//@AstarPro
using UnityEngine;
using System.Collections;
using Pathfinding;

/** Attach to any GameObject and the object will be clamped to the navmesh.
 * If a GameObject has this component attached, one or more graph linecasts will be carried out every frame to ensure that the object
 * does not leave the navmesh area.\n
 * It can be used with GridGraphs, but Navmesh based ones are prefered.
 *
 * \note This has partly been replaced by using an RVOController along with RVONavmesh.
 * It will not yield exactly the same results though, so this script is still useful in some cases.
 *
 * \astarpro */
public class NavmeshClamp : MonoBehaviour {

    Node prevNode;
    Vector3 prevPos;

    // Update is called once per frame
    void LateUpdate () {

        if (prevNode == null) {
            NNInfo nninfo = AstarPath.active.GetNearest (transform.position);
            prevNode = nninfo.node;
            prevPos = transform.position;

        }

        if (prevNode == null) {
            return;
        }

        if (prevNode != null) {


            IRaycastableGraph graph = AstarData.GetGraph (prevNode) as IRaycastableGraph;
            if (graph != null) {
                GraphHitInfo hit;
                if (graph.Linecast (prevPos,transform.position,prevNode, out hit)) {
                    hit.point.y = transform.position.y;
                    Vector3 closest = Mathfx.NearestPoint (hit.tangentOrigin,hit.tangentOrigin+hit.tangent,transform.position);
                    Vector3 ohit = hit.point;
                    ohit = ohit + Vector3.ClampMagnitude((Vector3)hit.node.position-ohit,0.01f);
                    if (graph.Linecast (ohit,closest,hit.node, out hit)) {
                        hit.point.y = transform.position.y;
                        transform.position = hit.point;
                    } else {
                        closest.y = transform.position.y;

                        transform.position = closest;
                    }
                }
                prevNode = hit.node;
            }
        }

        prevPos = transform.position;
    }
}