Fixed bug #526 SDL-1.2
authorSam Lantinga <>
Mon, 13 Apr 2009 00:53:12 +0000
changeset 416869bcba65c388
parent 4167 a6f635e5eaa6
child 4169 27c0db0fbfad
Fixed bug #526

Comment #1 From Simon Howard 2009-03-20 16:50:56


I'm the author of Chocolate Doom, one of the other source ports that James
mentioned. This is a patch against the current SVN version of SDL 1.2 that
fixes the bug. It has been tested and hopefully should be obviously correct
from examining the changes. I'll give a brief explanation.

When the palette is set with SDL_SetPalette, the IDirectDrawPalette_SetEntries
DirectX function is invoked. However, when this happens, a WM_PALETTECHANGED
message is sent to the window.

A WM_PALETTECHANGED message can also be received if the palette is changed for
some other reason, like if the system palette is changed. Therefore, the
palette change handler (DX5_PaletteChanged) has code to deal with this case.
It distinguishes "expected" palette changes (set with SDL_SetPalette) from
"unexpected" palette changes using the colorchange_expected variable, which is
set before calling IDirectDrawPalette_SetEntries. However, the code to set
this variable is missing in the fullscreen code path. By setting this
variable, the palette change is handled properly and the freezes go away.
     1.1 --- a/src/video/windx5/SDL_dx5video.c	Thu Apr 02 04:43:36 2009 +0000
     1.2 +++ b/src/video/windx5/SDL_dx5video.c	Mon Apr 13 00:53:12 2009 +0000
     1.3 @@ -2266,6 +2266,8 @@
     1.4  				SDL_colors[j].peGreen = colors[i].g;
     1.5  				SDL_colors[j].peBlue = colors[i].b;
     1.6  			}
     1.7 +			/* This sends an WM_PALETTECHANGED message to us */
     1.8 +			colorchange_expected = 1;
     1.9  			IDirectDrawPalette_SetEntries(SDL_palette, 0,
    1.10  				firstcolor, ncolors, &SDL_colors[firstcolor]);
    1.11  			alloct_all = 1;