Beispiel #1
0
        public static void InitializeHoles(List <Contour> holes, ITriangulatable parent, ConstrainedPointSet cps)
        {
            int numHoles = holes.Count;
            int holeIdx  = 0;

            // pass 1 - remove duplicates
            while (holeIdx < numHoles)
            {
                int hole2Idx = holeIdx + 1;
                while (hole2Idx < numHoles)
                {
                    bool bSamePolygon = PolygonUtil.PolygonsAreSame2D(holes [holeIdx], holes [hole2Idx]);
                    if (bSamePolygon)
                    {
                        // remove one of them
                        holes.RemoveAt(hole2Idx);
                        --numHoles;
                    }
                    else
                    {
                        ++hole2Idx;
                    }
                }
                ++holeIdx;
            }

            // pass 2: Intersections and Containment
            holeIdx = 0;
            while (holeIdx < numHoles)
            {
                bool bIncrementHoleIdx = true;
                int  hole2Idx          = holeIdx + 1;
                while (hole2Idx < numHoles)
                {
                    if (PolygonUtil.PolygonContainsPolygon(holes [holeIdx], holes [holeIdx].Bounds, holes [hole2Idx], holes [hole2Idx].Bounds, false))
                    {
                        holes [holeIdx].AddHole(holes [hole2Idx]);
                        holes.RemoveAt(hole2Idx);
                        --numHoles;
                    }
                    else if (PolygonUtil.PolygonContainsPolygon(holes [hole2Idx], holes [hole2Idx].Bounds, holes [holeIdx], holes [holeIdx].Bounds, false))
                    {
                        holes [hole2Idx].AddHole(holes [holeIdx]);
                        holes.RemoveAt(holeIdx);
                        --numHoles;
                        bIncrementHoleIdx = false;
                        break;
                    }
                    else
                    {
                        bool bIntersect = PolygonUtil.PolygonsIntersect2D(holes [holeIdx], holes [holeIdx].Bounds, holes [hole2Idx], holes [hole2Idx].Bounds);
                        if (bIntersect)
                        {
                            // this is actually an error condition
                            // fix by merging hole1 and hole2 into hole1 (including the holes inside hole2!) and delete hole2
                            // Then, because hole1 is now changed, restart it's check.
                            PolygonOperationContext ctx = new PolygonOperationContext();
                            if (!ctx.Init(PolygonUtil.PolyOperation.Union | PolygonUtil.PolyOperation.Intersect, holes [holeIdx], holes [hole2Idx]))
                            {
                                if (ctx.mError == PolygonUtil.PolyUnionError.Poly1InsidePoly2)
                                {
                                    holes [hole2Idx].AddHole(holes [holeIdx]);
                                    holes.RemoveAt(holeIdx);
                                    --numHoles;
                                    bIncrementHoleIdx = false;
                                    break;
                                }
                                else
                                {
                                    throw new Exception("PolygonOperationContext.Init had an error during initialization");
                                }
                            }
                            PolygonUtil.PolyUnionError pue = PolygonUtil.PolygonOperation(ctx);
                            if (pue == PolygonUtil.PolyUnionError.None)
                            {
                                Point2DList union        = ctx.Union;
                                Point2DList intersection = ctx.Intersect;

                                // create a new contour for the union
                                Contour c = new Contour(parent);
                                c.AddRange(union);
                                c.Name         = "(" + holes [holeIdx].Name + " UNION " + holes [hole2Idx].Name + ")";
                                c.WindingOrder = Point2DList.WindingOrderType.Default;

                                // add children from both of the merged contours
                                int numChildHoles = holes [holeIdx].GetNumHoles();
                                for (int i = 0; i < numChildHoles; ++i)
                                {
                                    c.AddHole(holes [holeIdx].GetHole(i));
                                }
                                numChildHoles = holes [hole2Idx].GetNumHoles();
                                for (int i = 0; i < numChildHoles; ++i)
                                {
                                    c.AddHole(holes [hole2Idx].GetHole(i));
                                }

                                // make sure we preserve the contours of the intersection
                                Contour cInt = new Contour(c);
                                cInt.AddRange(intersection);
                                cInt.Name         = "(" + holes [holeIdx].Name + " INTERSECT " + holes [hole2Idx].Name + ")";
                                cInt.WindingOrder = Point2DList.WindingOrderType.Default;
                                c.AddHole(cInt);

                                // replace the current contour with the merged contour
                                holes [holeIdx] = c;

                                // toss the second contour
                                holes.RemoveAt(hole2Idx);
                                --numHoles;

                                // current hole is "examined", so move to the next one
                                hole2Idx = holeIdx + 1;
                            }
                            else
                            {
                                throw new Exception("PolygonOperation had an error!");
                            }
                        }
                        else
                        {
                            ++hole2Idx;
                        }
                    }
                }
                if (bIncrementHoleIdx)
                {
                    ++holeIdx;
                }
            }

            numHoles = holes.Count;
            holeIdx  = 0;
            while (holeIdx < numHoles)
            {
                int numPoints = holes [holeIdx].Count;
                for (int i = 0; i < numPoints; ++i)
                {
                    int  j = holes [holeIdx].NextIndex(i);
                    uint constraintCode        = TriangulationConstraint.CalculateContraintCode(holes [holeIdx] [i], holes [holeIdx] [j]);
                    TriangulationConstraint tc = null;
                    if (!cps.TryGetConstraint(constraintCode, out tc))
                    {
                        tc = new TriangulationConstraint(holes [holeIdx] [i], holes [holeIdx] [j]);
                        cps.AddConstraint(tc);
                    }

