/// <summary> /// Triangulate simple polygon with holes /// </summary> public static void Triangulate(DTSweepContext tcx) { tcx.CreateAdvancingFront(); Sweep(tcx); // Finalize triangulation if (tcx.TriangulationMode == TriangulationMode.Polygon) { FinalizationPolygon(tcx); } else { FinalizationConvexHull(tcx); } tcx.Done(); }
public int[] Triangulate(UnityEngine.Vector2[] verts) { PolygonPoint[] points = new PolygonPoint[verts.Length]; for (int i = 0; i < verts.Length; i++) points[i] = new PolygonPoint(verts[i].x, verts[i].y); Polygon polygon = new Polygon(points); DTSweepContext tcx = new DTSweepContext(); tcx.PrepareTriangulation(polygon); DTSweep.Triangulate(tcx); int[] resultPoints = new int[polygon.Triangles.Count * 3]; int idx = 0; foreach (DelaunayTriangle triangle in polygon.Triangles) { resultPoints[idx++] = FindIndex(points, triangle.Points._0); resultPoints[idx++] = FindIndex(points, triangle.Points._1); resultPoints[idx++] = FindIndex(points, triangle.Points._2); } return resultPoints; }
/// <summary> /// Start sweeping the Y-sorted point set from bottom to top /// </summary> private static void Sweep(DTSweepContext tcx) { List<TriangulationPoint> points = tcx.Points; TriangulationPoint point; AdvancingFrontNode node; for (int i = 1; i < points.Count; i++) { point = points[i]; node = PointEvent(tcx, point); if (point.HasEdges) { foreach (DTSweepConstraint e in point.Edges) { EdgeEvent(tcx, e, node); } } tcx.Update(null); } }
/// <summary> /// Returns true if triangle was legalized /// </summary> private static bool Legalize(DTSweepContext tcx, DelaunayTriangle t) { int oi; bool inside; TriangulationPoint p, op; DelaunayTriangle ot; // To legalize a triangle we start by finding if any of the three edges // violate the Delaunay condition for (int i = 0; i < 3; i++) { // TODO: fix so that cEdge is always valid when creating new triangles then we can check it here // instead of below with ot if (t.EdgeIsDelaunay[i]) { continue; } ot = t.Neighbors[i]; if (ot != null) { p = t.Points[i]; op = ot.OppositePoint(t, p); oi = ot.IndexOf(op); // If this is a Constrained Edge or a Delaunay Edge(only during recursive legalization) // then we should not try to legalize if (ot.EdgeIsConstrained[oi] || ot.EdgeIsDelaunay[oi]) { t.EdgeIsConstrained[i] = ot.EdgeIsConstrained[oi]; // XXX: have no good way of setting this property when creating new triangles so lets set it here continue; } inside = TriangulationUtil.SmartIncircle(p, t.PointCCW(p), t.PointCW(p), op); if (inside) { bool notLegalized; // Lets mark this shared edge as Delaunay t.EdgeIsDelaunay[i] = true; ot.EdgeIsDelaunay[oi] = true; // Lets rotate shared edge one vertex CW to legalize it RotateTrianglePair(t, p, ot, op); // We now got one valid Delaunay Edge shared by two triangles // This gives us 4 new edges to check for Delaunay // Make sure that triangle to node mapping is done only one time for a specific triangle notLegalized = !Legalize(tcx, t); if (notLegalized) { tcx.MapTriangleToNodes(t); } notLegalized = !Legalize(tcx, ot); if (notLegalized) { tcx.MapTriangleToNodes(ot); } // Reset the Delaunay edges, since they only are valid Delaunay edges // until we add a new triangle or point. // XXX: need to think about this. Can these edges be tried after we // return to previous recursive level? t.EdgeIsDelaunay[i] = false; ot.EdgeIsDelaunay[oi] = false; // If triangle have been legalized no need to check the other edges since // the recursive legalization will handles those so we can end here. return true; } } } return false; }
private static bool IsShallow(DTSweepContext tcx, AdvancingFrontNode node) { double height; if (tcx.Basin.leftHighest) { height = tcx.Basin.leftNode.Point.Y - node.Point.Y; } else { height = tcx.Basin.rightNode.Point.Y - node.Point.Y; } if (tcx.Basin.width > height) { return true; } return false; }
/// <summary> /// Fills holes in the Advancing Front /// </summary> private static void FillAdvancingFront(DTSweepContext tcx, AdvancingFrontNode n) { AdvancingFrontNode node; double angle; // Fill right holes node = n.Next; while (node.HasNext) { angle = HoleAngle(node); if (angle > PI_div2 || angle < -PI_div2) { break; } Fill(tcx, node); node = node.Next; } // Fill left holes node = n.Prev; while (node.HasPrev) { angle = HoleAngle(node); if (angle > PI_div2 || angle < -PI_div2) { break; } Fill(tcx, node); node = node.Prev; } // Fill right basins if (n.HasNext && n.Next.HasNext) { angle = BasinAngle(n); if (angle < PI_3div4) { FillBasin(tcx, n); } } }
