MAT4),
+			       	(const void *)&rotate_view);
+		glBindBuffer(GL_UNIFORM_BUFFER, 0);
+		glBindVertexArray(skybox_cube_vao);
+		glBindTexture(GL_TEXTURE_CUBE_MAP, skybox_texture);
+		glDrawArrays(GL_TRIANGLES, 0, 36);
+		glBindVertexArray(0);
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		last_time = current_time;
+	}
+
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/8.geometry_shader/geometry_shader b/advanced_opengl/8.geometry_shader/geometry_shader
index 77fcab4..0bea785 100755
--- a/advanced_opengl/8.geometry_shader/geometry_shader
+++ b/advanced_opengl/8.geometry_shader/geometry_shader
diff --git a/advanced_opengl/8.geometry_shader/geometry_shader.c b/advanced_opengl/8.geometry_shader/geometry_shader.c
index 678708c..f242709 100644
--- a/advanced_opengl/8.geometry_shader/geometry_shader.c
+++ b/advanced_opengl/8.geometry_shader/geometry_shader.c
@@ -2,338 +2,299 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
-
-#define WIDTH 1024
-#define HEIGHT 768
-
-static F32 dt;
-static Input input;
-
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
+void draw_cube(U32 cube_vao, U32 texture)
 {
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_SPACE: {
-                    input.jump.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_SPACE: {
-                    input.jump.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
+	glBindVertexArray(cube_vao);
+	glBindTexture(GL_TEXTURE_2D, texture);
+	glDrawArrays(GL_TRIANGLES, 0, 36);
+	glBindTexture(GL_TEXTURE_2D, 0);
+	glBindVertexArray(0);
 }
 
