107530 - [FIX] Error in transformation in nsTransform2D.cpp

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Dainis Jonitis]

Bug in functions Transform () and TransformCoord () in case of MG_2DGENERAL
transformation case. In case of calculating aWidth and aHeight the aHeight is
calculated twice, but aWidth is not changed at all.

Comment 1

[Dainis Jonitis]

Attachment: Fix of logic of Transform () and TransformCoord ()

Comment 2

[Mike Kaply [:mkaply]]

Attachment: Diff using -u

Comment 3

[Mike Kaply [:mkaply]]

Comment on attachment 55920 [details] [diff] [review]
Diff using -u

This is definitely just a bug
r=mkaply

Comment 4

[Marc Attinasi]

So, is this code just not being exercised currently (it is so wrong)?

Comment 5

[Dainis Jonitis]

In Transform () there is special case optimization for:
1. coordinate transformation only. MG_2DTRANSLATION
2. coordinate scaling only. MG_2DSCALE
3. Scaling and translation. (MG_2DSCALE | MG_2DTRANSLATION). This is used most
of the time in rendering context. Scaling does the twip->pixel conversion and
translation is changed all the time in ViewManager.

Thus MG_2DGENERAL should have rotation in the matrix to be used in Transform. I
am almost sure that this is not used in the Mozilla anywhere. There is no public
interface  (yet) to change the m10 and m01 which are responsible for rotation.

No risk to change. Just an obvious bug (copy-paste) which should be fixed.

Comment 6

[Marc Attinasi]

OK, thanks for the info. Will check-in (oh yea, sr=attinasi)

Comment 7

[Marc Attinasi]

Checking in nsTransform2D.cpp;
/cvsroot/mozilla/gfx/src/nsTransform2D.cpp,v  <--  nsTransform2D.cpp
new revision: 3.11; previous revision: 3.10
done