/// <summary> /// After a flip we have two triangles and know that only one will still be /// intersecting the edge. So decide which to contiune with and legalize the other /// </summary> /// <param name="tcx"></param> /// <param name="o">should be the result of an TriangulationUtil.orient2d( eq, op, ep )</param> /// <param name="t">triangle 1</param> /// <param name="ot">triangle 2</param> /// <param name="p">a point shared by both triangles</param> /// <param name="op">another point shared by both triangles</param> /// <returns>returns the triangle still intersecting the edge</returns> private static DelaunayTriangle NextFlipTriangle(DTSweepContext tcx, Orientation o, DelaunayTriangle t, DelaunayTriangle ot, TriangulationPoint p, TriangulationPoint op) { int edgeIndex; if (o == Orientation.CCW) { // ot is not crossing edge after flip edgeIndex = ot.EdgeIndex(p, op); ot.EdgeIsDelaunay[edgeIndex] = true; Legalize(tcx, ot); ot.EdgeIsDelaunay.Clear(); return t; } // t is not crossing edge after flip edgeIndex = t.EdgeIndex(p, op); t.EdgeIsDelaunay[edgeIndex] = true; Legalize(tcx, t); t.EdgeIsDelaunay.Clear(); return ot; }
private static void FlipEdgeEvent(DTSweepContext tcx, TriangulationPoint ep, TriangulationPoint eq, DelaunayTriangle t, TriangulationPoint p) { TriangulationPoint op, newP; DelaunayTriangle ot; bool inScanArea; ot = t.NeighborAcross(p); op = ot.OppositePoint(t, p); if (ot == null) { // If we want to integrate the fillEdgeEvent do it here // With current implementation we should never get here throw new InvalidOperationException("[BUG:FIXME] FLIP failed due to missing triangle"); } inScanArea = TriangulationUtil.InScanArea(p, t.PointCCW(p), t.PointCW(p), op); if (inScanArea) { // Lets rotate shared edge one vertex CW RotateTrianglePair(t, p, ot, op); tcx.MapTriangleToNodes(t); tcx.MapTriangleToNodes(ot); if (p == eq && op == ep) { if (eq == tcx.EdgeEvent.ConstrainedEdge.Q && ep == tcx.EdgeEvent.ConstrainedEdge.P) { if (tcx.IsDebugEnabled) Console.WriteLine("[FLIP] - constrained edge done"); // TODO: remove t.MarkConstrainedEdge(ep, eq); ot.MarkConstrainedEdge(ep, eq); Legalize(tcx, t); Legalize(tcx, ot); } else { if (tcx.IsDebugEnabled) Console.WriteLine("[FLIP] - subedge done"); // TODO: remove // XXX: I think one of the triangles should be legalized here? } } else { if (tcx.IsDebugEnabled) Console.WriteLine("[FLIP] - flipping and continuing with triangle still crossing edge"); // TODO: remove Orientation o = TriangulationUtil.Orient2d(eq, op, ep); t = NextFlipTriangle(tcx, o, t, ot, p, op); FlipEdgeEvent(tcx, ep, eq, t, p); } } else { newP = NextFlipPoint(ep, eq, ot, op); FlipScanEdgeEvent(tcx, ep, eq, t, ot, newP); EdgeEvent(tcx, ep, eq, t, p); } }
private static void FillLeftAboveEdgeEvent(DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node) { while (node.Prev.Point.X > edge.P.X) { // Check if next node is below the edge Orientation o1 = TriangulationUtil.Orient2d(edge.Q, node.Prev.Point, edge.P); if (o1 == Orientation.CW) { FillLeftBelowEdgeEvent(tcx, edge, node); } else { node = node.Prev; } } }
/// <summary> /// If this is a Delaunay Triangulation of a pointset we need to fill so the triangle mesh gets a ConvexHull /// </summary> private static void FinalizationConvexHull(DTSweepContext tcx) { AdvancingFrontNode n1, n2; DelaunayTriangle t1, t2; TriangulationPoint first, p1; n1 = tcx.aFront.Head.Next; n2 = n1.Next; first = n1.Point; TurnAdvancingFrontConvex(tcx, n1, n2); // TODO: implement ConvexHull for lower right and left boundary // Lets remove triangles connected to the two "algorithm" points // XXX: When the first the nodes are points in a triangle we need to do a flip before // removing triangles or we will lose a valid triangle. // Same for last three nodes! // !!! If I implement ConvexHull for lower right and left boundary this fix should not be // needed and the removed triangles will be added again by default n1 = tcx.aFront.Tail.Prev; if (n1.Triangle.Contains(n1.Next.Point) && n1.Triangle.Contains(n1.Prev.Point)) { t1 = n1.Triangle.NeighborAcross(n1.Point); RotateTrianglePair(n1.Triangle, n1.Point, t1, t1.OppositePoint(n1.Triangle, n1.Point)); tcx.MapTriangleToNodes(n1.Triangle); tcx.MapTriangleToNodes(t1); } n1 = tcx.aFront.Head.Next; if (n1.Triangle.Contains(n1.Prev.Point) && n1.Triangle.Contains(n1.Next.Point)) { t1 = n1.Triangle.NeighborAcross(n1.Point); RotateTrianglePair(n1.Triangle, n1.Point, t1, t1.OppositePoint(n1.Triangle, n1.Point)); tcx.MapTriangleToNodes(n1.Triangle); tcx.MapTriangleToNodes(t1); } // Lower right boundary first = tcx.aFront.Head.Point; n2 = tcx.aFront.Tail.Prev; t1 = n2.Triangle; p1 = n2.Point; n2.Triangle = null; do { tcx.RemoveFromList(t1); p1 = t1.PointCCW(p1); if (p1 == first) break; t2 = t1.NeighborCCW(p1); t1.Clear(); t1 = t2; } while (true); // Lower left boundary first = tcx.aFront.Head.Next.Point; p1 = t1.PointCW(tcx.aFront.Head.Point); t2 = t1.NeighborCW(tcx.aFront.Head.Point); t1.Clear(); t1 = t2; while (p1 != first) //TODO: Port note. This was do while before. { tcx.RemoveFromList(t1); p1 = t1.PointCCW(p1); t2 = t1.NeighborCCW(p1); t1.Clear(); t1 = t2; } // Remove current head and tail node now that we have removed all triangles attached // to them. Then set new head and tail node points tcx.aFront.Head = tcx.aFront.Head.Next; tcx.aFront.Head.Prev = null; tcx.aFront.Tail = tcx.aFront.Tail.Prev; tcx.aFront.Tail.Next = null; tcx.FinalizeTriangulation(); }
