public void RayCast(IRayCastCallback callback, ref RayCastInput input)
{
ElementRayCastCallbackHelper helper = new ElementRayCastCallbackHelper()
{
callback = callback
};
_quadTree.RayCast(helper, ref input);
}
/// <summary>
/// Ray-cast the world for all fixtures in the path of the ray. Your callback controls whether you
/// get the closest point, any point, or n-points. The ray-cast ignores shapes that contain the
/// starting point.
/// </summary>
/// <param name="callback">a user implemented callback class.</param>
/// <param name="point1">the ray starting point</param>
/// <param name="point2">the ray ending point</param>
public void Raycast(IRayCastCallback callback, Vec2 point1, Vec2 point2)
{
wrcwrapper.BroadPhase = ContactManager.BroadPhase;
wrcwrapper.Callback = callback;
input.MaxFraction = 1.0f;
input.P1.Set(point1);
input.P2.Set(point2);
ContactManager.BroadPhase.Raycast(wrcwrapper, input);
}
/// <summary>
/// Ray-cast against the proxies in the tree. This relies on the callback
/// to perform a exact ray-cast in the case were the proxy contains a shape.
/// The callback also performs the any collision filtering. This has performance
/// roughly equal to k * log(n), where k is the number of collisions and n is the
/// number of proxies in the tree.
/// </summary>
/// <param name="callback">A callback class that is called for each proxy that is hit by the ray.</param>
/// <param name="input">The ray-cast input data. The ray extends from p1 to p1 + maxFraction * (p2 - p1).</param>
public void RayCast(IRayCastCallback callback, ref RayCastInput input)
{
_tree.RayCast(callback, ref input);
}
/// <summary>
/// Ray-cast against the proxies in the tree. This relies on the callback
/// to perform a exact ray-cast in the case were the proxy contains a Shape.
/// The callback also performs the any collision filtering. This has performance
/// roughly equal to k * log(n), where k is the number of collisions and n is the
/// number of proxies in the tree.
/// </summary>
/// <param name="callback">A callback class that is called for each proxy that is hit by the ray.</param>
/// <param name="input">The ray-cast input data. The ray extends from p1 to p1 + maxFraction * (p2 - p1).</param>
public void RayCast(IRayCastCallback callback, ref RayCastInput input)
{
Vector2 p1 = input.Point1;
Vector2 p2 = input.Point2;
Vector2 r = p2 - p1;
Debug.Assert(r.LengthSquared() > 0.0f);
r.Normalize();
// v is perpendicular to the segment.
Vector2 absV = MathUtils.Abs(new Vector2(-r.Y, r.X));
// Separating axis for segment (Gino, p80).
// |dot(v, p1 - c)| > dot(|v|, h)
float maxFraction = input.MaxFraction;
// Build a bounding box for the segment.
AABB segmentAABB = new AABB();
{
Vector2 t = p1 + maxFraction * (p2 - p1);
Vector2.Min(ref p1, ref t, out segmentAABB.LowerBound);
Vector2.Max(ref p1, ref t, out segmentAABB.UpperBound);
}
_stack.Clear();
_stack.Push(_root);
while (_stack.Count > 0)
{
int nodeId = _stack.Pop();
if (nodeId == NullNode)
{
continue;
}
DynamicTreeNode <T> node = _nodes[nodeId];
if (AABB.TestOverlap(ref node.AABB, ref segmentAABB) == false)
{
continue;
}
// Separating axis for segment (Gino, p80).
// |dot(v, p1 - c)| > dot(|v|, h)
Vector2 c = node.AABB.Center;
Vector2 h = node.AABB.Extents;
float separation = Math.Abs(Vector2.Dot(new Vector2(-r.Y, r.X), p1 - c)) - Vector2.Dot(absV, h);
if (separation > 0.0f)
{
continue;
}
if (node.IsLeaf())
{
RayCastInput subInput;
subInput.Point1 = input.Point1;
subInput.Point2 = input.Point2;
subInput.MaxFraction = maxFraction;
float value = callback.RayCastCallback(ref subInput, nodeId);
if (value == 0.0f)
{
// the client has terminated the raycast.
return;
}
if (value > 0.0f)
{
// Update segment bounding box.
maxFraction = value;
Vector2 t = p1 + maxFraction * (p2 - p1);
segmentAABB.LowerBound = Vector2.Min(p1, t);
segmentAABB.UpperBound = Vector2.Max(p1, t);
}
}
else
{
_stack.Push(node.Child1);
_stack.Push(node.Child2);
}
}
}