-void
-draw_cube(U32 cube_vao, U32 texture)
+int main(void)
 {
-    glBindVertexArray(cube_vao);
-    glBindTexture(GL_TEXTURE_2D, texture);
-    glDrawArrays(GL_TRIANGLES, 0, 36);
-    glBindTexture(GL_TEXTURE_2D, 0);
-    glBindVertexArray(0);
-}
+	GLFWwindow *window;
+	State state;
+	S32 width, height;
+	Input input;
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    glfwWindowHint(GLFW_RESIZABLE, 0);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(WIDTH, HEIGHT, "depth testing", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetKeyCallback(window, key_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glEnable(GL_DEPTH_TEST);
-    
-    U32 shader = create_shader_program_geom("shaders/base.vs",
-                                            "shaders/base.fs",
-                                            "shaders/base.gs");
-    U32 explosion_shader = create_shader_program_geom("shaders/explosion.vs",
-                                                      "shaders/explosion.fs",
-                                                      "shaders/explosion.gs");
-    U32 normals_shader = create_shader_program_geom("shaders/normals.vs",
-                                                    "shaders/normals.fs",
-                                                    "shaders/normals.gs");
-    U32 basic_shader = create_shader_program("shaders/basic.vs", "shaders/basic.fs");
-    
-    U32 grid_texture = load_texture("../../data/textures/grid.png");
-    
-    F32 points[] = {
-        -0.5f,  0.5f, 1.0f, 0.0f, 0.0f,
-        0.5f,  0.5f, 0.0f, 1.0f, 0.0f,
-        0.5f, -0.5f, 0.0f, 0.0f, 1.0f,
-        -0.5f, -0.5f, 1.0f, 1.0f, 0.0f
-    };
-    
-    GLuint points_vao, vbo;
-    glGenVertexArrays(1, &points_vao);
-    glBindVertexArray(points_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(points), points, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(2*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    F32 a = 0.5f;
-    /* NOTE(pryazha): Counter-clockwise order */
-    F32 cube_vertices[] = {
-        /* NOTE(pryazha): Back face */
-        a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a,  a, -a,  1.0f, 1.0f, /* top-right */
-        a,  a, -a,  0.0f, 1.0f, /* top-left */
-        a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a, -a, -a,  1.0f, 0.0f, /* bottom-right */
-        -a,  a, -a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Front face */
-        -a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a,  a,  1.0f, 1.0f, /* top-right */
-        -a,  a,  a,  0.0f, 1.0f, /* top-left */
-        -a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a, -a,  a,  1.0f, 0.0f, /* bottom-right */
-        a,  a,  a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Left face */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a,  a,  a,  1.0f, 1.0f, /* top-right */
-        -a,  a, -a,  0.0f, 1.0f, /* top-left */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        -a, -a,  a,  1.0f, 0.0f, /* bottom-right */
-        -a,  a,  a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Right face */
-        a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        a,  a,  a,  0.0f, 1.0f, /* top-left */
-        a, -a,  a,  0.0f, 0.0f, /* bottom-left */
-        a, -a, -a,  1.0f, 0.0f, /* bottom-right */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Top face */
-        -a,  a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        -a,  a, -a,  0.0f, 1.0f, /* top-left */
-        -a,  a,  a,  0.0f, 0.0f, /* bottom-left */
-        a,  a,  a,  1.0f, 0.0f, /* bottom-right */
-        a,  a, -a,  1.0f, 1.0f, /* top-right */
-        
-        /* NOTE(pryazha): Bottom face */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        a, -a,  a,  1.0f, 1.0f, /* top-right */
-        -a, -a,  a,  0.0f, 1.0f, /* top-left */
-        -a, -a, -a,  0.0f, 0.0f, /* bottom-left */
-        a, -a, -a,  1.0f, 0.0f, /* bottom-right */
-        a, -a,  a,  1.0f, 1.0f, /* top-right */
-    };
-    
-    U32 cube_vao;
-    glGenVertexArrays(1, &cube_vao);
-    glBindVertexArray(cube_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(cube_vertices), cube_vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    F32 vertices[] = {
-        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
-        0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
-        0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
-        0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
-        -0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
-        -0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
-        
-        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
-        0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
-        0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
-        0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
-        -0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
-        -0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
-        
-        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
-        -0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
-        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
-        -0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
-        -0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
-        -0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
-        
-        0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
-        0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
-        0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
-        0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
-        0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
-        0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
-        
-        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
-        0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
-        0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
-        0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
-        -0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
-        -0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
-        
-        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
-        0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
-        0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
-        0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
-        -0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
-        -0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
-    };
-    
-    U32 normals_cube_vao;
-    glGenVertexArrays(1, &normals_cube_vao);
-    glBindVertexArray(normals_cube_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8*sizeof(F32), (void *)(3*sizeof(F32)));
-    glEnableVertexAttribArray(2);
-    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8*sizeof(F32), (void *)(6*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    F32 target_fps = 60.0f;
-    F32 target_spf = 1.0f/target_fps;
-    
-    F32 last_time = glfwGetTime();
-    F32 time = last_time;
-    
-    S32 scene = 0;
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* NOTE(pryazha): Update */
-        if (key_first_press(input.jump))
-        {
-            scene++;
-            scene %= 3;
-        }
-        
-        input_update_last_state(&input);
-        
-        /* NOTE(pryazha): Render */
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        
-        if (scene == 0)
-        {
-            glUseProgram(shader);
-            glBindVertexArray(points_vao);
-            glDrawArrays(GL_POINTS, 0, 4);
-            glBindVertexArray(0);
-        }
-        else if (scene == 1)
-        {
-            F32 radius = 2.0f;
-            F32 x = f32_sin(0.5*time)*radius;
-            F32 z = f32_cos(0.5*time)*radius;
-            MAT4 projection = perspective(90.0f, (F32)WIDTH/(F32)HEIGHT, 0.1f, 100.0f);
-            MAT4 view = look_at(v3f(x, 1.0f, z), v3f_zero(), v3f(0.0f, 1.0f, 0.0f));
-            MAT4 model = mat4_identity();
-            glUseProgram(explosion_shader);
-            shader_set_mat4fv(explosion_shader, "projection", projection);
-            shader_set_mat4fv(explosion_shader, "view", view);
-            shader_set_mat4fv(explosion_shader, "model", model);
-            shader_set_1f(explosion_shader, "time", time);
-            glBindVertexArray(cube_vao);
-            glBindTexture(GL_TEXTURE_2D, grid_texture);
-            glDrawArrays(GL_TRIANGLES, 0, 36);
-            glBindVertexArray(0);
-        }
-        else
-        {
-            MAT4 projection, view, model;
-            F32 radius, x, z;
-            
-            radius = 2.0f;
-            x = f32_sin(0.5*time)*radius;
-            z = f32_cos(0.5*time)*radius;
-            
-            projection = perspective(90.0f, (F32)WIDTH/(F32)HEIGHT, 0.1f, 100.0f);
-            view = look_at(v3f(x, 1.0f, z), v3f_zero(), v3f(0.0f, 1.0f, 0.0f));
-            model = mat4_identity();
-            
-            glUseProgram(basic_shader);
-            shader_set_mat4fv(basic_shader, "projection", projection);
-            shader_set_mat4fv(basic_shader, "view", view);
-            shader_set_mat4fv(basic_shader, "model", model);
-            draw_cube(normals_cube_vao, grid_texture);
-            
-            glUseProgram(normals_shader);
-            shader_set_mat4fv(normals_shader, "projection", projection);
-            shader_set_mat4fv(normals_shader, "view", view);
-            shader_set_mat4fv(normals_shader, "model", model);
-            draw_cube(normals_cube_vao, grid_texture);
-        }
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf)
-        {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0)
-                sleep(sleep_time);
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        time += dt;
-        last_time = current_time;
-    }
-    
-    glDeleteBuffers(1, &vbo);
-    glDeleteVertexArrays(1, &points_vao);
-    
-    glfwTerminate();
-    return(0);
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
+
+	width = 1024;
+	height = 768;
+
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "depth testing", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glfwMakeContextCurrent(window);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glEnable(GL_DEPTH_TEST);
+
+	U32 shader = create_shader_program_geom("shaders/base.vert",
+						"shaders/base.frag",
+						"shaders/base.geom");
+	U32 explosion_shader = create_shader_program_geom("shaders/explosion.vert",
+							  "shaders/explosion.frag",
+							  "shaders/explosion.geom");
+	U32 normals_shader = create_shader_program_geom("shaders/normals.vert",
+							"shaders/normals.frag",
+							"shaders/normals.geom");
+	U32 basic_shader = create_shader_program("shaders/basic.vert",
+						 "shaders/basic.frag");
+
+	U32 grid_texture = load_texture("../../data/textures/grid.png");
+
+	F32 points[] = {
+		-0.5f,  0.5f, 1.0f, 0.0f, 0.0f,
+		 0.5f,  0.5f, 0.0f, 1.0f, 0.0f,
+		 0.5f, -0.5f, 0.0f, 0.0f, 1.0f,
+		-0.5f, -0.5f, 1.0f, 1.0f, 0.0f
+	};
+
+	GLuint points_vao, vbo;
+	glGenVertexArrays(1, &points_vao);
+	glBindVertexArray(points_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(points), points, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(2*sizeof(F32)));
+	glBindVertexArray(0);
+
+	F32 a = 0.5f;
+	/* NOTE(pryazha): Counter-clockwise order */
+	F32 cube_vertices[] = {
+		/* NOTE(pryazha): Back face */
+		 a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a,  a, -a,  1.0f, 1.0f, /* top-right */
+		 a,  a, -a,  0.0f, 1.0f, /* top-left */
+		 a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a, -a, -a,  1.0f, 0.0f, /* bottom-right */
+		-a,  a, -a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Front face */
+		-a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a,  a,  1.0f, 1.0f, /* top-right */
+		-a,  a,  a,  0.0f, 1.0f, /* top-left */
+		-a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a, -a,  a,  1.0f, 0.0f, /* bottom-right */
+		 a,  a,  a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Left face */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a,  a,  a,  1.0f, 1.0f, /* top-right */
+		-a,  a, -a,  0.0f, 1.0f, /* top-left */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		-a, -a,  a,  1.0f, 0.0f, /* bottom-right */
+		-a,  a,  a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Right face */
+		 a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+		 a,  a,  a,  0.0f, 1.0f, /* top-left */
+		 a, -a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a, -a, -a,  1.0f, 0.0f, /* bottom-right */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Top face */
+		-a,  a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+		-a,  a, -a,  0.0f, 1.0f, /* top-left */
+		-a,  a,  a,  0.0f, 0.0f, /* bottom-left */
+		 a,  a,  a,  1.0f, 0.0f, /* bottom-right */
+		 a,  a, -a,  1.0f, 1.0f, /* top-right */
+
+		/* NOTE(pryazha): Bottom face */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		 a, -a,  a,  1.0f, 1.0f, /* top-right */
+		-a, -a,  a,  0.0f, 1.0f, /* top-left */
+		-a, -a, -a,  0.0f, 0.0f, /* bottom-left */
+		 a, -a, -a,  1.0f, 0.0f, /* bottom-right */
+		 a, -a,  a,  1.0f, 1.0f, /* top-right */
+	};
+
+	U32 cube_vao;
+	glGenVertexArrays(1, &cube_vao);
+	glBindVertexArray(cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(cube_vertices), cube_vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(3*sizeof(F32)));
+	glBindVertexArray(0);
+
+	F32 vertices[] = {
+		-0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+		 0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
+		 0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+		 0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
+		-0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
+		-0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
+
+		-0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+		 0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
+		 0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+		 0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
+		-0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
+		-0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
+
+		-0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+		-0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+		-0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+		-0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+		-0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+		-0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+		 0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+		 0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
+		 0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+		 0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
+		 0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
+		 0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
+
+		-0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+		 0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
+		 0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+		 0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
+		-0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
+		-0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
+
+		-0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
+		 0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
+		 0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+		 0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
+		-0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
+		-0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f
+	};
+
+	U32 normals_cube_vao;
+	glGenVertexArrays(1, &normals_cube_vao);
+	glBindVertexArray(normals_cube_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8*sizeof(F32), (void *)(3*sizeof(F32)));
+	glEnableVertexAttribArray(2);
+	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8*sizeof(F32), (void *)(6*sizeof(F32)));
+	glBindVertexArray(0);
+
+	state.camera = (Camera) {
+		v3f(2.0f, 1.0f, 2.0f),
+		90.0f, 0.1f, 100.0f,
+		0.0f, 0.0f
+	};
+
+	F32 target_fps = 60.0f;
+	F32 target_spf = 1.0f/target_fps;
+	F32 last_time = glfwGetTime();
+	F32 time = last_time;
+
+	S32 scene = 0;
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		process_glfw_keyboard(window, &input);
+		glfwGetFramebufferSize(window, &width, &height);
+
+		/* NOTE(pryazha): Update */
+		V3F target = v3f_zero();
+
+		if (key_first_press(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		if (key_first_press(input.jump)) {
+			scene++;
+			scene %= 3;
+		}
+
+		input_update_last_state(&input);
+
+		/* NOTE(pryazha): Render */
+		MAT4 view, proj, model;
+		
+		view = look_at(state.camera.pos, target, v3f(0.0f, 1.0f, 0.0f));
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+
+		model = mat4_identity();
+
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		if (scene == 0) {
+			glUseProgram(shader);
+			glBindVertexArray(points_vao);
+			glDrawArrays(GL_POINTS, 0, 4);
+			glBindVertexArray(0);
+		} else if (scene == 1) {
+			glUseProgram(explosion_shader);
+			shader_set_mat4fv(explosion_shader, "proj", proj);
+			shader_set_mat4fv(explosion_shader, "view", view);
+			shader_set_mat4fv(explosion_shader, "model", model);
+			shader_set_1f(explosion_shader, "time", time);
+			glBindVertexArray(cube_vao);
+			glBindTexture(GL_TEXTURE_2D, grid_texture);
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+			glBindVertexArray(0);
+		} else {
+			glUseProgram(basic_shader);
+			shader_set_mat4fv(basic_shader, "proj", proj);
+			shader_set_mat4fv(basic_shader, "view", view);
+			shader_set_mat4fv(basic_shader, "model", model);
+			draw_cube(normals_cube_vao, grid_texture);
+
+			glUseProgram(normals_shader);
+			shader_set_mat4fv(normals_shader, "proj", proj);
+			shader_set_mat4fv(normals_shader, "view", view);
+			shader_set_mat4fv(normals_shader, "model", model);
+			draw_cube(normals_cube_vao, grid_texture);
+		}
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		time += state.dt;
+		last_time = current_time;
+	}
+
+	glDeleteBuffers(1, &vbo);
+	glDeleteVertexArrays(1, &points_vao);
+
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/8.geometry_shader/shaders/base.fs b/advanced_opengl/8.geometry_shader/shaders/base.frag
index 73897db..70d5585 100644
--- a/advanced_opengl/8.geometry_shader/shaders/base.fs
+++ b/advanced_opengl/8.geometry_shader/shaders/base.frag
@@ -4,8 +4,7 @@ in vec3 fcolor;
 
