quite a lot of changes that I, of course, are not going to describe;)

1 files changed, 263 insertions, 405 deletions

diff --git a/advanced_lighting/3.1.shadow_mapping/shadow_mapping.c b/advanced_lighting/3.1.shadow_mapping/shadow_mapping.c
index 7f03415..fd03ed9 100644
--- a/advanced_lighting/3.1.shadow_mapping/shadow_mapping.c
+++ b/advanced_lighting/3.1.shadow_mapping/shadow_mapping.c
@@ -1,417 +1,275 @@
-#include "pwyazh.h"
-
 #include "GL/glew.h"
 #include "GLFW/glfw3.h"
 
+#include "pwyazh.h"
 #include "pwyazh_GL.h"
 
 #include "common.h"
 
-static S32 global_screen_width = 800, global_screen_height = 600;
-static U32 global_shadow_width = 1024, global_shadow_height = 1024;
-
-static Input global_input;
-
-static V3F camera_dp = (V3F){ 0.0f, 0.0f, 0.0f };
-
-static U32 global_depth_map_fbo, global_depth_map;
-
-static U32 global_debug_quad_shader, global_simple_depth_shader,
-           global_shadow_shader, global_color_shader;
-
-static U32 global_wood_texture;
-
-static U32 global_quad_vao;
-
-static U32 shadows_ortho = 1;
-
-static V3F light_pos;
-
-void
-glfw_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_UP: {
-                    global_input.action_up.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_LEFT: {
-                    global_input.action_left.state = KeyState_PRESS;
-                } break;
-                case GLFW_KEY_DOWN: {
-                    global_input.action_down.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_UP: {
-                    global_input.action_up.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_LEFT: {
-                    global_input.action_left.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_DOWN: {
-                    global_input.action_down.state = KeyState_RELEASE;
-                } break;
-                case GLFW_KEY_ESCAPE: {
-                    global_input.exit.state = KeyState_RELEASE;
-                } break;
-            }
-        } break;
-    }
-}
-
-void
-resize_callback(GLFWwindow* window, int width, int height)
-{
-    global_screen_width = width;
-    global_screen_height = height;
-    glViewport(0, 0, global_screen_width, global_screen_height);
-}
-
-void
-error_callback(int error, const char *desc)
-{
-    fprintf(stderr, "[ERROR] GLFW: %s\n", desc);
-}
-
-void
-update(State *state, F32 time)
-{
-    F32 radius;
-
-    V3F camera_dv = get_dv_camera_orbital(&global_input, state->camera.pos,
-                                          v3f_zero(), state->dt, 2.0f);
-    if (key_is_pressed(global_input.action_up))
-        camera_dv = v3f_scalef(camera_dv, 3.0f);
-    camera_dp = v3f_add(camera_dp, camera_dv);
-    camera_dp = v3f_scalef(camera_dp, 0.8f);
-    state->camera.pos = v3f_add(state->camera.pos, camera_dp);
-
-    if (key_first_press(global_input.action_down))
-        shadows_ortho = !shadows_ortho;
-    
-    input_update_last_state(&global_input);
-
-    F32 x, z, angular_speed;
-
-    angular_speed = 1.0f;
-    radius = 4.0f;
-    x = f32_sin(time*angular_speed)*radius;
-    z = f32_cos(time*angular_speed)*radius;
-
-    light_pos = v3f(x, 4.0f, z);
-}
-
-void
-render_scene(U32 shader, Mesh *cube, Mesh *plane)
-{
-    MAT4 model;
-
-    model = mat4_identity();
-    shader_set_mat4fv(shader, "model", model); 
-    mesh_draw(plane);
-
-    /*
-    model = mat4_identity();
