//Function to check if a point is inside a polygon (only works for convex polygons)
public bool IsInsidePolygon(List <geoPoint> Polygon, geoPoint Q)
{
//float Theta = 0;
float SumTheta = 0;
float m1 = 0;
float m2 = 0;
float costheta = 0;
float EPSILON = 0;
geoPoint P1 = null;
geoPoint P2 = null;
//X_Boundary.Insert(0, X_Boundary.Last)
//Y_Boundary.Insert(0, Y_Boundary.Last)
EPSILON = 0.0001F;
//Theta = 0;
for (int j = 0; j <= Polygon.Count - 1; j++)
{
// Point #j - Q
P1 = Polygon[j].subtract(Q);
// Point #j+1 - Q
P2 = Polygon[(j + 1) % Polygon.Count].subtract(Q);
m1 = Mathf.Pow((float)(P1.DotProduct(P1)), 0.5F);
m2 = Mathf.Pow((float)(P2.DotProduct(P2)), 0.5F);
if ((m1 * m2 <= EPSILON))
{
return(true);
//We are on a node, consider this inside
}
else
{
costheta = (P1.DotProduct(P2)) / (m1 * m2);
}
SumTheta = SumTheta + Mathf.Acos((float)costheta);
}
if (Mathf.Abs((float)(SumTheta - 2 * Mathf.PI)) < EPSILON | Mathf.Abs((float)(SumTheta + 2 * Math.PI)) < EPSILON)
{
return(true);
}
else
{
return(false);
}
}
private float PintToPlaneClosestPoint(geoPoint Q, geoPoint V0, ref geoPoint V1, geoPoint V2, ref geoPoint projection)
{
// Input: P = a 3D point
// PL = a plane with point V0 and normal n
// Output: ClosestPt = base point on PL of perpendicular from P
float sb = 0;
float sn = 0;
float sd = 0;
geoPoint a = null;
geoPoint b = null;
geoPoint n = null;
a = V0.subtract(V1);
b = V0.subtract(V2);
n = a.CrossProduct(b);
sn = -n.DotProduct(Q.subtract(V0));
sd = n.DotProduct(n);
sb = sn / sd;
projection = Q.Addition(n.Multiply(sb));
return(projection.distance(ref Q));
}
