Date: Sat, 7 Feb 2004 13:26:01 +0100

From: delq Subject: Re: [SDL] better ILBM support for SDL_Image - fixed reading of colorkeyed images (they were previously assumed to have a stencil bitplane, but since the body didn't have it, the decoding failed). Added a missing call to SDL_SetColorKey() too. - fixed colormap for images with a stencil (mask) bitplane. Those images can have say 7+1 bitplanes but only 128 colors defined. In that case, the end of the SDL_Image colormap was uninitialized, resulting in garbled surfaces.
libsdl-org · Feb 9, 2004 · f5ce018 · f5ce018
1 parent b04e82b
commit f5ce018
Showing 1 changed file with 18 additions and 5 deletions.
diff --git a/IMG_lbm.c b/IMG_lbm.c
@@ -29,6 +29,7 @@
    POINT fr) in December 2002.
    EHB and HAM (specific Amiga graphic chip modes) support added by Marc Le Douarain
    (mavati AT club-internet POINT fr) in December 2003.
+   Stencil and colorkey fixes by David Raulo (david.raulo@free.fr) in February 2004.
 */
 
 #include <stdio.h>
@@ -230,7 +231,7 @@ SDL_Surface *IMG_LoadLBM_RW( SDL_RWops *src )
 		nbplanes = 1;
 	}
 
-	if ( bmhd.mask ) ++nbplanes;       /* There is a mask ( 'stencil' ) */
+	if ( bmhd.mask & 1 ) ++nbplanes;   /* There is a mask ( 'stencil' ) */
 
 	/* Allocate memory for a temporary buffer ( used for
            decompression/deinterleaving ) */
@@ -244,13 +245,14 @@ SDL_Surface *IMG_LoadLBM_RW( SDL_RWops *src )
 	if ( ( Image = SDL_CreateRGBSurface( SDL_SWSURFACE, width, bmhd.h, (bmhd.planes==24 || flagHAM==1)?24:8, 0, 0, 0, 0 ) ) == NULL )
 	   goto done;
 
+	if ( bmhd.mask & 2 )               /* There is a transparent color */
+		SDL_SetColorKey( Image, SDL_SRCCOLORKEY, bmhd.tcolor );
+
 	/* Update palette informations */
 
 	/* There is no palette in 24 bits ILBM file */
 	if ( nbcolors>0 && flagHAM==0 )
 	{
-		Image->format->palette->ncolors = nbcolors;
-
 		ptr = &colormap[0];
 
 		for ( i=0; i<nbcolors; i++ )
@@ -263,11 +265,11 @@ SDL_Surface *IMG_LoadLBM_RW( SDL_RWops *src )
 		/* Amiga EHB mode (Extra-Half-Bright) */
 		/* 6 bitplanes mode with a 32 colors palette */
 		/* The 32 last colors are the same but divided by 2 */
-		/* Some Amiga pictures save 64 colors with 32 last wrong colors,
+		/* Some Amiga pictures save 64 colors with 32 last wrong colors, */
 		/* they shouldn't !, and here we overwrite these 32 bad colors. */
 		if ( (nbcolors==32 || flagEHB ) && (1<<bmhd.planes)==64 )
 		{
-			Image->format->palette->ncolors = 64;
+			nbcolors = 64;
 			ptr = &colormap[0];
 			for ( i=32; i<64; i++ )
 			{
@@ -276,6 +278,17 @@ SDL_Surface *IMG_LoadLBM_RW( SDL_RWops *src )
 				Image->format->palette->colors[i].b = (*ptr++)/2;
 			}
 		}
+
+		/* If nbcolors < 2^nbplanes, repeat the colormap */
+		/* This happens when pictures have a stencil mask */
+		for ( i=nbcolors; i < (1 << nbplanes); i++ )
+		{
+			Image->format->palette->colors[i].r = Image->format->palette->colors[i%nbcolors].r;
+			Image->format->palette->colors[i].g = Image->format->palette->colors[i%nbcolors].g;
+			Image->format->palette->colors[i].b = Image->format->palette->colors[i%nbcolors].b;
+		}
+
+		Image->format->palette->ncolors = 1 << nbplanes;
 	}
 
 	/* Get the bitmap */