Hi Jim, I am answering your first message:
Area is overkill for this as it tries to find exact intersection points of arbitrary geometry. You simply need something that will trace accurately around the outside of a clip to get from an exit point back to an entry point. That is a much simpler operation. OK, I started such approach but as it skips segments on the left side, it will not preserve crossing counts for the even-odd winding rule, I suppose. The key point is to reduce the edges / crossings processed by the Renderer in the left and right sides of the clip at every scanlines. For example, it will be worth when rendering a large text as a transformed shapes as many letter (closed paths) will be out the L/R sides... Top/Bottom clipping in Renderer already ignores such edges (except for curves). Moreover I agree Marlin does not need a proper path clipper (intersections) but just needs skipping useless segments like a path simplifier as I did in the Stroker. Another case: you provided a Test class using a path made with 10000 line segments on the left side. If it is converted by createStrokedShape(), then the Renderer will again deal with thousands crossings and it will be slow again. Also, I thought that the Renderer already did basic clipping along the lines that you indicate. It does that on a per-segment basis, but all it would take is a simple test at the top of quadTo() and curveTo() to completely reject all curves that lie outside the fill region (and simply shadow any part that is entirely to the left so that we maintain the proper crossings count)... Agreed but closed subpaths can also be ignored on either left or right sides like circles, letters... What do you mean by shadow any part on the left ? For the Even-odd filling rule, I think it needs exact segment intersections on the left side, so I am focused on the Non-zero filling rule for now. Finally I tried two approach: - basic subpath outside test (derived from the ClosedPathDetector) to ignore closed sub-paths outside of the clip. - more general clipper that follows the path, detect enter/exit the clip but it needs to insert/remove corner points. I am improving this latter approach. Thanks for your advices, Laurent
