/// <summary>
/// Reduce the number of sides in this footprint
/// </summary>
/// <param name="footprint"></param>
/// <returns></returns>
private static IReadOnlyList <Vector2> Reduce(IReadOnlyList <Vector2> footprint)
{
Contract.Requires(footprint != null);
Contract.Ensures(Contract.Result <IReadOnlyList <Vector2> >() != null);
Contract.Ensures(Contract.Result <IReadOnlyList <Vector2> >().Count <= footprint.Count);
//Early exit, we can't do anything useful with a line!
if (footprint.Count <= 3)
{
return(footprint);
}
//Create a list with the points in
var p = new Point2DList();
p.AddRange(footprint.Select(a => new Point2D(a.X, a.Y)).ToArray());
//If two consecutive points are in the same position, remove one
p.RemoveDuplicateNeighborPoints();
//Merge edges which are parallel (with a tolerance of 1 degree)
//p.MergeParallelEdges(0.01745240643);
p.Simplify();
//Ensure shape is clockwise wound
p.CalculateWindingOrder();
if (p.WindingOrder != Point2DList.WindingOrderType.Clockwise)
{
if (p.WindingOrder != Point2DList.WindingOrderType.AntiClockwise)
{
throw new InvalidOperationException("Winding order is neither clockwise or anticlockwise");
}
//We're done (but we need to correct the winding)
return(p.Select(a => new Vector2(a.Xf, a.Yf)).ToArray());
}
//We're done :D
return(p.Select(a => new Vector2(a.Xf, a.Yf)).ToArray());
}
/// <summary>
/// Performs one or more polygon operations on the 2 provided polygons
/// </summary>
/// <param name="polygon1">The first polygon.</param>
/// <param name="polygon2">The second polygon</param>
/// <param name="subtract">The result of the polygon subtraction</param>
/// <returns>error code</returns>
public static PolygonUtil.PolyUnionError PolygonOperation(PolygonUtil.PolyOperation operations, Point2DList polygon1, Point2DList polygon2, out Dictionary<uint, Point2DList> results)
{
PolygonOperationContext ctx = new PolygonOperationContext();
ctx.Init(operations, polygon1, polygon2);
results = ctx.mOutput;
return PolygonUtil.PolygonOperation(ctx);
}
/// Merges two polygons, given that they intersect.
/// </summary>
/// <param name="polygon1">The first polygon.</param>
/// <param name="polygon2">The second polygon.</param>
/// <param name="union">The union of the two polygons</param>
/// <returns>The error returned from union</returns>
public static PolygonUtil.PolyUnionError PolygonUnion(Point2DList polygon1, Point2DList polygon2, out Point2DList union)
{
PolygonOperationContext ctx = new PolygonOperationContext();
ctx.Init(PolygonUtil.PolyOperation.Union, polygon1, polygon2);
PolygonUnionInternal(ctx);
union = ctx.Union;
return ctx.mError;
}
/// <summary>
/// Subtracts one polygon from another.
/// </summary>
/// <param name="polygon1">The base polygon.</param>
/// <param name="polygon2">The polygon to subtract from the base.</param>
/// <param name="subtract">The result of the polygon subtraction</param>
/// <returns>error code</returns>
public static PolygonUtil.PolyUnionError PolygonSubtract(Point2DList polygon1, Point2DList polygon2, out Point2DList subtract)
{
PolygonOperationContext ctx = new PolygonOperationContext();
ctx.Init(PolygonUtil.PolyOperation.Subtract, polygon1, polygon2);
PolygonSubtractInternal(ctx);
subtract = ctx.Subtract;
return ctx.mError;
}
/// <summary>
/// Check and return polygon intersections
/// </summary>
/// <param name="polygon1"></param>
/// <param name="polygon2"></param>
/// <param name="intersections"></param>
/// <returns></returns>
private bool VerticesIntersect(Point2DList polygon1, Point2DList polygon2, out List<EdgeIntersectInfo> intersections)
{
intersections = new List<EdgeIntersectInfo>();
double epsilon = Math.Min(polygon1.Epsilon, polygon2.Epsilon);
// Iterate through polygon1's edges
for (int i = 0; i < polygon1.Count; i++)
{
// Get edge vertices
Point2D p1 = polygon1[i];
Point2D p2 = polygon1[polygon1.NextIndex(i)];
// Get intersections between this edge and polygon2
for (int j = 0; j < polygon2.Count; j++)
{
Point2D point = new Point2D();
Point2D p3 = polygon2[j];
Point2D p4 = polygon2[polygon2.NextIndex(j)];
// Check if the edges intersect
if (TriangulationUtil.LinesIntersect2D(p1, p2, p3, p4, ref point, epsilon))
{
// Rounding is not needed since we compare using an epsilon.
