private static PolygonIsland[] GetIslands(Point[][] polygons, EdgeIntersection[] intersections)
{
// Figure out which polygons are in which islands
var islands = GetIslandsSprtIndices(polygons, intersections);
if (islands.Length == 1)
{
return new PolygonIsland[] { new PolygonIsland(polygons, intersections) };
}
PolygonIsland[] retVal = new PolygonIsland[islands.Length];
// Make new intersections that only know about the polygons in their island
for (int cntr = 0; cntr < retVal.Length; cntr++)
{
List<Point[]> localPolys = new List<Point[]>();
SortedList<int, int> mapping = new SortedList<int, int>();
foreach (int index in islands[cntr].Item1)
{
mapping.Add(index, localPolys.Count);
localPolys.Add(polygons[index]);
}
EdgeIntersection[] localIntersections = islands[cntr].Item2.Select(o => new EdgeIntersection(mapping[o.Poly1Index], o.Poly1Edge, mapping[o.Poly2Index], o.Poly2Edge, o.IntersectionPoint)).ToArray();
retVal[cntr] = new PolygonIsland(localPolys.ToArray(), localIntersections);
}
// Exit Function
return retVal;
}
private static Polygon2D[] MergeIsland(PolygonIsland island)
{
// Convert into line segments
Tuple<Point, Point>[] allSegments = MergeIslandSprtSegments(island);
List<Tuple<Point, bool>> mids;
// Remove segments that are inside a polygon
Tuple<Point, Point>[] segments = MergeIslandSprtRemoveInternal(out mids, allSegments, island.Polygons);
// Stitch together the remaining segments
//Point[][] polys = StitchSegments2.Stitch(segments);
return StitchSegments2.Stitch(segments);
//OLD
//if (polys == null)
//{
// //NOTE: This assumes that the segments form a convex hull, which is likely incorrect
// //retVal = GetConvexHull(segments);
// throw new ApplicationException("Fix this");
//}
//if (polys.Length == 1)
//{
// return new Polygon2D[] { new Polygon2D(polys[0]) };
//}
//else
//{
// return MergeIslandSprtFindAHoles(polys);
//}
}
private static Tuple<Point, Point>[] MergeIslandSprtSegments(PolygonIsland island)
{
List<Tuple<Point, Point>> retVal = new List<Tuple<Point, Point>>();
// Shoot through all the polygons in this island
for (int polyCntr = 0; polyCntr < island.Polygons.Length; polyCntr++)
{
// Shoot through each edge of this polygon
foreach (Edge2D edge in Math2D.IterateEdges(island.Polygons[polyCntr], null))
{
// Get all intersections of this edge
EdgeIntersection[] intersections = MergeIslandSprtSegmentsSprtIntersections(polyCntr, edge, island.Intersections);
if (intersections.Length == 0)
{
// Nothing is intersecting this edge, so add the entire edge
retVal.Add(Tuple.Create(edge.Point0, edge.Point1Ext));
}
else
{
// This edge has intersections. Convert into segments
retVal.AddRange(MergeIslandSprtSegmentsSprtDivide(polyCntr, edge, intersections));
}
}
}
// Exit Function
return retVal.ToArray();
}
private static Point[] MergeIsland(PolygonIsland island)
{
// Convert into line segments
Tuple<Point, Point>[] allSegments = MergeIslandSprtSegments(island);
List<Tuple<Point, bool>> mids;
// Remove segments that are inside a polygon
Tuple<Point, Point>[] segments = MergeIslandSprtRemoveInternal(out mids, allSegments, island.Polygons);
// Stitch together the remaining segments
Point[] retVal = StitchSegments(segments);
if (retVal == null)
{
//NOTE: This assumes that the segments form a convex hull, which is likely incorrect
//retVal = GetConvexHull(segments);
throw new ApplicationException("Fix this");
}
return retVal;
}