-    model = mat4_make_scale(v3f(10.0f, 0.1f, 10.0f));
-    model = mat4_translate(model, v3f(0.0f, -0.6f, 0.0f));
-    shader_set_mat4fv(shader, "model", model);
-    mesh_draw(cube);
-    */
-
-    model = mat4_identity();
-    model = mat4_make_scale(v3f(0.5f, 0.5f, 0.5f));
-    model = mat4_translate(model, v3f(0.0f, 1.5f, 0.0f));
-    shader_set_mat4fv(shader, "model", model);
-    mesh_draw(cube);
-
-    model = mat4_identity();
-    model = mat4_make_scale(v3f(0.5f, 0.5f, 0.5f));
-    model = mat4_translate(model, v3f(2.0f, 0.0f, 1.0f));
-    shader_set_mat4fv(shader, "model", model);
-    mesh_draw(cube);
-
-    model = mat4_identity();
-    model = mat4_make_scale(v3f(0.25f, 0.25f, 0.25f));
-    model = mat4_rotate_angles(model, v3f(60.0f, 0.0f, 0.0f));
-    model = mat4_translate(model, v3f(-1.0f, 0.0f, 2.0f));
-    shader_set_mat4fv(shader, "model", model);
-    mesh_draw(cube);
-}
-
-void
-render(State *state, Mesh *cube, Mesh *plane)
+void render_scene(U32 shader, Mesh *cube, Mesh *plane)
 {
-    /* MAT4 projection, view, model; */
-    MAT4 light_projection, light_view, model;
-    F32 near, far, fovx;
-    V3F target, up;
-
-    if (shadows_ortho)
-    {
-        near = 1.0f;
-        far = 10.0f;
-        F32 half_side = 10.0f;
-        light_projection = ortho(-half_side, half_side, -half_side, half_side, near, far);
-    }
-    else
-    {
-        fovx = 90.0f;
-        near = 1.0f;
-        far = 50.0f;
-        light_projection = perspective(fovx, (F32)global_shadow_width/(F32)global_shadow_height,
-                                       near, far);
-    }
-
-    target = v3f_zero();
-    up = v3f(0.0f, 1.0f, 0.0f);
-    light_view = look_at(light_pos, target, up);
-    MAT4 light_space_matrix = mat4_mul(light_projection, light_view);
-
-    glUseProgram(global_simple_depth_shader);
-    shader_set_mat4fv(global_simple_depth_shader, "light_space_matrix", light_space_matrix); 
-    glViewport(0, 0, global_shadow_width, global_shadow_height);
-    glBindFramebuffer(GL_FRAMEBUFFER, global_depth_map_fbo);
-    glClear(GL_DEPTH_BUFFER_BIT);
-    // glCullFace(GL_FRONT);
-    render_scene(global_simple_depth_shader, cube, plane);
-    // glCullFace(GL_BACK);
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
-
-    glViewport(0, 0, global_screen_width, global_screen_height);
-    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
-    MAT4 projection = perspective(state->camera.fovx, (F32)global_screen_width/(F32)global_screen_height,
-                                  state->camera.near, state->camera.far);
-    MAT4 view = look_at(state->camera.pos, v3f_zero(), v3f(0.0f, 1.0f, 0.0f));
-    glUseProgram(global_shadow_shader);
-    shader_set_mat4fv(global_shadow_shader, "projection", projection); 
-    shader_set_mat4fv(global_shadow_shader, "view", view);
-
-    shader_set_3fv(global_shadow_shader, "light_pos", light_pos);
-    shader_set_3fv(global_shadow_shader, "view_pos", state->camera.pos);
-    shader_set_mat4fv(global_shadow_shader, "light_space_matrix", light_space_matrix); 
-    glActiveTexture(GL_TEXTURE0);
-    glBindTexture(GL_TEXTURE_2D, global_wood_texture);
-    glActiveTexture(GL_TEXTURE1);
-    glBindTexture(GL_TEXTURE_2D, global_depth_map);
-    render_scene(global_shadow_shader, cube, plane);
-
-    glUseProgram(global_color_shader);