//// Here, we round the returned intersection point to its nearest whole number.
//// This prevents floating point anomolies where 99.9999-> is returned instead of 100.
//point = new Point2D((float)Math.Round(point.X, 0), (float)Math.Round(point.Y, 0));
// Record the intersection
intersections.Add(new EdgeIntersectInfo(new Edge(p1, p2), new Edge(p3, p4), point));
}
}
}
// true if any intersections were found.
return (intersections.Count > 0);
}
/// <summary>
/// * ref: http://ozviz.wasp.uwa.edu.au/~pbourke/geometry/insidepoly/ - Solution 2
/// * Compute the sum of the angles made between the test point and each pair of points making up the polygon.
/// * If this sum is 2pi then the point is an interior point, if 0 then the point is an exterior point.
/// </summary>
public bool PointInPolygonAngle(Point2D point, Point2DList polygon)
{
double angle = 0;
// Iterate through polygon's edges
for (int i = 0; i < polygon.Count; i++)
{
// Get points
Point2D p1 = polygon[i] - point;
Point2D p2 = polygon[polygon.NextIndex(i)] - point;
angle += VectorAngle(p1, p2);
}
if (Math.Abs(angle) < Math.PI)
{
return false;
}
return true;
}
public bool Init(PolygonUtil.PolyOperation operations, Point2DList polygon1, Point2DList polygon2)
{
Clear();
mOperations = operations;
mOriginalPolygon1 = polygon1;
mOriginalPolygon2 = polygon2;
// Make a copy of the polygons so that we dont modify the originals, and
// force vertices to integer (pixel) values.
mPoly1 = new Point2DList(polygon1);
mPoly1.WindingOrder = Point2DList.WindingOrderType.Default;
mPoly2 = new Point2DList(polygon2);
mPoly2.WindingOrder = Point2DList.WindingOrderType.Default;
// Find intersection points
if (!VerticesIntersect(mPoly1, mPoly2, out mIntersections))
{
// No intersections found - polygons do not overlap.
mError = PolygonUtil.PolyUnionError.NoIntersections;
return false;
}
// make sure edges that intersect more than once are updated to have correct start points
int numIntersections = mIntersections.Count;
for (int i = 0; i < numIntersections; ++i)
{
for (int j = i + 1; j < numIntersections; ++j)
{
if (mIntersections[i].EdgeOne.EdgeStart.Equals(mIntersections[j].EdgeOne.EdgeStart) &&
mIntersections[i].EdgeOne.EdgeEnd.Equals(mIntersections[j].EdgeOne.EdgeEnd))
{
mIntersections[j].EdgeOne.EdgeStart = mIntersections[i].IntersectionPoint;
}
if (mIntersections[i].EdgeTwo.EdgeStart.Equals(mIntersections[j].EdgeTwo.EdgeStart) &&
mIntersections[i].EdgeTwo.EdgeEnd.Equals(mIntersections[j].EdgeTwo.EdgeEnd))
{
mIntersections[j].EdgeTwo.EdgeStart = mIntersections[i].IntersectionPoint;
}
}
}
// Add intersection points to original polygons, ignoring existing points.
foreach (EdgeIntersectInfo intersect in mIntersections)
{
if (!mPoly1.Contains(intersect.IntersectionPoint))
{
mPoly1.Insert(mPoly1.IndexOf(intersect.EdgeOne.EdgeStart) + 1, intersect.IntersectionPoint);
}
if (!mPoly2.Contains(intersect.IntersectionPoint))
{
mPoly2.Insert(mPoly2.IndexOf(intersect.EdgeTwo.EdgeStart) + 1, intersect.IntersectionPoint);
}
}
mPoly1VectorAngles = new List<int>();
for (int i = 0; i < mPoly2.Count; ++i)
{
mPoly1VectorAngles.Add(-1);
}
mPoly2VectorAngles = new List<int>();
for (int i = 0; i < mPoly1.Count; ++i)
{
mPoly2VectorAngles.Add(-1);
}
// Find starting point on the edge of polygon1 that is outside of
// the intersected area to begin polygon trace.
