Correct game screenshot saving: Always save as 8-bit data, always use

Gui::gui->screenshot

Src/gui/game_info_menu.cpp

@@ -58,7 +58,7 @@ public:
 		{
 		case 0:
 		{
-			SDL_Surface *tmp = SDL_DisplayFormat(Gui::gui->screenshot);
+			SDL_Surface *tmp = sdl_surface_8bit_copy(Gui::gui->screenshot);
 
 			this->box->gi->setScreenshot(tmp);
 		} break;
@@ -83,7 +83,7 @@ public:
 		/* If we haven't' saved a screenshot, save it anyway */
 		if (!this->box->gi->screenshot)
 		{
-			SDL_Surface *p = TheC64->TheDisplay->SurfaceFromC64Display();
+			SDL_Surface *p = sdl_surface_8bit_copy(Gui::gui->screenshot);
 
 			this->box->gi->setScreenshot(p);
 		}

Src/gui/save_game_menu.cpp

@@ -182,7 +182,7 @@ void SaveGameView::saveSnapshot()
 	if (!was_paused)
 		TheC64->Resume();
 
-	Gui::gui->cur_gameInfo->setScreenshot(TheC64->TheDisplay->SurfaceFromC64Display());
+	Gui::gui->cur_gameInfo->setScreenshot(sdl_surface_8bit_copy(Gui::gui->screenshot));
 	Gui::gui->saveGameInfo(Gui::gui->save_game_path, out_name);
 	ThePrefs.Save(prefs_name);
 

Src/utils.cpp

@@ -172,8 +172,6 @@ static int png_colortype_from_surface(SDL_Surface *surface)
 
 	if (surface->format->palette)
 		colortype |= PNG_COLOR_MASK_PALETTE;
-	else if (surface->format->Amask)
-		colortype |= PNG_COLOR_MASK_ALPHA;
 
 	return colortype;
 }
@@ -287,6 +285,39 @@ SDL_Surface *sdl_surface_from_data(void *data, size_t sz)
 	return out;
 }
 
+SDL_Surface *sdl_surface_8bit_copy(SDL_Surface *src)
+{
+	Uint32 rmask,gmask,bmask,amask;
+	SDL_Surface *out;
+
+#if SDL_BYTEORDER == SDL_BIG_ENDIAN
+	rmask = 0xff000000;
+	gmask = 0x00ff0000;
+	bmask = 0x0000ff00;
+	amask = 0x000000ff;
+#else
+	rmask = 0x000000ff;
+	gmask = 0x0000ff00;
+	bmask = 0x00ff0000;
+	amask = 0xff000000;
+#endif
+	if (!src)
+		return NULL;
+	if (src->format->BitsPerPixel != 8)
+		return NULL;
+
+	out = SDL_CreateRGBSurface(SDL_SWSURFACE, src->w, src->h, 8,
+			rmask, gmask, bmask, amask);
+	if (!out)
+		return NULL;
+	memcpy(out->pixels, src->pixels, src->h * src->pitch);
+
+	SDL_SetColors(out, sdl_palette, 0, PALETTE_SIZE);
+
+	return out;
+}
+
+
 void highlight_background(SDL_Surface *where, Font *font,
 		SDL_Surface *bg_left, SDL_Surface *bg_middle, SDL_Surface *bg_right,
 		int x, int y, int w, int h)

Src/utils.hh

@@ -88,4 +88,6 @@ const char *ip_to_str(uint8_t *ip_in);
 
 const char *region_to_str(int region);
 
+SDL_Surface *sdl_surface_8bit_copy(SDL_Surface *src);
+
 #endif /* __UTILS_H__ */