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[Bug 12705] setTransform spec silent on what to do with singular matrices

From: <bugzilla@jessica.w3.org>
Date: Sun, 22 May 2011 22:38:29 +0000
To: public-html-bugzilla@w3.org
Message-Id: <E1QOHI5-0007YW-3Z@jessica.w3.org>
http://www.w3.org/Bugs/Public/show_bug.cgi?id=12705

--- Comment #10 from Aryeh Gregor <Simetrical+w3cbug@gmail.com> 2011-05-22 22:38:28 UTC ---
Your "almost singular" matrix isn't very close to singular at all.  It has a
determinant of .00002.  That's quite a lot, since your lineWidth is 1999999. 
Try something like this instead:

http://software.hixie.ch/utilities/js/live-dom-viewer/saved/1002

If I set e to 0.0000001, Firefox draws the red square successfully.  If I add
one more zero, so it's 0.00000001, Firefox doesn't draw anything, even though
w(1 - e == 1) logs "false".  WebKit seems to have the same magic threshold,
after which it just ignores the operation (even though the width variable is
large enough that it should really draw the big black line).  So it doesn't
seem to be just testing whether it's actually singular, it looks like they're
testing that it's just "close" to singular.

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Received on Sunday, 22 May 2011 22:38:30 UTC

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