现代opengl和glad写一个简单代码，并在窗口上画一个三角形

以下是一个使用现代OpenGL和GLAD库创建窗口并在窗口上绘制三角形的示例代码：

#include <GL/gl.h>
#include <GLFW/glfw3.h>
#include <glad/glad.h>

#include <iostream>

// 顶点shader
const char* vertexShaderSource = R"(
    #version 330 core
    layout (location = 0) in vec3 aPos;
    void main()
    {
        gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);
    }
)";

// 片段shader
const char* fragmentShaderSource = R"(
    #version 330 core
    out vec4 FragColor;
    void main()
    {
        FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);
    }
)";

int main()
{
    glfwInit(); // 初始化GLFW

    // 配置GLFW
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    // 创建窗口对象
    GLFWwindow* window = glfwCreateWindow(800, 600, "Triangle", NULL, NULL);
    if (window == NULL)
    {
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window); // 将窗口的上下文设置为当前线程的主上下文

    // 初始化GLAD
    if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
    {
        std::cout << "Failed to initialize GLAD" << std::endl;
        return -1;
    }

    // 创建顶点shader对象
    unsigned int vertexShader;
    vertexShader = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
    glCompileShader(vertexShader);

    // 检查顶点shader是否编译成功
    int success;
    char infoLog[512];
    glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
    if (!success)
    {
        glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
        std::cout << "Failed to compile vertex shader:\n" << infoLog << std::endl;
    }

    // 创建片段shader对象
    unsigned int fragmentShader;
    fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
    glCompileShader(fragmentShader);

    // 检查片段shader是否编译成功
    glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
    if (!success)
    {
        glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
        std::cout << "Failed to compile fragment shader:\n" << infoLog << std::endl;
    }

    // 创建shader程序对象
    unsigned int shaderProgram;
    shaderProgram = glCreateProgram();
    glAttachShader(shaderProgram, vertexShader);
    glAttachShader(shaderProgram, fragmentShader);
    glLinkProgram(shaderProgram);

    // 检查shader程序是否链接成功
    glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
    if (!success)
    {
        glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
        std::cout << "Failed to link shader program:\n" << infoLog << std::endl;
    }

    glDeleteShader(vertexShader);
    glDeleteShader(fragmentShader);

    // 定义三角形的顶点坐标
    float vertices[] = {
        -0.5f, -0.5f, 0.0f,
         0.5f, -0.5f, 0.0f,
         0.0f,  0.5f, 0.0f
    };

    // 创建顶点缓冲区对象和顶点数组对象
    unsigned int VBO, VAO;
    glGenBuffers(1, &VBO);
    glGenVertexArrays(1, &VAO);

    glBindVertexArray(VAO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);

    // 渲染loop
    while (!glfwWindowShouldClose(window))
    {
        // 处理输入事件
        if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
            glfwSetWindowShouldClose(window, true);

        // 渲染指令
        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        glUseProgram(shaderProgram);
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 3);

        // 交换缓冲区和轮询事件
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    // 清理资源
    glDeleteVertexArrays(1, &VAO);
    glDeleteBuffers(1, &VBO);
    glDeleteProgram(shaderProgram);

    glfwTerminate();
    return 0;
}

此代码使用GLFW库创建一个800x600的窗口。它使用GLAD库加载OpenGL函数指针，并使用顶点和片段shader创建一个shader程序来绘制三角形。在渲染循环中，它清除颜色缓冲区并绘制三角形。最后，它清理所有已分配的资源并终止GLFW。