[OpenJDK 2D-Dev] Java's definition of the SRC operator
james.graham at oracle.com
Fri Oct 29 12:23:22 PDT 2010
SRC behaves like SRC, but AA is another part of the equation. It works
like this (for any rule):
blendresult = PORTER_DUFF(rule, rendercolor, dstcolor, extraalpha)
// For SRC, blendresult = rendercolor modulated by extra alpha
storedresult = INTERP(dstcolor, blendresult, aacoverage)
// For full aa coverage, storedresult = blendresult
The only part of this that could possibly be interpreted as "behaving
like SRC_OVER" would be the second INTERP and it depends on the aa
coverage, not on the alpha of the colors involved. Is that what they
were talking about?
But, the interior of shapes should all have full aa coverage and so
should just store the blendresult (which, in the case of SRC is
On 10/29/10 12:06 PM, Clemens Eisserer wrote:
> Some users reported problems with the IntelliJ Idea's editor when
> running with xrender enabled.
> It turned out that there are some differences between how Java and
> xrender interpret the SRC operator.
> Is the general rule, that SRC behaves like SRC_OVER when antialiasing
> is enabled?
> Are there some special cases that need to be taken care of?
> Thanks, Clemens
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