 out vec4 frag_color;
 
-void
-main(void)
+void main(void)
 {
     frag_color = vec4(fcolor, 1.0);
 }
diff --git a/advanced_opengl/8.geometry_shader/shaders/base.gs b/advanced_opengl/8.geometry_shader/shaders/base.geom
index 6b140c5..10d5c45 100644
--- a/advanced_opengl/8.geometry_shader/shaders/base.gs
+++ b/advanced_opengl/8.geometry_shader/shaders/base.geom
@@ -8,8 +8,7 @@ in VS_OUT {
 
 out vec3 fcolor;
 
-void
-main(void)
+void main(void)
 {
     fcolor = gs_in[0].color;
     gl_Position = gl_in[0].gl_Position+vec4(-0.2, -0.2, 0.0, 0.0);
diff --git a/advanced_opengl/8.geometry_shader/shaders/base.vs b/advanced_opengl/8.geometry_shader/shaders/base.vert
index 9ad9e7a..5178f92 100644
--- a/advanced_opengl/8.geometry_shader/shaders/base.vs
+++ b/advanced_opengl/8.geometry_shader/shaders/base.vert
@@ -6,8 +6,7 @@ out VS_OUT {
     vec3 color;
 } vs_out;
 
-void
-main(void)
+void main(void)
 {
     vs_out.color = acolor;
     gl_Position = vec4(apos, 0.0, 1.0);
diff --git a/advanced_opengl/8.geometry_shader/shaders/basic.frag b/advanced_opengl/8.geometry_shader/shaders/basic.frag
new file mode 100644
index 0000000..09244b5
--- /dev/null
+++ b/advanced_opengl/8.geometry_shader/shaders/basic.frag
@@ -0,0 +1,12 @@
+#version 330 core
+
+in vec2 tex_coords;
+
+out vec4 frag_color;
+
+uniform sampler2D texture1;
+
+void main(void)
+{
+    frag_color = texture(texture1, tex_coords);
+}
diff --git a/advanced_opengl/8.geometry_shader/shaders/basic.fs b/advanced_opengl/8.geometry_shader/shaders/basic.fs
deleted file mode 100644
index bdd4b9a..0000000
--- a/advanced_opengl/8.geometry_shader/shaders/basic.fs
+++ /dev/null
@@ -1,13 +0,0 @@
-#version 330 core
-
-in vec2 tex_coords;
-
-out vec4 frag_color;
-
-uniform sampler2D texture1;
-
-void
-main(void)
-{
-    frag_color = texture(texture1, tex_coords);
-}
diff --git a/advanced_opengl/8.geometry_shader/shaders/basic.vs b/advanced_opengl/8.geometry_shader/shaders/basic.vert
index 77e8b70..10ce805 100644
--- a/advanced_opengl/8.geometry_shader/shaders/basic.vs
+++ b/advanced_opengl/8.geometry_shader/shaders/basic.vert
@@ -6,11 +6,10 @@ out vec2 tex_coords;
 
 uniform mat4 model;
 uniform mat4 view;
-uniform mat4 projection;
+uniform mat4 proj;
 
-void
-main(void)
+void main(void)
 {
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
     tex_coords = atex_coords;
 }
diff --git a/advanced_opengl/8.geometry_shader/shaders/explosion.fs b/advanced_opengl/8.geometry_shader/shaders/explosion.frag
index 70e7151..b751460 100644
--- a/advanced_opengl/8.geometry_shader/shaders/explosion.fs
+++ b/advanced_opengl/8.geometry_shader/shaders/explosion.frag
@@ -6,8 +6,7 @@ out vec4 frag_color;
 
 uniform sampler2D texture0;
 
