public bool Intersects(FloatCircle circle, out float overlap)
{
var dx = circle.X - X;
var dy = circle.Y - Y;
var mSquared = dx * dx + dy * dy;
var r = Radius + circle.Radius;
var rSquared = (r) * (r);
overlap = r - (float)Math.Sqrt(mSquared);
return(mSquared <= rSquared);
}
private Vector2f[] IntersectionPoints(FloatLine ray, CircleShape shape)
{
var circle = new FloatCircle(shape.Position, shape.Radius);
var circleDelta = (shape.Position - Position);
var product = Direction.Dot(circleDelta);
if (product <= 0) // if ray is facing in the opposite direction of the circle
{
return(Array.Empty <Vector2f>());
}
return(ray.Intersects(circle));
}
public Vector2f[] Intersects(FloatCircle circle)
{
var circlePos = new Vector2f(circle.X, circle.Y);
var r = circle.Radius;
var p1 = P1 - circlePos; // translate p1 to circle local space
var p2 = P2 - circlePos; // translate p2 to circle local space
var d = p2 - p1;
var a = d.SqrLength();
var b = 2 * ((d.X * p1.X) + (d.Y * p1.Y));
var c = p1.SqrLength() - (r * r);
var delta = b * b - (4 * a * c);
if (delta < 0)
{
return new Vector2f[] {}
}
;
if (delta == 1)
{
var u = -b / (2 * a);
var intersection = P1 + (u * d);
return(new[] { intersection });
}
var sqrDelta = -Math.Sqrt(delta);
var u1 = (float)(-b - sqrDelta) / (2 * a);
var u2 = (float)(-b + sqrDelta) / (2 * a);
var intersection1 = P1 + (u1 * d);
var intersection2 = P1 + (u2 * d);
return(new[] { intersection1, intersection2 });
}
public T[] QueryRange(FloatCircle boundary)
{
var rect = new FloatRect(
boundary.X - boundary.Radius,
boundary.Y - boundary.Radius,
boundary.Radius,
boundary.Radius
);
if (!_boundary.Intersects(rect))
{
return(Array.Empty <T>());
}
var inRange = new List <T>();
_data.ForEach(datum =>
{
if (boundary.Contains(datum.Point.X, datum.Point.Y))
{
inRange.Add(datum.Data);
}
});
if (_northWest == null)
{
return(inRange.ToArray());
}
inRange.AddRange(_northEast.QueryRange(boundary));
inRange.AddRange(_northWest.QueryRange(boundary));
inRange.AddRange(_southEast.QueryRange(boundary));
inRange.AddRange(_southWest.QueryRange(boundary));
return(inRange.ToArray());
}
//**********************************************************
//** methods:
//**********************************************************
public bool Intersects(FloatCircle circle) => Intersects(circle, out _);
