public static PathStorage PolygonToPathStorage(Polygons polygons)
		{
			PathStorage output = new PathStorage();

			foreach (Polygon polygon in polygons)
			{
				bool first = true;
				foreach (IntPoint point in polygon)
				{
					if (first)
					{
						output.Add(point.X, point.Y, ShapePath.FlagsAndCommand.CommandMoveTo);
						first = false;
					}
					else
					{
						output.Add(point.X, point.Y, ShapePath.FlagsAndCommand.CommandLineTo);
					}
				}

				output.ClosePolygon();
			}
			output.Add(0, 0, ShapePath.FlagsAndCommand.CommandStop);

			return output;
		}

		public static void AddAll(this Polygons polygons, Polygons other)
		{
			for (int n = 0; n < other.Count; n++)
			{
				polygons.Add(other[n]);
			}
		}

 private void LoadButton_Click(object sender, EventArgs e)
 {
     if (openFileDialog.ShowDialog() == DialogResult.OK)
     {
         pathText.Text = openFileDialog.FileName;
         _polygons = DataLoader.LoadPolygons(openFileDialog.OpenFile());
     }
 }

 public void AddPolygons(Polygons poly)
 {
     if (poly.Count == 0) return;
     PolyInfo pi = new PolyInfo();
     pi.polygons = poly;
     pi.si = style.Clone();
     PolyInfoList.Add(pi);
 }

		public AvoidCrossingPerimeters(Polygons bounderyPolygons)
		{
			this.bounderyPolygons = bounderyPolygons;
			minXPosition = new long[bounderyPolygons.Count];
			maxXPosition = new long[bounderyPolygons.Count];
			indexOfMinX = new int[bounderyPolygons.Count];
			indexOfMaxX = new int[bounderyPolygons.Count];
		}

		public void Calculate(Polygons polys)
		{
			min = new IntPoint(long.MaxValue, long.MaxValue);
			max = new IntPoint(long.MinValue, long.MinValue);
			for (int i = 0; i < polys.Count; i++)
			{
				for (int j = 0; j < polys[i].Count; j++)
				{
					if (min.X > polys[i][j].X) min.X = polys[i][j].X;
					if (min.Y > polys[i][j].Y) min.Y = polys[i][j].Y;
					if (max.X < polys[i][j].X) max.X = polys[i][j].X;
					if (max.Y < polys[i][j].Y) max.Y = polys[i][j].Y;
				}
			}
		}

		public static void GenerateLinePaths(Polygons polygonToInfill, ref Polygons infillLinesToPrint, int lineSpacing, int infillExtendIntoPerimeter_um, double rotation, long rotationOffset = 0)
		{
			if (polygonToInfill.Count > 0)
			{
				Polygons outlines = polygonToInfill.Offset(infillExtendIntoPerimeter_um);
				if (outlines.Count > 0)
				{
					PointMatrix matrix = new PointMatrix(-(rotation + 90)); // we are rotating the part so we rotate by the negative so the lines go the way we expect

					outlines.ApplyMatrix(matrix);

					Aabb boundary = new Aabb(outlines);

					boundary.min.X = ((boundary.min.X / lineSpacing) - 1) * lineSpacing - rotationOffset;
					int xLineCount = (int)((boundary.max.X - boundary.min.X + (lineSpacing - 1)) / lineSpacing);
					Polygons unclipedPatern = new Polygons();

					long firstX = boundary.min.X / lineSpacing * lineSpacing;
					for (int lineIndex = 0; lineIndex < xLineCount; lineIndex++)
					{
						Polygon line = new Polygon();
						line.Add(new IntPoint(firstX + lineIndex * lineSpacing, boundary.min.Y));
						line.Add(new IntPoint(firstX + lineIndex * lineSpacing, boundary.max.Y));
						unclipedPatern.Add(line);
					}

					PolyTree ret = new PolyTree();
					Clipper clipper = new Clipper();
					clipper.AddPaths(unclipedPatern, PolyType.ptSubject, false);
					clipper.AddPaths(outlines, PolyType.ptClip, true);
					clipper.Execute(ClipType.ctIntersection, ret, PolyFillType.pftPositive, PolyFillType.pftEvenOdd);

