Use preTranslate instead of postTranslate when correcting for the mask offset
Categories
(Core :: Graphics, enhancement, P3)
Tracking
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| Tracking | Status | |
|---|---|---|
| firefox67 | --- | fixed |
People
(Reporter: jrmuizel, Assigned: jrmuizel)
References
Details
Attachments
(1 file)
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(deleted),
text/x-phabricator-request
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Details |
DTO = DrawTargetOffset = (-Origin.x, -Origin.y)
CTM = CurrentTransform
MASKT = MaskTransform = Inv(CurrentTransform)
MASKO = MaskOffset = (GetRect().x, GetRect().y)
The transform to device space is:
MASKT * CTM * DTO
Currently we do:
MASKT = MASKT * MASKO
Which gives us MASKT * MASKO * CTM * DTO. This works fine if there's no scale but
will not properly cancel out if there is.
I believe we want:
MASKO * MASKT * CTM * DTO
To get this we need to preTranslate instead of postTranslate.
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Assignee | |
Comment 1•6 years ago
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DTO = DrawTargetOffset = (-Origin.x, -Origin.y)
CTM = CurrentTransform
MASKT = MaskTransform = Inv(CurrentTransform)
MASKO = MaskOffset = (GetRect().x, GetRect().y)
The transform to device space is:
MASKT * CTM * DTO
Currently we do:
MASKT = MASKT * MASKO
Which gives us MASKT * MASKO * CTM * DTO. This works fine if there's no scale but
will not properly cancel out if there is.
I believe we want:
MASKO * MASKT * CTM * DTO
To get this we need to preTranslate instead of postTranslate.
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Assignee | |
Updated•6 years ago
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Comment 4•6 years ago
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| bugherder | ||
https://hg.mozilla.org/mozilla-central/rev/10304db77c0a
https://hg.mozilla.org/mozilla-central/rev/ffd3366e43f3
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Updated•6 years ago
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Description
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