private static void FillRightBelowEdgeEvent(DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node) { if (node.Point.x < edge.P.x) // needed? { if (TriangulationUtil.Orient2d(node.Point, node.Next.Point, node.Next.Next.Point) == Orientation.CCW) { // Concave FillRightConcaveEdgeEvent(tcx, edge, node); } else { // Convex FillRightConvexEdgeEvent(tcx, edge, node); // Retry this one FillRightBelowEdgeEvent(tcx, edge, node); } } }
public void CreateMesh(Vector2[] vertsToCopy, Transform transform) { List<Vector3> resultsLocal = new List<Vector3>(); List<int> resultsTriIndexesLocal = new List<int>(); List<int> resultsTriIndexesReversedLocal = new List<int>(); List<Vector2> uvsLocal = new List<Vector2>(); List<Vector3> normalsLocal = new List<Vector3>(); Sprite spr = transform.GetComponent<SpriteRenderer>().sprite; Rect rec = spr.rect; Vector3 bound = transform.GetComponent<Renderer>().bounds.max- transform.GetComponent<Renderer>().bounds.min ; TextureImporter textureImporter = AssetImporter.GetAtPath(AssetDatabase.GetAssetPath(spr)) as TextureImporter; int i = 0; Polygon poly = new Polygon(); for (i=0; i <vertsToCopy.Length;i++) { poly.Points.Add(new TriangulationPoint(vertsToCopy[i].x, vertsToCopy[i].y)); } DTSweepContext tcx = new DTSweepContext(); tcx.PrepareTriangulation(poly); DTSweep.Triangulate(tcx); int indexNumber = 0; bool multiSprites = false; foreach (DelaunayTriangle triangle in poly.Triangles) { Vector3 v = new Vector3(); foreach (TriangulationPoint p in triangle.Points) { v = new Vector3((float)p.X, (float)p.Y,0); if(!resultsLocal.Contains(v)) { resultsLocal.Add(v); resultsTriIndexesLocal.Add(indexNumber); Vector2 newUv = new Vector2((v.x /bound.x) + 0.5f, (v.y /bound.y) + 0.5f); newUv.x *= rec.width/ spr.texture.width; newUv.y *= rec.height/ spr.texture.height; //Debug.Log(spr.textureRectOffset); newUv.x += (rec.x)/ spr.texture.width; newUv.y += (rec.y) / spr.texture.height; //Debug.Log(Application.unityVersion); SpriteMetaData[] smdArray = textureImporter.spritesheet; Vector2 pivot = new Vector2(.0f,.0f);; for (int j = 0; j < smdArray.Length; j++) { if (smdArray[j].name == spr.name) { switch(smdArray[j].alignment) { case(0): smdArray[j].pivot = Vector2.zero; break; case(1): smdArray[j].pivot = new Vector2(0f,1f) -new Vector2(.5f,.5f); break; case(2): smdArray[j].pivot = new Vector2(0.5f,1f) -new Vector2(.5f,.5f); break; case(3): smdArray[j].pivot = new Vector2(1f,1f) -new Vector2(.5f,.5f); break; case(4): smdArray[j].pivot = new Vector2(0f,.5f) -new Vector2(.5f,.5f); break; case(5): smdArray[j].pivot = new Vector2(1f,.5f) -new Vector2(.5f,.5f); break; case(6): smdArray[j].pivot = new Vector2(0f,0f) -new Vector2(.5f,.5f); break; case(7): smdArray[j].pivot = new Vector2(0.5f,0f) -new Vector2(.5f,.5f); break; case(8): smdArray[j].pivot = new Vector2(1f,0f) -new Vector2(.5f,.5f); break; case(9): smdArray[j].pivot -= new Vector2(.5f,.5f); break; } pivot = smdArray[j].pivot ; } } if(textureImporter.spriteImportMode == SpriteImportMode.Single) pivot = textureImporter.spritePivot-new Vector2(.5f,.5f); newUv.x += ((pivot.x)*rec.width)/ spr.texture.width; newUv.y += ((pivot.y)*rec.height)/ spr.texture.height; /* if(Application.unityVersion != "4.3.0f4") { Debug.Log(spr.textureRectOffset.x); newUv.x += (spr.textureRectOffset.x)/ spr.texture.width; newUv.y += (spr.textureRectOffset.y)/ spr.texture.height; } */ uvsLocal.Add(newUv); normalsLocal.Add(new Vector3(0,0,-1)); indexNumber++; } else { resultsTriIndexesLocal.Add(resultsLocal.LastIndexOf(v)); } } } if(!multiSprites) Debug.Log("Tip: Sprite Pivot should be set to Center, with no custom pivot before conversion"); for (int j = resultsTriIndexesLocal.Count-1; j >=0; j--) { resultsTriIndexesReversedLocal.Add(resultsTriIndexesLocal[j]); } results.AddRange(resultsLocal); resultsTriIndexes.AddRange(resultsTriIndexesLocal); resultsTriIndexesReversed.AddRange(resultsTriIndexesReversedLocal); uvs.AddRange(uvsLocal); normals.AddRange(normalsLocal); resultsLocal.Clear(); resultsTriIndexesLocal.Clear(); resultsTriIndexesReversedLocal.Clear(); uvsLocal.Clear(); normalsLocal.Clear(); finalVertices = results.ToArray(); finalNormals = normals.ToArray(); finalUvs= uvs.ToArray(); finalTriangles = resultsTriIndexesReversed.ToArray(); //results.Clear(); //resultsTriIndexesReversed.Clear(); }
