initial commit

6 files changed, 340 insertions, 0 deletions

diff --git a/stencil/build.sh b/stencil/build.sh
new file mode 100755
index 0000000..435d0b3
--- /dev/null
+++ b/stencil/build.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+. ../config
+TARGET='stencil'
+set -x
+gcc -o $TARGET $CFLAGS $INCLUDE $LFLAGS $TARGET.c $LIBS && ./$TARGET
diff --git a/stencil/shaders/outline.fs b/stencil/shaders/outline.fs
new file mode 100644
index 0000000..b935555
--- /dev/null
+++ b/stencil/shaders/outline.fs
@@ -0,0 +1,9 @@
+#version 330 core
+
+out vec4 frag_color;
+
+void
+main(void)
+{
+    frag_color = vec4(0.76f, 0.47f, 0.84f, 1.0f);
+}
diff --git a/stencil/shaders/stencil.fs b/stencil/shaders/stencil.fs
new file mode 100644
index 0000000..ff7dd9b
--- /dev/null
+++ b/stencil/shaders/stencil.fs
@@ -0,0 +1,13 @@
+#version 330 core
+
+out vec4 frag_color;
+
+in vec2 tex_coords;
+
+uniform sampler2D our_texture;
+
+void
+main(void)
+{
+    frag_color = texture(our_texture, tex_coords);
+}
diff --git a/stencil/shaders/stencil.vs b/stencil/shaders/stencil.vs
new file mode 100644
index 0000000..d3d92d1
--- /dev/null
+++ b/stencil/shaders/stencil.vs
@@ -0,0 +1,16 @@
+#version 330 core
+layout(location = 0) in vec3 apos;
+layout(location = 1) in vec2 atex_coords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+out vec2 tex_coords;
+
+void
+main(void)
+{
+    gl_Position = projection*view*model*vec4(apos, 1.0f);
+    tex_coords = atex_coords;
+}
diff --git a/stencil/stencil b/stencil/stencil
new file mode 100755
index 0000000..00f577f
--- /dev/null
+++ b/stencil/stencil
diff --git a/stencil/stencil.c b/stencil/stencil.c
new file mode 100644
index 0000000..a7c58f3
--- /dev/null
+++ b/stencil/stencil.c
@@ -0,0 +1,297 @@
+#include "GL/glew.h"
+#include "GLFW/glfw3.h"
+
+#include "pwyazh.h"
+
+#include "common.h"
+
+#include <unistd.h>
+
+#define WIDTH 1280
+#define HEIGHT 720
+
+static V3F camera_pos;
+static F32 dt;
+static Input input;
+
+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;
+    }
+}
+
+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);
+
+    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);
+}