Fixed bug affecting open paths and REVERSE_ORIENTATION

Other minor tweaks

CPP/Clipper2Lib/clipper.engine.cpp

@@ -3163,76 +3163,64 @@ namespace Clipper2Lib {
 
 	bool BuildPath(OutPt& op, bool isOpen, Path64& path)
 	{
-		try
-		{
-			int cnt = PointCount(&op);
-			if (cnt < 2) return false;
-			path.resize(0);
-			path.reserve(cnt);
-			Point64 lastPt = op.pt;
-			path.push_back(lastPt);
-			{
+		int cnt = PointCount(&op);
+		if (cnt < 2) return false;
+		path.resize(0);
+		path.reserve(cnt);
 #ifdef REVERSE_ORIENTATION
-				OutPt* op2 = op.next;
+		op = op.next;
+		Point64 lastPt = op.pt;
+		path.push_back(lastPt);
+		OutPt* op2 = op.next;
 #else
-				OutPt* op2 = op.prev;
+		Point64 lastPt = op.pt;
+		path.push_back(lastPt);
+		OutPt* op2 = op.prev;
 #endif
-				while (op2 != &op)
-				{
-					if (op2->pt != lastPt)
-					{
-						lastPt = op2->pt;
-						path.push_back(lastPt);
-					}
+		while (op2 != &op)
+		{
+			if (op2->pt != lastPt)
+			{
+				lastPt = op2->pt;
+				path.push_back(lastPt);
+			}
 #ifdef REVERSE_ORIENTATION
-					op2 = op2->next;
+			op2 = op2->next;
 #else
-					op2 = op2->prev;
+			op2 = op2->prev;
 #endif
-				}
-			}
-		}
-		catch (...)
-		{
-			return false;
 		}
-
-		return true;
+	return true;
 	}
 	//------------------------------------------------------------------------------
 
-	bool ClipperBase::BuildPaths(Paths64& solutionClosed, Paths64* solutionOpen)
+	void ClipperBase::BuildPaths(Paths64& solutionClosed, Paths64* solutionOpen)
 	{
-		try
+		solutionClosed.resize(0);
+		//solutionClosed.reserve(outrec_list_.size());
+		if (solutionOpen)
+		{
+			solutionOpen->resize(0);
+			solutionOpen->reserve(outrec_list_.size());
+		}
+		for(OutRec* outrec : outrec_list_)
 		{
-			solutionClosed.resize(0);
-			//solutionClosed.reserve(outrec_list_.size());
-			if (solutionOpen)
+			if (outrec->pts == NULL) continue;
+			Path64 path;
+			if (solutionOpen && outrec->state == OutRecState::Open)
 			{
-				solutionOpen->resize(0);
-				solutionOpen->reserve(outrec_list_.size());
+				if (BuildPath(*outrec->pts, true, path))
+					solutionOpen->emplace_back(std::move(path));
+				path.resize(0);
 			}
-			for(OutRec* outrec : outrec_list_)
+			else
 			{
-				if (outrec->pts == NULL) continue;
-				Path64 path;
-				if (solutionOpen && outrec->state == OutRecState::Open)
-				{
-					if (BuildPath(*outrec->pts, true, path))
-						solutionOpen->emplace_back(std::move(path));
-					path.resize(0);
-				}
-				else
-				{
-					if (BuildPath(*outrec->pts, false, path))
-						solutionClosed.emplace_back(std::move(path));
-					path.resize(0);
-				}
-
+				if (BuildPath(*outrec->pts, false, path))
+					solutionClosed.emplace_back(std::move(path));
+				path.resize(0);
 			}
+
 		}
-		catch(...) { return false; }		
-		return true;
 	}
 	//------------------------------------------------------------------------------
 

CPP/Clipper2Lib/clipper.engine.h

@@ -211,6 +211,9 @@ namespace Clipper2Lib {
 		void DeleteJoin(Joiner* joiner);
 		void ProcessJoinerList();
 		OutRec* ProcessJoin(Joiner* joiner);
+		virtual bool ExecuteInternal(ClipType ct, FillRule ft);
+		void BuildPaths(Paths64& solutionClosed, Paths64* solutionOpen);
+		void BuildTree(PolyPath64& polytree, Paths64& open_paths);
 #ifdef USINGZ
 		ZFillCallback zfill_func_; //custom callback 
 		void SetZ(const Active& e1, const Active& e2, Point64& pt);
@@ -220,9 +223,6 @@ namespace Clipper2Lib {
 		void CleanUp();  //unlike Clear, CleanUp preserves added paths
 		void AddPath(const Path64& path, PathType polytype, bool is_open);
 		void AddPaths(const Paths64& paths, PathType polytype, bool is_open);
-		virtual bool ExecuteInternal(ClipType ct, FillRule ft);
-		bool BuildPaths(Paths64& solutionClosed, Paths64* solutionOpen);
-		void BuildTree(PolyPath64& polytree, Paths64& open_paths);
 
 		virtual bool Execute(ClipType clip_type,
 			FillRule fill_rule, Paths64& solution_closed);

