[Pixman] [cairo] pixman: New ARM NEON optimizations
spitzak at gmail.com
Thu Feb 17 13:42:55 PST 2011
Siarhei Siamashka wrote:
>> I agree with Soeren that treating one-channel images as though
>> r==g==b==a (ie it is a white premultiplied image) is much more useful
>> than as a black premultiplied image and should be done.
> I was worried about the 'component alpha would become completely regular with
> no need for the "component_alpha" bit in pictures' part. It sounded like this
> case of 'using a 4-channel image as a mask is the same as using the alpha
> channel' was considered to be dropped.
If an image is used as component alpha mask then it has to have 3
channels, not 4. I believe if there are 4 channels then the intention is
to use the alpha channel only, rather than ignore it.
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