-    shader_set_mat4fv(global_shadow_shader, "projection", projection); 
-    shader_set_mat4fv(global_shadow_shader, "view", view);
-    model = mat4_make_scale(v3f(0.1f, 0.1f, 0.1f));
-    model = mat4_translate(model, light_pos);
-    shader_set_mat4fv(global_shadow_shader, "model", model);
-    mesh_draw(cube);
-
-    glDisable(GL_DEPTH_TEST);
-    glUseProgram(global_debug_quad_shader);
-    F32 scale = 0.3f;
-    Transform transform = transform_make_scale_translate(v3f(scale, scale, scale),
-                                                         v3f(1.0f-scale, 1.0f-scale, 0.0f));
-    model = transform_apply(transform);
-    shader_set_mat4fv(global_debug_quad_shader, "model", model);
-    shader_set_1f(global_debug_quad_shader, "near", near);
-    shader_set_1f(global_debug_quad_shader, "far", far);
-    glActiveTexture(GL_TEXTURE0);
-    glBindTexture(GL_TEXTURE_2D, global_depth_map);
-    glBindVertexArray(global_quad_vao);
-    glDrawArrays(GL_TRIANGLES, 0, 6);
-    glBindVertexArray(0);
-    glEnable(GL_DEPTH_TEST);
+	MAT4 model;
+
+	model = mat4_identity();
+	shader_set_mat4fv(shader, "model", model); 
+	mesh_draw(plane);
+
+	/*
+	   model = mat4_identity();
+	   model = mat4_make_scale(v3f(10.0f, 0.1f, 10.0f));
+	   model = mat4_translate(model, v3f(0.0f, -0.6f, 0.0f));
+	   shader_set_mat4fv(shader, "model", model);
+	   mesh_draw(cube);
+	   */
+
+	model = mat4_identity();
+	model = mat4_make_scale(v3f(0.5f, 0.5f, 0.5f));
+	model = mat4_translate(model, v3f(0.0f, 1.5f, 0.0f));
+	shader_set_mat4fv(shader, "model", model);
+	mesh_draw(cube);
+
+	model = mat4_identity();
+	model = mat4_make_scale(v3f(0.5f, 0.5f, 0.5f));
+	model = mat4_translate(model, v3f(2.0f, 0.0f, 1.0f));
+	shader_set_mat4fv(shader, "model", model);
+	mesh_draw(cube);
+
+	model = mat4_identity();
+	model = mat4_make_scale(v3f(0.25f, 0.25f, 0.25f));
+	model = mat4_rotate_angles(model, v3f(60.0f, 0.0f, 0.0f));
+	model = mat4_translate(model, v3f(-1.0f, 0.0f, 2.0f));
+	shader_set_mat4fv(shader, "model", model);
+	mesh_draw(cube);
 }
 
-int
-main(void)
+int main(void)
 {
-    GLFWwindow *window;
-    Arena *arena;
-    State state;
-    Mesh *cube_mesh, *plane_mesh;
-    F64 time, last_time;
-    
-    glfwSetErrorCallback(error_callback);
-    
-    if (glfwInit() == GLFW_FALSE)
-        return(1);
-    
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
-    glfwWindowHint(GLFW_SAMPLES, 4);
-    window = glfwCreateWindow(global_screen_width, global_screen_height, "Shadow mapping", 0, 0);
-    if (!window)
-        goto error;
-    
-    glfwSetKeyCallback(window, glfw_key_callback);
-    glfwSetWindowSizeCallback(window, resize_callback);
-    
-    glfwMakeContextCurrent(window);
-    
-    if (glewInit() != GLEW_OK)
-        goto error;
-    
-    glEnable(GL_DEPTH_TEST);
-    // glEnable(GL_CULL_FACE);
-    
-    /* NOTE(pryazha): Init */
-    arena = arena_alloc(Megabytes(64));
-    
-    state.camera = (Camera){ v3f(0.0f, 1.0f, 3.0f), 90.0f, 0.1f, 100.0f };
-    light_pos = v3f(-2.0f, 4.0f, -2.0f);
-
-    /* NOTE(pryazha): Meshes */
-    Vertex plane_vertices[] = {
-        // positions            // normals         // texcoords
-        vertex(v3f(-25.0f, -0.5f,  25.0f),  v3f(0.0f, 1.0f, 0.0f),   v2f(0.0f,  0.0f)),
-        vertex(v3f(25.0f, -0.5f,  25.0f),  v3f(0.0f, 1.0f, 0.0f),  v2f(25.0f,  0.0f)),
