public static bool IsPointOnRay(HPoint p, HRay ray)
{
if (!HAccuracy.DoubleEqual(0, ((p - ray.Source) * (ray.Direction)).Length())) //is not on line(colinear)
{
return(false);
}
return(HAccuracy.DoubleGreater((p - ray.Source) % (ray.Direction), 0)); //is codirectional
}
public HPoint CollisionPoint(HRay ray)
{
HPoint intersectionPoint = HGeometry.OldIntersectPlaneLine(A, B, C, ray.Source, ray.Source + ray.Direction);
if (intersectionPoint == null) //no intersection point with plane
{
return(null);
}
if (!HGeometry.IsPointOnRay(intersectionPoint, ray)) //point is invisible
{
return(null);
}
double firstSquare = HGeometry.TriangleSquare(A, B, C);
double secondSquare = HGeometry.TriangleSquare(A, B, intersectionPoint) +
HGeometry.TriangleSquare(A, C, intersectionPoint) +
HGeometry.TriangleSquare(C, B, intersectionPoint);
return(HAccuracy.DoubleEqual(firstSquare, secondSquare) ? intersectionPoint : null);
}
