+inline void SDLInitBufferedDisplay(DrawBuffer *backbuffer, DrawWindow *window)
+{
+ /* initialize SDL video */
+ if (SDL_Init(SDL_INIT_VIDEO) < 0)
+ Error(ERR_EXIT, "SDL_Init() failed: %s", SDL_GetError());
+
+ /* automatically cleanup SDL stuff after exit() */
+ atexit(SDL_Quit);
+
+ /* open SDL video output device (window or fullscreen mode) */
+ if (!SDLSetVideoMode(backbuffer))
+ Error(ERR_EXIT, "setting video mode failed");
+
+ /* set window and icon title */
+ SDL_WM_SetCaption(WINDOW_TITLE_STRING, WINDOW_TITLE_STRING);
+
+ /* create additional buffer for double-buffering */
+ pix[PIX_DB_BACK] = CreateBitmap(WIN_XSIZE, WIN_YSIZE, DEFAULT_DEPTH);
+
+ /* SDL cannot directly draw to the visible video framebuffer like X11,
+ but always uses a backbuffer, which is then blitted to the visible
+ video framebuffer with 'SDL_UpdateRect' (or replaced with the current
+ visible video framebuffer with 'SDL_Flip', if the hardware supports
+ this). Therefore do not use an additional backbuffer for drawing, but
+ use a symbolic buffer (distinguishable from the SDL backbuffer) called
+ 'window', which indicates that the SDL backbuffer should be updated to
+ the visible video framebuffer when attempting to blit to it.
+
+ For convenience, it seems to be a good idea to create this symbolic
+ buffer 'window' at the same size as the SDL backbuffer. Although it
+ should never be drawn to directly, it would do no harm nevertheless. */
+
+ *window = pix[PIX_DB_BACK]; /* 'window' is only symbolic buffer */
+ pix[PIX_DB_BACK] = *backbuffer; /* 'backbuffer' is SDL screen buffer */
+}
+
+inline boolean SDLSetVideoMode(DrawBuffer *backbuffer)
+{
+ boolean success = TRUE;
+
+ if (setup.fullscreen && !fullscreen_enabled && fullscreen_available)
+ {
+ /* switch display to fullscreen mode, if available */
+ DrawWindow window_old = *backbuffer;
+ DrawWindow window_new;
+
+ if ((window_new = SDL_SetVideoMode(WIN_XSIZE, WIN_YSIZE, WIN_SDL_DEPTH,
+ SDL_HWSURFACE|SDL_FULLSCREEN))
+ == NULL)
+ {
+ /* switching display to fullscreen mode failed */
+ Error(ERR_WARN, "SDL_SetVideoMode() failed: %s", SDL_GetError());
+
+ /* do not try it again */
+ fullscreen_available = FALSE;
+ success = FALSE;
+ }
+ else
+ {
+ if (window_old)
+ SDL_FreeSurface(window_old);
+ *backbuffer = window_new;
+
+ fullscreen_enabled = TRUE;
+ success = TRUE;
+ }
+ }
+
+ if ((!setup.fullscreen && fullscreen_enabled) || !*backbuffer)
+ {
+ /* switch display to window mode */
+ DrawWindow window_old = *backbuffer;
+ DrawWindow window_new;
+
+ if ((window_new = SDL_SetVideoMode(WIN_XSIZE, WIN_YSIZE, WIN_SDL_DEPTH,
+ SDL_HWSURFACE))
+ == NULL)
+ {
+ /* switching display to window mode failed -- should not happen */
+ Error(ERR_WARN, "SDL_SetVideoMode() failed: %s", SDL_GetError());
+
+ success = FALSE;
+ }
+ else
+ {
+ if (window_old)
+ SDL_FreeSurface(window_old);
+ *backbuffer = window_new;
+
+ fullscreen_enabled = FALSE;
+ success = TRUE;
+ }
+ }
+
+ return success;
+}
+