// This is a special case version of intersect where we have the vector // perpendicular to the second line rather than the vector parallel to it. static SkScalar perp_intersect(const SkPoint& p0, const SkPoint& n0, const SkPoint& p1, const SkPoint& perp) { const SkPoint v = p1 - p0; SkScalar perpDot = n0.dot(perp); return v.dot(perp) / perpDot; }