Fix of #8724, #8747, and #8753: Crash when Voronoi vertexes of a finite edge have some coordinate NaN or infinite.

4 files changed, 28 insertions, 3 deletions

diff --git a/src/libslic3r/Arachne/SkeletalTrapezoidation.cpp b/src/libslic3r/Arachne/SkeletalTrapezoidation.cpp
index 7bd37df11..e9afa0305 100644
--- a/src/libslic3r/Arachne/SkeletalTrapezoidation.cpp
+++ b/src/libslic3r/Arachne/SkeletalTrapezoidation.cpp
@@ -451,8 +451,23 @@ SkeletalTrapezoidation::SkeletalTrapezoidation(const Polygons& polys, const Bead
     constructFromPolygons(polys);
 }
 
+static bool has_finite_edge_with_non_finite_vertex(const Geometry::VoronoiDiagram &voronoi_diagram)
+{
+    for (const VoronoiUtils::vd_t::edge_type &edge : voronoi_diagram.edges()) {
+        if (edge.is_finite()) {
+            assert(edge.vertex0() != nullptr && edge.vertex1() != nullptr);
+            if (edge.vertex0() == nullptr || edge.vertex1() == nullptr || !VoronoiUtils::is_finite(*edge.vertex0()) ||
+                !VoronoiUtils::is_finite(*edge.vertex1()))
+                return true;
+        }
+    }
+    return false;
+}
 
 static bool detect_missing_voronoi_vertex(const Geometry::VoronoiDiagram &voronoi_diagram, const std::vector<SkeletalTrapezoidation::Segment> &segments) {
+    if (has_finite_edge_with_non_finite_vertex(voronoi_diagram))
+        return true;
+
     for (VoronoiUtils::vd_t::cell_type cell : voronoi_diagram.cells()) {
         if (!cell.incident_edge())
             continue; // There is no spoon
@@ -471,7 +486,8 @@ static bool detect_missing_voronoi_vertex(const Geometry::VoronoiDiagram &vorono
             VoronoiUtils::vd_t::edge_type *ending_vd_edge                  = nullptr;
             VoronoiUtils::vd_t::edge_type *edge                            = cell.incident_edge();
             do {
-                if (edge->is_infinite()) continue;
+                if (edge->is_infinite() || edge->vertex0() == nullptr || edge->vertex1() == nullptr || !VoronoiUtils::is_finite(*edge->vertex0()) || !VoronoiUtils::is_finite(*edge->vertex1()))
+                    continue;
 
                 Vec2i64 v0 = VoronoiUtils::p(edge->vertex0());
                 Vec2i64 v1 = VoronoiUtils::p(edge->vertex1());
diff --git a/src/libslic3r/Arachne/utils/VoronoiUtils.cpp b/src/libslic3r/Arachne/utils/VoronoiUtils.cpp
index 3da556b47..82bd79523 100644
--- a/src/libslic3r/Arachne/utils/VoronoiUtils.cpp
+++ b/src/libslic3r/Arachne/utils/VoronoiUtils.cpp
@@ -15,6 +15,7 @@ Vec2i64 VoronoiUtils::p(const vd_t::vertex_type *node)
 {
     const double x = node->x();
     const double y = node->y();
+    assert(std::isfinite(x) && std::isfinite(y));
     assert(x <= double(std::numeric_limits<int64_t>::max()) && x >= std::numeric_limits<int64_t>::lowest());
     assert(y <= double(std::numeric_limits<int64_t>::max()) && y >= std::numeric_limits<int64_t>::lowest());
     return {int64_t(x + 0.5 - (x < 0)), int64_t(y + 0.5 - (y < 0))}; // Round to the nearest integer coordinates.
diff --git a/src/libslic3r/Arachne/utils/VoronoiUtils.hpp b/src/libslic3r/Arachne/utils/VoronoiUtils.hpp
index e736f98bc..aa4693643 100644
--- a/src/libslic3r/Arachne/utils/VoronoiUtils.hpp
+++ b/src/libslic3r/Arachne/utils/VoronoiUtils.hpp
@@ -35,6 +35,11 @@ public:
      * The \p approximate_step_size is measured parallel to the \p source_segment, not along the parabola.
      */
     static std::vector<Point> discretizeParabola(const Point &source_point, const Segment &source_segment, Point start, Point end, coord_t approximate_step_size, float transitioning_angle);
+
+    static inline bool is_finite(const VoronoiUtils::vd_t::vertex_type &vertex)
+    {
+        return std::isfinite(vertex.x()) && std::isfinite(vertex.y());
+    }
 };
 
 } // namespace Slic3r::Arachne
diff --git a/src/libslic3r/Geometry/VoronoiUtilsCgal.cpp b/src/libslic3r/Geometry/VoronoiUtilsCgal.cpp
index caaf1ee9c..062a3b397 100644
--- a/src/libslic3r/Geometry/VoronoiUtilsCgal.cpp
+++ b/src/libslic3r/Geometry/VoronoiUtilsCgal.cpp
@@ -3,6 +3,7 @@
 #include <CGAL/Surface_sweep_2_algorithms.h>
 
 #include "libslic3r/Geometry/Voronoi.hpp"
+#include "libslic3r/Arachne/utils/VoronoiUtils.hpp"
 
 #include "VoronoiUtilsCgal.hpp"
 
@@ -28,7 +29,8 @@ bool VoronoiUtilsCgal::is_voronoi_diagram_planar_intersection(const VD &voronoi_
         if (edge.color() != 0)
             continue;
 
-        if (edge.is_finite() && edge.is_linear()) {
+        if (edge.is_finite() && edge.is_linear() && edge.vertex0() != nullptr && edge.vertex1() != nullptr &&
+            Arachne::VoronoiUtils::is_finite(*edge.vertex0()) && Arachne::VoronoiUtils::is_finite(*edge.vertex1())) {
             segments.emplace_back(to_cgal_point(*edge.vertex0()), to_cgal_point(*edge.vertex1()));
             edge.color(1);
             assert(edge.twin() != nullptr);
@@ -73,7 +75,8 @@ bool VoronoiUtilsCgal::is_voronoi_diagram_planar_angle(const VoronoiDiagram &vor
 
         do {
             // FIXME Lukas H.: Also process parabolic segments.
-            if (edge->is_finite() && edge->is_linear())
+            if (edge->is_finite() && edge->is_linear() && edge->vertex0() != nullptr && edge->vertex1() != nullptr &&
+                Arachne::VoronoiUtils::is_finite(*edge->vertex0()) && Arachne::VoronoiUtils::is_finite(*edge->vertex1()))
                 edges.emplace_back(edge);
 
             edge = edge->rot_next();