a-game

commit 4515542024925cd35387f4106fb509b19840a1db
parent 3885c5b602323f1b955680b32b48f7462c6cf1d9
Author: amin <dev@aminmesbah.com>
Date:   Wed, 16 May 2018 07:35:05 +0000

Render a lovely triangle

FossilOrigin-Name: 95bf65f2c6dbd585b375d715ac41c78d3074202284915ee0a858bdeedcf6d21c
Diffstat:
A
shader/triangle_f.glsl
 | 
10
++++++++++
A
shader/triangle_v.glsl
 | 
12
++++++++++++
M
src/main.c
 | 
37
++++++++++++++++++++++++++++++++++++-

3 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/shader/triangle_f.glsl b/shader/triangle_f.glsl
@@ -0,0 +1,10 @@
+#version 330 core
+
+in vec4 vertex_color;
+
+out vec4 color;
+
+void main()
+{
+    color = vertex_color;
+}
diff --git a/shader/triangle_v.glsl b/shader/triangle_v.glsl
@@ -0,0 +1,12 @@
+#version 330 core
+
+layout (location = 0) in vec2 position;
+layout (location = 1) in vec3 color;
+
+out vec4 vertex_color;
+
+void main()
+{
+    gl_Position = vec4(position, 0.0f, 1.0f);
+    vertex_color = vec4(color, 1.0f);
+}
diff --git a/src/main.c b/src/main.c
@@ -51,16 +51,51 @@ int main(void)
         return -1;
     }
 
-    glViewport(0, 0, SCR_WIDTH, SCR_HEIGHT);
+    struct Shader triangle_shader = shader_compile("shader/triangle_v.glsl", "shader/triangle_f.glsl");
+
+    GLfloat triangle_vertices[] = {
+        // positions   // colors
+        -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,
+         0.5f, -0.5f,  0.0f,  1.0f,  0.0f,
+         0.0f,  0.5f,  0.0f,  0.0f,  1.0f,
+    };
+
+    GLuint VBO;
+    GLuint VAO;
+    glGenVertexArrays(1, &VAO);
+    glGenBuffers(1, &VBO);
+
+    glBindVertexArray(VAO);
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(triangle_vertices), triangle_vertices, GL_STATIC_DRAW);
+
+    // positions
+    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)0);
+    glEnableVertexAttribArray(0);
+
+    // colors
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(2 * sizeof(GLfloat)));
+    glEnableVertexAttribArray(1);
+    glBindVertexArray(0);
 
     while (!glfwWindowShouldClose(window))
     {
         glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
         glClear(GL_COLOR_BUFFER_BIT);
+
+        glUseProgram(triangle_shader.program);
+
+        glBindVertexArray(VAO);
+        glDrawArrays(GL_TRIANGLES, 0, 3);
+        glBindVertexArray(0);
+
         glfwSwapBuffers(window);
         glfwPollEvents();
     }
 
+    glDeleteVertexArrays(1, &VAO);
+    glDeleteBuffers(1, &VBO);
+
     glfwDestroyWindow(window);
     glfwTerminate();
     return 0;