SDL-获取本机屏幕分辨率 [英] SDL - Get native Screen Resolution

问题描述

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");
}

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;
};

它可以正常编译，但是在编译之后，我得到了这个丑陋的错误:

It compiles fine, but then, after compiling, I'm getting this ugly error:

我出现问题的原因是什么?为什么我会得到这么奇怪的数字?

What's the reason of my problem? Why do I get so weird numbers?

我的目标是存储原始屏幕分辨率以供进一步使用(例如切换到全屏)，我必须在致电SDL_SetVideoMode()之前执行此操作.这就是为什么它在构造函数中.

My aim is to store original screen resolution for further use (like toggling to fullscreen), and I have to do this before calling SDL_SetVideoMode(). That's why it is in the constructor.

推荐答案

在实际初始化SDL之前，调用SDL视频功能会遇到问题.

You have a problem with calling SDL Video Functions before actually initializing SDL.

SDL_Init( SDL_INIT_EVERYTHING )

必须被称为之前

SDL_GetVideoInfo(); 

在您的情况下，您首先致电SDL_GetVideoInfo();

In your case you call SDL_GetVideoInfo(); first

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

因此解决方案很简单；在程序开始时立即调用SDL_Init( SDL_INIT_EVERYTHING )，然后您可以随意调用SDL_GetVideoInfo();. 您将不得不稍微重新调整您的类Window.

So the solution is simple; make the call SDL_Init( SDL_INIT_EVERYTHING ) immediately at the start of your program, then you can call SDL_GetVideoInfo(); as much as you like. You will have to restructure your class Window slightly.

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