用 SDL2 显示一张图片

来源：

http://adolfans.github.io/sdltutorialcn/ （中文教程）

http://www.willusher.io/pages/sdl2/ （英文教程）

环境：SDL2 + VC++2015

下面的代码将打开一个窗口显示hello.bmp

 #include <iostream>
 #include <SDL.h>

 int main(int argc, char** argv)
 {
     //初始化SDL
     if (SDL_Init(SDL_INIT_VIDEO) != )
     {
         std::cout << "SDL_Init Error: " << SDL_GetError() << std::endl;
         return ;
     }

     //创建窗口
     SDL_Window *win = nullptr;
     win = SDL_CreateWindow("Hello World!",
         SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
         , , SDL_WINDOW_SHOWN);
     if (win == nullptr)
     {
         std::cout << SDL_GetError() << std::endl;
         return ;
     }

     //创建渲染器
     SDL_Renderer *ren = nullptr;
     ren = SDL_CreateRenderer(win, -,
         SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
     if (ren == nullptr)
     {
         std::cout << SDL_GetError() << std::endl;
         return ;
     }

     //创建表面
     SDL_Surface *bmp = nullptr;
     bmp = SDL_LoadBMP("hello.bmp");
     if (bmp == nullptr) {
         std::cout << SDL_GetError() << std::endl;
         return ;
     }

     //创建材质
     SDL_Texture *tex = nullptr;
     tex = SDL_CreateTextureFromSurface(ren, bmp);
     SDL_FreeSurface(bmp);

     //清空渲染器
     SDL_RenderClear(ren);
     //将材质复制到渲染器
     SDL_RenderCopy(ren, tex, NULL, NULL);
     //呈现渲染器
     SDL_RenderPresent(ren);
     //窗口延时
     SDL_Delay();

     //释放资源
     SDL_DestroyTexture(tex);
     SDL_DestroyRenderer(ren);
     SDL_DestroyWindow(win);
     //退出SDL
     SDL_Quit();

     return ;
 }