-void
-main(void)
+void main(void)
 {
     frag_color = texture(texture0, ftex_coords);
 }
diff --git a/advanced_opengl/8.geometry_shader/shaders/explosion.gs b/advanced_opengl/8.geometry_shader/shaders/explosion.geom
index 3498878..e708591 100644
--- a/advanced_opengl/8.geometry_shader/shaders/explosion.gs
+++ b/advanced_opengl/8.geometry_shader/shaders/explosion.geom
@@ -10,16 +10,14 @@ out vec2 ftex_coords;
 
 uniform float time;
 
-vec3
-get_normal(void)
+vec3 get_normal(void)
 {
     vec3 a = vec3(gl_in[0].gl_Position)-vec3(gl_in[1].gl_Position);
     vec3 b = vec3(gl_in[2].gl_Position)-vec3(gl_in[1].gl_Position);
     return(normalize(cross(a, b)));
 }
 
-vec4
-explode(vec4 position, vec3 normal)
+vec4 explode(vec4 position, vec3 normal)
 {
     float magnitude = 0.2;
     vec3 direction = normal*magnitude*((sin(time)+1.0)/2.0);
@@ -27,8 +25,7 @@ explode(vec4 position, vec3 normal)
     return(result);
 }
 
-void
-main(void)
+void main(void)
 {
     vec3 normal = get_normal();
     gl_Position = explode(gl_in[0].gl_Position, normal);
diff --git a/advanced_opengl/8.geometry_shader/shaders/explosion.vs b/advanced_opengl/8.geometry_shader/shaders/explosion.vert
index 46abd27..a79b432 100644
--- a/advanced_opengl/8.geometry_shader/shaders/explosion.vs
+++ b/advanced_opengl/8.geometry_shader/shaders/explosion.vert
@@ -6,13 +6,12 @@ out VS_OUT {
     vec2 gtex_coords;
 } vs_out;
 
-uniform mat4 projection;
+uniform mat4 proj;
 uniform mat4 view;
 uniform mat4 model;
 
-void
-main(void)
+void main(void)
 {
     vs_out.gtex_coords = atex_coords;
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
 }
diff --git a/advanced_opengl/7.uniform_buffer/shaders/color_cube.fs b/advanced_opengl/8.geometry_shader/shaders/normals.frag
index fbbafbf..d40d866 100644
--- a/advanced_opengl/7.uniform_buffer/shaders/color_cube.fs
+++ b/advanced_opengl/8.geometry_shader/shaders/normals.frag
@@ -2,8 +2,7 @@
 
 out vec4 frag_color;
 
-void
-main(void)
+void main(void)
 {
     frag_color = vec4(1.0, 0.0, 0.0, 1.0);
 }
diff --git a/advanced_opengl/8.geometry_shader/shaders/normals.gs b/advanced_opengl/8.geometry_shader/shaders/normals.geom
index 3720a5f..f0e1a75 100644
--- a/advanced_opengl/8.geometry_shader/shaders/normals.gs
+++ b/advanced_opengl/8.geometry_shader/shaders/normals.geom
@@ -6,23 +6,21 @@ in VS_OUT {
     vec3 normal;
 } gs_in[];
 
-uniform mat4 projection;
+uniform mat4 proj;
 
 const float MAGNITUDE = 0.4;
 
-void
-generate_line(int index)
+void generate_line(int index)
 {
-    gl_Position = projection*gl_in[index].gl_Position;
+    gl_Position = proj*gl_in[index].gl_Position;
     EmitVertex();
-    gl_Position = projection*(gl_in[index].gl_Position+
+    gl_Position = proj*(gl_in[index].gl_Position+
                               vec4(gs_in[index].normal, 0.0)*MAGNITUDE);
     EmitVertex();
     EndPrimitive();
 }
 
-void
-main(void)
+void main(void)
 {
     /*
     vec4 center = (gl_in[0].gl_Position+
@@ -32,9 +30,9 @@ main(void)
                              gs_in[1].normal+
                              gs_in[2].normal)/3.0),
                            0.0)*MAGNITUDE;
-    gl_Position = projection*center;
+    gl_Position = proj*center;
     EmitVertex();
-    gl_Position = projection*end;
+    gl_Position = proj*end;
     EmitVertex();
     EndPrimitive();
     */
diff --git a/advanced_opengl/8.geometry_shader/shaders/normals.vs b/advanced_opengl/8.geometry_shader/shaders/normals.vert
index 3b728e5..14f7d8b 100644
--- a/advanced_opengl/8.geometry_shader/shaders/normals.vs
+++ b/advanced_opengl/8.geometry_shader/shaders/normals.vert
@@ -9,8 +9,7 @@ out VS_OUT {
 uniform mat4 view;
 uniform mat4 model;
 
-void
-main(void)
+void main(void)
 {
     mat3 normal_matrix = mat3(transpose(inverse(view*model)));
     vs_out.normal = normalize(normal_matrix*anormal);
diff --git a/advanced_opengl/9.instancing/instancing b/advanced_opengl/9.instancing/instancing
index c722860..c1a31f8 100755
--- a/advanced_opengl/9.instancing/instancing
+++ b/advanced_opengl/9.instancing/instancing
diff --git a/advanced_opengl/9.instancing/instancing.c b/advanced_opengl/9.instancing/instancing.c
index f24a258..e77c693 100644
--- a/advanced_opengl/9.instancing/instancing.c
+++ b/advanced_opengl/9.instancing/instancing.c
@@ -2,403 +2,293 @@
 #include "GLFW/glfw3.h"
 
 #include "pwyazh.h"
-
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-#include <unistd.h>
+int main(void)
+{
+	GLFWwindow *window;
+	State state;
+	S32 width, height;
+	Input input;
+	Arena *arena = 0;
+	B32 move_camera;
 
-static S32 global_width = 1024, global_height = 768;
-static Input global_input;
+	if (glfwInit() == GLFW_FALSE) {
+		fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
+		return(1);
+	}
 
-void
-key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    switch (action)
-    {
-        case GLFW_PRESS: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    global_input.move_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_W: {
-                    global_input.move_forward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_A: {
-                    global_input.move_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_S: {
-                    global_input.move_backward.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_E: {
-                    global_input.move_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_Q: {
-                    global_input.move_down.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_SPACE: {
-                    global_input.jump.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_RIGHT: {
-                    global_input.action_right.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_LEFT: {
-                    global_input.action_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_ESCAPE: {
-                    global_input.exit.state = KeyState_PRESS;
-                } break;
-            }
-        } break;
-        
-        case GLFW_RELEASE: {
-            switch (key)
-            {
-                case GLFW_KEY_D: {
-                    global_input.move_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_W: {
-                    global_input.move_forward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_A: {
-                    global_input.move_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_S: {
-                    global_input.move_backward.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_E: {
-                    global_input.move_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_Q: {
-                    global_input.move_down.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_SPACE: {
-                    global_input.jump.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_RIGHT: {
-                    global_input.action_right.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_LEFT: {
-                    global_input.action_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_ESCAPE: {
-                    global_input.exit.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
+	width = 1024;
+	height = 768;
 
