// ---------------------------------------------------------------
// 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);
}
// ----------------------------------------------------------
// Checks if a point is on the positive side of the template
// ----------------------------------------------------------
public bool IsAbove(Vector3 v)
{
Vector3 pv = plane.Project(v);
float dMin;
int i0;
Vector3 dif;
float lastLineDist;
if (isClosed)
{
dif = VectorUtil.VectorToEdge(pv, points.Last(), points.First());
lastLineDist = VectorUtil.DistanceToLine(pv, points.Last(), points.First());
i0 = points.Count - 1;
dMin = dif.magnitude;
}
else
{
dif = VectorUtil.VectorToEdge(pv, points[0], points[1]);
lastLineDist = VectorUtil.DistanceToLine(pv, points[0], points[1]);
i0 = 0;
dMin = dif.magnitude;
}
for (int i = 0; i < points.Count - 1; i++)
{
float lineDist = VectorUtil.DistanceToLine(pv, points[i], points[i + 1]);
Vector3 vec = VectorUtil.VectorToEdge(pv, points[i], points[i + 1]);
if (vec.magnitude == dMin)
{
if (lineDist > lastLineDist)
{
i0 = i;
dMin = vec.magnitude;
dif = vec;
}
}
else if (vec.magnitude < dMin)
{
i0 = i;
dMin = vec.magnitude;
dif = vec;
}
lastLineDist = lineDist;
}
int i1 = i0 + 1 == points.Count ? 0 : i0 + 1;
return(Vector3.Dot(
Vector3.Cross(
dif,
points[i1] - points[i0]
),
normal
) > 0);
}