//public bool ReverseNormals; public GameObject Run(Transform transform,bool ReverseNormals ) { PolygonCollider2D polygonCollider = transform.GetComponent<PolygonCollider2D>(); Sprite spr = transform.GetComponent<SpriteRenderer>().sprite; Rect rec = spr.rect; //for(int path =0;path<polygonCollider.pathCount;path++) //{ int path =0; bool overwrite = false; MeshedSprite = new GameObject(); Undo.RegisterCreatedObjectUndo (MeshedSprite, "Created Mesh"); mf = MeshedSprite.AddComponent<MeshFilter>(); mr = MeshedSprite.AddComponent<MeshRenderer>(); mesh = new Mesh(); if(AssetDatabase.LoadAssetAtPath("Assets/Puppet2D/Models/"+transform.name+"_MESH.asset",typeof(Mesh))) { if(EditorUtility.DisplayDialog("Overwrite Asset?","Do you want to overwrite the current Mesh & Material?","Yes, Overwrite","No, Create New Mesh & Material")) { mesh = AssetDatabase.LoadAssetAtPath("Assets/Puppet2D/Models/"+transform.name+"_MESH.asset",typeof(Mesh))as Mesh; overwrite = true; } else { string meshPath = AssetDatabase.GenerateUniqueAssetPath("Assets/Puppet2D/Models/"+transform.name+"_MESH.asset"); AssetDatabase.CreateAsset(mesh,meshPath); } } else { string meshPath = AssetDatabase.GenerateUniqueAssetPath("Assets/Puppet2D/Models/"+transform.name+"_MESH.asset"); AssetDatabase.CreateAsset(mesh,meshPath); } Vector3 bound = transform.renderer.bounds.max- transform.renderer.bounds.min ; List<Vector3> results = new List<Vector3>(); List<int> resultsTriIndexes = new List<int>(); List<int> resultsTriIndexesReversed = new List<int>(); List<Vector2> uvs = new List<Vector2>(); List<Vector3> normals = new List<Vector3>(); Vector2[] vertsToCopy = polygonCollider.GetPath(path); int i = 0; Polygon poly = new Polygon(); for (i=0; i <vertsToCopy.Length;i++) { poly.Points.Add(new TriangulationPoint(vertsToCopy[i].x, vertsToCopy[i].y)); } DTSweepContext tcx = new DTSweepContext(); tcx.PrepareTriangulation(poly); DTSweep.Triangulate(tcx); int indexNumber = 0; foreach (DelaunayTriangle triangle in poly.Triangles) { Vector3 v = new Vector3(); foreach (TriangulationPoint p in triangle.Points) { v = new Vector3((float)p.X, (float)p.Y,0); if(!results.Contains(v)) { results.Add(v); resultsTriIndexes.Add(indexNumber); Vector2 newUv = new Vector2((v.x /bound.x) + 0.5f, (v.y /bound.y) + 0.5f); newUv.x *= rec.width/ spr.texture.width; newUv.y *= rec.height/ spr.texture.height; //Debug.Log(spr.textureRectOffset); newUv.x += (rec.x)/ spr.texture.width; newUv.y += (rec.y) / spr.texture.height; uvs.Add(newUv); normals.Add(new Vector3(0,0,-1)); indexNumber++; } else { resultsTriIndexes.Add(results.LastIndexOf(v)); } } } for (int j = resultsTriIndexes.Count-1; j >=0; j--) { resultsTriIndexesReversed.Add(resultsTriIndexes[j]); } mf.mesh = mesh; mesh.vertices = results.ToArray(); mesh.uv = uvs.ToArray(); mesh.normals = normals.ToArray(); mesh.triangles = resultsTriIndexesReversed.ToArray(); mesh.RecalculateBounds(); results.Clear(); resultsTriIndexesReversed.Clear(); //} if(overwrite) { mr.material = AssetDatabase.LoadAssetAtPath("Assets/Puppet2D/Models/Materials/"+transform.name+"_MAT.mat",typeof(Material)) as Material; } else { Material newMat = new Material(Shader.Find("Unlit/Transparent")); string materialPath = AssetDatabase.GenerateUniqueAssetPath("Assets/Puppet2D/Models/Materials/"+transform.name+"_MAT.mat"); AssetDatabase.CreateAsset(newMat, materialPath); mr.material = newMat; } return MeshedSprite; }
private static void FlipEdgeEvent(DTSweepContext tcx, TriangulationPoint ep, TriangulationPoint eq, DelaunayTriangle t, TriangulationPoint p) { DelaunayTriangle ot = t.NeighborAcrossFrom(p); TriangulationPoint op = ot.OppositePoint(t, p); if (ot == null) { // If we want to integrate the fillEdgeEvent do it here // With current implementation we should never get here throw new InvalidOperationException("[BUG:FIXME] FLIP failed due to missing triangle"); } if (tcx.IsDebugEnabled) { tcx.DebugContext.PrimaryTriangle = t; tcx.DebugContext.SecondaryTriangle = ot; } // TODO: remove bool inScanArea = TriangulationUtil.InScanArea(p, t.PointCCWFrom(p), t.PointCWFrom(p), op); if (inScanArea) { // Lets rotate shared edge one vertex CW RotateTrianglePair(t, p, ot, op); tcx.MapTriangleToNodes(t); tcx.MapTriangleToNodes(ot); if (p.Equals(eq) && op.Equals(ep)) { if (eq.Equals(tcx.EdgeEvent.ConstrainedEdge.Q) && ep.Equals(tcx.EdgeEvent.ConstrainedEdge.P)) { if (tcx.IsDebugEnabled) { Console.WriteLine("[FLIP] - constrained edge done"); // TODO: remove } t.MarkConstrainedEdge(ep, eq); ot.MarkConstrainedEdge(ep, eq); Legalize(tcx, t); Legalize(tcx, ot); } else { if (tcx.IsDebugEnabled) { Console.WriteLine("[FLIP] - subedge done"); // TODO: remove } // XXX: I think one of the triangles should be legalized here? } } else { if (tcx.IsDebugEnabled) { Console.WriteLine("[FLIP] - flipping and continuing with triangle still crossing edge"); // TODO: remove } Orientation o = TriangulationUtil.Orient2d(eq, op, ep); t = NextFlipTriangle(tcx, o, t, ot, p, op); FlipEdgeEvent(tcx, ep, eq, t, p); } } else { TriangulationPoint newP; if (NextFlipPoint(ep, eq, ot, op, out newP)) { FlipScanEdgeEvent(tcx, ep, eq, t, ot, newP); EdgeEvent(tcx, ep, eq, t, p); } } }
