[whatwg] [Canvas] Behavior on non-invertable CTM

Justin Novosad junov at google.com
Mon Mar 17 13:47:02 PDT 2014

>> I have a fix in flight that fixes that problem in Blink by storing the
>> current path in transformed coordinates instead. I've had the fix on the
>> back burner pending the outcome of this thread.
> That seems like an expensive solution because this causes the coordinates
> to be transformed twice.
> Why not store the matrix that was applied to the path coordinates and use
> that to undo the transformation?

If we decide that the right thing is to do nothing when when the CTM is
non-invertible, then sure, we can just do that. The idea of storing the
current path in transformed coordinates was to also support drawing with a
non-invertible CTM, like Firefox does, which is what Ian stated was the
correct behavior earlier in this thread. See why I kept the fix on the
backburner? :-)

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