public static float Len(VtPoint a, VtPoint b)
{
var dx = a.X - b.X;
var dy = a.Y - b.Y;
return((float)Math.Sqrt(dx * dx + dy * dy));
}
public static void DelanuaStep(ref List <VtTriangle> triangles, VtPoint newPoint)
{
var badTriangles = new List <VtTriangle>();
var edges = new List <VtEdge>();
FindInvalidTriangles(triangles, newPoint, out badTriangles, out edges);
edges = RemoveDuplicateEdges(edges);
triangles = RemoveBadTriangles(triangles, badTriangles);
FillHole(ref triangles, edges, newPoint);
}
public static List <VtTriangle> GetTriangles(List <VtTriangle> triangles, VtPoint pt)
{
var result = new List <VtTriangle>();
for (int i = 0; i < triangles.Count; i++)
{
var tr = triangles[i];
if (tr.A == pt || tr.B == pt || tr.C == pt)
{
result.Add(tr);
}
}
return(result);
}
internal static void FindInvalidTriangles(List <VtTriangle> triangles, VtPoint newPoint, out List <VtTriangle> badTriangles, out List <VtEdge> allEdges)
{
badTriangles = new List <VtTriangle>();
allEdges = new List <VtEdge>();
for (int triCounter = 0; triCounter < triangles.Count; triCounter++)
{
if (EMath.Len(triangles[triCounter].CirC, newPoint) < triangles[triCounter].CirR)
{
badTriangles.Add(triangles[triCounter]);
allEdges.Add(triangles[triCounter].AB);
allEdges.Add(triangles[triCounter].BC);
allEdges.Add(triangles[triCounter].AC);
}
}
}
public static List <VtEdge> MissedEdges(this List <VtEdge> edges, float minX, float minY, float maxX, float maxY)
{
List <VtEdge> result = new List <VtEdge>();
var points = new List <VtPoint>();
for (int i = 0; i < edges.Count; i++)
{
var edge = edges[i];
var ex = points.FirstOrDefault(point => point == edge.S);
if (ex != null)
{
points.Remove(ex);
}
else
{
points.Add(edge.S);
}
ex = points.FirstOrDefault(point => point == edge.E);
if (ex != null)
{
points.Remove(ex);
}
else
{
points.Add(edge.E);
}
}
if (points.Count != 2)
{
return(result);
}
var pt1 = points[0];
var pt2 = points[1];
if (Math.Abs(pt1.X - pt2.X) < float.Epsilon || Math.Abs(pt1.Y - pt2.Y) < float.Epsilon)
{
result.Add(new VtEdge(pt1, pt2));
return(result);
}
float x = 0, y = 0;
if (Math.Abs(pt1.X - minX) < float.Epsilon || Math.Abs(pt1.X - maxX) < float.Epsilon)
{
x = pt1.X;
}
else
if (Math.Abs(pt2.X - minX) < float.Epsilon || Math.Abs(pt2.X - maxX) < float.Epsilon)
{
x = pt2.X;
}
if (Math.Abs(pt1.Y - minY) < float.Epsilon || Math.Abs(pt1.Y - maxY) < float.Epsilon)
{
y = pt1.Y;
}
else
if (Math.Abs(pt2.Y - minY) < float.Epsilon || Math.Abs(pt2.Y - maxY) < float.Epsilon)
{
y = pt2.Y;
}
var pt = new VtPoint(x, y);
result.Add(new VtEdge(pt1, pt));
result.Add(new VtEdge(pt, pt2));
return(result);
}
private static void FillHole(ref List <VtTriangle> triangles, List <VtEdge> polygonHole, VtPoint newPoint)
{
for (int polyCounter = 0; polyCounter < polygonHole.Count; polyCounter++)
{
triangles.Add(new VtTriangle(polygonHole[polyCounter].S, polygonHole[polyCounter].E, newPoint));
}
}