-void
-window_resize_callback(GLFWwindow* window, int width, int height)
-{
-    global_width = width;
-    global_height = height;
-    glViewport(0, 0, global_width, global_height);
-}
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+	window = glfwCreateWindow(width, height, "Instancing", 0, 0);
+	if (!window) {
+		fprintf(stderr, "[ERROR] Failed to create window.\n");
+		glfwTerminate();
+		return(1);
+	}
 
-int
-main(void)
-{
-    GLFWwindow *window;
-    Arena *arena = 0;
-    
-    if (glfwInit() == GLFW_FALSE)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glfw.\n");
-        return(1);
-    }
-    
-    /* glfwWindowHint(GLFW_RESIZABLE, 0); */
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
-    window = glfwCreateWindow(global_width, global_height, "Instancing", 0, 0);
-    if (!window)
-    {
-        fprintf(stderr, "[ERROR] Failed to create window.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glfwMakeContextCurrent(window);
-    
-    glfwSetKeyCallback(window, key_callback);
-    glfwSetWindowSizeCallback(window, window_resize_callback);
-    
-    if (glewInit() != GLEW_OK)
-    {
-        fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
-        glfwTerminate();
-        return(1);
-    }
-    
-    glEnable(GL_DEPTH_TEST);
-    
-    U32 instancing_uniform_array_shader = 
-        create_shader_program("shaders/instancing_uniform_array.vs",
-                              "shaders/instancing_uniform_array.fs");
-    U32 instanced_arrays_shader = 
-        create_shader_program("shaders/instanced_arrays.vs",
-                              "shaders/instanced_arrays.fs");
-    
-    F32 quad_vertices[] = {
-        -0.05f,  0.05f,  1.0f, 0.0f, 0.0f,
-        0.05f, -0.05f,  0.0f, 1.0f, 0.0f,
-        -0.05f, -0.05f,  0.0f, 0.0f, 1.0f,
-        
-        -0.05f,  0.05f,  1.0f, 0.0f, 0.0f,
-        0.05f, -0.05f,  0.0f, 1.0f, 0.0f,
-        0.05f,  0.05f,  0.0f, 1.0f, 1.0f,
-    };
-    
-    GLuint quad_vao, vbo;
-    glGenVertexArrays(1, &quad_vao);
-    glBindVertexArray(quad_vao);
-    glGenBuffers(1, &vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(quad_vertices), quad_vertices, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(2*sizeof(F32)));
-    glBindVertexArray(0);
-    
-    V2F translations[100];
-    S32 index = 0;
-    F32 offset = 0.1f;
-    for (S32 y = -10;
-         y < 10;
-         y += 2)
-    {
-        for (S32 x = -10;
-             x < 10;
-             x += 2)
-        {
-            V2F translation = v2f((F32)x, (F32)y);
-            translation = v2f_scalef(translation, 1.0f/10.0f);
-            translation = v2f_add(translation, v2f(offset, offset));
-            translations[index++] = translation;
-        }
-    }
-    
-    U32 instance_vbo;
-    glBindVertexArray(quad_vao);
-    glGenBuffers(1, &instance_vbo);
-    glBindBuffer(GL_ARRAY_BUFFER, instance_vbo);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(translations), translations, GL_STATIC_DRAW);
-    glEnableVertexAttribArray(2);
-    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(V2F), (void *)0);
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-    glVertexAttribDivisor(2, 1);
-    glBindVertexArray(0);
-    
-    arena = arena_alloc(Megabytes(64));
-    
-    U32 default_shader = create_shader_program("shaders/default.vs", "shaders/default.fs");
-    U32 instanced_shader = create_shader_program("shaders/instanced_mat4.vs",
-                                                 "shaders/instanced_mat4.fs");
-    Mesh *planet_mesh = mesh_load_obj(arena, "../../data/models/planet/planet.obj");
-    U32 planet_texture = load_texture("../../data/models/planet/mars.png");
-    Mesh *rock_mesh = mesh_load_obj(arena, "../../data/models/rock/rock.obj");
-    U32 rock_texture = load_texture("../../data/models/rock/rock.png");
-    
-    S32 amount = 80000;
-    F32 radius = 150.0f;
-    offset = 25.0f;
-    MAT4 trns[amount];
-    for (S32 i = 0; i < amount; ++i)
-    {
-        F32 angle, displacement, x, y, z, scale;
-        MAT4 model = mat4_identity();
-        
-        angle = rand()%360;
-        model = mat4_rotate_angles(model, v3f(angle, angle, angle));
-        
-        scale = (rand()%20)/100.0f+0.05f;
-        model = mat4_scale(model, v3f(scale, scale, scale));
-        
-        angle = ((F32)i/(F32)amount)*360.0f;
-        displacement = (rand()%(S32)(2.0f*offset))-offset;
-        x = f32_sin(DEG2RAD*angle)*radius+displacement;
-        displacement = (rand()%(S32)(2.0f*offset))-offset;
-        y = 0.4f*displacement;
-        displacement = (rand()%(S32)(2.0f*offset))-offset;
-        z = f32_cos(DEG2RAD*angle)*radius;
-        model = mat4_translate(model, v3f(x, y, z));
-        
-        trns[i] = model;
-    }
-    
-    U32 buffer;
-    glGenBuffers(1, &buffer);
-    glBindBuffer(GL_ARRAY_BUFFER, buffer);
-    glBufferData(GL_ARRAY_BUFFER, amount*sizeof(MAT4), &trns[0], GL_STATIC_DRAW);
-    glBindVertexArray(rock_mesh->vao);
-    glEnableVertexAttribArray(3);
-    glVertexAttribPointer(3, 4, GL_FLOAT, GL_FALSE, 4*sizeof(V4F), (void *)0);
-    glEnableVertexAttribArray(4);
-    glVertexAttribPointer(4, 4, GL_FLOAT, GL_FALSE, 4*sizeof(V4F), (void *)(1*sizeof(V4F)));
-    glEnableVertexAttribArray(5);
-    glVertexAttribPointer(5, 4, GL_FLOAT, GL_FALSE, 4*sizeof(V4F), (void *)(2*sizeof(V4F)));
-    glEnableVertexAttribArray(6);
-    glVertexAttribPointer(6, 4, GL_FLOAT, GL_FALSE, 4*sizeof(V4F), (void *)(3*sizeof(V4F)));
-    
-    glVertexAttribDivisor(3, 1);
-    glVertexAttribDivisor(4, 1);
-    glVertexAttribDivisor(5, 1);
-    glVertexAttribDivisor(6, 1);
-    glBindVertexArray(0);
-    
-    F32 target_fps = 60.0f;
-    F32 target_spf = 1.0f/target_fps;
-    
-    F32 last_time = glfwGetTime();
-    F32 time = last_time;
-    F32 dt;
-    
-    S32 scene = 0;
-    S32 number_scene = 4;
-    
-    MAT4 projection, view, model;
-    
-    V3F camera_pos = v3f(0.0f, 50.0f, 220.0f);
-    F32 camera_speed = 10.0f;
-    F32 fovx = 90.0f;
-    F32 near = 0.1f;
-    F32 far = 1000.0f;
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        
-        /* NOTE(pryazha): Update */
-        if (key_is_pressed(global_input.exit))
-        {
-            glfwSetWindowShouldClose(window, GLFW_TRUE);
-        }
-        if (key_first_press(global_input.jump) ||
-            key_first_press(global_input.action_right))
-        {
-            scene++;
-        }
-        else if (key_first_press(global_input.action_left))
-        {
-            scene--;
-            if (scene < 0)
-                scene = number_scene-1;
-        }
-        scene %= number_scene;