private static void EdgeEvent(DTSweepContext tcx, TriangulationPoint ep, TriangulationPoint eq, DelaunayTriangle triangle, TriangulationPoint point) { if (tcx.IsDebugEnabled) { tcx.DebugContext.PrimaryTriangle = triangle; } if (IsEdgeSideOfTriangle(triangle, ep, eq)) { return; } TriangulationPoint p1 = triangle.PointCCWFrom(point); Orientation o1 = TriangulationUtil.Orient2d(eq, p1, ep); if (o1 == Orientation.Collinear) { if (triangle.Contains(eq) && triangle.Contains(p1)) { triangle.MarkConstrainedEdge(eq, p1); // We are modifying the constraint maybe it would be better to // not change the given constraint and just keep a variable for the new constraint tcx.EdgeEvent.ConstrainedEdge.Q = p1; triangle = triangle.NeighborAcrossFrom(point); EdgeEvent(tcx, ep, p1, triangle, p1); } else { throw new PointOnEdgeException("EdgeEvent - Point on constrained edge not supported yet", ep, eq, p1); } if (tcx.IsDebugEnabled) { Console.WriteLine("EdgeEvent - Point on constrained edge"); } return; } TriangulationPoint p2 = triangle.PointCWFrom(point); Orientation o2 = TriangulationUtil.Orient2d(eq, p2, ep); if (o2 == Orientation.Collinear) { if (triangle.Contains(eq) && triangle.Contains(p2)) { triangle.MarkConstrainedEdge(eq, p2); // We are modifying the constraint maybe it would be better to // not change the given constraint and just keep a variable for the new constraint tcx.EdgeEvent.ConstrainedEdge.Q = p2; triangle = triangle.NeighborAcrossFrom(point); EdgeEvent(tcx, ep, p2, triangle, p2); } else { throw new PointOnEdgeException("EdgeEvent - Point on constrained edge not supported yet", ep, eq, p2); } if (tcx.IsDebugEnabled) { Console.WriteLine("EdgeEvent - Point on constrained edge"); } return; } if (o1 == o2) { // Need to decide if we are rotating CW or CCW to get to a triangle // that will cross edge triangle = o1 == Orientation.Clockwise ? triangle.NeighborCCWFrom(point) : triangle.NeighborCWFrom(point); EdgeEvent(tcx, ep, eq, triangle, point); } else { // This triangle crosses constraint so lets flippin start! FlipEdgeEvent(tcx, ep, eq, triangle, point); } }
/// <summary> /// If this is a Delaunay Triangulation of a pointset we need to fill so the triangle mesh gets a ConvexHull /// </summary> private static void FinalizationConvexHull(DTSweepContext tcx) { DelaunayTriangle t1, t2; AdvancingFrontNode n1 = tcx.Front.Head.Next; AdvancingFrontNode n2 = n1.Next; TurnAdvancingFrontConvex(tcx, n1, n2); // Lets remove triangles connected to the two "algorithm" points // XXX: When the first three nodes are points in a triangle we need to do a flip before // removing triangles or we will lose a valid triangle. // Same for last three nodes! // !!! If I implement ConvexHull for lower right and left boundary this fix should not be // needed and the removed triangles will be added again by default n1 = tcx.Front.Tail.Prev; if (n1.Triangle.Contains(n1.Next.Point) && n1.Triangle.Contains(n1.Prev.Point)) { t1 = n1.Triangle.NeighborAcrossFrom(n1.Point); RotateTrianglePair(n1.Triangle, n1.Point, t1, t1.OppositePoint(n1.Triangle, n1.Point)); tcx.MapTriangleToNodes(n1.Triangle); tcx.MapTriangleToNodes(t1); } n1 = tcx.Front.Head.Next; if (n1.Triangle.Contains(n1.Prev.Point) && n1.Triangle.Contains(n1.Next.Point)) { t1 = n1.Triangle.NeighborAcrossFrom(n1.Point); RotateTrianglePair(n1.Triangle, n1.Point, t1, t1.OppositePoint(n1.Triangle, n1.Point)); tcx.MapTriangleToNodes(n1.Triangle); tcx.MapTriangleToNodes(t1); } // Lower right boundary TriangulationPoint first = tcx.Front.Head.Point; n2 = tcx.Front.Tail.Prev; t1 = n2.Triangle; TriangulationPoint p1 = n2.Point; n2.Triangle = null; do { tcx.RemoveFromList(t1); p1 = t1.PointCCWFrom(p1); if (p1.Equals(first)) { break; } t2 = t1.NeighborCCWFrom(p1); t1.Clear(); t1 = t2; } while (true); // Lower left boundary first = tcx.Front.Head.Next.Point; p1 = t1.PointCWFrom(tcx.Front.Head.Point); t2 = t1.NeighborCWFrom(tcx.Front.Head.Point); t1.Clear(); t1 = t2; while (p1.Equals(first)) { tcx.RemoveFromList(t1); p1 = t1.PointCCWFrom(p1); t2 = t1.NeighborCCWFrom(p1); t1.Clear(); t1 = t2; } // Remove current head and tail node now that we have removed all triangles attached // to them. Then set new head and tail node points tcx.Front.Head = tcx.Front.Head.Next; tcx.Front.Head.Prev = null; tcx.Front.Tail = tcx.Front.Tail.Prev; tcx.Front.Tail.Next = null; }
private static void FillLeftBelowEdgeEvent(DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node) { if (node.Point.X > edge.P.X) { if (TriangulationUtil.Orient2d(node.Point, node.Prev.Point, node.Prev.Prev.Point) == Orientation.CW) { // Concave FillLeftConcaveEdgeEvent(tcx, edge, node); } else { // Convex FillLeftConvexEdgeEvent(tcx, edge, node); // Retry this one FillLeftBelowEdgeEvent(tcx, edge, node); } } }
