SDL - 获取原生屏幕分辨率

Question

我的代码:

1. window.cpp

   Window::Window(int w, int h, const char *title, const char *icon)
   {
       height = h;
       width = w;
   
       if(SDL_Init( SDL_INIT_EVERYTHING ) == 0)
       {
           SDL_WM_SetCaption(title, NULL);
           SDL_WM_SetIcon(SDL_LoadBMP(icon),NULL);
   
           screen = SDL_SetVideoMode(width, height, 32,
                        SDL_SWSURFACE | SDL_RESIZABLE | SDL_DOUBLEBUF);
           if(screen == NULL)
           {
               running = false;
               return;
           }
           fullscreen = false;
       }
       else
           running = false;
           return;
   }
   
   Window::Window()
   {
       const SDL_VideoInfo* info = SDL_GetVideoInfo();
       screenWidth = info->current_w;
       screenHeight = info->current_h;
       Window(640, 480, "Flatgu game", "rsc/img/icon.bmp");
   }
   

2. 在window.h

   class Window
   {
   public:
       Window();
       ~Window();
   
       int getWidth() {return width;}
       int getHeight() {return height;}
       bool isFullscreen() {return fullscreen;}
   
       void toggleFullscreen();
   
   private:
       Window(int w, int h, const char *title, const char *icon);
   
       bool fullscreen, running;
       int height, width, screenWidth, screenHeight;
       SDL_Surface *screen;
   };
   

它编译得很好,但是在编译之后,我得到了这个丑陋的错误:

我的问题是什么原因？为什么我会得到如此奇怪的数字？

我的目标是存储原始屏幕分辨率以供进一步使用(如切换到全屏),我必须在调用之前执行此操作SDL_SetVideoMode().这就是它在构造函数中的原因.

Answer 1

在实际初始化SDL之前调用SDL视频功能时遇到问题.

SDL_Init( SDL_INIT_EVERYTHING )

一直被称为前

SDL_GetVideoInfo(); 

在你的情况下,你SDL_GetVideoInfo();先打电话

const SDL_VideoInfo* info = SDL_GetVideoInfo();   //<-- calls SDL_GetVideoInfo();   
screenWidth = info->current_w;
screenHeight = info->current_h;
Window(640, 480, "Flatgu game", "rsc/img/icon.bmp");    //<-- initializes SDL

所以解决方案很简单; SDL_Init( SDL_INIT_EVERYTHING )在程序开始时立即拨打电话,然后您可以随意拨打电话SDL_GetVideoInfo();.您将不得不稍微重构您的类窗口.