-        
-        /* NOTE(pryazha): Render */
-        glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
-        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-        
-        switch (scene)
-        {
-            case 0: {
-                glUseProgram(instancing_uniform_array_shader);
-                for (S32 translation_index = 0;
-                     translation_index < 100;
-                     ++translation_index)
-                {
-                    char temp[256];
-                    snprintf(temp, 256, "offsets[%d]", translation_index);
-                    shader_set_2fv(instancing_uniform_array_shader,
-                                   temp, translations[translation_index]);
-                }
-                glBindVertexArray(quad_vao);
-                glDrawArraysInstanced(GL_TRIANGLES, 0, 6, 100);
-                glBindVertexArray(0);
-            } break;
-            
-            case 1: {
-                glUseProgram(instanced_arrays_shader);
-                glBindVertexArray(quad_vao);
-                glDrawArraysInstanced(GL_TRIANGLES, 0, 6, 100);
-                glBindVertexArray(0);
-            } break;
-            
-            case 2: {
-                V3F camera_dv = get_dv_camera_orbital(&global_input,
-                                                      camera_pos, v3f_zero(),
-                                                      dt, camera_speed);
-                camera_pos = v3f_add(camera_pos, camera_dv);
-                
-                projection = perspective(fovx, (F32)global_width/(F32)global_height, near, far);
-                V3F world_up = v3f(0.0f, 1.0f, 0.0f);
-                view = look_at(camera_pos, v3f_zero(), world_up);
-                
-                glUseProgram(default_shader);
-                shader_set_mat4fv(default_shader, "projection", projection);
-                shader_set_mat4fv(default_shader, "view", view);
-                
-                F32 scale = 5.0f;
-                model = mat4_make_scale(v3f(scale, scale, scale));
-                shader_set_mat4fv(default_shader, "model", model);
-                glBindTexture(GL_TEXTURE_2D, planet_texture);
-                mesh_draw(planet_mesh);
-                
-                glBindTexture(GL_TEXTURE_2D, rock_texture);
-                for (S32 i = 0; i < amount; ++i)
-                {
-                    model = trns[i];
-                    shader_set_mat4fv(default_shader, "model", model);
-                    mesh_draw(rock_mesh);
-                }
-            } break;
-            
-            case 3: {
-                V3F camera_dv = get_dv_camera_orbital(&global_input,
-                                                      camera_pos, v3f_zero(),
-                                                      dt, camera_speed);
-                camera_pos = v3f_add(camera_pos, camera_dv);
-                
-                projection = perspective(fovx, (F32)global_width/(F32)global_height, near, far);
-                V3F world_up = v3f(0.0f, 1.0f, 0.0f);
-                view = look_at(camera_pos, v3f_zero(), world_up);
-                
-                glUseProgram(default_shader);
-                shader_set_mat4fv(default_shader, "projection", projection);
-                shader_set_mat4fv(default_shader, "view", view);
-                F32 scale = 5.0f;
-                model = mat4_make_scale(v3f(scale, scale, scale));
-                shader_set_mat4fv(default_shader, "model", model);
-                glBindTexture(GL_TEXTURE_2D, planet_texture);
-                mesh_draw(planet_mesh);
-                glBindTexture(GL_TEXTURE_2D, 0);
-                
-                glUseProgram(instanced_shader);
-                shader_set_mat4fv(default_shader, "projection", projection);
-                shader_set_mat4fv(default_shader, "view", view);
-                glBindTexture(GL_TEXTURE_2D, rock_texture);
-                glBindVertexArray(rock_mesh->vao);
-                glDrawElementsInstanced(GL_TRIANGLES, rock_mesh->index_count,
-                                        GL_UNSIGNED_INT, 0, amount);
-                glBindVertexArray(0);
-                glBindTexture(GL_TEXTURE_2D, 0);
-            } break;
-        }
-        
-        input_update_last_state(&global_input);
-        
-        glfwSwapBuffers(window);
-        
-        F32 elapsed = glfwGetTime()-last_time;
-        if (elapsed < target_spf)
-        {
-            U32 sleep_time = (U32)(target_spf-elapsed);
-            if (sleep_time > 0)
-                sleep(sleep_time);
-        }
-        F32 current_time = glfwGetTime();
-        dt = current_time-last_time;
-        time += dt;
-        last_time = current_time;
-    }
-    
-    glfwTerminate();
-    return(0);
+	glfwMakeContextCurrent(window);
+	glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+
+	if (glewInit() != GLEW_OK) {
+		fprintf(stderr, "[ERROR] Failed to initialize glew.\n");
+		glfwTerminate();
+		return(1);
+	}
+
+	glEnable(GL_DEPTH_TEST);
+
+	U32 instancing_uniform_array_shader = create_shader_program("shaders/instancing_uniform_array.vert",
+								    "shaders/instancing_uniform_array.frag");
+	U32 instanced_arrays_shader = create_shader_program("shaders/instanced_arrays.vert",
+							    "shaders/instanced_arrays.frag");
+	U32 default_shader = create_shader_program("shaders/default.vert",
+						   "shaders/default.frag");
+	U32 instanced_shader = create_shader_program("shaders/instanced_mat4.vert",
+						     "shaders/instanced_mat4.frag");
+
+	F32 quad_vertices[] = {
+		-0.05f,  0.05f,  1.0f, 0.0f, 0.0f,
+		0.05f, -0.05f,  0.0f, 1.0f, 0.0f,
+		-0.05f, -0.05f,  0.0f, 0.0f, 1.0f,
+
+		-0.05f,  0.05f,  1.0f, 0.0f, 0.0f,
+		0.05f, -0.05f,  0.0f, 1.0f, 0.0f,
+		0.05f,  0.05f,  0.0f, 1.0f, 1.0f,
+	};
+
+	GLuint quad_vao, vbo;
+	glGenVertexArrays(1, &quad_vao);
+	glBindVertexArray(quad_vao);
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(quad_vertices), quad_vertices, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)0);
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 5*sizeof(F32), (void *)(2*sizeof(F32)));
+	glBindVertexArray(0);
+
+	V2F translations[100];
+	S32 index = 0;
+	F32 offset = 0.1f;
+	for (S32 y = -10; y < 10; y += 2) {
+		for (S32 x = -10; x < 10; x += 2) {
+			V2F translation = v2f((F32)x, (F32)y);
+			translation = v2f_scalef(translation, 1.0f/10.0f);
+			translation = v2f_add(translation, v2f(offset, offset));
+			translations[index++] = translation;
+		}
+	}
+
+	U32 instance_vbo;
+	glBindVertexArray(quad_vao);
