// ---------------------------------------------------------------
// Determine shortest distance to ring perimeter
// i0 and i1 are indices for vertexes around closest line in ring
// In the case of equality, one is chosen specifically to handle
// the degenerate case in point-in-polygon test
// ---------------------------------------------------------------
public float DistanceToRingPerimeter(Vector3 v, out int i0, out int i1)
{
int prevIndex = verts.Count - 1;
i0 = prevIndex;
i1 = 0;
float dMin = float.PositiveInfinity;
float lastLineDist = VectorUtil.DistanceToLine(v, verts[prevIndex - 1], verts[prevIndex]);
for (int i = 0; i < verts.Count; i++)
{
float lineDist = VectorUtil.DistanceToLine(v, verts[prevIndex], verts[i]);;
float d = VectorUtil.DistanceToEdge(v, verts[prevIndex], verts[i]);
if (d == dMin) // handle degenerate case for point-in-polygon test
{
if (lineDist > lastLineDist)
{
dMin = d;
i0 = prevIndex;
i1 = i;
}
}
else if (d < dMin)
{
dMin = d;
i0 = prevIndex;
i1 = i;
}
lastLineDist = lineDist;
prevIndex = i;
}
return(dMin);
}
