Bug 58267

Summary:

[CG] drawImage with a subimage bleeds pixel data at borders

Product:

WebKit

Reporter:

Matthew Delaney <mdelaney7>

Component:

Canvas

Assignee:

Matthew Delaney <mdelaney7>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

cmarrin, mdelaney7, simon.fraser

Priority:

Version:

528+ (Nightly build)

Hardware:

OS:

OS X 10.5

Attachments:

Description	Flags
testcase	none
Patch	mitz: review+

Description Matthew Delaney 2011-04-11 14:13:36 PDT

I'm attaching a testcase that shows the issue. It takes a very pixelated small image of white/orange pixels and does a drawImage with a source width/height of 1. The whole canvas should be uniformly one color. It was previously thought that non-"high"/"default" interpolation qualities in CG would not bleed pixel data from the source, but this appears to not be the case.

The fix is to have the useSubImage portion of ImageCG be used all the time. Uploading this patch now.

Comment 1 Matthew Delaney 2011-04-11 14:15:56 PDT

Created attachment 89086 [details]
testcase

Comment 2 Matthew Delaney 2011-04-11 14:36:29 PDT

Created attachment 89092 [details]
Patch

Comment 3 mitz 2011-04-11 14:48:47 PDT

Comment on attachment 89092 [details]
Patch

r=me if you replace the tabs in the test case with spaces

Comment 4 Matthew Delaney 2011-04-11 15:31:20 PDT

Committed r83521: <http://trac.webkit.org/changeset/83521>