// BUGGO: Yikes this suddenly broke dramatically when I re-ordered the
// constructor arguments for BBox's. I thought I fixed all the instances
// where that mattered though!
public override Intersection IntersectBBox(BBox other)
{
var intersectionBBox = bbox.Intersection(other);
if (intersectionBBox == null)
{
return(null);
}
var contact = intersectionBBox.Center();
// XXX: rather kludgy and approximate; should take into account starting velocity, etc.
var dx0 = contact.X - other.Left;
var dx1 = other.Right - contact.X;
var dx = Math.Min(dx0, dx1);
var xside = dx0 < dx1 ? -Vector2d.UnitX : Vector2d.UnitX;
var dy0 = contact.Y - other.Bottom;
var dy1 = other.Top - contact.Y;
var dy = Math.Min(dy0, dy1);
var yside = dy0 < dy1 ? Vector2d.UnitY : -Vector2d.UnitY;
var ds = Math.Min(dx, dy);
var sideNormal = dx < dy ? xside : yside;
var flat = dx < dy ? intersectionBBox.Dy : intersectionBBox.Dx;
return(new Intersection(contact, sideNormal, 0.5 * ds, -0.5 * ds, flat, -flat));
}
