C++驱动屏幕

Godot 的源代码

在C++中驱动屏幕通常指的是通过编程方式控制图形用户界面（GUI）或直接与硬件交互以显示内容。根据你的具体需求，这里有两种主要的方法来实现屏幕的驱动：

1. 使用图形库（如SDL, SFML, OpenGL, DirectX等）

这些库提供了更高级的API来处理图形和用户界面，使得屏幕内容的显示更加方便和高效。

示例：使用SDL库

SDL（Simple DirectMedia Layer）是一个跨平台的开发库，用于提供低级别的访问音频、键盘、鼠标、游戏手柄和图形硬件。

安装SDL：

• 在Ubuntu上，你可以使用sudo apt-get install libsdl2-dev来安装SDL2。

示例代码：

#include <SDL2/SDL.h>
 
int main(int argc, char* argv[]) {
    SDL_Window* window = nullptr;
    SDL_Init(SDL_INIT_VIDEO);
    window = SDL_CreateWindow(
        "Hello SDL",                  // window title
        SDL_WINDOWPOS_UNDEFINED,      // initial x position
        SDL_WINDOWPOS_UNDEFINED,      // initial y position
        640,                          // width, in pixels
        480,                          // height, in pixels
        SDL_WINDOW_OPENGL             // flags - see documentation for details
    );
 
    if (window == nullptr) {
        SDL_Log("Could not create window: %s\n", SDL_GetError());
        return -1;
    }
 
    bool running = true;
    SDL_Event e;
    while (running) {
        while (SDL_PollEvent(&e) != 0) {
            if (e.type == SDL_QUIT) {
                running = false;
            }
        }
    }
 
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}

 

2. 直接与硬件交互（如使用Windows API或Linux的Framebuffer）

如果你需要更底层的控制，例如直接在Linux上操作framebuffer或者使用Windows API进行绘图，你可以使用以下方法：

示例：在Linux上使用Framebuffer直接绘图

示例代码：

#include <fcntl.h>
#include <linux/fb.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <iostream>
#include <cstring>
 
int main() {
    int fbfd = open("/dev/fb0", O_RDWR);
    if (fbfd == -1) {
        perror("Error: cannot open framebuffer device");
        return 1;
    }
    printf("The framebuffer device was opened successfully.\n");
    struct fb_var_screeninfo vinfo;
    struct fb_fix_screeninfo finfo;
    long int screensize = 0;
    char *fbp = 0;  // framebuffer pointer
    // Get fixed screen information
    if (ioctl(fbfd, FBIOGET_FSCREENINFO, &finfo)) {
        perror("Error reading fixed information");
        return 2;
    }
    // Get variable screen information
    if (ioctl(fbfd, FBIOGET_VSCREENINFO, &vinfo)) {
        perror("Error reading variable information");
        return 3;
    }
    printf("%dx%d, %dbpp\n", vinfo.xres, vinfo.yres, vinfo.bits_per_pixel);
    screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
    // Map the device to memory
    fbp = (char *)mmap(0, screensize, PROT_READ | PROT_WRITE, MAP_SHARED, fbfd, 0);
    memset(fbp, 255, screensize);  // clear to red (white on my monitor) - for testing purposes only! 255 is white on my monitor. Adjust based on your monitor's color depth. 0 would be black for 8-bit depth. For example, for a 16-bit color depth monitor you might use 65535 for white. Adjust accordingly. 32-bit depth would be 0xFFFFFF or similar for white. Check your monitor's capabilities and adjust accordingly. 255 is a generic value that might not work for all setup