fix reversed perimeters

supermerill · Mar 27, 2023 · a0ec413 · a0ec413
2 parents 603c301 + 7c92519
commit a0ec413
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Showing 16 changed files with 257 additions and 180 deletions.
diff --git a/src/libslic3r/Brim.cpp b/src/libslic3r/Brim.cpp
@@ -820,11 +820,11 @@ void extrude_brim_from_tree(const Print& print, std::vector<std::vector<BrimLoop
             for (Polyline& pline : to_cut.lines) {
                 assert(pline.size() > 0);
                 if (pline.back() == pline.front()) {
-                    ExtrusionPath path(erSkirt, mm3_per_mm, width, height);
+                    ExtrusionPath path(erSkirt, mm3_per_mm, width, height, false);
                     path.polyline = pline;
                     to_add.push_back(new ExtrusionLoop(std::move(path), elrSkirt));
                 } else {
-                    ExtrusionPath* extrusion_path = new ExtrusionPath(erSkirt, mm3_per_mm, width, height);
+                    ExtrusionPath* extrusion_path = new ExtrusionPath(erSkirt, mm3_per_mm, width, height, false);
                     to_add.push_back(extrusion_path);
                     extrusion_path->polyline = pline;
                 }
@@ -851,16 +851,16 @@ void extrude_brim_from_tree(const Print& print, std::vector<std::vector<BrimLoop
         } else {
             ExtrusionEntityCollection* print_me_first = new ExtrusionEntityCollection();
             print_me_first->set_can_sort_reverse(false, false);
-            parent->append({ print_me_first });
+            parent->append(ExtrusionEntitiesPtr{ print_me_first });
             ExtrusionEntitiesPtr to_add;
             for (Polyline& pline : to_cut.lines) {
                 assert(pline.size() > 0);
                 if (pline.back() == pline.front()) {
-                    ExtrusionPath path(erSkirt, mm3_per_mm, width, height);
+                    ExtrusionPath path(erSkirt, mm3_per_mm, width, height, false);
                     path.polyline = pline;
                     to_add.push_back(new ExtrusionLoop(std::move(path), elrSkirt));
                 } else {
-                    ExtrusionPath* extrusion_path = new ExtrusionPath(erSkirt, mm3_per_mm, width, height);
+                    ExtrusionPath* extrusion_path = new ExtrusionPath(erSkirt, mm3_per_mm, width, height, false);
                     to_add.push_back(extrusion_path);
                     extrusion_path->polyline = pline;
                 }

diff --git a/src/libslic3r/ClipperUtils.cpp b/src/libslic3r/ClipperUtils.cpp
@@ -825,22 +825,37 @@ ClipperLib_Z::Paths clip_extrusion(const ClipperLib_Z::Paths& subjects, const Cl
     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<double>().squaredNorm();
-            double dist_sqr = (pt - start).cast<double>().squaredNorm();
-            double t = std::sqrt(dist_sqr / length_sqr);
+                double length_sqr = (end - start).cast<double>().squaredNorm();
+                double dist_sqr = (pt - start).cast<double>().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);
+            }
         });
 
     //TODO: //scale to have some more precision to do some Y-bugfix like in _clipper_pl_open

diff --git a/src/libslic3r/ExtrusionEntity.cpp b/src/libslic3r/ExtrusionEntity.cpp
@@ -237,8 +237,8 @@ void ExtrusionLoop::split_at(const Point &point, bool prefer_non_overhang, const
 
     // now split path_idx in two parts
     const ExtrusionPath &path = this->paths[path_idx];
-    ExtrusionPath p1(path.role(), path.mm3_per_mm, path.width, path.height);
-    ExtrusionPath p2(path.role(), path.mm3_per_mm, path.width, path.height);
+    ExtrusionPath p1(path.role(), path.mm3_per_mm, path.width, path.height, can_reverse());
+    ExtrusionPath p2(path.role(), path.mm3_per_mm, path.width, path.height, can_reverse());
     path.polyline.split_at(p, &p1.polyline, &p2.polyline);
 
     if (this->paths.size() == 1) {