SDL: Switch to full screen updates when the OSD is transparent

Previous releases also did full screen updates for transparent OSD messages.
There should be no performance regression with that regard.

Computing smaller update rects is non trivial, but should be looked into if
performance is an issue for OSD icons.

Fixes #9598

1 files changed, 5 insertions, 10 deletions

diff --git a/backends/graphics/surfacesdl/surfacesdl-graphics.cpp b/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
index adb84bfb24..46e243c945 100644
--- a/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
+++ b/backends/graphics/surfacesdl/surfacesdl-graphics.cpp
@@ -2176,9 +2176,8 @@ void SurfaceSdlGraphicsManager::displayActivityIconOnOSD(const Graphics::Surface
 	Common::StackLock lock(_graphicsMutex);	// Lock the mutex until this function ends
 
 	if (_osdIconSurface && !icon) {
-		// Add a dirty rect to clear the icon on the next update
-		SDL_Rect dstRect = getOSDIconRect();
-		addDirtyRect(dstRect.x, dstRect.y, dstRect.w, dstRect.h, true);
+		// Force a redraw to clear the icon on the next update
+		_forceFull = true;
 	}
 
 	if (_osdIconSurface) {
@@ -2249,6 +2248,7 @@ void SurfaceSdlGraphicsManager::updateOSD() {
 				_osdMessageAlpha = startAlpha + diff * (SDL_ALPHA_TRANSPARENT - startAlpha) / kOSDFadeOutDuration;
 			}
 			SDL_SetAlpha(_osdMessageSurface, SDL_RLEACCEL | SDL_SRCCOLORKEY | SDL_SRCALPHA, _osdMessageAlpha);
+			_forceFull = true;
 		}
 
 		if (_osdMessageAlpha == SDL_ALPHA_TRANSPARENT) {
@@ -2256,14 +2256,9 @@ void SurfaceSdlGraphicsManager::updateOSD() {
 		}
 	}
 
-	if (_osdMessageSurface) {
-		SDL_Rect dstRect = getOSDMessageRect();
-		addDirtyRect(dstRect.x, dstRect.y, dstRect.w, dstRect.h, true);
-	}
-
 	if (_osdIconSurface) {
-		SDL_Rect dstRect = getOSDIconRect();
-		addDirtyRect(dstRect.x, dstRect.y, dstRect.w, dstRect.h, true);
+		// Redraw the area below the icon for the transparent blit to give correct results.
+		_forceFull = true;
 	}
 }