					Polygons newSegments = Clipper.OpenPathsFromPolyTree(ret);
					PointMatrix inversematrix = new PointMatrix((rotation + 90));
					newSegments.ApplyMatrix(inversematrix);

					infillLinesToPrint.AddRange(newSegments);
				}
			}
		}

		public static Polygons Offset(this Polygons polygons, long distance)
		{
			ClipperOffset offseter = new ClipperOffset();
			offseter.AddPaths(polygons, JoinType.jtMiter, EndType.etClosedPolygon);
			Paths solution = new Polygons();
			offseter.Execute(ref solution, distance);
			return solution;
		}

		public static Polygons DeepCopy(this Polygons polygons)
		{
			Polygons deepCopy = new Polygons();
			foreach (Polygon poly in polygons)
			{
				deepCopy.Add(new Polygon(poly));
			}

			return deepCopy;
		}

		public static Polygons CreateUnion(this Polygons polygons, Polygons other)
		{
			Clipper clipper = new Clipper();
			clipper.AddPaths(polygons, PolyType.ptSubject, true);
			clipper.AddPaths(other, PolyType.ptSubject, true);

			Polygons ret = new Polygons();
			clipper.Execute(ClipType.ctUnion, ret, PolyFillType.pftNonZero, PolyFillType.pftNonZero);
			return ret;
		}

		public static Polygons CreateLineIntersections(this Polygons polygons, Polygons other)
		{
			Clipper clipper = new Clipper();

			clipper.AddPaths(other, PolyType.ptSubject, false);
			clipper.AddPaths(polygons, PolyType.ptClip, true);

			PolyTree clippedLines = new PolyTree();

			clipper.Execute(ClipType.ctIntersection, clippedLines);

			return Clipper.OpenPathsFromPolyTree(clippedLines);
		}

		public static Polygons CreateIntersection(this Polygons polygons, Polygons other)
		{
			Polygons ret = new Polygons();
			Clipper clipper = new Clipper();
			clipper.AddPaths(polygons, PolyType.ptSubject, true);
			clipper.AddPaths(other, PolyType.ptClip, true);
			clipper.Execute(ClipType.ctIntersection, ret);
			return ret;
		}

        //------------------------------------------------------------------------------

        private void BuildResult(Polygons polyg)
        {
            polyg.Clear();
            polyg.Capacity = m_PolyOuts.Count;
            for (int i = 0; i < m_PolyOuts.Count; i++)
            {
                OutRec outRec = m_PolyOuts[i];
                if (outRec.pts == null) continue;
                OutPt p = outRec.pts;
                int cnt = PointCount(p);
                if (cnt < 3) continue;
                Polygon pg = new Polygon(cnt);
                for (int j = 0; j < cnt; j++)
                {
                    pg.Add(p.pt);
                    p = p.prev;
                }
                polyg.Add(pg);
            }
        }

		public static Polygons ProcessEvenOdd(this Polygons polygons)
		{
			Polygons ret = new Polygons();
			Clipper clipper = new Clipper();
			clipper.AddPaths(polygons, PolyType.ptSubject, true);
			clipper.Execute(ClipType.ctUnion, ret);
			return ret;
		}

		public static Mesh[] SplitIntoMeshesOnOrthographicZ(Mesh meshToSplit, Vector3 buildVolume, ReportProgressRatio reportProgress)
		{
			// check if the part is bigger than the build plate (if it is we need to use that as our size)
			AxisAlignedBoundingBox partBounds = meshToSplit.GetAxisAlignedBoundingBox();

			buildVolume.x = Math.Max(buildVolume.x, partBounds.XSize + 2);
			buildVolume.y = Math.Max(buildVolume.y, partBounds.YSize + 2);
			buildVolume.z = Math.Max(buildVolume.z, partBounds.ZSize + 2);

			// Find all the separate objects that are on the plate
			// Create a 2D image the size of the printer bed at some scale with the parts draw on it top down

			double scaleFactor = 5;
			ImageBuffer partPlate = new ImageBuffer((int)(buildVolume.x * scaleFactor), (int)(buildVolume.y * scaleFactor), 32, new BlenderBGRA());
			Vector2 renderOffset = new Vector2(buildVolume.x / 2, buildVolume.y / 2) - new Vector2(partBounds.Center.x, partBounds.Center.y);

