Use poly2tri for triangulation. This fixes some cases where polyPartition couldn't triangulate successfully. Reported as issue #9 in polyPartition repository. Tested with MotorHalter_0.stl cut at 1.2

xs/src/poly2tri/sweep/advancing_front.h

@@ -0,0 +1,118 @@
+/*
+ * Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
+ * http://code.google.com/p/poly2tri/
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * * Neither the name of Poly2Tri nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without specific
+ *   prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef ADVANCED_FRONT_H
+#define ADVANCED_FRONT_H
+
+#include "../common/shapes.h"
+
+namespace p2t {
+
+struct Node;
+
+// Advancing front node
+struct Node {
+  Point* point;
+  Triangle* triangle;
+
+  Node* next;
+  Node* prev;
+
+  double value;
+
+  Node(Point& p) : point(&p), triangle(NULL), next(NULL), prev(NULL), value(p.x)
+  {
+  }
+
+  Node(Point& p, Triangle& t) : point(&p), triangle(&t), next(NULL), prev(NULL), value(p.x)
+  {
+  }
+
+};
+
+// Advancing front
+class AdvancingFront {
+public:
+
+AdvancingFront(Node& head, Node& tail);
+// Destructor
+~AdvancingFront();
+
+Node* head();
+void set_head(Node* node);
+Node* tail();
+void set_tail(Node* node);
+Node* search();
+void set_search(Node* node);
+
+/// Locate insertion point along advancing front
+Node* LocateNode(double x);
+
+Node* LocatePoint(const Point* point);
+
+private:
+
+Node* head_, *tail_, *search_node_;
+
+Node* FindSearchNode(double x);
+};
+
+inline Node* AdvancingFront::head()
+{
+  return head_;
+}
+inline void AdvancingFront::set_head(Node* node)
+{
+  head_ = node;
+}
+
+inline Node* AdvancingFront::tail()
+{
+  return tail_;
+}
+inline void AdvancingFront::set_tail(Node* node)
+{
+  tail_ = node;
+}
+
+inline Node* AdvancingFront::search()
+{
+  return search_node_;
+}
+
+inline void AdvancingFront::set_search(Node* node)
+{
+  search_node_ = node;
+}
+
+}
+
+#endif