+	glGenBuffers(1, &instance_vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, instance_vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(translations), translations, GL_STATIC_DRAW);
+	glEnableVertexAttribArray(2);
+	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(V2F), (void *)0);
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+	glVertexAttribDivisor(2, 1);
+	glBindVertexArray(0);
+
+	arena = arena_alloc(Megabytes(64));
+
+	Mesh *planet_mesh = mesh_load_obj(arena, "../../data/models/planet/planet.obj");
+	Mesh *rock_mesh = mesh_load_obj(arena, "../../data/models/rock/rock.obj");
+
+	U32 planet_texture = load_texture("../../data/models/planet/mars.png");
+	U32 rock_texture = load_texture("../../data/models/rock/rock.png");
+
+	S32 amount = 80000;
+	F32 radius = 150.0f;
+	offset = 25.0f;
+	MAT4 trns[amount];
+	for (S32 i = 0; i < amount; ++i) {
+		F32 angle, displacement, x, y, z, scale;
+		MAT4 model = mat4_identity();
+
+		angle = rand()%360;
+		model = mat4_rotate_angles(model, v3f(angle, angle, angle));
+
+		scale = (rand()%20)/100.0f+0.05f;
+		model = mat4_scale(model, v3f(scale, scale, scale));
+
+		angle = ((F32)i/(F32)amount)*360.0f;
+		displacement = (rand()%(S32)(2.0f*offset))-offset;
+		x = f32_sin(DEG2RAD*angle)*radius+displacement;
+		displacement = (rand()%(S32)(2.0f*offset))-offset;
+		y = 0.4f*displacement;
+		displacement = (rand()%(S32)(2.0f*offset))-offset;
+		z = f32_cos(DEG2RAD*angle)*radius;
+		model = mat4_translate(model, v3f(x, y, z));
+
+		trns[i] = model;
+	}
+
+	U32 buffer;
+	glGenBuffers(1, &buffer);
+	glBindBuffer(GL_ARRAY_BUFFER, buffer);
+	glBufferData(GL_ARRAY_BUFFER, amount*sizeof(MAT4), &trns[0], GL_STATIC_DRAW);
+	glBindVertexArray(rock_mesh->vao);
+	glEnableVertexAttribArray(3);
+	glVertexAttribPointer(3, 4, GL_FLOAT, GL_FALSE, 4*sizeof(V4F), (void *)0);
+	glEnableVertexAttribArray(4);
+	glVertexAttribPointer(4, 4, GL_FLOAT, GL_FALSE, 4*sizeof(V4F), (void *)(1*sizeof(V4F)));
+	glEnableVertexAttribArray(5);
+	glVertexAttribPointer(5, 4, GL_FLOAT, GL_FALSE, 4*sizeof(V4F), (void *)(2*sizeof(V4F)));
+	glEnableVertexAttribArray(6);
+	glVertexAttribPointer(6, 4, GL_FLOAT, GL_FALSE, 4*sizeof(V4F), (void *)(3*sizeof(V4F)));
+
+	glVertexAttribDivisor(3, 1);
+	glVertexAttribDivisor(4, 1);
+	glVertexAttribDivisor(5, 1);
+	glVertexAttribDivisor(6, 1);
+	glBindVertexArray(0);
+
+	state.camera = (Camera) {
+		v3f(0.0f, 50.0f, 220.0f),
+		90.0f, 0.1f, 1000.0f,
+		0.0f, 0.0f
+	};
+	F32 camera_speed = 10.0f;
+
+	F32 target_fps = 60.0f;
+	F32 target_spf = 1.0f/target_fps;
+	F32 last_time = glfwGetTime();
+	F32 time = last_time;
+
+	S32 scene = 0;
+	S32 number_scene = 4;
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		/* NOTE(pryazha): Update */
+		glfwGetFramebufferSize(window, &width, &height);
+		process_glfw_keyboard(window, &input);
+		process_glfw_mouse_pos(window, &input);
+
+		if (key_is_pressed(input.exit))
+			glfwSetWindowShouldClose(window, GLFW_TRUE);
+
+		if (key_first_press(input.jump) ||
+		    key_first_press(input.action_right)) {
+			scene++;
+		} else if (key_first_press(input.action_left)) {
+			scene--;
+			if (scene < 0)
+				scene = number_scene-1;
+		}
+		scene %= number_scene;
+
+		move_camera = (scene > 1) ? 1 : 0;
+
+		if (move_camera) {
+			V3F dv = get_dv_camera_first_person(&input, &state.camera,
+							    4.0f, state.dt);
+			state.camera.pos = v3f_add(state.camera.pos, dv);
+			F32 sensitivity = 0.1f;
+			input.mouse_offset = v2f_scalef(input.mouse_offset, sensitivity);
+			state.camera.yaw += input.mouse_offset.x;
+			state.camera.pitch += input.mouse_offset.y;
+			if (state.camera.pitch > 89.0f)
+				state.camera.pitch = 89.0f;
+			if (state.camera.pitch < -89.0f)
+				state.camera.pitch = -89.0f;
+		}
+
+		input_update_last_state(&input);
+
+		/* NOTE(pryazha): Render */
+		MAT4 proj, view, model;
+		F32 scale = 5.0f;
+
+		view = get_view_matrix(&state.camera);
+		proj = perspective(state.camera.fovx, (F32)width/(F32)height,
+				   state.camera.near, state.camera.far);
+
+		glClearColor(0.15f, 0.15f, 0.15f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		switch (scene) {
+		case 0:
+			glUseProgram(instancing_uniform_array_shader);
+			for (S32 i = 0; i < 100; ++i) {
+				char temp[256];
+				snprintf(temp, 256, "offsets[%d]", i);
+				shader_set_2fv(instancing_uniform_array_shader,
+					       temp, translations[i]);
+			}
+			glBindVertexArray(quad_vao);
+			glDrawArraysInstanced(GL_TRIANGLES, 0, 6, 100);
+			glBindVertexArray(0);
+			break;
+		case 1:
+			glUseProgram(instanced_arrays_shader);
+			glBindVertexArray(quad_vao);
+			glDrawArraysInstanced(GL_TRIANGLES, 0, 6, 100);
+			glBindVertexArray(0);
+			break;
+		case 2:
+			glUseProgram(default_shader);
+			shader_set_mat4fv(default_shader, "proj", proj);
+			shader_set_mat4fv(default_shader, "view", view);
+
+			model = mat4_make_scale(v3f(scale, scale, scale));
+			shader_set_mat4fv(default_shader, "model", model);
+			glBindTexture(GL_TEXTURE_2D, planet_texture);
+			mesh_draw(planet_mesh);
+
+			glBindTexture(GL_TEXTURE_2D, rock_texture);
+			for (S32 i = 0; i < amount; ++i) {
+				model = trns[i];
+				shader_set_mat4fv(default_shader, "model", model);
+				mesh_draw(rock_mesh);
+			}
+			break;
+		case 3:
+			glUseProgram(default_shader);
+			shader_set_mat4fv(default_shader, "proj", proj);
+			shader_set_mat4fv(default_shader, "view", view);
+			model = mat4_make_scale(v3f(scale, scale, scale));
+			shader_set_mat4fv(default_shader, "model", model);
+			glBindTexture(GL_TEXTURE_2D, planet_texture);
+			mesh_draw(planet_mesh);
+			glBindTexture(GL_TEXTURE_2D, 0);
+
+			glUseProgram(instanced_shader);
+			shader_set_mat4fv(default_shader, "proj", proj);
+			shader_set_mat4fv(default_shader, "view", view);
+			glBindTexture(GL_TEXTURE_2D, rock_texture);
+			glBindVertexArray(rock_mesh->vao);
+			glDrawElementsInstanced(GL_TRIANGLES, rock_mesh->index_count,
+						GL_UNSIGNED_INT, 0, amount);
+			glBindVertexArray(0);
+			glBindTexture(GL_TEXTURE_2D, 0);
+			break;
+		}
+
+		glfwSwapBuffers(window);
+
+		F32 elapsed = glfwGetTime()-last_time;
+		if (elapsed < target_spf) {
+			U32 sleep_time = (U32)(target_spf-elapsed);
+			if (sleep_time > 0)
+				sleep(sleep_time);
+		}
+		F32 current_time = glfwGetTime();
+		state.dt = current_time-last_time;
+		time += state.dt;
+		last_time = current_time;
+	}
+
+	glfwTerminate();
+	return(0);
 }
diff --git a/advanced_opengl/9.instancing/shaders/default.fs b/advanced_opengl/9.instancing/shaders/default.frag
index c655ac8..8ae5c3b 100644
--- a/advanced_opengl/9.instancing/shaders/default.fs
+++ b/advanced_opengl/9.instancing/shaders/default.frag
@@ -6,8 +6,7 @@ out vec4 frag_color;
 
