Esempio n. 1
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 public AdvancingFront( AdvancingFrontNode head, AdvancingFrontNode tail )
 {
     this.Head = head;
     this.Tail = tail;
     this.Search = head;
     AddNode(head);
     AddNode(tail);
 }
Esempio n. 2
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 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
         }
     }
 }
Esempio n. 3
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        private static void FillRightBelowEdgeEvent( DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node )
        {
            if (tcx.IsDebugEnabled) tcx.DTDebugContext.ActiveNode = 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);
                }

            }
        }
Esempio n. 4
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 private static void FillRightAboveEdgeEvent( DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node )
 {
     while (node.Next.Point.X < edge.P.X) {
         if (tcx.IsDebugEnabled) { tcx.DTDebugContext.ActiveNode = node; }
         // Check if next node is below the edge
         Orientation o1 = TriangulationUtil.Orient2d(edge.Q, node.Next.Point, edge.P);
         if (o1 == Orientation.CCW) {
             FillRightBelowEdgeEvent(tcx, edge, node);
         } else {
             node = node.Next;
         }
     }
 }
Esempio n. 5
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 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
             }
         }
     }
 }
Esempio n. 6
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 private static void FillEdgeEvent( DTSweepContext tcx, DTSweepConstraint edge, AdvancingFrontNode node )
 {
     if (tcx.EdgeEvent.Right) {
         FillRightAboveEdgeEvent(tcx, edge, node);
     } else {
         FillLeftAboveEdgeEvent(tcx, edge, node);
     }
 }
Esempio n. 7
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 private AdvancingFrontNode LocateNode( double x )
 {
     AdvancingFrontNode node = FindSearchNode(x);
     if (x < node.Value) {
         while ((node = node.Prev) != null)
             if (x >= node.Value) {
                 Search = node;
                 return node;
             }
     } else {
         while ((node = node.Next) != null)
             if (x < node.Value) {
                 Search = node.Prev;
                 return node.Prev;
             }
     }
     return null;
 }
Esempio n. 8
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        /// <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 (tcx.IsDebugEnabled) tcx.DTDebugContext.ActiveNode = newNode;

            if (!Legalize(tcx, triangle)) tcx.MapTriangleToNodes(triangle);

            return newNode;
        }
Esempio n. 9
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        /// <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);
            }
        }
Esempio n. 10
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        /// <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);
        }
Esempio n. 11
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        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 (tcx.IsDebugEnabled) { tcx.DTDebugContext.PrimaryTriangle = node.Triangle; }

                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 {
                //Debug.WriteLine( String.Format( "Warning: Skipping Edge: {0}", e.Message ) );
                throw;
            }
        }
Esempio n. 12
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 /// <summary>
 /// The basin angle is decided against the horizontal line [1,0]
 /// </summary>
 private static double BasinAngle( AdvancingFrontNode node )
 {
     double ax = node.Point.X - node.Next.Next.Point.X;
     double ay = node.Point.Y - node.Next.Next.Point.Y;
     return Math.Atan2(ay, ax);
 }
Esempio n. 13
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        /// <summary>
        /// This implementation will use simple node traversal algorithm to find a point on the front
        /// </summary>
        public AdvancingFrontNode LocatePoint( TriangulationPoint point )
        {
            double px = point.X;
            AdvancingFrontNode node = FindSearchNode(px);
            double nx = node.Point.X;

            if (px == nx) {
                if (point != node.Point) {
                    // We might have two nodes with same x value for a short time
                    if (point == node.Prev.Point) {
                        node = node.Prev;
                    } else if (point == node.Next.Point) {
                        node = node.Next;
                    } else {
                        throw new Exception("Failed to find Node for given afront point");
                    }
                }
            } else if (px < nx) {
                while ((node = node.Prev) != null) if (point == node.Point) break;
            } else {
                while ((node = node.Next) != null) if (point == node.Point) break;
            }
            Search = node;
            return node;
        }
Esempio n. 14
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 public void AddNode( AdvancingFrontNode node )
 {
 }
Esempio n. 15
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 /// <summary>
 /// ???
 /// </summary>
 /// <param name="node">middle node</param>
 /// <returns>the angle between 3 front nodes</returns>
 private static double HoleAngle( AdvancingFrontNode node )
 {
     // XXX: do we really need a signed angle for holeAngle?
     //      could possible save some cycles here
     /* Complex plane
      * ab = cosA +i*sinA
      * ab = (ax + ay*i)(bx + by*i) = (ax*bx + ay*by) + i(ax*by-ay*bx)
      * atan2(y,x) computes the principal value of the argument function
      * applied to the complex number x+iy
      * Where x = ax*bx + ay*by
      *       y = ax*by - ay*bx
      */
     double px = node.Point.X;
     double py = node.Point.Y;
     double ax = node.Next.Point.X - px;
     double ay = node.Next.Point.Y - py;
     double bx = node.Prev.Point.X - px;
     double by = node.Prev.Point.Y - py;
     return Math.Atan2(ax * by - ay * bx, ax * bx + ay * by);
 }
Esempio n. 16
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        /// <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) return; // No valid basin

            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) return; // No valid basins

            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);
        }
Esempio n. 17
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        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;
        }
Esempio n. 18
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        /// <summary>
        /// Recursive algorithm to fill a Basin with triangles
        /// </summary>
        private static void FillBasinReq( DTSweepContext tcx, AdvancingFrontNode node )
        {
            if (IsShallow(tcx, node)) return; // if shallow stop filling

            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);
        }
Esempio n. 19
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        /// <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.Front.Tail) {
                if (tcx.IsDebugEnabled) tcx.DTDebugContext.ActiveNode = c;

                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;
                    }
                }
            }
        }
Esempio n. 20
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 public void RemoveNode( AdvancingFrontNode node )
 {
 }