/// <summary>
/// Find the closest polygon possible in the tile under certain constraints.
/// </summary>
/// <param name="tile">Current tile</param>
/// <param name="center">Center starting point</param>
/// <param name="extents">Range of search</param>
/// <param name="nearestPt">Resulting nearest point</param>
/// <returns>Polygon Reference which contains nearest point</returns>
public PolyId FindNearestPolyInTile(MeshTile tile, Vector3 center, Vector3 extents, ref Vector3 nearestPt)
{
BBox3 bounds;
bounds.Min = center - extents;
bounds.Max = center + extents;
//Get nearby polygons from proximity grid
List <PolyId> polys = new List <PolyId>(128);
int polyCount = QueryPolygonsInTile(tile, bounds, polys);
//Find nearest polygon amongst the nearby polygons
PolyId nearest = PolyId.Null;
float nearestDistanceSqr = float.MaxValue;
//Iterate throuh all the polygons
for (int i = 0; i < polyCount; i++)
{
PolyId reference = polys[i];
Vector3 closestPtPoly = new Vector3();
tile.ClosestPointOnPoly(reference.DecodePolyIndex(polyBits), center, ref closestPtPoly);
float d = (center - closestPtPoly).LengthSquared();
if (d < nearestDistanceSqr)
{
nearestPt = closestPtPoly;
nearestDistanceSqr = d;
nearest = reference;
}
}
return(nearest);
}
/// <summary>
/// Connect Off-Mesh links between polygons from two different tiles.
/// </summary>
/// <param name="tile">Current Tile</param>
/// <param name="target">Target Tile</param>
/// <param name="side">Polygon edge</param>
public void ConnectExtOffMeshLinks(ref MeshTile tile, ref MeshTile target, BoundarySide side)
{
if (tile == null)
{
return;
}
//Connect off-mesh links, specifically links which land from target tile to this tile
BoundarySide oppositeSide = side.GetOpposite();
//Iterate through all the off-mesh connections of target tile
for (int i = 0; i < target.Header.OffMeshConCount; i++)
{
OffMeshConnection targetCon = target.OffMeshConnections[i];
if (targetCon.Side != oppositeSide)
{
continue;
}
Poly targetPoly = target.Polys[targetCon.Poly];
//Skip off-mesh connections which start location could not be connected at all
if (!IsLinkAllocated(targetPoly.FirstLink))
{
continue;
}
Vector3 extents = new Vector3(targetCon.Radius, target.Header.WalkableClimb, targetCon.Radius);
//Find polygon to connect to
Vector3 p = targetCon.Pos1;
Vector3 nearestPt = new Vector3();
PolyId reference = FindNearestPolyInTile(tile, p, extents, ref nearestPt);
if (reference == PolyId.Null)
{
continue;
}
//Further checks
if ((nearestPt.X - p.X) * (nearestPt.X - p.X) + (nearestPt.Z - p.Z) * (nearestPt.Z - p.Z) >
(targetCon.Radius * targetCon.Radius))
{
continue;
}
//Make sure the location is on the current mesh
target.Verts[targetPoly.Verts[1]] = nearestPt;
//Link off-mesh connection to target poly
int idx = AllocLink(target);
if (IsLinkAllocated(idx))
{
target.Links[idx].Reference = reference;
target.Links[idx].Edge = i;
target.Links[idx].Side = oppositeSide;
target.Links[idx].BMin = target.Links[idx].BMax = 0;
//add to linked list
target.Links[idx].Next = target.Polys[i].FirstLink;
target.Polys[i].FirstLink = idx;
}
//link target poly to off-mesh connection
if ((targetCon.Flags & OffMeshConnectionFlags.Bidirectional) != 0)
{
int tidx = AllocLink(tile);
if (IsLinkAllocated(tidx))
{
int landPolyIdx = reference.DecodePolyIndex(polyBits);
PolyId id;
id = GetPolyRefBase(target);
PolyId.SetPolyIndex(ref id, targetCon.Poly, out id);
tile.Links[tidx].Reference = id;
tile.Links[tidx].Edge = 0xff;
tile.Links[tidx].Side = side;
tile.Links[tidx].BMin = tile.Links[tidx].BMax = 0;
//add to linked list
tile.Links[tidx].Next = tile.Polys[landPolyIdx].FirstLink;
tile.Polys[landPolyIdx].FirstLink = tidx;
}
}
}
}
/// <summary>
/// Begin creating off-mesh links between the tile polygons.
/// </summary>
/// <param name="tile">Current Tile</param>
public void BaseOffMeshLinks(ref MeshTile tile)
{
if (tile == null)
{
return;
}
PolyId polyBase = GetPolyRefBase(tile);
//Base off-mesh connection start points
for (int i = 0; i < tile.Header.OffMeshConCount; i++)
{
int con = i;
int poly = tile.OffMeshConnections[con].Poly;
Vector3 extents = new Vector3(tile.OffMeshConnections[con].Radius, tile.Header.WalkableClimb, tile.OffMeshConnections[con].Radius);
//Find polygon to connect to
Vector3 p = tile.OffMeshConnections[con].Pos0;
Vector3 nearestPt = new Vector3();
PolyId reference = FindNearestPolyInTile(tile, p, extents, ref nearestPt);
if (reference == PolyId.Null)
{
continue;
}
//Do extra checks
if ((nearestPt.X - p.X) * (nearestPt.X - p.X) + (nearestPt.Z - p.Z) * (nearestPt.Z - p.Z) >
tile.OffMeshConnections[con].Radius * tile.OffMeshConnections[con].Radius)
{
continue;
}
//Make sure location is on current mesh
tile.Verts[tile.Polys[poly].Verts[0]] = nearestPt;
//Link off-mesh connection to target poly
int idx = AllocLink(tile);
if (IsLinkAllocated(idx))
{
//Initialize a new link
tile.Links[idx].Reference = reference;
tile.Links[idx].Edge = 0;
tile.Links[idx].Side = BoundarySide.Internal;
tile.Links[idx].BMin = tile.Links[idx].BMax = 0;
//Add to polygon's links list
tile.Links[idx].Next = tile.Polys[poly].FirstLink;
tile.Polys[poly].FirstLink = idx;
}
//Start end-point always conects back to off-mesh connection
int tidx = AllocLink(tile);
if (IsLinkAllocated(tidx))
{
//Initialize a new link
int landPolyIdx = reference.DecodePolyIndex(polyBits);
PolyId id;
PolyId.SetPolyIndex(ref polyBase, tile.OffMeshConnections[con].Poly, out id);
tile.Links[idx].Reference = id;
tile.Links[idx].Edge = 0xff;
tile.Links[idx].Side = BoundarySide.Internal;
tile.Links[idx].BMin = tile.Links[idx].BMax = 0;
//Add to polygon's links list
tile.Links[idx].Next = tile.Polys[landPolyIdx].FirstLink;
tile.Polys[landPolyIdx].FirstLink = tidx;
}
}
}
