Windows Show Glyph Bug

View: New views
2 Messages — Rating Filter:   Alert me  

Windows Show Glyph Bug

by Gerdus van Zyl :: Rate this Message:

Reply to Author | View Threaded | Show Only this Message

I found a bug that only appears on windows surface without alpha.
Surface with alpha uses the fallbacks and does not show this bug.
It looks like it's setting a clip when showing glyphs and does not
remove the clip again.
My cairo using code worked in 1.8.8 but does not in current git
version. See attached images for illustration and patch that fixes the
bug. Probably the wrong way to fix it but works in my limited testing
using my code.

thanks.

~Gerdus




_______________________________________________
cairo mailing list
cairo@...
http://lists.cairographics.org/mailman/listinfo/cairo

err.png (4K) Download Attachment
good.png (4K) Download Attachment
0002-Move-SaveDC-before-setting-clip.patch (1K) Download Attachment

Re: Windows Show Glyph Bug

by Chris Wilson-11 :: Rate this Message:

Reply to Author | View Threaded | Show Only this Message

Excerpts from Gerdus van Zyl's message of Tue Oct 27 19:07:08 +0000 2009:
> I found a bug that only appears on windows surface without alpha.
> Surface with alpha uses the fallbacks and does not show this bug.
> It looks like it's setting a clip when showing glyphs and does not
> remove the clip again.
> My cairo using code worked in 1.8.8 but does not in current git
> version. See attached images for illustration and patch that fixes the
> bug. Probably the wrong way to fix it but works in my limited testing
> using my code.

Sounds definitely like something I broke when pushing the clip down into
the actual backend operations. Hmm, not convinced that your patch would
restore behaviour without closer inspection... However, as always I'm in
the middle of completely breaking the backends once more, joy!

Thanks for the report and the patch, I'll try to do some win32 testing
before the next overhaul (mainly because I'm optimistic that this
rewiring will have a noticeable performance benefit for win32 in
particular).
-ickle
--
Chris Wilson, Intel Open Source Technology Centre
_______________________________________________
cairo mailing list
cairo@...
http://lists.cairographics.org/mailman/listinfo/cairo