internal EdgeEnumerable(WeVertex vtx)
{
_vtx = vtx;
}
private bool FCheckDoublyInfinite(List <Vector> ptsBox, out IEnumerable <Vector> ptsToBeClipped)
{
ptsToBeClipped = null;
// This case will always have exactly three vertices - one finite and two infinite
if (Vertices.Count() != 3)
{
return(false);
}
// Get the finite vertex
WeVertex vtx = null;
var vtxs = Vertices.ToArray();
var ptTailDir = new Vector(0, 0);
var ptHeadDir = new Vector(0, 0);
for (var ivtx = 0; ivtx < 3; ivtx++)
{
if (vtxs[ivtx].FAtInfinity)
{
continue;
}
ptTailDir = vtxs[(ivtx + 1) % 3].Pt;
ptHeadDir = vtxs[(ivtx + 2) % 3].Pt;
vtx = vtxs[ivtx];
break;
}
// If it's only got two edges emanating from it (a doubly infinite line)
// ReSharper disable once PossibleNullReferenceException
if (vtx.Edges.Count() == 2)
{
// TODO: We should probably do this manually rather than relying on ConvexPolyIntersection
// Figure out a satisfactory distance for our ray length
var maxDist = 2.0 * Math.Sqrt(ptsBox.Select(pt => DistanceSq(pt, vtx.Pt)).Max());
var ptTail = vtx.Pt + ptTailDir * maxDist;
var ptHead = vtx.Pt + ptHeadDir * maxDist;
// For every point in the box
//
// We have to include the points to the left of the line in our rectangle we want clipped
// So find the max distance and extend a rect that length to the side of our line
// segment. We double the offset just to be safe.
var leftDistances = ptsBox.
// Get the distance to our line
Select(p => PtToLineDistance(p, ptHead, ptTail)).
// Keep only the ones to the left of the line
Where(d => d > 0);
// If there were no points to the left
var leftDistancesArray = leftDistances as double[] ?? leftDistances.ToArray();
if (!leftDistancesArray.Any())
{
// return an empty array
ptsToBeClipped = new List <Vector>();
return(true);
}
// Our rect width will be twice the largest of the left distances
var maxLineDist = 2 * leftDistancesArray.Max();
// Return the rectangle formed from our line segment extended out by maxLineDist
var vcOffset = (ptTail - ptHead).Normalize().Flip90Ccw() * maxLineDist;
//var vcOffset = (ptHead - ptTail).Normalize().Flip90Ccw() * maxLineDist;
ptsToBeClipped = new List <Vector>
{
ptHead,
ptTail,
ptTail + vcOffset,
ptHead + vcOffset
};
return(true);
}
return(false);
}
private readonly WeVertex _vtx; // The vertex we're enumerating around
#endregion
#region Constructor
internal EdgeEnumerator(WeVertex vtx)
{
_vtx = vtx;
}
