Re: [OpenJDK 2D-Dev] Different rounding applied by ProcessPath and ShapeSpanIterator

2016-09-28 Thread Clemens Eisserer
Hi Jim, > They do operate differently. They aren't meant to be mixed and matched. Thanks a lot for the detailed description of the relationship between SSI and ProcessPath. I did some further digging as to why the xrender pipeline has issues with the test attached to the mentioned bug report - b

Re: [OpenJDK 2D-Dev] Different rounding applied by ProcessPath and ShapeSpanIterator

2016-09-26 Thread Jim Graham
Trying to remember some ancient reasoning (and probably failing at the memory thing), I think the original issue was that the existing non-AA rasterizer could only output spans, so rendering a tall line (one with a wide Y range) would result in a lot of rendering operations being sent to a hw ras

Re: [OpenJDK 2D-Dev] Different rounding applied by ProcessPath and ShapeSpanIterator

2016-09-26 Thread Jim Graham
They do operate differently. They aren't meant to be mixed and matched. One thing that may shed some light is the STROKE_CONTROL hint. If it is sent to Pure then there is no heuristic for how to rasterize and all rasterizers should agree on how to scan convert shapes. But, if it is set to an

[OpenJDK 2D-Dev] Different rounding applied by ProcessPath and ShapeSpanIterator

2016-09-25 Thread Clemens Eisserer
Hi, I recently tried to track down JDK-8156100 (xrender: Subpixel drawing bug in Java 8) - under some circumstances paths do not align with fills when subpixel coordinates are used. The issue seems to be caused by ProcessPath and ShapeSpanIterator behaving differently with regards to rounding. I