Attachment 67311 Details for Bug 51360 – Better hack to try to fix negative srcX/Y cases without fallbacks

[patch] Better hack to try to fix negative srcX/Y cases without fallbacks

0001-Preliminary-patch-for-negative-srcX-and-or-srcY-Pict.patch (text/plain), 3.68 KB, created by Mart Raudsepp on 2012-09-18 05:16:13 UTC

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Creator: Mart Raudsepp

Created: 2012-09-18 05:16:13 UTC

Size: 3.68 KB

patch

obsolete

>From 9c5376d81c4518cc4459dabea26008d20867fc04 Mon Sep 17 00:00:00 2001
>From: Mart Raudsepp <leio@gentoo.org>
>Date: Tue, 18 Sep 2012 07:45:37 +0300
>Subject: [PATCH] Preliminary patch for negative srcX and/or srcY PictOpSrc
> operations
>
>Adds handling of negative srcX or srcY coordinates, which is used by gtk3
>GtkTrayIcon implementation via cairo for centering icons on top of the
>destination area (e.g negative srcX takes transparency from out of bounds from
>the left and as such the icon itself is shifted right).
>
>The completely out of bounds special case check (which need further checking if
>they are warranted at all per spec) didn't work correctly for negative srcX or
>srcY because exaScratch.srcWidth/Height are unsigned types, so the negative
>srcX or srcY got casted to unsigned, which resulted in a big number, so
>srcX >= 0 was always true (but GCC managed to not warn of the cast). Modified
>check to be what I believe it was meant to be, but will be double checked later.
>
>Various special cases for accelerating more complex cases made the compositing
>loop not exit out immediately in case of no repeat modes, so we would end up
>looping a lot and causing misrendering because the tracking variables aren't
>suitable in this case anymore due to the modifications to shift the coordinates.
>So exit again immediately for REPEAT_NONE, but this needs a different approach
>still, as it likely breaks these other complex special cases where the looping
>is supposedly needed even without repeat mode.
>
>Should fix bug 51360, but due to the above may cause other misrendering instead
>until corrected.
>---
> src/lx_exa.c |   28 ++++++++++++++++++++++++----
> 1 files changed, 24 insertions(+), 4 deletions(-)
>
>diff --git a/src/lx_exa.c b/src/lx_exa.c
>index bcff23e..9e548ff 100644
>--- a/src/lx_exa.c
>+++ b/src/lx_exa.c
>@@ -1295,8 +1295,8 @@ lx_do_composite(PixmapPtr pxDst, int srcX, int srcY, int maskX,
>         if (exaScratch.type == COMP_TYPE_ONEPASS) {
>             /* This is the condition srcX or/and srcY is/are out of source
>              * region */
>-            if (((srcX >= 0 && srcY >= exaScratch.srcHeight)
>-                 || (srcX >= exaScratch.srcWidth && srcY >= 0)) &&
>+            if (((srcY >= 0 && srcY >= exaScratch.srcHeight)
>+                 || (srcX >= 0 && srcX >= exaScratch.srcWidth)) &&
>                 (exaScratch.op == PictOpOver || exaScratch.op == PictOpSrc)) {
>                 if (exaScratch.repeat == 1) {
>                     opWidth = width;
>@@ -1337,8 +1337,25 @@ lx_do_composite(PixmapPtr pxDst, int srcX, int srcY, int maskX,
>                     opHeight = height;
>                 }
>                 else {
>-                    /* Have not met this condition till now */
>-                    return;
>+                    if (srcX < 0) {
>+                        opX -= srcX;
>+                        opWidth -= srcX;
>+                        width -= srcX;
>+                        srcX = -srcX;
>+                    }
>+                    if (srcY < 0) {
>+                        opY -= srcY;
>+                        opHeight -= srcY;
>+                        height -= srcY;
>+                        srcY = -srcY;
>+                    }
>+
>+                    if (exaScratch.srcWidth < opWidth)
>+                        opWidth = exaScratch.srcWidth;
>+
>+                    if (exaScratch.srcHeight < opHeight) {
>+                        opHeight = exaScratch.srcHeight;
>+                    }
>                 }
>             }
>             else {
>@@ -1407,6 +1424,9 @@ lx_do_composite(PixmapPtr pxDst, int srcX, int srcY, int maskX,
>             break;
>         }
> 
>+        if (!exaScratch.repeat && !exaScratch.maskrepeat)
>+            break;
>+
>         opX += opWidth;
> 
>         if (opX >= dstX + width) {
>-- 
>1.7.8.6
>

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Attachments on bug 51360: 63374 | 65214 | 65250 | 67311

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