private static bool CircleHalfPlane(CircleCollider c, HalfPlaneCollider hp)
{
// Distance from the circle's center to the half-plane.
float distance = Math.Abs(hp.A * (c.position.X + c.center.X) + hp.B * (c.position.Y + c.center.Y) + hp.C) / (float)Math.Sqrt(hp.A * hp.A + hp.B * hp.B);
if (distance < c.Radius)
{
return(true);
}
return(false);
}
private static bool PolygonHalfPlane(PolygonCollider p, HalfPlaneCollider hp)
{
// Just check if any of the polygon's vertices satisfies the half-plane's equation.
foreach (Vector2 v in p.vertices)
{
if (hp.A * v.X + hp.B * v.Y <= hp.C)
{
return(true);
}
}
// If none does, there is no intersection.
return(false);
}
private static bool HalfPlane(HalfPlaneCollider k, HalfPlaneCollider l)
{
if ((k.A * l.B) - (k.B * l.A) == 0)
{
// The two lines defining the half-planes are parallel.
// The lines can't intersect, but the half-planes still might!
// @todo I'm not sure about this, should make sure!
if (k.C < l.C)
{
return(true);
}
return(false);
}
// The lines are intersecting, so the half-planes are, too.
return(true);
}
private static bool AABBHalfPlane(AABBCollider a, HalfPlaneCollider hp)
{
// Check if any of the AABB's vertices satisfies the half-plane's equation.
if (hp.A * a.position.X + hp.B * a.position.Y <= hp.C)
{
return(true);
}
if (hp.A * a.position.X + hp.B * (a.position.Y + a.Height) <= hp.C)
{
return(true);
}
if (hp.A * (a.position.X + a.Width) + hp.B * a.position.Y <= hp.C)
{
return(true);
}
if (hp.A * (a.position.X + a.Width) + hp.B * (a.position.Y + a.Height) <= hp.C)
{
return(true);
}
return(false);
}
