Fixed gamma correction in Atari video drivers (thanks Patrice!)

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%40509

src/video/gem/SDL_gemvideo.c

@@ -600,7 +600,6 @@ SDL_Surface *GEM_SetVideoMode(_THIS, SDL_Surface *current,
 	Uint32 modeflags, screensize;
 	SDL_bool use_shadow;
 
-	modeflags = SDL_HWPALETTE;
 	GEM_FreeBuffers(this);
 
 	/*--- Verify if asked mode can be used ---*/
@@ -659,6 +658,11 @@ SDL_Surface *GEM_SetVideoMode(_THIS, SDL_Surface *current,
 	}
 
 	/*--- Initialize screen ---*/
+	modeflags = 0;
+	if (VDI_bpp == 8) {
+		modeflags |= SDL_HWPALETTE;
+	}
+
 	if (flags & SDL_FULLSCREEN) {
 		GEM_LockScreen(this);
 

src/video/xbios/SDL_xbios.c

@@ -454,7 +454,7 @@ static SDL_Surface *XBIOS_SetVideoMode(_THIS, SDL_Surface *current,
 		return(NULL);
 	}
 
-	modeflags = (SDL_FULLSCREEN|SDL_HWPALETTE);
+	modeflags = SDL_FULLSCREEN;
 
 	/* Allocate needed buffers: simple/double buffer and shadow surface */
 	new_video_mode = XBIOS_videomodes[bpp][mode];
@@ -475,7 +475,7 @@ static SDL_Surface *XBIOS_SetVideoMode(_THIS, SDL_Surface *current,
 		} else {
 			Atari_C2pConvert = Atari_C2pConvert8;
 		}
-		modeflags |= SDL_SWSURFACE;
+		modeflags |= SDL_SWSURFACE|SDL_HWPALETTE;
 	} else {
 		modeflags |= SDL_HWSURFACE;
 	}