Bug 57388

Summary: Need a way to specify that a ShareableBitmap has no alpha channel
Product: WebKit Reporter: Adam Roben (:aroben) <aroben>
Component: PlatformAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: andersca
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Bug Depends on: 57397    
Bug Blocks: 45567    
Attachments:
Description Flags
Add a way to specify that a ShareableBitmap has no alpha channel andersca: review+

Adam Roben (:aroben)
Reported 2011-03-29 14:13:44 PDT
ShareableBitmap currently always honors the alpha channel of its underlying data. This doesn't work well for use with APIs like GDI, which don't support alpha channels. (See bug 45567 comment 17 for one specific bug that this causes.) We should have a way of specifying that a particular ShareableBitmap doesn't have an alpha channel.
Attachments
Add a way to specify that a ShareableBitmap has no alpha channel (18.06 KB, patch)
2011-03-29 16:14 PDT, Adam Roben (:aroben) 		andersca: review+
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Adam Roben (:aroben)
Comment 1 2011-03-29 14:15:38 PDT
In theory, this should make blitting into the window's backing store faster on Windows, since CG will be able to ignore the alpha channel entirely.
Adam Roben (:aroben)
Comment 2 2011-03-29 16:14:24 PDT
Created attachment 87426 [details] Add a way to specify that a ShareableBitmap has no alpha channel
Adam Roben (:aroben)
Comment 3 2011-03-30 07:43:41 PDT
Committed r82442: <http://trac.webkit.org/changeset/82442>
Adam Roben (:aroben)
Comment 4 2011-03-30 08:08:06 PDT
Mac build fix Committed r82445: <http://trac.webkit.org/changeset/82445>
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