public Triangle(Point a, Point b, Point c)
{
_a = a;
_b = b;
_c = c;
Vector tmp1 = new Vector(a, b);
Vector tmp2 = new Vector(a, c);
_polyNormal = tmp1.CrossProduct(tmp2);
_polyNormal.Normalise();
CalculatePolygonCenter();
}
public bool IsFrontFacing(Triangle triangle)
{
// on prend en compte que les normales sont unitaires...
double dot = _polyNormal.DotProduct(triangle._polyNormal);
Vector vecProj = new Vector(_polyNormal);
vecProj.MultiplyBy(dot);
vecProj.Normalise();
vecProj.AddVector(_polyNormal);
vecProj.Normalise();
if(vecProj.Norm >= -Definition.EPSILON && vecProj.Norm <= Definition.EPSILON)
return false;
else
return true;
}