			PolygonMesh.Rendering.OrthographicZProjection.DrawTo(partPlate.NewGraphics2D(), meshToSplit, renderOffset, scaleFactor, RGBA_Bytes.White);

			bool continueProcessin = true;
			if (reportProgress != null)
			{
				reportProgress(.2, "", out continueProcessin);
			}

			//ImageIO.SaveImageData("test part plate 0.png", partPlate);
			// expand the bounds a bit so that we can collect all the vertices and polygons within each bound
			Dilate.DoDilate3x3Binary(partPlate, 1);
			//ImageIO.SaveImageData("test part plate 1.png", partPlate);

			// trace all the bounds of the objects on the plate
			PolyTree polyTreeForPlate = FindDistictObjectBounds(partPlate);
			if (polyTreeForPlate == null)
			{
				Mesh[] singleMesh = new Mesh[1];
				singleMesh[0] = meshToSplit;
				return singleMesh;
			}

			// get all the discrete areas that are polygons so we can search them
			Polygons discreteAreas = new Polygons();
			GetAreasRecursive(polyTreeForPlate, discreteAreas);
			if (discreteAreas.Count == 0)
			{
				return null;
			}
			else if (discreteAreas.Count == 1)
			{
				Mesh[] singleMesh = new Mesh[1];
				singleMesh[0] = meshToSplit;
				return singleMesh;
			}

			Graphics2D graphics2D = partPlate.NewGraphics2D();
			graphics2D.Clear(RGBA_Bytes.Black);
			Random rand = new Random();
			foreach (Polygon polygon in discreteAreas)
			{
				graphics2D.Render(PlatingHelper.PolygonToPathStorage(polygon), new RGBA_Bytes(rand.Next(128, 255), rand.Next(128, 255), rand.Next(128, 255)));
			}
			if (reportProgress != null)
			{
				reportProgress(.5, "", out continueProcessin);
			}
			//ImageIO.SaveImageData("test part plate 2.png", partPlate);

			// add each of the separate bounds polygons to new meshes
			Mesh[] discreteMeshes = new Mesh[discreteAreas.Count];
			for (int i = 0; i < discreteAreas.Count; i++)
			{
				discreteMeshes[i] = new Mesh();
			}

			foreach (Face face in meshToSplit.Faces)
			{
				bool faceDone = false;
				// figure out which area one or more of the vertices are in add the face to the right new mesh
				foreach (FaceEdge faceEdge in face.FaceEdges())
				{
					Vector2 position = new Vector2(faceEdge.firstVertex.Position.x, faceEdge.firstVertex.Position.y);
					position += renderOffset;
					position *= scaleFactor;

					for (int areaIndex = discreteAreas.Count - 1; areaIndex >= 0; areaIndex--)
					{
						if (PointInPolygon(discreteAreas[areaIndex], new IntPoint((int)position.x, (int)position.y)))
						{
							List<Vertex> faceVertices = new List<Vertex>();
							foreach (FaceEdge faceEdgeToAdd in face.FaceEdges())
							{
								Vertex newVertex = discreteMeshes[areaIndex].CreateVertex(faceEdgeToAdd.firstVertex.Position);
								faceVertices.Add(newVertex);
							}

							discreteMeshes[areaIndex].CreateFace(faceVertices.ToArray());
							faceDone = true;
							break;
						}
					}

					if (faceDone)
//.........这里部分代码省略.........

		private static void ProcessPolyTreeNodeIntoSeparatIslands(this Polygons polygonsIn, PolyNode node, List<Polygons> ret)
		{
			for (int n = 0; n < node.ChildCount; n++)
			{
				PolyNode child = node.Childs[n];
				Polygons polygons = new Polygons();
				polygons.Add(child.Contour);
				for (int i = 0; i < child.ChildCount; i++)
				{
					polygons.Add(child.Childs[i].Contour);
					polygonsIn.ProcessPolyTreeNodeIntoSeparatIslands(child.Childs[i], ret);
				}
				ret.Add(polygons);
			}
		}

        //------------------------------------------------------------------------------

        public static void PolyTreeToPolygons(PolyTree polytree, Polygons polygons)
        {
            polygons.Clear();
            polygons.Capacity = polytree.Total;
            AddPolyNodeToPolygons(polytree, polygons);
        }

