public static CCPoint GetSeparationVector(Circle circle, Polygon polygon)
{
bool isCircleCenterInPolygon = polygon.IsPointInside(
circle.PositionWorldspace.X, circle.PositionWorldspace.Y);
float distance;
var normal = polygon.GetNormalClosestTo(circle.PositionWorldspace, out distance);
if (isCircleCenterInPolygon)
{
distance += circle.Radius;
}
else
{
distance = circle.Radius - distance;
}
// increase the distance by a small amount to make sure that the objects do separate:
distance += .5f;
var separation = normal * distance;
return separation;
}
private void CreateCollision()
{
Collision = new Circle ();
Collision.Radius = GameCoefficients.FruitRadius;
this.AddChild (Collision);
}
public bool CollideAgainst(Circle circle)
{
UpdateAbsolutePoints ();
// This method will test the following things:
// * Is the circle's center inside the polygon?
// * Are any of the polygon's points inside the circle?
// * Is the circle within Radius distance from any of the polygon's edges?
// Of course none of this is done if the radius check fails
if ((circle.Radius + boundingRadius) * (circle.Radius + boundingRadius) >
(circle.PositionX - PositionX) * (circle.Position.X - Position.X) +
(circle.PositionY - PositionY) * (circle.Position.Y - Position.Y))
{
// First see if the circle is inside the polygon.
if (IsPointInside(circle.PositionWorldspace.X, circle.PositionWorldspace.Y))
{
LastCollisionPoint.X = circle.Position.X;
LastCollisionPoint.Y = circle.Position.Y;
return true;
}
int i;
// Next see if any of the Polygon's points are inside the circle
for (i = 0; i < absolutePoints.Length; i++)
{
if (circle.IsPointInside(absolutePoints[i]))
{
LastCollisionPoint.X = absolutePoints[i].X;
LastCollisionPoint.Y = absolutePoints[i].Y;
return true;
}
}
int k;
Segment s1 = new Segment();
Segment s2 = new Segment();
// Next check if the circle is within Radius units of any segment.
for (i = 0; i < absolutePoints.Length; i++)
{
k = i + 1 < absolutePoints.Length ? i + 1 : 0;
s1.Point1 = absolutePoints [i];
s1.Point2 = absolutePoints[k];
var position = circle.PositionWorldspace;
var segmentDistance = s1.DistanceTo (ref position, out s2);
if (segmentDistance < circle.Radius)
{
LastCollisionPoint.X = s2.Point2.X;
LastCollisionPoint.Y = s2.Point2.Y;
return true;
}
}
}
return false;
}