// Triangle3d methods
bool Triangle3d::Intof(const Line& l, Point3d& intof)const {
// returns intersection triangle to line in intof
// funtion returns true for intersection, false for no intersection
// method based on Möller & Trumbore(1997) (Barycentric coordinates)
// based on incorrect Pseudo code from "Geometric Tools for Computer Graphics" p.487
if(box.outside(l.box) == true) return false;
Vector3d line(l.v);
line.normalise();
Vector3d p = line ^ v1; // cross product
double tmp = p * v0; // dot product
if(FEQZ(tmp)) return false;
tmp = 1 / tmp;
Vector3d s(vert1, l.p0);
double u = tmp * (s * p); // barycentric coordinate
if(u < 0 || u > 1) return false; // not inside triangle
Vector3d q = s ^ v0;
double v = tmp * (line * q); // barycentric coordinate
if(v < 0 || v > 1) return false; // not inside triangle
if( u + v > 1) return false; // not inside triangle
double t = tmp * (v1 * q);
intof = line * t + l.p0;
return true;
}
bool Line::atZ(double z, Point3d& p)const {
// returns p at z on line
if(FEQZ(this->v.getz())) return false;
double t = (z - this->p0.z) / this->v.getz();
p = Point3d(this->p0.x + t * this->v.getx(), this->p0.y + t * this->v.gety(), z);
return true;
}
// vector
Vector2d::Vector2d(const Vector3d &v){
if(FEQZ(v.getz())) FAILURE(L"Converting Vector3d to Vector2d illegal");
dx = v.getx();
dy = v.gety();
}