/// <summary> /// We will traverse the entire advancing front and fill it to form a convex hull. /// </summary> private static void TurnAdvancingFrontConvex(DTSweepContext tcx, AdvancingFrontNode b, AdvancingFrontNode c) { AdvancingFrontNode first = b; while (c != tcx.aFront.Tail) { if (TriangulationUtil.Orient2d(b.Point, c.Point, c.Next.Point) == Orientation.CCW) { // [b,c,d] Concave - fill around c Fill(tcx, c); c = c.Next; } else { // [b,c,d] Convex if (b != first && TriangulationUtil.Orient2d(b.Prev.Point, b.Point, c.Point) == Orientation.CCW) { // [a,b,c] Concave - fill around b Fill(tcx, b); b = b.Prev; } else { // [a,b,c] Convex - nothing to fill b = c; c = c.Next; } } } }
private static void EdgeEvent(DTSweepContext tcx, TriangulationPoint ep, TriangulationPoint eq, DelaunayTriangle triangle, TriangulationPoint point) { TriangulationPoint p1, p2; if (IsEdgeSideOfTriangle(triangle, ep, eq)) { return; } p1 = triangle.PointCCW(point); Orientation o1 = TriangulationUtil.Orient2d(eq, p1, ep); if (o1 == Orientation.Collinear) { if (triangle.Contains(eq, p1)) { triangle.MarkConstrainedEdge(eq, p1); // We are modifying the constraint maybe it would be better to // not change the given constraint and just keep a variable for the new constraint tcx.EdgeEvent.ConstrainedEdge.Q = p1; triangle = triangle.NeighborAcross(point); EdgeEvent(tcx, ep, p1, triangle, p1); } else { throw new PointOnEdgeException("EdgeEvent - Point on constrained edge not supported yet"); } if (tcx.IsDebugEnabled) { Debug.WriteLine("EdgeEvent - Point on constrained edge"); } return; } p2 = triangle.PointCW(point); Orientation o2 = TriangulationUtil.Orient2d(eq, p2, ep); if (o2 == Orientation.Collinear) { if (triangle.Contains(eq, p2)) { triangle.MarkConstrainedEdge(eq, p2); // We are modifying the constraint maybe it would be better to // not change the given constraint and just keep a variable for the new constraint tcx.EdgeEvent.ConstrainedEdge.Q = p2; triangle = triangle.NeighborAcross(point); EdgeEvent(tcx, ep, p2, triangle, p2); } else { throw new PointOnEdgeException("EdgeEvent - Point on constrained edge not supported yet"); } if (tcx.IsDebugEnabled) { Debug.WriteLine("EdgeEvent - Point on constrained edge"); } return; } if (o1 == o2) { // Need to decide if we are rotating CW or CCW to get to a triangle // that will cross edge if (o1 == Orientation.CW) { triangle = triangle.NeighborCCW(point); } else { triangle = triangle.NeighborCW(point); } EdgeEvent(tcx, ep, eq, triangle, point); } else { // This triangle crosses constraint so lets flippin start! FlipEdgeEvent(tcx, ep, eq, triangle, point); } }
private static void FinalizationPolygon(DTSweepContext tcx) { // Get an Internal triangle to start with DelaunayTriangle t = tcx.aFront.Head.Next.Triangle; TriangulationPoint p = tcx.aFront.Head.Next.Point; while (!t.GetConstrainedEdgeCW(p)) { t = t.NeighborCCW(p); } // Collect interior triangles constrained by edges tcx.MeshClean(t); }
/// <summary> /// Find closes node to the left of the new point and /// create a new triangle. If needed new holes and basins /// will be filled to. /// </summary> private static AdvancingFrontNode PointEvent(DTSweepContext tcx, TriangulationPoint point) { AdvancingFrontNode node, newNode; node = tcx.LocateNode(point); newNode = NewFrontTriangle(tcx, point, node); // Only need to check +epsilon since point never have smaller // x value than node due to how we fetch nodes from the front if (point.X <= node.Point.X + TriangulationUtil.EPSILON) { Fill(tcx, node); } tcx.AddNode(newNode); FillAdvancingFront(tcx, newNode); return newNode; }
/// <summary> /// Creates a new front triangle and legalize it /// </summary> private static AdvancingFrontNode NewFrontTriangle(DTSweepContext tcx, TriangulationPoint point, AdvancingFrontNode node) { AdvancingFrontNode newNode; DelaunayTriangle triangle; triangle = new DelaunayTriangle(point, node.Point, node.Next.Point); triangle.MarkNeighbor(node.Triangle); tcx.Triangles.Add(triangle); newNode = new AdvancingFrontNode(point); newNode.Next = node.Next; newNode.Prev = node; node.Next.Prev = newNode; node.Next = newNode; tcx.AddNode(newNode); // XXX: BST if (!Legalize(tcx, triangle)) { tcx.MapTriangleToNodes(triangle); } return newNode; }
