public static void Erode(TerraMesh _tMesh, float _maxErosionRate, float[] _waterFlux)
{
var sitePositions = _tMesh.GetAllSitePositions(); //TODO SLOW
//Get all site slope vectors and slope values
var slopeVecs = new Vector3[sitePositions.Length];
var slopeVals = new float[sitePositions.Length];
for (var pIdx = 0; pIdx < sitePositions.Length; ++pIdx)
{
var p = sitePositions[pIdx];
var aveSlp = Vector3.zero;
var nbrCnt = 0;
foreach (var nIdx in _tMesh.SiteNeighbors[pIdx])
{
if (nIdx == SiteIdxNull)
{
continue;
}
nbrCnt++;
var n = sitePositions[nIdx];
var slpVec = n - p;
if (slpVec.z > 0)
{
slpVec = -slpVec;
}
aveSlp += slpVec;
}
var slpVecCell = aveSlp / nbrCnt;
slopeVecs[pIdx] = slpVecCell;
slopeVals[pIdx] = slpVecCell.z / new Vector2(slpVecCell.x, slpVecCell.y).magnitude;
}
//Apply erosion to terra mesh surface
for (var pIdx = 0; pIdx < _waterFlux.Length; ++pIdx)
{
var sitePos = sitePositions[pIdx];
var fx = (float)Math.Sqrt(_waterFlux[pIdx]);
var slp = slopeVals[pIdx];
var erosionShift = Math.Min(-slp * fx, _maxErosionRate);
//var newPos = new Vector3(sitePos.x, sitePos.y, sitePos.z - erosionShift);
SetSiteHeight(_tMesh, pIdx, sitePos.z - erosionShift);
}
_tMesh.RecalculateBounds();
}
public static Vector3[] PlanchonDarboux(TerraMesh _tMesh, float _minSlope, Progress.OnUpdate _onUpdate)
{
var prog = new Progress("PlanchonDarboux");
prog.SetOnUpdate(_onUpdate);
var sitePosArr = _tMesh.GetAllSitePositions(); //TODO slow?
var hullSites = new HashSet <int>(_tMesh.HullSites);
//var hullSites = _tMesh.HullSites;
//Generate waterflow surface points
var newSurf = new Vector3[sitePosArr.Length];
for (var pIdx = 0; pIdx < sitePosArr.Length; ++pIdx)
{
var sPos = sitePosArr[pIdx];
var z = float.PositiveInfinity;
if (hullSites.Contains(pIdx))
{
z = sPos.z;
}
newSurf[pIdx] = new Vector3(sPos.x, sPos.y, z);
}
Func <int, float> Z = _idx => sitePosArr[_idx].z;
Func <int, float> W = _idx => newSurf[_idx].z;
Func <int, int, float> E = (_cIdx, _nIdx) =>
{
var cVert = sitePosArr[_cIdx];
var nVert = sitePosArr[_nIdx];
var subX = nVert.x - cVert.x;
var subY = nVert.y - cVert.y;
return((float)Math.Sqrt(subX * subX + subY * subY) * _minSlope);
};
var opDone = false;
var wCnt = 0; //DEBUG todo
do
{
opDone = false;
var sitePosArrLen = sitePosArr.Length; //TODO Debug
for (var pIdx = 0; pIdx < sitePosArrLen; ++pIdx)
{
var progPct = (float)pIdx / sitePosArrLen;
prog.Update(progPct, pIdx + " of " + sitePosArrLen);
if (hullSites.Contains(pIdx))
{
continue;
}
var sitePos = sitePosArr[pIdx];
var c = pIdx;
if (!(W(c) > Z(c)))
{
continue;
}
var cVertZ = sitePos;
foreach (var n in _tMesh.SiteNeighbors[pIdx])
{
var e = E(c, n);
var wpn = W(n) + e;
if (cVertZ.z >= wpn)
{
newSurf[c].Set(cVertZ.x, cVertZ.y, cVertZ.z);
opDone = true;
break;
}
if (W(c) > wpn)
{
newSurf[c].Set(cVertZ.x, cVertZ.y, wpn);
opDone = true;
}
}
}
if (++wCnt > 2)
{
break; // TODO DEBUG
}
} while (opDone);
return(newSurf);
}