-        vertex(v3f(-25.0f, -0.5f, -25.0f),  v3f(0.0f, 1.0f, 0.0f),   v2f(0.0f, 25.0f)),
-
-        vertex(v3f(25.0f, -0.5f,  25.0f),  v3f(0.0f, 1.0f, 0.0f),  v2f(25.0f,  0.0f)),
-        vertex(v3f(25.0f, -0.5f, -25.0f),  v3f(0.0f, 1.0f, 0.0f),  v2f(25.0f, 25.0f)),
-        vertex(v3f(-25.0f, -0.5f, -25.0f),  v3f(0.0f, 1.0f, 0.0f),   v2f(0.0f, 25.0f)),
-    };
-    U32 indices[] = { 0, 1, 2, 3, 4, 5 };
-    plane_mesh = mesh_init(arena, plane_vertices, ArrayCount(plane_vertices), indices, ArrayCount(indices));
-    cube_mesh = mesh_load_obj(arena, "../../data/models/cube.obj");
-    
-    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
-    };
-    
-    U32 vbo;    
-    glGenVertexArrays(1, &global_quad_vao);
-    glBindVertexArray(global_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);
-
-    /* NOTE(pryazha): Shaders */
-    global_debug_quad_shader = create_shader_program("shaders/debug_quad.vs",
-                                                     "shaders/debug_quad.fs");
-    global_simple_depth_shader = create_shader_program("shaders/simple_depth.vs",
-                                                       "shaders/simple_depth.fs");
-    global_shadow_shader = create_shader_program("shaders/shadow.vs", "shaders/shadow.fs");
-    global_color_shader = create_shader_program("shaders/color.vs", "shaders/color.fs");
-    
-    glUseProgram(global_shadow_shader);
-    shader_set_1i(global_shadow_shader, "diffuse_texture", 0);
-    shader_set_1i(global_shadow_shader, "shadow_map", 1);
-    glUseProgram(0);
-
-    global_wood_texture = load_texture_gamma("../../data/textures/wood.png", 1);
-
-    glGenFramebuffers(1, &global_depth_map_fbo);
-    glGenTextures(1, &global_depth_map);
-    glBindTexture(GL_TEXTURE_2D, global_depth_map);
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, global_shadow_width,
-                 global_shadow_height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
-    glBindFramebuffer(GL_FRAMEBUFFER, global_depth_map_fbo);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D,
-                           global_depth_map, 0);
-    V4F border_color = v4f(1.0f, 1.0f, 1.0f, 1.0f);
-    glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, (const F32 *)&border_color);
-    glDrawBuffer(GL_NONE);
-    glReadBuffer(GL_NONE);
-    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
-        fprintf(stderr, "[ERROR]: Failed to complete depth map framebuffer.\n");
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
-
-    last_time = glfwGetTime();
-    
-    while (!glfwWindowShouldClose(window))
-    {
-        glfwPollEvents();
-        if (key_first_press(global_input.exit))
-            glfwSetWindowShouldClose(window, GLFW_TRUE);
-        update(&state, time);
-        render(&state, cube_mesh, plane_mesh);
-        glfwSwapBuffers(window);
-        
-        time = glfwGetTime();
-        state.dt = time-last_time;
-        last_time = time;
-#if 0
-        fprintf(stdout, "[INFO]: dt: %f\n", state.dt);
-#endif
-    }
-
-    glfwTerminate();
-    return(0);
-    
-    error:
-    glfwTerminate();
-    return(1);
+	GLFWwindow *window;
+	Arena *arena;
+	State state;
+	F64 time, last_time;
+	S32 screen_width = 800, screen_height = 600;
+	U32 shadow_width = 1024, shadow_height = 1024;
+	Input input;
+	U32 shadows_ortho = 1;