int currentIndex = 0;
do
{
bool bPointInPolygonAngle = PointInPolygonAngle(mPoly1[currentIndex], mPoly2);
mPoly2VectorAngles[currentIndex] = bPointInPolygonAngle ? 1 : 0;
if (bPointInPolygonAngle)
{
mStartingIndex = currentIndex;
break;
}
currentIndex = mPoly1.NextIndex(currentIndex);
} while (currentIndex != 0);
// If we don't find a point on polygon1 thats outside of the
// intersect area, the polygon1 must be inside of polygon2,
// in which case, polygon2 IS the union of the two.
if (mStartingIndex == -1)
{
mError = PolygonUtil.PolyUnionError.Poly1InsidePoly2;
return false;
}
return true;
}
public void Clear()
{
mOperations = PolygonUtil.PolyOperation.None;
mOriginalPolygon1 = null;
mOriginalPolygon2 = null;
mPoly1 = null;
mPoly2 = null;
mIntersections = null;
mStartingIndex = -1;
mError = PolygonUtil.PolyUnionError.None;
mPoly1VectorAngles = null;
mPoly2VectorAngles = null;
mOutput = new Dictionary<uint, Point2DList>();
}
private static List<Point2DList> SplitComplexPolygonCleanup(IList<Point2D> orig)
{
List<Point2DList> l = new List<Point2DList>();
Point2DList origP2DL = new Point2DList(orig);
l.Add(origP2DL);
int listIdx = 0;
int numLists = l.Count;
while (listIdx < numLists)
{
int numPoints = l[listIdx].Count;
for (int i = 0; i < numPoints; ++i)
{
for (int j = i + 1; j < numPoints; ++j)
{
if (l[listIdx][i].Equals(l[listIdx][j], origP2DL.Epsilon))
{
// found a self-intersection loop - split it off into it's own list
int numToRemove = j - i;
Point2DList newList = new Point2DList();
for (int k = i + 1; k <= j; ++k)
{
newList.Add(l[listIdx][k]);
}
l[listIdx].RemoveRange(i + 1, numToRemove);
l.Add(newList);
++numLists;
numPoints -= numToRemove;
j = i + 1;
}
}
}
l[listIdx].Simplify();
++listIdx;
}
return l;
}
/// <summary>
/// Trace the edge of a non-simple polygon and return a simple polygon.
///
///Method:
///Start at vertex with minimum y (pick maximum x one if there are two).
///We aim our "lastDir" vector at (1.0, 0)
///We look at the two rays going off from our start vertex, and follow whichever
///has the smallest angle (in -Pi . Pi) wrt lastDir ("rightest" turn)
///
///Loop until we hit starting vertex:
///
///We add our current vertex to the list.
///We check the seg from current vertex to next vertex for intersections
/// - if no intersections, follow to next vertex and continue
/// - if intersections, pick one with minimum distance
/// - if more than one, pick one with "rightest" next point (two possibilities for each)
///
/// </summary>
/// <param name="verts"></param>
/// <returns></returns>
public static List<Point2DList> SplitComplexPolygon(Point2DList verts, double epsilon)
{
int numVerts = verts.Count;
int nNodes = 0;
List<SplitComplexPolygonNode> nodes = new List<SplitComplexPolygonNode>();
//Add base nodes (raw outline)
for (int i = 0; i < verts.Count; ++i)
{
SplitComplexPolygonNode newNode = new SplitComplexPolygonNode(new Point2D(verts[i].X, verts[i].Y));
nodes.Add(newNode);
}
for (int i = 0; i < verts.Count; ++i)
{
int iplus = (i == numVerts - 1) ? 0 : i + 1;
int iminus = (i == 0) ? numVerts - 1 : i - 1;
nodes[i].AddConnection(nodes[iplus]);
nodes[i].AddConnection(nodes[iminus]);
}
nNodes = nodes.Count;
//Process intersection nodes - horribly inefficient
bool dirty = true;
int counter = 0;
while (dirty)
{
dirty = false;
for (int i = 0; !dirty && i < nNodes; ++i)
{
for (int j = 0; !dirty && j < nodes[i].NumConnected; ++j)
{
for (int k = 0; !dirty && k < nNodes; ++k)
{
if (k == i || nodes[k] == nodes[i][j])
{
continue;
}
for (int l = 0; !dirty && l < nodes[k].NumConnected; ++l)
{
if (nodes[k][l] == nodes[i][j] || nodes[k][l] == nodes[i])
{
continue;
}
//Check intersection
Point2D intersectPt = new Point2D();
