SDL程序冻结

Question

我正在编写一个用于测试鼠标的简单程序。 它可以正常编译，但是不起作用。 当我启动它时，窗口冻结。 我究竟做错了什么？

#include <SDL/SDL.h>
#undef main

int main()
{
    if (SDL_Init (SDL_INIT_EVERYTHING) != 0)
        return 1;
    SDL_Surface* Scr;
    if ((Scr = SDL_SetVideoMode (300, 200, 32, 0)) == 0)
        return 2;

    SDL_Rect Mouse1 = {50, 50, 50, 100};
    SDL_Rect Mouse3 = {150, 50, 50, 100};
    SDL_Rect Mouse2 = {250, 50, 50, 100};
    SDL_Surface Colors;
    SDL_Rect Click = {0, 0, 50, 100};
    SDL_Rect NoClick = {50, 0, 50, 100};

    SDL_FillRect (Scr, 0, SDL_MapRGB (Scr->format, 255, 255, 255));
    SDL_FillRect (&Colors, &Click, SDL_MapRGB (Colors.format, 255, 0, 0));
    SDL_FillRect (&Colors, &NoClick, SDL_MapRGB (Colors.format, 0, 0, 255));

    while (true)
    {
        if (SDL_GetMouseState (0, 0) & SDL_BUTTON(1))
            SDL_BlitSurface (&Colors, &Click, Scr, &Mouse1);
        else
            SDL_BlitSurface (&Colors, &NoClick, Scr, &Mouse1);

        if (SDL_GetMouseState (0, 0) & SDL_BUTTON(2))
            SDL_BlitSurface (&Colors, &Click, Scr, &Mouse2);
        else
            SDL_BlitSurface (&Colors, &NoClick, Scr, &Mouse2);

        if (SDL_GetMouseState (0, 0) & SDL_BUTTON(3))
            SDL_BlitSurface (&Colors, &Click, Scr, &Mouse3);
        else
            SDL_BlitSurface (&Colors, &NoClick, Scr, &Mouse3);

        if (SDL_GetKeyState (0) [SDLK_ESCAPE])
            return 0;

        SDL_Delay (17);
    }
}

Answer 1

您不处理任何事件。 在您的情况下，请调用SDL_PumpEvents以使SDL处理它们并更新其所有内部状态：

while (true)
{
  SDL_PumpEvents();

  // The rest is the same ...
}