Attachment 36080 Details for Bug 23581 – Do not recurse looking for an alpha map

[patch] Do not recurse looking for an alpha map

fix-alpha-maps (text/plain), 2.97 KB, created by Keith Packard on 2010-06-05 19:52:45 UTC

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Creator: Keith Packard

Created: 2010-06-05 19:52:45 UTC

Size: 2.97 KB

patch

obsolete

>commit e7aa5e101dedd9f636fda06137c992fff8b02ce4
>Author: Keith Packard <keithp@keithp.com>
>Date:   Fri May 21 09:01:43 2010 -0700
>
>    Don't let alpha maps recurse in fb. Bug 23581.
>    
>    Recursive alpha maps (where one picture's alpha map is set to a
>    picture with an external alpha map) would be all fine and dandy,
>    except for the case where the client constructs a loop. Detecting this
>    case when setting the alpha map values would be difficult as any time
>    an alpha map is set, the server would have to check for the looping
>    case.
>    
>    Instead, a far simpler fix is to simply disallow recursive alpha maps
>    in the rendering code, the Render spec is ambiguous in this area and
>    allows us to to ignore the recursive case.
>    
>    Signed-off-by: Keith Packard <keithp@keithp.com>
>
>diff --git a/fb/fbpict.c b/fb/fbpict.c
>index 896d33e..18a5204 100644
>--- a/fb/fbpict.c
>+++ b/fb/fbpict.c
>@@ -332,8 +332,11 @@ create_bits_picture (PicturePtr pict,
>     return image;
> }
> 
>+static pixman_image_t *
>+image_from_pict_internal (PicturePtr pict, Bool has_clip, int *xoff, int *yoff, Bool is_alpha_map);
>+
> static void
>-set_image_properties (pixman_image_t *image, PicturePtr pict, Bool has_clip, int *xoff, int *yoff)
>+set_image_properties (pixman_image_t *image, PicturePtr pict, Bool has_clip, int *xoff, int *yoff, Bool is_alpha_map)
> {
>     pixman_repeat_t repeat;
>     pixman_filter_t filter;
>@@ -382,10 +385,13 @@ set_image_properties (pixman_image_t *image, PicturePtr pict, Bool has_clip, int
>     
>     pixman_image_set_repeat (image, repeat);
>     
>-    if (pict->alphaMap)
>+    /* Fetch alpha map unless 'pict' is being used
>+     * as the alpha map for this operation
>+     */
>+    if (pict->alphaMap && !is_alpha_map)
>     {
> 	int alpha_xoff, alpha_yoff;
>-	pixman_image_t *alpha_map = image_from_pict (pict->alphaMap, FALSE, &alpha_xoff, &alpha_yoff);
>+	pixman_image_t *alpha_map = image_from_pict_internal (pict->alphaMap, FALSE, &alpha_xoff, &alpha_yoff, TRUE);
> 	
> 	pixman_image_set_alpha_map (
> 	    image, alpha_map, pict->alphaOrigin.x, pict->alphaOrigin.y);
>@@ -417,8 +423,8 @@ set_image_properties (pixman_image_t *image, PicturePtr pict, Bool has_clip, int
>     pixman_image_set_source_clipping (image, TRUE);
> }
> 
>-pixman_image_t *
>-image_from_pict (PicturePtr pict, Bool has_clip, int *xoff, int *yoff)
>+static pixman_image_t *
>+image_from_pict_internal (PicturePtr pict, Bool has_clip, int *xoff, int *yoff, Bool is_alpha_map)
> {
>     pixman_image_t *image = NULL;
> 
>@@ -452,11 +458,17 @@ image_from_pict (PicturePtr pict, Bool has_clip, int *xoff, int *yoff)
>     }
>     
>     if (image)
>-	set_image_properties (image, pict, has_clip, xoff, yoff);
>+	set_image_properties (image, pict, has_clip, xoff, yoff, is_alpha_map);
>     
>     return image;
> }
> 
>+pixman_image_t *
>+image_from_pict (PicturePtr pict, Bool has_clip, int *xoff, int *yoff)
>+{
>+    return image_from_pict_internal (pict, has_clip, xoff, yoff, FALSE);
>+}
>+
> void
> free_pixman_pict (PicturePtr pict, pixman_image_t *image)
> {

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Attachments on bug 23581: 28987 | 36080

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