#dasd

#include<Windows.h>
#include <glad/glad.h>
#include <iostream>
#include <GLFW/glfw3.h>

typedef HGLRC (WINAPI * PFNWGLCREATECONTEXT)(HDC);
PFNWGLCREATECONTEXT wglCreateContextPtr;

typedef BOOL (WINAPI * PFNWGLMAKECURRENT)(HDC, HGLRC);
PFNWGLMAKECURRENT wglMakeCurrentPtr;

///显示在屏幕上

int main(){
    HMODULE hOpenGL = LoadLibrary("OpenGL32.dll");
    wglCreateContextPtr = (PFNWGLCREATECONTEXT)GetProcAddress(hOpenGL, "wglCreateContext");
    wglMakeCurrentPtr = (PFNWGLMAKECURRENT)GetProcAddress(hOpenGL, "wglMakeCurrent");
    // 像素表格描述器
    PIXELFORMATDESCRIPTOR pfd;
    pfd.nSize=40;
    pfd.nVersion=1;
    //
    pfd.dwFlags=PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_SUPPORT_GDI;
    pfd.iPixelType=PFD_TYPE_RGBA;
    pfd.cColorBits=0;
    //
    pfd.cRedBits=0;
    pfd.cRedShift=0;
    pfd.cGreenBits=0;
    pfd.cGreenShift=0;
    pfd.cBlueBits=0;
    pfd.cBlueShift=0;
    pfd.cAlphaBits=0;
    pfd.cAlphaShift=0;
    //
    pfd.cAccumBits=0;
    pfd.cAccumRedBits=0;
    pfd.cAccumBlueBits=0;
    pfd.cAccumGreenBits=0;
    pfd.cAccumAlphaBits=0;
    //
    pfd.cDepthBits=0;
    pfd.cStencilBits=0;
    pfd.cAuxBuffers=0;
    pfd.iLayerType=PFD_MAIN_PLANE;
    pfd.bReserved=0;
    pfd.dwLayerMask=0;
    pfd.dwVisibleMask=0;
    pfd.dwDamageMask=0;

    // glfwInit();
    // glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
    // GLFWwindow* window = glfwCreateWindow(640, 480, "OpenGL", NULL, NULL);
    // glfwMakeContextCurrent(window);
    // 获取设备屏幕
    HDC hdc=GetDC(NULL);
    int pixelFormat=ChoosePixelFormat(hdc,&pfd);
    SetPixelFormat(hdc,pixelFormat,&pfd);
    HGLRC hglrc=wglCreateContextPtr(hdc);
    wglMakeCurrentPtr(hdc,hglrc);

    // 绘制
    if (!gladLoadGL()) {
        std::cout << "GLAD failed to load" << std::endl;
        return -1;
    }
    int i=1;
    while (i<100){
        ++i;
        glViewport(0,0,800,800);
        glColor3f(1.0f,0.0f,0.0f);
        glBegin(GL_TRIANGLES);
        glVertex2f(-0.5f,-0.5f);
        glVertex2f(0.0f,0.5f);
        glVertex2f(0.5f,-0.5);
        glEnd();
        glFlush();
    }
    std::cout<<"normal end"<<std::endl;
    // glfwTerminate();
    return 0;
    
}



//     glad
//     int i =0;
//     while(i<1000){
//         ++i;
//         glDrawArrays( GL_LINES, 0, 2 );
//     }
//     return 0;
// }


// #include <glad/glad.h>
// #include <Windows.h>
// #include <iostream>

// int main(){
    
//     if (!gladLoadGL()) {
//         std::cout << "GLAD failed to load" << std::endl;
//         return -1;
//     }

//     // 绘制三角形
//     float vertices[] = {
//         -0.5f, -0.5f, 0.0f,
//         0.5f, -0.5f, 0.0f,
//         0.0f,  0.5f, 0.0f
//     };

//     unsigned int VBO, VAO;
//     glGenVertexArrays(1, &VAO);
//     glGenBuffers(1, &VBO);

//     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);

//     glDrawArrays(GL_TRIANGLES, 0, 3);

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

//     glDeleteVertexArrays(1, &VAO);
//     glDeleteBuffers(1, &VBO);

//     // 在屏幕上绘制
//     glFinish();
//     HDC hdc = GetDC(NULL);
//     glReadBuffer(GL_FRONT);
//     glDrawBuffer(GL_BACK);
//     glBlitFramebuffer(0, 0, 640, 480, 0, 0, 640, 480, GL_COLOR_BUFFER_BIT, GL_NEAREST);
//     SwapBuffers(hdc);
//     ReleaseDC(NULL, hdc);
//     std::cout << "finish" << std::endl;
//     return 0;
// }