/// <summary> /// Combine a list of triangles into a list of convex polygons. /// /// Note: This only works on triangles. /// </summary> ///<param name="triangles">The triangles.</param> ///<param name="maxPolys">The maximun number of polygons to return.</param> ///<param name="tolerance">The tolerance</param> public static List <Vertices> PolygonizeTriangles(List <Vertices> triangles, int maxPolys = int.MaxValue, float tolerance = 0.001f) { if (triangles.Count <= 0) { return(triangles); } List <Vertices> polys = new List <Vertices>(); bool[] covered = new bool[triangles.Count]; for (int i = 0; i < triangles.Count; ++i) { covered[i] = false; //Check here for degenerate triangles Vertices triangle = triangles[i]; TSVector2 a = triangle[0]; TSVector2 b = triangle[1]; TSVector2 c = triangle[2]; if ((a.x == b.x && a.y == b.y) || (b.x == c.x && b.y == c.y) || (a.x == c.x && a.y == c.y)) { covered[i] = true; } } int polyIndex = 0; bool notDone = true; while (notDone) { int currTri = -1; for (int i = 0; i < triangles.Count; ++i) { if (covered[i]) { continue; } currTri = i; break; } if (currTri == -1) { notDone = false; } else { Vertices poly = new Vertices(3); for (int i = 0; i < 3; i++) { poly.Add(triangles[currTri][i]); } covered[currTri] = true; int index = 0; for (int i = 0; i < 2 * triangles.Count; ++i, ++index) { while (index >= triangles.Count) { index -= triangles.Count; } if (covered[index]) { continue; } Vertices newP = AddTriangle(triangles[index], poly); if (newP == null) { continue; // is this right } if (newP.Count > Settings.MaxPolygonVertices) { continue; } if (newP.IsConvex()) { //Or should it be IsUsable? Maybe re-write IsConvex to apply the angle threshold from Box2d poly = new Vertices(newP); covered[index] = true; } } //We have a maximum of polygons that we need to keep under. if (polyIndex < maxPolys) { SimplifyTools.MergeParallelEdges(poly, tolerance); //If identical points are present, a triangle gets //borked by the MergeParallelEdges function, hence //the vertex number check if (poly.Count >= 3) { polys.Add(new Vertices(poly)); } else { Debug.WriteLine("Skipping corrupt poly."); } } if (poly.Count >= 3) { polyIndex++; //Must be outside (polyIndex < polysLength) test } } } //TODO: Add sanity check //Remove empty vertice collections for (int i = polys.Count - 1; i >= 0; i--) { if (polys[i].Count == 0) { polys.RemoveAt(i); } } return(polys); }
public static List <Vertices> PolygonizeTriangles(List <Vertices> triangles, int maxPolys = 2147483647, float tolerance = 0.001f) { bool flag = triangles.Count <= 0; List <Vertices> result; if (flag) { result = triangles; } else { List <Vertices> list = new List <Vertices>(); bool[] array = new bool[triangles.Count]; for (int i = 0; i < triangles.Count; i++) { array[i] = false; Vertices vertices = triangles[i]; TSVector2 tSVector = vertices[0]; TSVector2 tSVector2 = vertices[1]; TSVector2 tSVector3 = vertices[2]; bool flag2 = (tSVector.x == tSVector2.x && tSVector.y == tSVector2.y) || (tSVector2.x == tSVector3.x && tSVector2.y == tSVector3.y) || (tSVector.x == tSVector3.x && tSVector.y == tSVector3.y); if (flag2) { array[i] = true; } } int num = 0; bool flag3 = true; while (flag3) { int num2 = -1; for (int j = 0; j < triangles.Count; j++) { bool flag4 = array[j]; if (!flag4) { num2 = j; break; } } bool flag5 = num2 == -1; if (flag5) { flag3 = false; } else { Vertices vertices2 = new Vertices(3); for (int k = 0; k < 3; k++) { vertices2.Add(triangles[num2][k]); } array[num2] = true; int l = 0; int m = 0; while (m < 2 * triangles.Count) { while (l >= triangles.Count) { l -= triangles.Count; } bool flag6 = array[l]; if (!flag6) { Vertices vertices3 = SimpleCombiner.AddTriangle(triangles[l], vertices2); bool flag7 = vertices3 == null; if (!flag7) { bool flag8 = vertices3.Count > Settings.MaxPolygonVertices; if (!flag8) { bool flag9 = vertices3.IsConvex(); if (flag9) { vertices2 = new Vertices(vertices3); array[l] = true; } } } } m++; l++; } bool flag10 = num < maxPolys; if (flag10) { SimplifyTools.MergeParallelEdges(vertices2, tolerance); bool flag11 = vertices2.Count >= 3; if (flag11) { list.Add(new Vertices(vertices2)); } else { Debug.WriteLine("Skipping corrupt poly."); } } bool flag12 = vertices2.Count >= 3; if (flag12) { num++; } } } for (int n = list.Count - 1; n >= 0; n--) { bool flag13 = list[n].Count == 0; if (flag13) { list.RemoveAt(n); } } result = list; } return(result); }