triangle achieved

1 files changed, 122 insertions, 7 deletions

diff --git a/main.c b/main.c
index 32aff4e..3e4754c 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,3 @@
-#include <KHR/khrplatform.h>
 #define GLFW_INCLUDE_NONE
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
@@ -13,6 +12,42 @@ void processInput(GLFWwindow* window);
 // END
 
 int main(void) {
+    int w_width = 1280;
+    int w_height = 820;
+    int shader_success;
+    unsigned int VBO, VAO, EBO;
+    // fragment shader
+    unsigned int vertex_shader;
+    unsigned int fragment_shader;
+    unsigned int shader_program;
+
+    char info_Log[512];
+    // vertex shader source
+    const char* vertex_shader_source =
+	"#version 460 core\n"
+	"layout (location = 0) in vec3 aPos;\n"
+	"\n"
+	"void main() {\n"
+	    "gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
+	"}\n\0";
+    // Fragment shader
+    // ---------------
+    const char* fragment_shader_source =
+	"#version 460 core\n"
+	"out vec4 FragColor;\n"
+	"\n"
+	"void main() {\n"
+	    "FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
+	"}\n\0";
+
+    // Triangle shenanigans
+    // --------------------
+    float verticies[] = {
+	-0.5f, -0.5f, 0.0f, // left
+	 0.5f, -0.5f, 0.0f, // right
+	 0.0f,  0.5f, 0.0f  // top
+    };
+
 
     // GLFW settings init and which version of opengl we should use
     // and which subset of opengl profiles
@@ -23,11 +58,8 @@ int main(void) {
     
     
 
-    // Window settings
-    // create window
-    int w_height = 1280;
-    int w_width = 820;
-    GLFWwindow* window = glfwCreateWindow(w_height, w_width, "Test", NULL, NULL);
+    // glfw window creation
+    GLFWwindow* window = glfwCreateWindow(w_width, w_height, "Test", NULL, NULL);
     if (window == NULL) {
 	printf("Failed to create GLFW window\n");
 	glfwTerminate();
@@ -46,23 +78,106 @@ int main(void) {
     // opengl viewport
     framebuffer_size_callback(window, w_width, w_height);
 
+
+    // build and compile our shader program
+    // ------------------------------------
+
+    // vertex_shader
+    vertex_shader = glCreateShader(GL_VERTEX_SHADER);
+    glShaderSource(vertex_shader, 1, &vertex_shader_source, NULL);
+    glCompileShader(vertex_shader);
+
+    // check for compilation error
+    glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &shader_success);
+    if (!shader_success) {
+	glGetShaderInfoLog(vertex_shader, 512, NULL, info_Log);
+	printf("ERROR SHADER VERTEX COMPILATION FAILED: %s\n", info_Log);
+    }
+
+    // fragment_shader
+    fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
+    glShaderSource(fragment_shader, 1, &fragment_shader_source, NULL);
+    glCompileShader(fragment_shader);
+
+    // check for compilation error
+    glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &shader_success);
+    if (!shader_success) {
+	glGetShaderInfoLog(fragment_shader, 512, NULL, info_Log);
+	printf("ERROR SHADER FRAGMENT COMPILATION FAILED: %s\n", info_Log);
+    }
+
+    // create shader program
+    // ---------------------
+    shader_program = glCreateProgram();
+    // attach to shader program id
+    glAttachShader(shader_program, vertex_shader);
+    glAttachShader(shader_program, fragment_shader);
+    glLinkProgram(shader_program);
+
+    // check for linking erros
+    glGetProgramiv(shader_program, GL_LINK_STATUS, &shader_success);
+    if (!shader_success) {
+	glGetProgramInfoLog(shader_program, 512, NULL, info_Log);
+	printf("ERROR WHILE LINKIN THE SHADERS TO THE PROGRAM: %s\n", info_Log);
+    }
+
+    // delete now unneeded shaders
+    glDeleteShader(vertex_shader);
+    glDeleteShader(fragment_shader);
+
+    // set up vertex data (and buffers) and configure vertex attributes
+    // ----------------------------------------------------------------
+    
+    glGenVertexArrays(1, &VAO);
+    glGenBuffers(1, &VBO);
+
+    // bind the vertex array object first, then bind and set vertex buffers, and then configure vertex attributes.
+    glBindVertexArray(VAO);
+
+    // 0. copy our vertices array in a buffer for OpenGL to use
+    glBindBuffer(GL_ARRAY_BUFFER, VBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(verticies), verticies, GL_STATIC_DRAW);
+    // 1. then set the vertex attributes pointer
+    // location of array, size of vertex attribute (vec3), type of data(float), normialition?, stride (space between data in array), offset of where the position data begins in the buffer
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+
     // -------------------------------------------------------------------------
     // render loop
     // -------------------------------------------------------------------------
     while (!glfwWindowShouldClose(window)) {
 	// input
+	// -----
 	processInput(window);
 
 	// rendering commands here
 	// -----------------------
-	glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+	static GLclampf c = 0.0f;
+	glClearColor(c, c, c, 0.0f);
 	glClear(GL_COLOR_BUFFER_BIT);
 	
+	c += 1.0f / 256.0f;
+	if (c >= 1.0f) c = 0.0f;
+
+	// render triangle
+	glUseProgram(shader_program);
+	glBindVertexArray(VAO);
+	glad_glDrawArrays(GL_TRIANGLES, 0, 3);
+
 	// check and call events and swap the buffers
+	// ------------------------------------------
 	glfwSwapBuffers(window);
 	glfwPollEvents();
     }
 
+    // de-allocate all resources
+    glDeleteVertexArrays(1, &VAO);
+    glDeleteBuffers(1, &VBO);
+    glDeleteProgram(shader_program);
+
+    // Terminate program
+    // -----------------
     glfwTerminate();
     return 0;
 }