CPP/Clipper2Lib/clipper.offset.cpp

@@ -347,6 +347,7 @@ void ClipperOffset::DoGroupOffset(PathGroup& group, double delta)
 	{
 		//clean up self-intersections ...
 		ClipperD c(0);
+		c.PreserveCollinear = false;
 		c.AddSubject(group.paths_out_);
 		if (group.is_reversed)
 			c.Execute(ClipType::Union, FillRule::Negative, group.paths_out_);
@@ -389,6 +390,7 @@ PathsD ClipperOffset::Execute(double delta)
 	{
 		//clean up self-intersections ...
 		ClipperD c(0);
+		c.PreserveCollinear = false;
 		c.AddSubject(result);
 		if (groups_[0].is_reversed)
 			c.Execute(ClipType::Union, FillRule::Negative, result);

CSharp/Clipper2Lib/Clipper.Engine.cs

@@ -3272,11 +3272,14 @@ internal bool BuildPath(OutPt op, bool isOpen, Path64 path)
         int cnt = PointCount(op);
         if (cnt < 2) return false;
         path.Clear();
+#if REVERSE_ORIENTATION
+        op = op.next;
         Point64 lastPt = op.pt;
         path.Add(lastPt);
-#if REVERSE_ORIENTATION
         op = op.next;
 #else
+        Point64 lastPt = op.pt;
+        path.Add(lastPt);
         op = op.prev;
 #endif
         for (int i = 1; i < cnt; i++)

CSharp/Clipper2Lib/Clipper.Offset.cs

@@ -141,6 +141,7 @@ public PathsD Execute(double delta)
       {
         //clean up self-intersections ...
         ClipperD c = new ClipperD(RoundingDecimalPrecision);
+        c.PreserveCollinear = false;
         c.AddSubject(solution);
         if (_pathGroups[0]._pathsReversed)
           c.Execute(ClipType.Union, FillRule.Negative, solution);
@@ -464,6 +465,7 @@ private void DoGroupOffset(PathGroup group, double delta)
       {
         //clean up self-intersections ...
         ClipperD c = new ClipperD(RoundingDecimalPrecision);
+        c.PreserveCollinear = false;
         c.AddSubject(group._outPaths);
         if (group._pathsReversed)
           c.Execute(ClipType.Union, FillRule.Negative, group._outPaths);

CSharp/Clipper2LibExample/Program.cs

@@ -1,14 +1,13 @@
 using System;
+using System.IO;
 using System.Collections.Generic;
 using Clipper2Lib;
 
 namespace Clipper2LibExample
 {
 
-  using Path64 = List<Point64>;
   using Paths64 = List<List<Point64>>;
   using PathD = List<PointD>;
-  using PathsD = List<List<PointD>>;
 
   internal class Program
   {
@@ -30,6 +29,14 @@ internal static PathD Ellipse(RectD rec)
       return result;
     }
 
+    internal static void OpenFile(string filename)
+    {
+      string path = Path.GetFullPath(filename);
+      System.Diagnostics.Process p = new System.Diagnostics.Process();
+      p.StartInfo = new System.Diagnostics.ProcessStartInfo(path) { UseShellExecute = true };
+      p.Start();
+    }
+
     internal static void MakeSvg(string caption, string filename,
       Paths64 subj, Paths64 openSubj, Paths64 clip,
       Paths64 solution, FillRule fill, bool hideSolutionCoords = false)
@@ -45,6 +52,8 @@ internal static void MakeSvg(string caption, string filename,
       if (solution != null)
         svg.AddPaths(solution, false, 0x4000FF00, 0x80000000, 1.2, !hideSolutionCoords);
       svg.SaveToFile(filename, 800, 600);
+
+      OpenFile(filename);
     }
 
     public static void Main()
@@ -97,10 +106,7 @@ public static void Main()
       MakeSvg("Sample 9 - inflate:10; end:joined", "../../../solution9.svg",
         null, subj, null, solution9, FillRule.EvenOdd);
 
-      //PathD pattern = ClipperFunc.MakePath(new double[] { -7,0, 0,-10, 7,0, 0,10 }); //diamond
-      //PathD pattern = ClipperFunc.MakePath(new double[] { -10,-5, 10,-5, 10,5, -10,5 }); //rectangle
       PathD pattern = Ellipse(new RectD(-10, -10, 10, 10)); //circle
-
       PathD path = ClipperFunc.MakePath(new double[] { 0, 0, 100, 200, 200, 0 });
       Paths64 solution10 = ClipperFunc.Paths64(Minkowski.Sum(pattern, path, true));
       MakeSvg("Sample 10 - Minkowski.Sum", "../../../solution10.svg",