示例#1
0
        /// <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, n3;
            DelaunayTriangle   t1;
            TriangulationPoint first, p1;

            n1    = tcx.Front.Head.Next;
            n2    = n1.Next;
            n3    = n2.Next;
            first = n1.Point;

            TurnAdvancingFrontConvex(tcx, n1, n2);

            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);
            }

            // TODO: implement ConvexHull for lower right and left boundary
            // Lower right boundary
            first = tcx.Front.Head.Point;
            n2    = tcx.Front.Tail.Prev;
            t1    = n2.Triangle;
            p1    = n2.Point;
            do
            {
                tcx.RemoveFromList(t1);
                p1 = t1.PointCCWFrom(p1);
                if (p1 == first)
                {
                    break;
                }
                t1 = t1.NeighborCCWFrom(p1);
            } while (true);

            // Lower left boundary
            first = tcx.Front.Head.Next.Point;
            p1    = t1.PointCWFrom(tcx.Front.Head.Point);
            t1    = t1.NeighborCWFrom(tcx.Front.Head.Point);
            do
            {
                tcx.RemoveFromList(t1);
                p1 = t1.PointCCWFrom(p1);
                t1 = t1.NeighborCCWFrom(p1);
            } while (p1 != first);

            tcx.FinalizeTriangulation();
        }
示例#2
0
        private static void FinalizationConvexHull(DTSweepContext tcx)
        {
            DelaunayTriangle   triangle;
            AdvancingFrontNode next  = tcx.Front.Head.Next;
            AdvancingFrontNode c     = next.Next;
            AdvancingFrontNode node3 = c.Next;
            TriangulationPoint point = next.Point;

            TurnAdvancingFrontConvex(tcx, next, c);
            next = tcx.Front.Tail.Prev;
            if (next.Triangle.Contains(next.Next.Point) && next.Triangle.Contains(next.Prev.Point))
            {
                triangle = next.Triangle.NeighborAcrossFrom(next.Point);
                RotateTrianglePair(next.Triangle, next.Point, triangle, triangle.OppositePoint(next.Triangle, next.Point));
                tcx.MapTriangleToNodes(next.Triangle);
                tcx.MapTriangleToNodes(triangle);
            }
            next = tcx.Front.Head.Next;
            if (next.Triangle.Contains(next.Prev.Point) && next.Triangle.Contains(next.Next.Point))
            {
                triangle = next.Triangle.NeighborAcrossFrom(next.Point);
                RotateTrianglePair(next.Triangle, next.Point, triangle, triangle.OppositePoint(next.Triangle, next.Point));
                tcx.MapTriangleToNodes(next.Triangle);
                tcx.MapTriangleToNodes(triangle);
            }
            point    = tcx.Front.Head.Point;
            c        = tcx.Front.Tail.Prev;
            triangle = c.Triangle;
            TriangulationPoint point2 = c.Point;

            while (true)
            {
                tcx.RemoveFromList(triangle);
                point2 = triangle.PointCCWFrom(point2);
                if (point2 == point)
                {
                    break;
                }
                triangle = triangle.NeighborCCWFrom(point2);
            }
            point    = tcx.Front.Head.Next.Point;
            point2   = triangle.PointCWFrom(tcx.Front.Head.Point);
            triangle = triangle.NeighborCWFrom(tcx.Front.Head.Point);
            do
            {
                tcx.RemoveFromList(triangle);
                point2   = triangle.PointCCWFrom(point2);
                triangle = triangle.NeighborCCWFrom(point2);
            }while (point2 != point);
            tcx.FinalizeTriangulation();
        }
示例#3
0
        /// <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;
            TriangulationPoint first, p1;

            n1 = tcx.Front.Head.Next;
            n2 = n1.Next;
            first = n1.Point;

            TurnAdvancingFrontConvex(tcx, n1, n2);

            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);
            }

            // TODO: implement ConvexHull for lower right and left boundary
            // Lower right boundary
            first = tcx.Front.Head.Point;
            n2 = tcx.Front.Tail.Prev;
            t1 = n2.Triangle;
            p1 = n2.Point;
            do {
                tcx.RemoveFromList(t1);
                p1 = t1.PointCCWFrom(p1);
                if (p1 == first) break;
                t1 = t1.NeighborCCWFrom(p1);
            } while (true);

            // Lower left boundary
            first = tcx.Front.Head.Next.Point;
            p1 = t1.PointCWFrom(tcx.Front.Head.Point);
            t1 = t1.NeighborCWFrom(tcx.Front.Head.Point);
            do {
                tcx.RemoveFromList(t1);
                p1 = t1.PointCCWFrom(p1);
                t1 = t1.NeighborCCWFrom(p1);
            } while (p1 != first);

            tcx.FinalizeTriangulation();
        }