openGl_plataform.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <stdbool.h>

static unsigned int CompileShader(const char source, unsigned int type);
// Code to compile shaders
static int CreateShader(const char vertexShader, const char fragmentsShader){
  unsigned int program = glCreateProgram();
  unsigned int vs = glCreateShader(GL_VERTEX_SHADER);
};

int main() {

  // Initialise GLFW library.
  glewExperimental = true; // Needed for core profile
  if( !glfwInit() )
  {
      fprintf( stderr, "Failed to initialize GLFW\n" );
      return -1;
  }

  glfwWindowHint(GLFW_SAMPLES, 4); // 4x Antialiasing // Sets the number of samples to 4, each pixel will be sampled 4 times to calculate its final color.
  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); // We want OpenGL 3.3
  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);  // 3.<3>
  glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // To make MacOS happy; should not be needed
  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // We don't want the old OpenGL 

  // Open a window and create its OpenGL context
  GLFWwindow* window; // (In the accompanying source code, this variable is global for simplicity)
  window = glfwCreateWindow( 1024, 768, "First Game", NULL, NULL);
  
    if( window == NULL ){
      fprintf( stderr, "Failed to open GLFW window.\n");
      glfwTerminate();
      return -1;
  }

// An array of 3 vectors which represents 3 vertices
static const GLfloat g_vertex_buffer_data[] = {
   -1.0f, -1.0f, 0.0f, // represents the lower-left corner of the triangle.
   1.0f, -1.0f, 0.0f,   // represents the lower-right corner of the triangle
   0.0f,  1.0f, 0.0f,  // represents the top-center of the triangle
};

glfwMakeContextCurrent(window); // Initialize GLEW
    if (glewInit() != GLEW_OK) {
      fprintf(stderr, "Failed to initialize GLEW\n");
      return -1;
  }

  GLuint VertexArrayID;
  glGenVertexArrays(1, &VertexArrayID);
  glBindVertexArray(VertexArrayID);

  // This will identify our vertex buffer
GLuint vertexbuffer;
// Generate 1 buffer, put the resulting identifier in vertexbuffer
glGenBuffers(1, &vertexbuffer);
// The following commands will talk about our 'vertexbuffer' buffer
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
// Give our vertices to OpenGL.
glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW);

    // Ensure we can capture the escape key being pressed below
glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);

do{
    // Clear the screen. It's not mentioned before Tutorial 02, but it can cause flickering, so it's there nonetheless.
    glClear( GL_COLOR_BUFFER_BIT );

    // Draw nothing, see you in tutorial 2 !
    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
    glVertexAttribPointer(
      0,                  // attribute 0. No particular reason for 0, but must match the layout in the shader.
      3,                  // size
      GL_FLOAT,           // type
      GL_FALSE,           // normalized?
      0,                  // stride
      (void*)0            // array buffer offset
    );
    // Draw the triangle !
    glDrawArrays(GL_TRIANGLES, 0, 3); // Starting from vertex 0; 3 vertices total -> 1 triangle
    glDisableVertexAttribArray(0);

    // Swap buffers
    glfwSwapBuffers(window);
    glfwPollEvents();

} // Check if the ESC key was pressed or the window was closed
while( glfwGetKey(window, GLFW_KEY_ESCAPE ) != GLFW_PRESS &&
       glfwWindowShouldClose(window) == 0 );
}