int main()
{
    if (!glfwInit())
    {
        fprintf(stderr, "Failed to initialize GLFW\n");
        getchar();
        return -1;
    }
 
    glfwWindowHint(GLFW_SAMPLES, 4);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 
    GLFWwindow* window = glfwCreateWindow(1024, 768, "Tutorial 01", NULL, NULL);
    if (window == NULL) {
        fprintf(stderr, "Failed to open GLFW window. If you have an Intel GPU, they are not 3.3 compatible. Try the 2.1 version of the tutorials.\n");
        getchar();
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
 
    glewExperimental = true;
   
    if (glewInit() != GLEW_OK) {
        fprintf(stderr, "Failed to initialize GLEW\n");
        getchar();
        glfwTerminate();
        return -1;
    }
 
    glfwSetInputMode(window, GLFW_STICKY_KEYS, GL_TRUE);
 
    glClearColor(0.0f, 0.0f, 0.4f, 0.0f);
 
    GLuint vertexArray;
    glGenVertexArrays(1, &vertexArray);
    glBindVertexArray(vertexArray);
 
    GLuint vbo;
    glGenBuffers(1, &vbo);
    glBindBuffer(GL_ARRAY_BUFFER, vbo);
 
    GLfloat vertices[] = {
        -1.0f, -1.0f, 0.0f,
        0.0f, 1.0f, 0.0f,
        1.0f, -1.0f, 0.0f
    };
 
	glEnableVertexAttribArray( 0 );
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
 
	glBindVertexArray( 0 );
    GLuint program = compileShaders();
 
    do {
        glClear(GL_COLOR_BUFFER_BIT);
        glUseProgram(program);
 
		glBindVertexArray(vertexArray);
        glDrawArrays(GL_TRIANGLES, 0, 3);
 		glBindVertexArray(0);
 
        glfwSwapBuffers(window);
        glfwPollEvents();
 
    }
    while (glfwGetKey(window, GLFW_KEY_ESCAPE) != GLFW_PRESS &&
        glfwWindowShouldClose(window) == 0);
 
    glDeleteBuffers(1, &vbo);
    glDeleteVertexArrays(1, &vertexArray);
    glDeleteProgram(program);
 
    glfwTerminate();
 
    return 0;
}