 uniform sampler2D texture0;
 
-void
-main(void)
+void main(void)
 {
     frag_color = texture(texture0, tex_coords);
-}
\ No newline at end of file
+}
diff --git a/advanced_opengl/9.instancing/shaders/default.vs b/advanced_opengl/9.instancing/shaders/default.vert
index 85d3c19..87cb538 100644
--- a/advanced_opengl/9.instancing/shaders/default.vs
+++ b/advanced_opengl/9.instancing/shaders/default.vert
@@ -6,13 +6,12 @@ layout(location = 2) in vec2 atex_coords;
 out vec3 normal;
 out vec2 tex_coords;
 
-uniform mat4 projection;
+uniform mat4 proj;
 uniform mat4 view;
 uniform mat4 model;
 
-void
-main(void)
+void main(void)
 {
     tex_coords = atex_coords;
-    gl_Position = projection*view*model*vec4(apos, 1.0);
+    gl_Position = proj*view*model*vec4(apos, 1.0);
 }
diff --git a/advanced_opengl/9.instancing/shaders/instanced_arrays.fs b/advanced_opengl/9.instancing/shaders/instanced_arrays.frag
index a32e52e..4865933 100644
--- a/advanced_opengl/9.instancing/shaders/instanced_arrays.fs
+++ b/advanced_opengl/9.instancing/shaders/instanced_arrays.frag
@@ -4,8 +4,7 @@ in vec3 color;
 
 out vec4 frag_color;
 
-void
-main(void)
+void main(void)
 {
     frag_color = vec4(color, 1.0);
 }
diff --git a/advanced_opengl/9.instancing/shaders/instanced_arrays.vs b/advanced_opengl/9.instancing/shaders/instanced_arrays.vert
index 4ea0fe4..ce3ea7d 100644
--- a/advanced_opengl/9.instancing/shaders/instanced_arrays.vs
+++ b/advanced_opengl/9.instancing/shaders/instanced_arrays.vert
@@ -5,8 +5,7 @@ layout(location = 2) in vec2 aoffset;
 
 out vec3 color;
 
-void
-main(void)
+void main(void)
 {
     color = acolor;
     vec2 pos = apos*(gl_InstanceID/100.0);
diff --git a/advanced_opengl/9.instancing/shaders/instanced_mat4.fs b/advanced_opengl/9.instancing/shaders/instanced_mat4.frag
index ae625b2..3b96d36 100644
--- a/advanced_opengl/9.instancing/shaders/instanced_mat4.fs
+++ b/advanced_opengl/9.instancing/shaders/instanced_mat4.frag
@@ -6,8 +6,7 @@ out vec4 frag_color;
 
 uniform sampler2D texture1;
 
-void
-main(void)
+void main(void)
 {
     frag_color = texture(texture1, tex_coords);
 }
diff --git a/advanced_opengl/9.instancing/shaders/instanced_mat4.vs b/advanced_opengl/9.instancing/shaders/instanced_mat4.vert
index c65be90..835cc5d 100644
--- a/advanced_opengl/9.instancing/shaders/instanced_mat4.vs
+++ b/advanced_opengl/9.instancing/shaders/instanced_mat4.vert
@@ -5,12 +5,11 @@ layout(location = 3) in mat4 instance_matrix;
 
 out vec2 tex_coords;
 
-uniform mat4 projection;
+uniform mat4 proj;
 uniform mat4 view;
 
-void
-main(void)
+void main(void)
 {
     tex_coords = atex_coords;
-    gl_Position = projection*view*instance_matrix*vec4(apos, 1.0);
+    gl_Position = proj*view*instance_matrix*vec4(apos, 1.0);
 }
diff --git a/advanced_opengl/9.instancing/shaders/instancing_uniform_array.fs b/advanced_opengl/9.instancing/shaders/instancing_uniform_array.frag
index a32e52e..4865933 100644
--- a/advanced_opengl/9.instancing/shaders/instancing_uniform_array.fs
+++ b/advanced_opengl/9.instancing/shaders/instancing_uniform_array.frag
@@ -4,8 +4,7 @@ in vec3 color;
 
 out vec4 frag_color;
 
-void
-main(void)
+void main(void)
 {
     frag_color = vec4(color, 1.0);
 }
diff --git a/advanced_opengl/9.instancing/shaders/instancing_uniform_array.vs b/advanced_opengl/9.instancing/shaders/instancing_uniform_array.vert
index a77be31..61b07a0 100644
--- a/advanced_opengl/9.instancing/shaders/instancing_uniform_array.vs
+++ b/advanced_opengl/9.instancing/shaders/instancing_uniform_array.vert
@@ -6,8 +6,7 @@ out vec3 color;
 
 uniform vec2 offsets[100];
 
-void
-main(void)
+void main(void)
 {
     color = acolor;
     gl_Position = vec4(apos+offsets[gl_InstanceID], 0.0, 1.0);