3D.ru

public bool TriContainsPt(Vector2 A, Vector2 B, Vector2 C, Vector2 P)
{
        bool result = false;
        if ((P.x - A.x) * (A.y - B.y) - (P.y - A.y) * (A.x - B.x) >= 0)
                if ((P.x - B.x) * (B.y - C.y) - (P.y - B.y) * (B.x - C.x) >= 0)
                        if ((P.x - C.x) * (C.y - A.y) - (P.y - C.y) * (C.x - A.x) >= 0)
                                result = true;
        return result;
}