#include "stdafx.h"
#include <GL/glew.h>
//#define GLFW_DLL
#include <GLFW/glfw3.h>int main(int argc, _TCHAR* argv[])
{// start GL context and O/S window using the GLFW helper libraryif (!glfwInit ()) {fprintf (stderr, "ERROR: could not start GLFW3\n");return 1;} GLFWwindow* window = glfwCreateWindow (800, 600, "Hello Triangle", NULL, NULL);if (!window) {fprintf (stderr, "ERROR: could not open window with GLFW3\n");glfwTerminate();return 1;}glfwMakeContextCurrent (window);// start GLEW extension handlerglewExperimental = GL_TRUE;glewInit ();// get version infoconst GLubyte* renderer = glGetString (GL_RENDERER); // get renderer stringconst GLubyte* version = glGetString (GL_VERSION); // version as a stringprintf ("Renderer: %s\n", renderer);printf ("OpenGL version supported %s\n", version);// tell GL to only draw onto a pixel if the shape is closer to the viewerglEnable (GL_DEPTH_TEST); // enable depth-testingglDepthFunc (GL_LESS); // depth-testing interprets a smaller value as "closer"float points[] = {0.0f,  0.5f,  0.0f,0.5f, -0.5f,  0.0f,-0.5f, -0.5f,  0.0f};GLuint vbo = 0;glGenBuffers (1, &vbo);glBindBuffer (GL_ARRAY_BUFFER, vbo);glBufferData (GL_ARRAY_BUFFER, 9 * sizeof (float), points, GL_STATIC_DRAW);GLuint vao = 0;glGenVertexArrays (1, &vao);glBindVertexArray (vao);glEnableVertexAttribArray (0);glBindBuffer (GL_ARRAY_BUFFER, vbo);glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 0, NULL);const char* vertex_shader ="#version 400\n""in vec3 vp;""void main () {""  gl_Position = vec4 (vp, 1.0);""}";const char* fragment_shader ="#version 400\n""out vec4 frag_colour;""void main () {""  frag_colour = vec4 (0.5, 0.0, 0.5, 1.0);""}";GLuint vs = glCreateShader (GL_VERTEX_SHADER);glShaderSource (vs, 1, &vertex_shader, NULL);glCompileShader (vs);GLuint fs = glCreateShader (GL_FRAGMENT_SHADER);glShaderSource (fs, 1, &fragment_shader, NULL);glCompileShader (fs);GLuint shader_programme = glCreateProgram ();glAttachShader (shader_programme, fs);glAttachShader (shader_programme, vs);glLinkProgram (shader_programme);// Loop until the user closes the windowwhile (!glfwWindowShouldClose(window)){// wipe the drawing surface clearglClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);glUseProgram (shader_programme);glBindVertexArray (vao);// draw points 0-3 from the currently bound VAO with current in-use shaderglDrawArrays (GL_TRIANGLES, 0, 3);// update other events like input handling
        glfwPollEvents ();// put the stuff we've been drawing onto the display
        glfwSwapBuffers (window);}// close GL context and any other GLFW resources
    glfwTerminate();return 0;
}