//if (counter > 100) printf("checking intersection: %d, %d, %d, %d\n",i,j,k,l);
bool crosses = TriangulationUtil.LinesIntersect2D( nodes[i].Position,
nodes[i][j].Position,
nodes[k].Position,
nodes[k][l].Position,
true, true, true,
ref intersectPt,
epsilon);
if (crosses)
{
/*if (counter > 100) {
printf("Found crossing at %f, %f\n",intersectPt.x, intersectPt.y);
printf("Locations: %f,%f - %f,%f | %f,%f - %f,%f\n",
nodes[i].position.x, nodes[i].position.y,
nodes[i].connected[j].position.x, nodes[i].connected[j].position.y,
nodes[k].position.x,nodes[k].position.y,
nodes[k].connected[l].position.x,nodes[k].connected[l].position.y);
printf("Memory addresses: %d, %d, %d, %d\n",(int)&nodes[i],(int)nodes[i].connected[j],(int)&nodes[k],(int)nodes[k].connected[l]);
}*/
dirty = true;
//Destroy and re-hook connections at crossing point
SplitComplexPolygonNode intersectionNode = new SplitComplexPolygonNode(intersectPt);
int idx = nodes.IndexOf(intersectionNode);
if (idx >= 0 && idx < nodes.Count)
{
intersectionNode = nodes[idx];
}
else
{
nodes.Add(intersectionNode);
nNodes = nodes.Count;
}
SplitComplexPolygonNode nodei = nodes[i];
SplitComplexPolygonNode connij = nodes[i][j];
SplitComplexPolygonNode nodek = nodes[k];
SplitComplexPolygonNode connkl = nodes[k][l];
connij.RemoveConnection(nodei);
nodei.RemoveConnection(connij);
connkl.RemoveConnection(nodek);
nodek.RemoveConnection(connkl);
if (!intersectionNode.Position.Equals(nodei.Position, epsilon))
{
intersectionNode.AddConnection(nodei);
nodei.AddConnection(intersectionNode);
}
if (!intersectionNode.Position.Equals(nodek.Position, epsilon))
{
intersectionNode.AddConnection(nodek);
nodek.AddConnection(intersectionNode);
}
if (!intersectionNode.Position.Equals(connij.Position, epsilon))
{
intersectionNode.AddConnection(connij);
connij.AddConnection(intersectionNode);
}
if (!intersectionNode.Position.Equals(connkl.Position, epsilon))
{
intersectionNode.AddConnection(connkl);
connkl.AddConnection(intersectionNode);
}
}
}
}
}
}
++counter;
//if (counter > 100) printf("Counter: %d\n",counter);
}
// /*
// // Debugging: check for connection consistency
// for (int i=0; i<nNodes; ++i) {
// int nConn = nodes[i].nConnected;
// for (int j=0; j<nConn; ++j) {
// if (nodes[i].connected[j].nConnected == 0) Assert(false);
// SplitComplexPolygonNode* connect = nodes[i].connected[j];
// bool found = false;
// for (int k=0; k<connect.nConnected; ++k) {
// if (connect.connected[k] == &nodes[i]) found = true;
// }
// Assert(found);
// }
// }*/
//Collapse duplicate points
bool foundDupe = true;
int nActive = nNodes;
double epsilonSquared = epsilon * epsilon;
while (foundDupe)
{
foundDupe = false;
for (int i = 0; i < nNodes; ++i)
{
if (nodes[i].NumConnected == 0)
{
continue;
}
for (int j = i + 1; j < nNodes; ++j)
{
if (nodes[j].NumConnected == 0)
{
continue;
}
Point2D diff = nodes[i].Position - nodes[j].Position;
if (diff.MagnitudeSquared() <= epsilonSquared)
{
if (nActive <= 3)
{
throw new Exception("Eliminated so many duplicate points that resulting polygon has < 3 vertices!");
}
//printf("Found dupe, %d left\n",nActive);
--nActive;
foundDupe = true;
SplitComplexPolygonNode inode = nodes[i];
SplitComplexPolygonNode jnode = nodes[j];
//Move all of j's connections to i, and remove j
int njConn = jnode.NumConnected;
for (int k = 0; k < njConn; ++k)
{
SplitComplexPolygonNode knode = jnode[k];
//Debug.Assert(knode != jnode);
if (knode != inode)
{
inode.AddConnection(knode);
knode.AddConnection(inode);
}
knode.RemoveConnection(jnode);
//printf("knode %d on node %d now has %d connections\n",k,j,knode.nConnected);
//printf("Found duplicate point.\n");
}
jnode.ClearConnections(); // to help with garbage collection