+	V3F light_pos = v3f(-2.0f, 4.0f, -2.0f);
+
+	glfwSetErrorCallback(error_callback);
+
+	if (glfwInit() == GLFW_FALSE)
+		return(1);
+
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+	glfwWindowHint(GLFW_SAMPLES, 4);
+	window = glfwCreateWindow(screen_width, screen_height, "Shadow mapping", 0, 0);
+	if (!window)
+		goto error;
+
+	glfwMakeContextCurrent(window);
+
+	if (glewInit() != GLEW_OK)
+		goto error;
+
+	glEnable(GL_DEPTH_TEST);
+	// glEnable(GL_CULL_FACE);
+
+	/* NOTE(pryazha): Init */
+	arena = arena_alloc(Megabytes(64));
+
+	state.camera = (Camera){ v3f(0.0f, 1.0f, 3.0f), 90.0f, 0.1f, 100.0f, 0.0f, 0.0f };
+
+	/* NOTE(pryazha): Meshes */
+	Vertex plane_vertices[] = {
+		// positions            // normals         // texcoords
+		vertex(v3f(-25.0f, -0.5f,  25.0f),  v3f(0.0f, 1.0f, 0.0f),  v2f( 0.0f,  0.0f)),
+		vertex(v3f( 25.0f, -0.5f,  25.0f),  v3f(0.0f, 1.0f, 0.0f),  v2f(25.0f,  0.0f)),
+		vertex(v3f(-25.0f, -0.5f, -25.0f),  v3f(0.0f, 1.0f, 0.0f),  v2f( 0.0f, 25.0f)),
+
+		vertex(v3f( 25.0f, -0.5f,  25.0f),  v3f(0.0f, 1.0f, 0.0f),  v2f(25.0f,  0.0f)),
+		vertex(v3f( 25.0f, -0.5f, -25.0f),  v3f(0.0f, 1.0f, 0.0f),  v2f(25.0f, 25.0f)),
+		vertex(v3f(-25.0f, -0.5f, -25.0f),  v3f(0.0f, 1.0f, 0.0f),  v2f( 0.0f, 25.0f)),
+	};
+	U32 indices[] = { 0, 1, 2, 3, 4, 5 };
+	Mesh *plane = mesh_init(arena, plane_vertices, ArrayCount(plane_vertices),
+				indices, ArrayCount(indices));
+	Mesh *cube = mesh_load_obj(arena, "../../data/models/cube.obj");
+
+	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
+	};
+
+	U32 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, 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);
+
+	/* NOTE(pryazha): Shaders */
+	U32 debug_quad_shader = create_shader_program("shaders/debug_quad.vert",
+						      "shaders/debug_quad.frag");
+	U32 simple_depth_shader = create_shader_program("shaders/simple_depth.vert",
+							"shaders/simple_depth.frag");
+	U32 shadow_shader = create_shader_program("shaders/shadow.vert",
+						  "shaders/shadow.frag");
+	U32 color_shader = create_shader_program("shaders/color.vert",
+						 "shaders/color.frag");
+
+	glUseProgram(shadow_shader);
+	shader_set_1i(shadow_shader, "diffuse_texture", 0);
+	shader_set_1i(shadow_shader, "shadow_map", 1);
+	glUseProgram(0);
+
+	U32 wood_texture = load_texture_gamma("../../data/textures/wood.png", 1);
+
+	U32 depth_map_fbo, depth_map;
+	glGenFramebuffers(1, &depth_map_fbo);
+	glGenTextures(1, &depth_map);
+	glBindTexture(GL_TEXTURE_2D, depth_map);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, shadow_width,
+		     shadow_height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+	glBindFramebuffer(GL_FRAMEBUFFER, depth_map_fbo);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D,
+			       depth_map, 0);
+	V4F border_color = v4f(1.0f, 1.0f, 1.0f, 1.0f);
+	glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, (const F32 *)&border_color);
+	glDrawBuffer(GL_NONE);
+	glReadBuffer(GL_NONE);
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
+		fprintf(stderr, "[ERROR]: Failed to complete depth map framebuffer.\n");
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+	last_time = glfwGetTime();
+
+	while (!glfwWindowShouldClose(window)) {
+		glfwPollEvents();
+
+		/* NOTE(pryazha): Update */
+		process_glfw_keyboard(window, &input);
+		glfwGetFramebufferSize(window, &screen_width, &screen_height);