/// <summary> /// Scan part of the FlipScan algorithm<br> /// When a triangle pair isn't flippable we will scan for the next /// point that is inside the flip triangle scan area. When found /// we generate a new flipEdgeEvent /// </summary> /// <param name="tcx"></param> /// <param name="ep">last point on the edge we are traversing</param> /// <param name="eq">first point on the edge we are traversing</param> /// <param name="flipTriangle">the current triangle sharing the point eq with edge</param> /// <param name="t"></param> /// <param name="p"></param> private static void FlipScanEdgeEvent(DTSweepContext tcx, TriangulationPoint ep, TriangulationPoint eq, DelaunayTriangle flipTriangle, DelaunayTriangle t, TriangulationPoint p) { DelaunayTriangle ot; TriangulationPoint op, newP; bool inScanArea; ot = t.NeighborAcross(p); op = ot.OppositePoint(t, p); if (ot == null) { // If we want to integrate the fillEdgeEvent do it here // With current implementation we should never get here throw new Exception("[BUG:FIXME] FLIP failed due to missing triangle"); } inScanArea = TriangulationUtil.InScanArea(eq, flipTriangle.PointCCW(eq), flipTriangle.PointCW(eq), op); if (inScanArea) { // flip with new edge op->eq FlipEdgeEvent(tcx, eq, op, ot, op); // TODO: Actually I just figured out that it should be possible to // improve this by getting the next ot and op before the the above // flip and continue the flipScanEdgeEvent here // set new ot and op here and loop back to inScanArea test // also need to set a new flipTriangle first // Turns out at first glance that this is somewhat complicated // so it will have to wait. } else { newP = NextFlipPoint(ep, eq, ot, op); FlipScanEdgeEvent(tcx, ep, eq, flipTriangle, ot, newP); } }
private static void EdgeEvent(DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node) { try { tcx.EdgeEvent.ConstrainedEdge = edge; tcx.EdgeEvent.Right = edge.P.X > edge.Q.X; if (IsEdgeSideOfTriangle(node.Triangle, edge.P, edge.Q)) { return; } // For now we will do all needed filling // TODO: integrate with flip process might give some better performance // but for now this avoid the issue with cases that needs both flips and fills FillEdgeEvent(tcx, edge, node); EdgeEvent(tcx, edge.P, edge.Q, node.Triangle, edge.Q); } catch (PointOnEdgeException e) { Debug.WriteLine(String.Format("Skipping Edge: {0}", e.Message)); } }
/// <summary> /// Fills a basin that has formed on the Advancing Front to the right /// of given node.<br> /// First we decide a left,bottom and right node that forms the /// boundaries of the basin. Then we do a reqursive fill. /// </summary> /// <param name="tcx"></param> /// <param name="node">starting node, this or next node will be left node</param> private static void FillBasin(DTSweepContext tcx, AdvancingFrontNode node) { if (TriangulationUtil.Orient2d(node.Point, node.Next.Point, node.Next.Next.Point) == Orientation.CCW) { // tcx.basin.leftNode = node.next.next; tcx.Basin.leftNode = node; } else { tcx.Basin.leftNode = node.Next; } // Find the bottom and right node tcx.Basin.bottomNode = tcx.Basin.leftNode; while (tcx.Basin.bottomNode.HasNext && tcx.Basin.bottomNode.Point.Y >= tcx.Basin.bottomNode.Next.Point.Y) { tcx.Basin.bottomNode = tcx.Basin.bottomNode.Next; } if (tcx.Basin.bottomNode == tcx.Basin.leftNode) { // No valid basins return; } tcx.Basin.rightNode = tcx.Basin.bottomNode; while (tcx.Basin.rightNode.HasNext && tcx.Basin.rightNode.Point.Y < tcx.Basin.rightNode.Next.Point.Y) { tcx.Basin.rightNode = tcx.Basin.rightNode.Next; } if (tcx.Basin.rightNode == tcx.Basin.bottomNode) { // No valid basins return; } tcx.Basin.width = tcx.Basin.rightNode.Point.X - tcx.Basin.leftNode.Point.X; tcx.Basin.leftHighest = tcx.Basin.leftNode.Point.Y > tcx.Basin.rightNode.Point.Y; FillBasinReq(tcx, tcx.Basin.bottomNode); }
private static void FillEdgeEvent(DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node) { if (tcx.EdgeEvent.Right) { FillRightAboveEdgeEvent(tcx, edge, node); } else { FillLeftAboveEdgeEvent(tcx, edge, node); } }
/// <summary> /// Recursive algorithm to fill a Basin with triangles /// </summary> private static void FillBasinReq(DTSweepContext tcx, AdvancingFrontNode node) { // if shallow stop filling if (IsShallow(tcx, node)) { return; } Fill(tcx, node); if (node.Prev == tcx.Basin.leftNode && node.Next == tcx.Basin.rightNode) { return; } else if (node.Prev == tcx.Basin.leftNode) { Orientation o = TriangulationUtil.Orient2d(node.Point, node.Next.Point, node.Next.Next.Point); if (o == Orientation.CW) { return; } node = node.Next; } else if (node.Next == tcx.Basin.rightNode) { Orientation o = TriangulationUtil.Orient2d(node.Point, node.Prev.Point, node.Prev.Prev.Point); if (o == Orientation.CCW) { return; } node = node.Prev; } else { // Continue with the neighbor node with lowest Y value if (node.Prev.Point.Y < node.Next.Point.Y) { node = node.Prev; } else { node = node.Next; } } FillBasinReq(tcx, node); }
private static void FillRightConvexEdgeEvent(DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node) { // Next concave or convex? if (TriangulationUtil.Orient2d(node.Next.Point, node.Next.Next.Point, node.Next.Next.Next.Point) == Orientation.CCW) { // Concave FillRightConcaveEdgeEvent(tcx, edge, node.Next); } else { // Convex // Next above or below edge? if (TriangulationUtil.Orient2d(edge.Q, node.Next.Next.Point, edge.P) == Orientation.CCW) { // Below FillRightConvexEdgeEvent(tcx, edge, node.Next); } else { // Above } } }
