创建一个三角形

#include <glad/glad.h>//必须是第一个头文件
#include <GLFW/glfw3.h>
#include <iostream>void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow *window);
void init();
void display();//创建一个VAO和VBO
unsigned int VBO, VAO;
//程序对象
unsigned int shaderProgram;const char* vertexShaderSource="#version 330 core\n""layout(location = 0) in vec3 aPos;\n""void main()\n""{\n""   gl_Position = vec4(aPos.x,aPos.y,aPos.z,1.0);\n""}\0";const char* fragmentShaderSource="#version 330 core\n""out vec4 FragColor;\n""void main()\n""{\n""   FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n""}\0";int main()
{//初始化GLFWglfwInit();//我们将主版本号(Major)和次版本号(Minor)都设为3glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);//我们同样明确告诉GLFW我们使用的是核心模式(Core-profile)。    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);//如果使用的是Mac OS X系统，你还需要加下面这行代码,GLFW配置才会生效#ifdef __APPLE__glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);#endif//创建窗口对象GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);if (window == NULL){std::cout << "Failed to create GLFW window" << std::endl;glfwTerminate();return -1;}//设置参数window中的窗口所关联的OpenGL环境为当前环境。glfwMakeContextCurrent(window);//GLAD是用来管理OpenGL的函数指针的，所以在调用任何OpenGL的函数之前我们需要初始化GLAD。if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)){std::cout << "Failed to initialize GLAD" << std::endl;return -1;}init();//设置窗口的维度,函数前两个参数控制窗口左下角的位置。第三个和第四个参数控制渲染窗口的宽度和高度（像素）glViewport(0, 0, 800, 600);//告诉GLFW我们希望每当窗口调整大小的时候调用这个函数glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);while(!glfwWindowShouldClose(window))//每次循环的开始前检查一次GLFW是否被要求退出{processInput(window);glClearColor(0.2f, 0.3f, 0.3f, 1.0f);//设置清空屏幕所用的颜色glClear(GL_COLOR_BUFFER_BIT);//清空颜色缓存，使得屏幕颜色为glClearColor里所设置的颜色display();glfwSwapBuffers(window);//交换颜色缓冲（它是一个储存着GLFW窗口每一个像素颜色值的大缓冲）glfwPollEvents(); //检查有没有触发什么事件,并调用}//释放资源glDeleteVertexArrays(1, &VAO);glDeleteBuffers(1, &VBO);glDeleteProgram(shaderProgram);//当渲染循环结束后正确释放/删除之前的分配的所有资源glfwTerminate();return 0;
}//回调函数，当用户改变窗口的大小的时候，视口也应该被调整
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{glViewport(0, 0, width, height);
}//检查用户是否按下了返回键（Esc），如果按下则关闭窗口
void processInput(GLFWwindow *window)
{if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)glfwSetWindowShouldClose(window, true);
}
void init()
{//顶点着色器int vertexShader = glCreateShader(GL_VERTEX_SHADER);//创建一个着色器对象glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);//着色器源码附加到着色器对象上glCompileShader(vertexShader);//编译// 检测在调用glCompileShader后编译是否成功int success;char infoLog[512];glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);if (!success){glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;}//片元着色器int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);//创建glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);//加源码glCompileShader(fragmentShader);//编译// 检测着色器编译是否成功glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);if (!success){glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;}//把两个着色器对象链接到一个用来渲染的着色器程序shaderProgram = glCreateProgram();//创建一个程序对象glAttachShader(shaderProgram, vertexShader);//把之前编译的着色器附加到程序对象上glAttachShader(shaderProgram, fragmentShader);glLinkProgram(shaderProgram);//链接// 检测链接着色器程序是否失败glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);if (!success) {glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;}//  ???//删除着色器对象，我们不再需要它们了glDeleteShader(vertexShader);glDeleteShader(fragmentShader);//顶点数据float vertices[] = {-0.5f, -0.5f, 0.0f, // left  0.5f, -0.5f, 0.0f, // right 0.0f,  0.5f, 0.0f  // top   };//VAO和VBO配置IDglGenVertexArrays(1, &VAO);glGenBuffers(1, &VBO);//绑定glBindVertexArray(VAO);glBindBuffer(GL_ARRAY_BUFFER, VBO);//把之前定义的顶点数据复制到缓冲的内存中glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);//解析顶点数据glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);glEnableVertexAttribArray(0);//启用顶点属性//解绑glBindBuffer(GL_ARRAY_BUFFER, 0); glBindVertexArray(0);}void display()
{//绘制三角形glUseProgram(shaderProgram);//激活程序对象glBindVertexArray(VAO); //绑定VAOglDrawArrays(GL_TRIANGLES, 0, 3);
}

运行截图