+
+		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);
+
+		if (key_first_press(input.action_down))
+			shadows_ortho = !shadows_ortho;
+
+		input_update_last_state(&input);
+
+		F32 radius, angular_speed, x, z;
+
+		angular_speed = 1.0f;
+		radius = 4.0f;
+		x = f32_sin(time*angular_speed)*radius;
+		z = f32_cos(time*angular_speed)*radius;
+
+		light_pos = v3f(x, 4.0f, z);
+
+		/* NOTE(pryazha): Render */
+		MAT4 proj, view, model, light_proj;
+		F32 fovx, near, far;
+
+		if (shadows_ortho) {
+			near = 1.0f;
+			far = 10.0f;
+			F32 half_side = 10.0f;
+			light_proj = ortho(-half_side, half_side, -half_side, half_side, near, far);
+		} else {
+			fovx = 90.0f;
+			near = 1.0f;
+			far = 50.0f;
+			light_proj = perspective(fovx, (F32)shadow_width/(F32)shadow_height,
+						 near, far);
+		}
+
+		V3F up = v3f(0.0f, 1.0f, 0.0f);
+		MAT4 light_view = look_at(light_pos, target, up);
+		MAT4 light_space_matrix = mat4_mul(light_proj, light_view);
+
+		glUseProgram(simple_depth_shader);
+		shader_set_mat4fv(simple_depth_shader, "light_space_matrix", light_space_matrix); 
+		glViewport(0, 0, shadow_width, shadow_height);
+		glBindFramebuffer(GL_FRAMEBUFFER, depth_map_fbo);
+		glClear(GL_DEPTH_BUFFER_BIT);
+		// glCullFace(GL_FRONT);
+		render_scene(simple_depth_shader, cube, plane);
+		// glCullFace(GL_BACK);
+		glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+		glViewport(0, 0, screen_width, screen_height);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		proj = perspective(state.camera.fovx, (F32)screen_width/(F32)screen_height, 
+				   state.camera.near, state.camera.far);
+		view = look_at(state.camera.pos, v3f_zero(), v3f(0.0f, 1.0f, 0.0f));
+
+		glUseProgram(shadow_shader);
+		shader_set_mat4fv(shadow_shader, "proj", proj); 
+		shader_set_mat4fv(shadow_shader, "view", view);
+		shader_set_3fv(shadow_shader, "light_pos", light_pos);
+		shader_set_3fv(shadow_shader, "view_pos", state.camera.pos);
+		shader_set_mat4fv(shadow_shader, "light_space_matrix", light_space_matrix); 
+		glActiveTexture(GL_TEXTURE0);
+		glBindTexture(GL_TEXTURE_2D, wood_texture);
+		glActiveTexture(GL_TEXTURE1);
+		glBindTexture(GL_TEXTURE_2D, depth_map);
+		render_scene(shadow_shader, cube, plane);
+
+		glUseProgram(color_shader);
+		shader_set_mat4fv(shadow_shader, "proj", proj); 
+		shader_set_mat4fv(shadow_shader, "view", view);
+		model = mat4_make_scale(v3f(0.1f, 0.1f, 0.1f));
+		model = mat4_translate(model, light_pos);
+		shader_set_mat4fv(shadow_shader, "model", model);
+		mesh_draw(cube);
+
+		glDisable(GL_DEPTH_TEST);
+		glUseProgram(debug_quad_shader);
+		F32 scale = 0.3f;
+		Transform transform = transform_make_scale_translate(v3f(scale, scale, scale),
+								     v3f(1.0f-scale, 1.0f-scale, 0.0f));
+		model = transform_apply(transform);
+		shader_set_mat4fv(debug_quad_shader, "model", model);
+		shader_set_1f(debug_quad_shader, "near", near);
+		shader_set_1f(debug_quad_shader, "far", far);
+		glActiveTexture(GL_TEXTURE0);
+		glBindTexture(GL_TEXTURE_2D, depth_map);
+		glBindVertexArray(quad_vao);
+		glDrawArrays(GL_TRIANGLES, 0, 6);
+		glBindVertexArray(0);
+		glEnable(GL_DEPTH_TEST);
+		glfwSwapBuffers(window);
+
+		time = glfwGetTime();
+		state.dt = time-last_time;
+		last_time = time;
+	}
+
+	glfwTerminate();
+	return(0);
+
+error:
+	glfwTerminate();
+	return(1);
 }