        //------------------------------------------------------------------------------

        public static Polygons SimplifyPolygons(Polygons polys,
            PolyFillType fillType = PolyFillType.pftEvenOdd)
        {
            Polygons result = new Polygons();
            Clipper c = new Clipper();
            c.AddPolygons(polys, PolyType.ptSubject);
            c.Execute(ClipType.ctUnion, result, fillType, fillType);
            return result;
        }

        //------------------------------------------------------------------------------

        public static Polygons OffsetPolygons(Polygons poly, double delta)
        {
            Polygons result = new Polygons(poly.Count);
            new PolyOffsetBuilder(poly, result, delta, JoinType.jtSquare, 2.0, true);
            return result;
        }

            public PolyOffsetBuilder(Polygons pts, Polygons solution, double delta, 
                JoinType jointype, double MiterLimit = 2, bool AutoFix = true)
            {
                //precondtion: solution != pts

                if (delta == 0)
                {
                    solution = pts;
                    return;
                }

                this.pts = pts;
                this.delta = delta;

                //AutoFix - fixes polygon orientation if necessary and removes 
                //duplicate vertices. Can be set false when you're sure that polygon
                //orientation is correct and that there are no duplicate vertices.
                if (AutoFix)
                {
                    int Len = pts.Count, botI = 0;
                    while (botI < Len && pts[botI].Count == 0) botI++;
                    if (botI == Len) return;

                    //botPt: used to find the lowermost (in inverted Y-axis) & leftmost point
                    //This point (on pts[botI]) must be on an outer polygon ring and if 
                    //its orientation is false (counterclockwise) then assume all polygons 
                    //need reversing ...
                    IntPoint botPt = pts[botI][0];
                    for (int i = botI; i < Len; ++i)
                    {
                        if (pts[i].Count == 0) continue;
                        if (UpdateBotPt(pts[i][0], ref botPt)) botI = i;
                        for (int j = pts[i].Count -1; j > 0; j--)
                        {
                            if (PointsEqual(pts[i][j], pts[i][j -1]))
                                pts[i].RemoveAt(j);
                            else if (UpdateBotPt(pts[i][j], ref botPt))
                                botI = i;
                        }
                    }
                    if (!Orientation(pts[botI]))
                        ReversePolygons(pts);
                }

                if (MiterLimit <= 1) MiterLimit = 1;
                double RMin = 2.0 / (MiterLimit*MiterLimit);

                normals = new List<DoublePoint>();

                double deltaSq = delta*delta;
                solution.Clear();
                solution.Capacity = pts.Count;
                for (m_i = 0; m_i < pts.Count; m_i++)
                {
                    int len = pts[m_i].Count;
                    if (len > 1 && pts[m_i][0].X == pts[m_i][len - 1].X &&
                        pts[m_i][0].Y == pts[m_i][len - 1].Y) len--;

                    if (len == 0 || (len < 3 && delta <= 0)) 
                        continue;
                    else if (len == 1)
                    {
                        Polygon arc;
                        arc = BuildArc(pts[m_i][len - 1], 0, 2 * Math.PI, delta);
                        solution.Add(arc);
                        continue;
                    }

                    //build normals ...
                    normals.Clear();
                    normals.Capacity = len;
                    for (int j = 0; j < len -1; ++j)
                        normals.Add(GetUnitNormal(pts[m_i][j], pts[m_i][j+1]));
                    normals.Add(GetUnitNormal(pts[m_i][len - 1], pts[m_i][0]));

                    currentPoly = new Polygon();
                    m_k = len - 1;
                    for (m_j = 0; m_j < len; ++m_j)
                    {
                        switch (jointype)
                        {
                            case JoinType.jtMiter:
                            {
                                m_R = 1 + (normals[m_j].X*normals[m_k].X + 
                                    normals[m_j].Y*normals[m_k].Y);
                                if (m_R >= RMin) DoMiter(); else DoSquare(MiterLimit);
                                break;
                            }
                            case JoinType.jtRound: 
                                DoRound();
                                break;
                            case JoinType.jtSquare:
                                DoSquare(1);
                                break;
                        }
                        m_k = m_j;
                    }
                    solution.Add(currentPoly);
                }

//.........这里部分代码省略.........