private void addCandidate(CellPathData c, int w, int di, int dj, List <CellPath> candidates, CellPath path)
{
var i = c.i;
var j = c.j;
// The total weight of the candidate is the weight of previous path
// plus its weight (calculated based on occupancy and speed factor)
var distanceToDestination = Math.Sqrt((di - i) * (di - i) + (dj - j) * (dj - j));
w = w / c.speed + c.weight;
if (c.candidateRef == null)
{
var candidateRef = new CellPath(i, j, path.w + w, (int)distanceToDestination, path);
//candidates.push(candidateRef);
candidates.Add(candidateRef);
c.candidateRef = candidateRef;
}
else
{
var currentWeight = c.candidateRef.w;
var newWeight = path.w + w;
if (newWeight < currentWeight)
{
c.candidateRef.w = newWeight;
c.candidateRef.path = path;
}
}
}
public PathfinderManager()
{
//init grid
for (var i = 0; i < WIDTH; i += 1)
{
var cellPathDatas = new CellPathData[HEIGHT];
for (var j = 0; j < HEIGHT; j += 1)
{
cellPathDatas[j] = new CellPathData(i, j);
}
Grid[i] = cellPathDatas;
}
//build map points
constructMapPoints();
}
private bool areCommunicating(CellPathData c1, CellPathData c2)
{
// Cells are compatible only if they either have the same floor height...
if (c1.floor == c2.floor)
{
// Same height
return(true);
}
// ... or the same zone, different from 0
// ... or a zone of 0 and a floor difference smaller than ELEVATION_TOLERANCE
if (c1.zone == c2.zone)
{
return(oldMovementSystem || (c1.zone != 0) || (Math.Abs(c1.floor - c2.floor) <= ELEVATION_TOLERANCE));
}
return(false);
}
private CellPathData updateCellPath(Cell cell, CellPathData cellPath)
{
if ((cell.L & 1) != 0)
{
cellPath.floor = cell.F;
cellPath.zone = cell.Z;
cellPath.speed = 1 + cell.S / 10;
if (cellPath.zone != firstCellZone)
{
oldMovementSystem = false;
}
}
else
{
cellPath.floor = -1;
cellPath.zone = -1;
}
return(cellPath);
}
private bool canMoveDiagonallyTo(CellPathData c1, CellPathData c2, CellPathData c3, CellPathData c4)
{
// Can move between c1 and c2 diagonally only if c1 and c2 are compatible and if c1 is compatible either with c3 or c4
return(areCommunicating(c1, c2) && (areCommunicating(c1, c3) || areCommunicating(c1, c4)));
}
public Task <int[]> GetPath(Map map, int startCellId, int destCellId, List <int> occupiedCells,
bool allowDiagonals = false,
bool stopNextToTarget = false)
{
CellPath candidate = null;
fillPathGrid(map, map.CellChangeMaps.Count == 0);
var srcPos = getMapPoint(startCellId); // source index
var dstPos = getMapPoint(destCellId); // source index
var si = srcPos.X + 1;
var sj = srcPos.Y + 1;
var srcCell = Grid[si][sj];
if (srcCell.zone == -1)
{
// Searching for accessible cell around source
CellPathData bestFit = null;
var bestDist = Math.Pow(10, 1000);
var bestFloorDiff = Math.Pow(10, 1000);
for (var i = -1; i <= 1; i += 1)
{
for (var j = -1; j <= 1; j += 1)
{
if (i == 0 && j == 0)
{
continue;
}
var cell = Grid[si + i][sj + j];
if (cell.zone == -1)
{
continue;
}
var floorDiff = Math.Abs(cell.floor - srcCell.floor);
var dist = Math.Abs(i) + Math.Abs(j);
if (bestFit == null || floorDiff < bestFloorDiff ||
(floorDiff <= bestFloorDiff && dist < bestDist))
{
bestFit = cell;
bestDist = dist;
bestFloorDiff = floorDiff;
}
}
}
if (bestFit != null)
{
return(Task.FromResult(new int[2] {
startCellId, getCellId(bestFit.i - 1, bestFit.j - 1)
}));
}
Console.WriteLine("[pathFinder.getPath] Player is stuck in {0}/{1}", si, sj);
return(Task.FromResult(new int[1] {
startCellId
}));
}
var di = dstPos.X + 1; // destination i
var dj = dstPos.Y + 1; // destination j
// marking cells as occupied
Point cellPos;
//var cellId = 0;
foreach (var cellId in occupiedCells)
{
cellPos = getMapPoint(cellId);
Grid[cellPos.X + 1][cellPos.Y + 1].weight += OCCUPIED_CELL_WEIGHT;
}
// First cell in the path
var distSrcDst = Math.Sqrt((si - di) * (si - di) + (sj - dj) * (sj - dj));
var selection = new CellPath(si, sj, 0, (int)distSrcDst, null);
List <CellPath> candidates = new List <CellPath>();
List <CellPath> selections = new List <CellPath>();
// Adding cells to path until destination has been reached
CellPath reachingPath = null;
var closestPath = selection;
while (selection.i != di || selection.j != dj)
{
addCandidates(selection, di, dj, candidates, allowDiagonals);
// Looking for candidate with the smallest additional length to path
// in O(number of candidates)
var n = candidates.Count;
if (n == 0)
{
// No possible path
// returning the closest path to destination
selection = closestPath;
break;
}
var minPotentialWeight = Math.Pow(10, 1000);
var selectionIndex = 0;
for (int c = 0; c < n; c += 1)
{
candidate = candidates[c];
if (candidate.w + candidate.d < minPotentialWeight)
{
selection = candidate;
minPotentialWeight = candidate.w + candidate.d;
selectionIndex = c;
}
}
selections.Add(selection);
candidates.RemoveAt(selectionIndex);
// If stopNextToTarget
// then when reaching a distance of less than Math.sqrt(2) the destination is considered as reached
// (the threshold has to be bigger than sqrt(2) but smaller than 2, to be safe we use the value 1.5)
if (selection.d == 0 || (stopNextToTarget && selection.d < 1.5))
{
// Selected path reached destination
if (reachingPath == null || selection.w < reachingPath.w)
{
reachingPath = selection;
closestPath = selection;
// Clearing candidates dominated by current solution to speed up the algorithm
List <CellPath> trimmedCandidates = new List <CellPath>();
for (int c = 0; c < candidates.Count; c += 1)
{
candidate = candidates[c];
if (candidate.w + candidate.d < reachingPath.w)
{
trimmedCandidates.Add(candidate);
}
else
{
Grid[candidate.i][candidate.j].candidateRef = null;
}
}
candidates = trimmedCandidates;
}
}
else
{
if (selection.d < closestPath.d)
{
// 'selection' is the new closest path to destination
closestPath = selection;
}
}
}
// Removing candidate reference in each cell in selections and active candidates
for (int c = 0; c < candidates.Count; c += 1)
{
candidate = candidates[c];
Grid[candidate.i][candidate.j].candidateRef = null;
}
for (var s = 0; s < selections.Count; s += 1)
{
selection = selections[s];
Grid[selection.i][selection.j].candidateRef = null;
}
// Marking cells as unoccupied
foreach (var cell in occupiedCells)
{
cellPos = getMapPoint(cell);
Grid[cellPos.X + 1][cellPos.Y + 1].weight -= OCCUPIED_CELL_WEIGHT;
}
List <int> shortestPath = new List <int>();
while (closestPath != null)
{
shortestPath.Add(getCellId(closestPath.i - 1, closestPath.j - 1));
closestPath = closestPath.path;
}
return(Task.FromResult(shortestPath.ToArray()));
}