nodes.RemoveAt(j);
--nNodes;
}
}
}
}
// /*
// // Debugging: check for connection consistency
// for (int i=0; i<nNodes; ++i) {
// int nConn = nodes[i].nConnected;
// printf("Node %d has %d connections\n",i,nConn);
// for (int j=0; j<nConn; ++j) {
// if (nodes[i].connected[j].nConnected == 0) {
// printf("Problem with node %d connection at address %d\n",i,(int)(nodes[i].connected[j]));
// Assert(false);
// }
// SplitComplexPolygonNode* connect = nodes[i].connected[j];
// bool found = false;
// for (int k=0; k<connect.nConnected; ++k) {
// if (connect.connected[k] == &nodes[i]) found = true;
// }
// if (!found) printf("Connection %d (of %d) on node %d (of %d) did not have reciprocal connection.\n",j,nConn,i,nNodes);
// Assert(found);
// }
// }//*/
//Now walk the edge of the list
//Find node with minimum y value (max x if equal)
double minY = double.MaxValue;
double maxX = -double.MaxValue;
int minYIndex = -1;
for (int i = 0; i < nNodes; ++i)
{
if (nodes[i].Position.Y < minY && nodes[i].NumConnected > 1)
{
minY = nodes[i].Position.Y;
minYIndex = i;
maxX = nodes[i].Position.X;
}
else if (nodes[i].Position.Y == minY && nodes[i].Position.X > maxX && nodes[i].NumConnected > 1)
{
minYIndex = i;
maxX = nodes[i].Position.X;
}
}
Point2D origDir = new Point2D(1.0f, 0.0f);
List<Point2D> resultVecs = new List<Point2D>();
SplitComplexPolygonNode currentNode = nodes[minYIndex];
SplitComplexPolygonNode startNode = currentNode;
//Debug.Assert(currentNode.nConnected > 0);
SplitComplexPolygonNode nextNode = currentNode.GetRightestConnection(origDir);
if (nextNode == null)
{
// Borked, clean up our mess and return
return PolygonUtil.SplitComplexPolygonCleanup(verts);
}
resultVecs.Add(startNode.Position);
while (nextNode != startNode)
{
if (resultVecs.Count > (4 * nNodes))
{
//printf("%d, %d, %d\n",(int)startNode,(int)currentNode,(int)nextNode);
//printf("%f, %f . %f, %f\n",currentNode.position.x,currentNode.position.y, nextNode.position.x, nextNode.position.y);
//verts.printFormatted();
//printf("Dumping connection graph: \n");
//for (int i=0; i<nNodes; ++i)
//{
// printf("nodex[%d] = %f; nodey[%d] = %f;\n",i,nodes[i].position.x,i,nodes[i].position.y);
// printf("//connected to\n");
// for (int j=0; j<nodes[i].nConnected; ++j)
// {
// printf("connx[%d][%d] = %f; conny[%d][%d] = %f;\n",i,j,nodes[i].connected[j].position.x, i,j,nodes[i].connected[j].position.y);
// }
//}
//printf("Dumping results thus far: \n");
//for (int i=0; i<nResultVecs; ++i)
//{
// printf("x[%d]=map(%f,-3,3,0,width); y[%d] = map(%f,-3,3,height,0);\n",i,resultVecs[i].x,i,resultVecs[i].y);
//}
//Debug.Assert(false);
//nodes should never be visited four times apiece (proof?), so we've probably hit a loop...crap
throw new Exception("nodes should never be visited four times apiece (proof?), so we've probably hit a loop...crap");
}
resultVecs.Add(nextNode.Position);
SplitComplexPolygonNode oldNode = currentNode;
currentNode = nextNode;
//printf("Old node connections = %d; address %d\n",oldNode.nConnected, (int)oldNode);
//printf("Current node connections = %d; address %d\n",currentNode.nConnected, (int)currentNode);
nextNode = currentNode.GetRightestConnection(oldNode);
if (nextNode == null)
{
return PolygonUtil.SplitComplexPolygonCleanup(resultVecs);
}
// There was a problem, so jump out of the loop and use whatever garbage we've generated so far
//printf("nextNode address: %d\n",(int)nextNode);
}
if (resultVecs.Count < 1)
{
// Borked, clean up our mess and return
return PolygonUtil.SplitComplexPolygonCleanup(verts);
}
else
{
return PolygonUtil.SplitComplexPolygonCleanup(resultVecs);
}
}
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;
}
}