From 468d89a8d779c177871e0fc1342147b7535446a0 Mon Sep 17 00:00:00 2001 From: Simon McVittie Date: Thu, 20 Jul 2023 14:20:33 +0100 Subject: [PATCH] Allocate video surface object statically as a global The SDL Perl bindings incorrectly call SDL_FreeSurface() on the result of functions that return a "borrowed" pointer to the video surface, namely SDL_SetVideoMode() and SDL_GetVideoSurface(). (See https://github.com/PerlGameDev/SDL/issues/305) When we would previously have allocated or freed the video surface wrapper object, instead allocate or free its contents in-place. When checking whether the video surface exists, because we never destroy it, we must now also check whether its underlying SDL2 video surface exists. Resolves: https://github.com/libsdl-org/sdl12-compat/issues/305 Signed-off-by: Simon McVittie --- src/SDL12_compat.c | 48 +++++++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/src/SDL12_compat.c b/src/SDL12_compat.c index c3cc2ee79..fe4ce974b 100644 --- a/src/SDL12_compat.c +++ b/src/SDL12_compat.c @@ -980,6 +980,7 @@ static SDL_Window *VideoWindow20 = NULL; static SDL_Renderer *VideoRenderer20 = NULL; static SDL_mutex *VideoRendererLock = NULL; static SDL_Texture *VideoTexture20 = NULL; +static SDL12_Surface VideoSurface12Location; static SDL12_Surface *VideoSurface12 = NULL; static SDL_Palette *VideoPhysicalPalette20 = NULL; static Uint32 VideoSurfacePresentTicks = 0; @@ -4689,7 +4690,7 @@ EventFilter20to12(void *data, SDL_Event *event20) } case SDL_MOUSEMOTION: - if (!VideoSurface12) { + if (!VideoSurface12 || !VideoSurface12->surface20) { return 1; /* we don't have a screen surface yet? Don't send this on to the app. */ } @@ -5541,11 +5542,9 @@ EndVidModeCreate(void) VideoPhysicalPalette20 = NULL; } if (VideoSurface12) { - SDL12_Surface *screen12 = VideoSurface12; SDL20_free(VideoSurface12->pixels); VideoSurface12->pixels = NULL; - VideoSurface12 = NULL; /* SDL_FreeSurface will ignore the screen surface, so NULL the global variable out. */ - SDL_FreeSurface(screen12); + FreeSurfaceContents(VideoSurface12); } if (VideoConvertSurface20) { SDL20_FreeSurface(VideoConvertSurface20); @@ -5579,16 +5578,27 @@ EndVidModeCreate(void) return NULL; } - -static SDL12_Surface * -CreateSurface12WithFormat(const int w, const int h, const Uint32 fmt) +/* Essentially the same as SDL_CreateRGBSurface, but in-place */ +static void +CreateVideoSurface(const Uint32 fmt) { Uint32 rmask, gmask, bmask, amask; int bpp; + SDL_Surface *surface20; + if (!SDL20_PixelFormatEnumToMasks(fmt, &bpp, &rmask, &gmask, &bmask, &amask)) { - return NULL; + return; } - return SDL_CreateRGBSurface(0, w, h, bpp, rmask, gmask, bmask, amask); + + SDL20_zerop(VideoSurface12); + surface20 = CreateRGBSurface(0, 0, 0, bpp, rmask, gmask, bmask, amask); + + if (!Surface20to12InPlace(surface20, VideoSurface12)) { + FreeSurfaceContents(VideoSurface12); + return; + } + + Surface12SetMasks(VideoSurface12, rmask, gmask, bmask, amask); } static SDL_Surface * @@ -5925,6 +5935,8 @@ SetVideoModeImpl(int width, int height, int bpp, Uint32 flags12) int scaled_height = height; const char *fromwin_env = NULL; + VideoSurface12 = &VideoSurface12Location; + if (flags12 & SDL12_OPENGL) { /* For now we default GL scaling to ENABLED. If an app breaks or is linked directly to glBindFramebuffer, they'll need to turn it off with this environment variable. @@ -6014,11 +6026,11 @@ SetVideoModeImpl(int width, int height, int bpp, Uint32 flags12) default: SDL20_SetError("Unsupported bits-per-pixel"); return NULL; } - SDL_assert((VideoSurface12 != NULL) == (VideoWindow20 != NULL)); + SDL_assert((VideoSurface12->surface20 != NULL) == (VideoWindow20 != NULL)); - if (VideoSurface12 && ((VideoSurface12->flags & SDL12_OPENGL) != (flags12 & SDL12_OPENGL))) { + if (VideoSurface12->surface20 && ((VideoSurface12->flags & SDL12_OPENGL) != (flags12 & SDL12_OPENGL))) { EndVidModeCreate(); /* rebuild the window if moving to/from a GL context */ - } else if (VideoSurface12 && (VideoSurface12->surface20->format->format != appfmt)) { + } else if (VideoSurface12->surface20 && (VideoSurface12->surface20->format->format != appfmt)) { EndVidModeCreate(); /* rebuild the window if changing pixel format */ } else if (VideoGLContext20) { /* SDL 1.2 (infuriatingly!) destroys the GL context on each resize in some cases, on various platforms. Try to match that. */ @@ -6160,11 +6172,11 @@ SetVideoModeImpl(int width, int height, int bpp, Uint32 flags12) SDL20_SetWindowResizable(VideoWindow20, (flags12 & SDL12_RESIZABLE) ? SDL_TRUE : SDL_FALSE); } - if (VideoSurface12) { + if (VideoSurface12->surface20) { SDL20_free(VideoSurface12->pixels); } else { - VideoSurface12 = CreateSurface12WithFormat(0, 0, appfmt); - if (!VideoSurface12) { + CreateVideoSurface(appfmt); + if (!VideoSurface12->surface20) { return EndVidModeCreate(); } } @@ -6680,7 +6692,7 @@ DECLSPEC12 SDL12_Surface * SDLCALL SDL_DisplayFormat(SDL12_Surface *surface12) { const Uint32 flags = surface12->flags & (SDL12_SRCCOLORKEY|SDL12_SRCALPHA|SDL12_RLEACCELOK); - if (!VideoSurface12) { + if (!VideoSurface12 || !VideoSurface12->surface20) { SDL20_SetError("No video mode has been set"); return NULL; } @@ -6696,7 +6708,7 @@ SDL_DisplayFormatAlpha(SDL12_Surface *surface12) SDL_PixelFormat *fmt20 = NULL; SDL12_PixelFormat fmt12; - if (!VideoSurface12) { + if (!VideoSurface12 || !VideoSurface12->surface20) { SDL20_SetError("No video mode has been set"); return NULL; } @@ -7281,7 +7293,7 @@ static void HandleInputGrab(SDL12_GrabMode mode) { /* SDL 1.2 always grabbed input if the video mode was fullscreen. */ - const SDL_bool isfullscreen = (VideoSurface12 && (VideoSurface12->flags & SDL12_FULLSCREEN)) ? SDL_TRUE : SDL_FALSE; + const SDL_bool isfullscreen = (VideoSurface12 && VideoSurface12->surface20 && (VideoSurface12->flags & SDL12_FULLSCREEN)) ? SDL_TRUE : SDL_FALSE; const SDL_bool wantgrab = (isfullscreen || (mode == SDL12_GRAB_ON)) ? SDL_TRUE : SDL_FALSE; if (VideoWindowGrabbed != wantgrab) { if (VideoWindow20) {