/// <summary> /// Adds a triangle to the advancing front to fill a hole. /// </summary> /// <param name="tcx"></param> /// <param name="node">middle node, that is the bottom of the hole</param> private static void Fill(DTSweepContext tcx, AdvancingFrontNode node) { DelaunayTriangle triangle = new DelaunayTriangle(node.Prev.Point, node.Point, node.Next.Point); // TODO: should copy the cEdge value from neighbor triangles // for now cEdge values are copied during the legalize triangle.MarkNeighbor(node.Prev.Triangle); triangle.MarkNeighbor(node.Triangle); tcx.Triangles.Add(triangle); // Update the advancing front node.Prev.Next = node.Next; node.Next.Prev = node.Prev; tcx.RemoveNode(node); // If it was legalized the triangle has already been mapped if (!Legalize(tcx, triangle)) { tcx.MapTriangleToNodes(triangle); } }
private static void FillLeftConcaveEdgeEvent(DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node) { Fill(tcx, node.Prev); if (node.Prev.Point != edge.P) { // Next above or below edge? if (TriangulationUtil.Orient2d(edge.Q, node.Prev.Point, edge.P) == Orientation.CW) { // Below if (TriangulationUtil.Orient2d(node.Point, node.Prev.Point, node.Prev.Prev.Point) == Orientation.CW) { // Next is concave FillLeftConcaveEdgeEvent(tcx, edge, node); } else { // Next is convex } } } }
public static List<Vertices> ConvexPartition(DetectedVertices vertices) { Polygon poly = new Polygon(); foreach (var vertex in vertices) poly.Points.Add(new TriangulationPoint(vertex.X, vertex.Y)); if (vertices.Holes != null) { foreach (var holeVertices in vertices.Holes) { Polygon hole = new Polygon(); foreach (var vertex in holeVertices) hole.Points.Add(new TriangulationPoint(vertex.X, vertex.Y)); poly.AddHole(hole); } } DTSweepContext tcx = new DTSweepContext(); tcx.PrepareTriangulation(poly); DTSweep.Triangulate(tcx); List<Vertices> results = new List<Vertices>(); foreach (DelaunayTriangle triangle in poly.Triangles) { Vertices v = new Vertices(); foreach (TriangulationPoint p in triangle.Points) { v.Add(new FVector2((float)p.X, (float)p.Y)); } results.Add(v); } return results; }
/// <summary> /// Returns true if triangle was legalized /// </summary> private static bool Legalize(DTSweepContext tcx, DelaunayTriangle t) { // To legalize a triangle we start by finding if any of the three edges // violate the Delaunay condition for (int i = 0; i < 3; i++) { // TODO: fix so that cEdge is always valid when creating new triangles then we can check it here // instead of below with ot if (t.EdgeIsDelaunay[i]) { continue; } DelaunayTriangle ot = t.Neighbors[i]; if (ot == null) { continue; } TriangulationPoint p = t.Points[i]; TriangulationPoint op = ot.OppositePoint(t, p); int oi = ot.IndexOf(op); // If this is a Constrained Edge or a Delaunay Edge(only during recursive legalization) // then we should not try to legalize if (ot.EdgeIsConstrained[oi] || ot.EdgeIsDelaunay[oi]) { t.SetConstrainedEdgeAcross(p, ot.EdgeIsConstrained[oi]); // XXX: have no good way of setting this property when creating new triangles so lets set it here continue; } if (!TriangulationUtil.SmartIncircle(p, t.PointCCWFrom(p), t.PointCWFrom(p), op)) { continue; } // Lets mark this shared edge as Delaunay t.EdgeIsDelaunay[i] = true; ot.EdgeIsDelaunay[oi] = true; // Lets rotate shared edge one vertex CW to legalize it RotateTrianglePair(t, p, ot, op); // We now got one valid Delaunay Edge shared by two triangles // This gives us 4 new edges to check for Delaunay // Make sure that triangle to node mapping is done only one time for a specific triangle if (!Legalize(tcx, t)) { tcx.MapTriangleToNodes(t); } if (!Legalize(tcx, ot)) { tcx.MapTriangleToNodes(ot); } // Reset the Delaunay edges, since they only are valid Delaunay edges // until we add a new triangle or point. // XXX: need to think about this. Can these edges be tried after we // return to previous recursive level? t.EdgeIsDelaunay[i] = false; ot.EdgeIsDelaunay[oi] = false; // If triangle have been legalized no need to check the other edges since // the recursive legalization will handles those so we can end here. return(true); } return(false); }
public static List<Vertices> ConvexPartition(Vertices vertices) { Polygon poly = new Polygon(); foreach (FVector2 vertex in vertices) { poly.Points.Add(new TriangulationPoint(vertex.X, vertex.Y)); } DTSweepContext tcx = new DTSweepContext(); tcx.PrepareTriangulation(poly); DTSweep.Triangulate(tcx); List<Vertices> results = new List<Vertices>(); foreach (DelaunayTriangle triangle in poly.Triangles) { Vertices v = new Vertices(); foreach (TriangulationPoint p in triangle.Points) { v.Add(new FVector2((float)p.X, (float)p.Y)); } results.Add(v); } return results; }