private Shape3 ShadowPoly(Vector3 viewpoint, float viewDistance)
{
var obsShape = new Shape3 ();
obsShape.AddVertex (rotationQ * new Vector3(sizeX * 0.5f, viewpoint.y, sizeZ * 0.5f) + position);
obsShape.AddVertex (rotationQ * new Vector3(sizeX*0.5f, viewpoint.y, -sizeZ*0.5f) + position);
obsShape.AddVertex (rotationQ * new Vector3(-sizeX*0.5f, viewpoint.y, -sizeZ*0.5f) + position);
obsShape.AddVertex (rotationQ * new Vector3(-sizeX*0.5f, viewpoint.y, sizeZ*0.5f) + position);
int first = 13; // bogus int for signalling uninitialization
// Detect whether an edge should be projected,
// or rather stick to the obstacle
var projectedEdge = new bool[4];
float farthest = 0;
int count = 0;
int i = 0;
bool inside = obsShape.PointInside(viewpoint);
foreach (Edge3Abs e in obsShape) {
if ((e.a - viewpoint).magnitude > farthest)
farthest = (e.a - viewpoint).magnitude;
projectedEdge[i] = !(inside || !(Vector3.Cross(e.a - viewpoint, e.GetDiff()).y > 0));
if (!projectedEdge[i]) {
count++;
if (first == 13)
first = i;
if (first == (i + 1) % 4)
first = i;
}
i++;
}
if (viewDistance > farthest)
farthest = viewDistance;
farthest *= 2f;
int v = 0;
var shape = new Shape3 ();
if (count == 4) {
IEnumerator obsShapeRH = obsShape.GetReverseEnumerator();
while(obsShapeRH.MoveNext()) {
var e = (Edge3Abs)obsShapeRH.Current;
//shape.addVertex ((e.a - viewpoint).normalized * farthest + viewpoint);
shape.AddVertex (e.a);
}
} else {
for (int j = first; j < 4 + first; j++) {
if (projectedEdge [j % 4]) {
// Should add an edge from unprojected to projected
if (!projectedEdge [((j - 1) % 4 + 4) % 4]) {
shape.AddVertex ((obsShape [j % 4] - viewpoint).normalized * farthest + viewpoint);
}
shape.AddVertex((obsShape [(j + 1) % 4] - viewpoint).normalized * farthest + viewpoint);
} else {
if (v == 0) {
shape.AddVertex (obsShape [j % 4]);
shape.AddVertex (obsShape [(j + 1) % 4]);
v = 2;
} else {
shape.AddVertex (obsShape [(j + 1) % 4]);
}
}
}
}
shape.Offset(3);
return shape;
}