[OpenJDK 2D-Dev] [9] Review Request: 8167310 The graphics clip is incorrectly rounded for some fractional scales

Sergey Bylokhov Sergey.Bylokhov at oracle.com
Tue Oct 11 19:13:38 UTC 2016

On 11.10.16 21:54, Jim Graham wrote:
> Additionally, for AA rendering, there is no such thing as
> "setClip(someShape)" and "fill(sameShape)" being identical no matter how
> much we predict which rules they may want because clips are inherently
> non-AA and so the fuzzy pixels along the boundary of an AA shape will be
> randomly clipped or included.
> When all is said and done I feel (not very strongly) it would be best to
> have clipping remain unaffected by the biasing of STROKE hints, but part
> of that is driven by the fact that I think it can be fixed with a couple
> of lines of code in SG2D/LoopPipe...

I guess a bottom line is that it is require an additional investigation. 
I am not exactly sure, but my expectation is that 
fillRect(x,y,w,h)/drawImage(x,y,w,h) + setClip(x,y,w,h) should work in a 
similar way(covers the same pixels). And the question should this 
behavior be exactly the same as fill(RectShape) + setClip(RectShape) is 
unclear (I am not sure is it a critical issue or not)
Right now I tried to fix overlapping, which produce visible artifacts 
and were considered as a bugs. The next issue which I would like to fix 
is a overlapping of drawImage().

Best regards, Sergey.

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