                    // replace the points in the holes with valid points
                    if (holes [holeIdx] [i].VertexCode == tc.P.VertexCode)
                    {
                        holes [holeIdx] [i] = tc.P;
                    }
                    else if (holes [holeIdx] [j].VertexCode == tc.P.VertexCode)
                    {
                        holes [holeIdx] [j] = tc.P;
                    }
                    if (holes [holeIdx] [i].VertexCode == tc.Q.VertexCode)
                    {
                        holes [holeIdx] [i] = tc.Q;
                    }
                    else if (holes [holeIdx] [j].VertexCode == tc.Q.VertexCode)
                    {
                        holes [holeIdx] [j] = tc.Q;
                    }
                }
                ++holeIdx;
            }
        }
        // Assumes that points being passed in the list are connected and form a polygon.
        // Note that some error checking is done for robustness, but for the most part,
        // we have to rely on the user to feed us "correct" data
        public bool AddHole(List <TriangulationPoint> points, string name)
        {
            if (points == null)
            {
                return(false);
            }

            //// split our self-intersection sections into their own lists
            List <Contour> pts     = new List <Contour> ();
            int            listIdx = 0;

            {
                Contour c = new Contour(this, points, WindingOrderType.Unknown);
                pts.Add(c);

                // only constrain the points if we actually HAVE a bounding rect
                if (mPoints.Count > 1)
                {
                    // constrain the points to bounding rect
                    int numPoints = pts [listIdx].Count;
                    for (int i = 0; i < numPoints; ++i)
                    {
                        ConstrainPointToBounds(pts [listIdx] [i]);
                    }
                }
            }

            while (listIdx < pts.Count)
            {
                // simple sanity checking - remove duplicate coincident points before
                // we check the polygon: fast, simple algorithm that eliminate lots of problems
                // that only more expensive checks will find
                pts [listIdx].RemoveDuplicateNeighborPoints();
                pts [listIdx].WindingOrder = Point2DList.WindingOrderType.Default;

                bool bListOK = true;
                Point2DList.PolygonError err = pts [listIdx].CheckPolygon();
                while (bListOK && err != PolygonError.None)
                {
                    if ((err & PolygonError.NotEnoughVertices) == PolygonError.NotEnoughVertices)
                    {
                        bListOK = false;
                        continue;
                    }
                    if ((err & PolygonError.NotSimple) == PolygonError.NotSimple)
                    {
                        // split the polygons, remove the current list and add the resulting list to the end
                        //List<Point2DList> l = TriangulationUtil.SplitSelfIntersectingPolygon(pts[listIdx], pts[listIdx].Epsilon);
                        List <Point2DList> l = PolygonUtil.SplitComplexPolygon(pts [listIdx], pts [listIdx].Epsilon);
                        pts.RemoveAt(listIdx);
                        foreach (Point2DList newList in l)
                        {
                            Contour c = new Contour(this);
                            c.AddRange(newList);
                            pts.Add(c);
                        }
                        err = pts [listIdx].CheckPolygon();
                        continue;
                    }
                    if ((err & PolygonError.Degenerate) == PolygonError.Degenerate)
                    {
                        pts [listIdx].Simplify(this.Epsilon);
                        err = pts [listIdx].CheckPolygon();
                        continue;
                        //err &= ~(PolygonError.Degenerate);
                        //if (pts[listIdx].Count < 3)
                        //{
                        //    err |= PolygonError.NotEnoughVertices;
                        //    bListOK = false;
                        //    continue;
                        //}
                    }
                    if ((err & PolygonError.AreaTooSmall) == PolygonError.AreaTooSmall ||
                        (err & PolygonError.SidesTooCloseToParallel) == PolygonError.SidesTooCloseToParallel ||
                        (err & PolygonError.TooThin) == PolygonError.TooThin ||
                        (err & PolygonError.Unknown) == PolygonError.Unknown)
                    {
                        bListOK = false;
                        continue;
                    }
                    // non-convex polygons are ok
                    //if ((err & PolygonError.NotConvex) == PolygonError.NotConvex)
                    //{
                    //}
                }
                if (!bListOK && pts [listIdx].Count != 2)
                {
                    pts.RemoveAt(listIdx);
                }
                else
                {
                    ++listIdx;
                }
            }

            bool bOK = true;

            listIdx = 0;
            while (listIdx < pts.Count)
            {
                int numPoints = pts [listIdx].Count;
                if (numPoints < 2)
                {
                    // should not be possible by this point...
                    ++listIdx;
                    bOK = false;
                    continue;
                }
                else if (numPoints == 2)
                {
                    uint constraintCode        = TriangulationConstraint.CalculateContraintCode(pts [listIdx] [0], pts [listIdx] [1]);
                    TriangulationConstraint tc = null;
                    if (!mConstraintMap.TryGetValue(constraintCode, out tc))
                    {
                        tc = new TriangulationConstraint(pts [listIdx] [0], pts [listIdx] [1]);
                        AddConstraint(tc);
                    }
                }
                else
                {
                    Contour ph = new Contour(this, pts [listIdx], Point2DList.WindingOrderType.Unknown);
                    ph.WindingOrder = Point2DList.WindingOrderType.Default;
                    ph.Name         = name + ":" + listIdx.ToString();
                    mHoles.Add(ph);
                }
                ++listIdx;
            }

            return(bOK);
        }