From 68c990a1de84aea59a17b338072820f25dd7909f Mon Sep 17 00:00:00 2001 From: "salt.wei" Date: Fri, 16 Jun 2023 16:08:03 +0800 Subject: [PATCH] ENH: fix one assert in wall generater Thanks PrusaSlicer Signed-off-by: salt.wei Change-Id: I39456246c0fa1bde68fdd86690e4ef015a349898 --- src/libslic3r/PerimeterGenerator.cpp | 30 +++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-) diff --git a/src/libslic3r/PerimeterGenerator.cpp b/src/libslic3r/PerimeterGenerator.cpp index 35b2e7f037..79fc1604c2 100644 --- a/src/libslic3r/PerimeterGenerator.cpp +++ b/src/libslic3r/PerimeterGenerator.cpp @@ -413,22 +413,38 @@ static ClipperLib_Z::Paths clip_extrusion(const ClipperLib_Z::Path& subject, con ClipperLib_Z::Clipper clipper; clipper.ZFillFunction([](const ClipperLib_Z::IntPoint& e1bot, const ClipperLib_Z::IntPoint& e1top, const ClipperLib_Z::IntPoint& e2bot, const ClipperLib_Z::IntPoint& e2top, ClipperLib_Z::IntPoint& pt) { + // The clipping contour may be simplified by clipping it with a bounding box of "subject" path. + // The clipping function used may produce self intersections outside of the "subject" bounding box. Such self intersections are + // harmless to the result of the clipping operation, + // Both ends of each edge belong to the same source: Either they are from subject or from clipping path. + assert(e1bot.z() >= 0 && e1top.z() >= 0); + assert(e2bot.z() >= 0 && e2top.z() >= 0); + assert((e1bot.z() == 0) == (e1top.z() == 0)); + assert((e2bot.z() == 0) == (e2top.z() == 0)); + + // Start & end points of the clipped polyline (extrusion path with a non-zero width). ClipperLib_Z::IntPoint start = e1bot; ClipperLib_Z::IntPoint end = e1top; - if (start.z() <= 0 && end.z() <= 0) { start = e2bot; end = e2top; } - assert(start.z() > 0 && end.z() > 0); + if (start.z() <= 0 && end.z() <= 0) { + // Self intersection on the source contour. + assert(start.z() == 0 && end.z() == 0); + pt.z() = 0; + } + else { + // Interpolate extrusion line width. + assert(start.z() > 0 && end.z() > 0); - // Interpolate extrusion line width. - double length_sqr = (end - start).cast().squaredNorm(); - double dist_sqr = (pt - start).cast().squaredNorm(); - double t = std::sqrt(dist_sqr / length_sqr); + double length_sqr = (end - start).cast().squaredNorm(); + double dist_sqr = (pt - start).cast().squaredNorm(); + double t = std::sqrt(dist_sqr / length_sqr); - pt.z() = start.z() + coord_t((end.z() - start.z()) * t); + pt.z() = start.z() + coord_t((end.z() - start.z()) * t); + } }); clipper.AddPath(subject, ClipperLib_Z::ptSubject, false);