Bug 6301 - Empty image if destination region is bigger than source bitmap
Summary: Empty image if destination region is bigger than source bitmap
Status: RESOLVED FIXED
Alias: None
Product: cairo
Classification: Unclassified
Component: win32 backend (show other bugs)
Version: 1.0.2
Hardware: Other Linux (All)
: high normal
Assignee: Owen Taylor
QA Contact: cairo-bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2006-03-17 21:55 UTC by Alexander Darovsky
Modified: 2008-01-11 09:07 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:

Attachments
fix (1.12 KB, patch)
2006-03-17 21:56 UTC, Alexander Darovsky 		Details | Splinter Review
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Description Alexander Darovsky 2006-03-17 21:55:32 UTC 
Here is a little bug in win32 backend, which, however, causes  
AlphaBlend to fail with "invalid argument" error code.   
  
The problem arises when src_x or src_y < 0, or when width or height is 
bigger than source bitmap. Applied patch solves this problem, and also 
fixes LoadLibrary issue. We must call LoadLibraryA or enclose "msimg32" 
into special macro.
Comment 1 Alexander Darovsky 2006-03-17 21:56:58 UTC 
Created attachment 4980 [details] [review]
fix

This patch fixes problems with msimg32 loading and AlphaBlend call
Comment 2 Chris Wilson 2008-01-11 09:07:55 UTC 
Adrian Johnson fixed the LoadLibraryA issue with commit f20a1a40c3f6d95b4dc89ae4198ad81b7092450c.

However, it should be impossible for AlphaBlend() to be called with a src rectangle that lies outside the source as it is fixed up by the caller (_cairo_win32_surface_composite, lines 1042-66 and added in commit 68ed40b6da242816a43cd68cc2c7feb779cf0acf by Vladimir Vukicevic).

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