const Zeni::Vector3f Utils::getSurfaceNormal(const Zeni::Point3f &p1, const Zeni::Point3f &p2, const Zeni::Point3f &p3) {
Zeni::Vector3f v1 = p2 - p1;
Zeni::Vector3f v2 = p3 - p2;
Zeni::Vector3f normal = Zeni::Vector3f();
normal.i = (v1.y * v2.z) - (v1.z * v2.y);
normal.j = (v1.z * v2.x) - (v1.x * v2.z);
normal.k = (v1.x * v2.y) - (v1.y * v2.x);
return normal.normalize();
}
void Energy::Update (Zeni::Time::Second_Type elapsedTime)
{
Zeni::Point2f hero = HeroComponent::GetInstance().GetPosition();
Zeni::Vector3f a (hero.x - position.x, hero.y - position.y, 0.0f);
a.normalize();
SetAcceleration (100.0f * a);
Simulateable::UpdatePosition (elapsedTime);
}
const double Utils::getAngleBetweenVectors(const Zeni::Vector3f &v0, const Zeni::Vector3f &v1) {
const double a = v0.magnitude();
const double b = v1.magnitude();
const double c = (v1 - v0).magnitude();
double d = (a * a + b * b - c * c) / (2 * a * b);
if (d > 1) {
d = 1.0f;
} else if (d < -1.0f) {
d = -1.0f;
}
return double(acos(d));
}
const Zeni::Vector3f Utils::getVectorComponent(const Zeni::Vector3f &vector, const Zeni::Vector3f &direction) {
return vector*direction/direction.magnitude() * direction.normalized();
}