418494 - tell image rendering to use SOURCE instead of OVER

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Attachment: use OPERATOR_SOURCE when possible

Image rendering can use the SOURCE operator instead of OVER in a bunch of cases; let's do that.

Comment 1

[Robert Longson [:longsonr]]

How does code with OPREATOR_OVER compile?

Comment 2

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

(In reply to comment #1)
> How does code with OPREATOR_OVER compile?

I'm not sure what you mean?

Comment 3

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

oh, the typo; I edited the patch manually because I caught that check that was needed.. then fixed it when I went to compile.  so yeah, fixed in my local tree ;)

Comment 4

[Jeff Muizelaar [:jrmuizel]]

This optimization is not correct for RGB24 unless we are sure that we will never sample outside of the image area. When EXTEND_NONE (or the xserver doesn't support PAD?) and the source is transformed it's hard to be sure of that.

I see symptoms of this when zoomed in on the mozilla.org page in fennec: There are grey/black borders that appear/disappear around the images.

Comment 5

[Joe Drew (not getting mail)]

Jeff, you reverted this patch and it fixed the fennec bug you saw, right?

Comment 6

[Jeff Muizelaar [:jrmuizel]]

Yes, it did.

Comment 7

[Markus Stange [:mstange]]

Jeff, did you file a bug on that? I've hit that exact issue just now.

Comment 8

[Jeff Muizelaar [:jrmuizel]]

I don't recall filing one, but this quite a while ago.

Comment 9

[Jeff Muizelaar [:jrmuizel]]

However, there is bug 566283 which is a recent regression.