public CapsuleCache(Capsule c)
{
capsule = c;
Vec2 d = c.p1 - c.p0;
length = d.Len();
invLength = Mathf.TryInvertPositive(length, out circle);
normal = d.Rot90() * invLength;
center = Vec2.Lerp(0.5f, c.p0, c.p1);
}
private static ClosestPoints CollideCircles(CapsuleCache c0, CapsuleCache c1)
{
Vec2 dir = c1.center - c0.center;
float dist = dir.Len();
return(new ClosestPoints(
point0: c0.center,
point1: c1.center,
normal: dir.SafeDivPositive(dist),
distance: dist - c0.capsule.radius - c1.capsule.radius
));
}