/// <summary>
/// Insert a segment into the array
/// </summary>
/// <param name="ints">The array of segments</param>
/// <param name="nints">The number of segments</param>
/// <param name="maxInts">The maximium number of segments allowed</param>
/// <param name="tmin">Parameter t minimum</param>
/// <param name="tmax">Parameter t maximum</param>
/// <param name="reference">Polygon reference</param>
public void InsertInterval(SegInterval[] ints, ref int nints, int maxInts, int tmin, int tmax, PolyId reference)
{
if (nints + 1 > maxInts)
return;
//find insertion point
int idx = 0;
while (idx < nints)
{
if (tmax <= ints[idx].TMin)
break;
idx++;
}
//move current results
if (nints - idx > 0)
{
for (int i = 0; i < nints - idx; i++)
ints[idx + 1 + i] = ints[idx + i];
}
//store
ints[idx].Reference = reference;
ints[idx].TMin = tmin;
ints[idx].TMax = tmax;
nints++;
}
/// <summary>
/// Collect all the edges from a polygon.
/// </summary>
/// <param name="reference">The polygon reference</param>
/// <param name="segmentVerts">Segment vertices</param>
/// <param name="segmentRefs">The polygon reference containing the segment</param>
/// <param name="segmentCount">The number of segments stored</param>
/// <param name="maxSegments">The maximum number of segments allowed</param>
/// <returns>True, unless the polygon reference is invalid</returns>
public bool GetPolyWallSegments(PolyId reference, Crowds.LocalBoundary.Segment[] segmentVerts, PolyId[] segmentRefs, ref int segmentCount, int maxSegments)
{
segmentCount = 0;
MeshTile tile;
Poly poly;
if (nav.TryGetTileAndPolyByRef(reference, out tile, out poly) == false)
return false;
int n = 0;
int MAX_INTERVAL = 16;
SegInterval[] ints = new SegInterval[MAX_INTERVAL];
int nints;
bool storePortals = segmentRefs.Length != 0;
for (int i = 0, j = poly.VertCount - 1; i < poly.VertCount; j = i++)
{
//skip non-solid edges
nints = 0;
if ((poly.Neis[j] & Link.External) != 0)
{
//tile border
for (int k = poly.FirstLink; k != Link.Null; k = tile.Links[k].Next)
{
Link link = tile.Links[k];
if (link.Edge == j)
{
if (link.Reference != PolyId.Null)
{
MeshTile neiTile;
Poly neiPoly;
nav.TryGetTileAndPolyByRefUnsafe(link.Reference, out neiTile, out neiPoly);
InsertInterval(ints, ref nints, MAX_INTERVAL, link.BMin, link.BMax, link.Reference);
}
}
}
}
else
{
//internal edge
PolyId neiRef = PolyId.Null;
if (poly.Neis[j] != 0)
{
int idx = poly.Neis[j] - 1;
PolyId id = nav.GetPolyRefBase(tile);
PolyId.SetPolyIndex(ref id, idx, out neiRef);
}
//if the edge leads to another polygon and portals are not stored, skip
if (neiRef != PolyId.Null && !storePortals)
continue;
if (n < maxSegments)
{
Vector3 vj = tile.Verts[poly.Verts[j]];
Vector3 vi = tile.Verts[poly.Verts[i]];
segmentVerts[n].Start = vj;
segmentVerts[n].End = vi;
segmentRefs[n] = neiRef;
n++; //could be n += 2, since segments have 2 vertices
}
continue;
}
//add sentinels
InsertInterval(ints, ref nints, MAX_INTERVAL, -1, 0, PolyId.Null);
InsertInterval(ints, ref nints, MAX_INTERVAL, 255, 256, PolyId.Null);
//store segments
Vector3 vj2 = tile.Verts[poly.Verts[j]];
Vector3 vi2 = tile.Verts[poly.Verts[i]];
for (int k = 1; k < nints; k++)
{
//portal segment
if (storePortals && ints[k].Reference != PolyId.Null)
{
float tmin = ints[k].TMin / 255.0f;
float tmax = ints[k].TMax / 255.0f;
if (n < maxSegments)
{
Vector3.Lerp(ref vj2, ref vi2, tmin, out segmentVerts[n].Start);
Vector3.Lerp(ref vj2, ref vi2, tmax, out segmentVerts[n].End);
segmentRefs[n] = ints[k].Reference;
n++;
}
}
//wall segment
int imin = ints[k - 1].TMax;
int imax = ints[k].TMin;
if (imin != imax)
{
float tmin = imin / 255.0f;
float tmax = imax / 255.0f;
if (n < maxSegments)
{
Vector3.Lerp(ref vj2, ref vi2, tmin, out segmentVerts[n].Start);
Vector3.Lerp(ref vj2, ref vi2, tmax, out segmentVerts[n].End);
segmentRefs[n] = PolyId.Null;
n++;
}
}
}
}
segmentCount = n;
return true;
}
