private static void identifySuccessors(JumpPointParam iParam, Node iNode)
{
HeuristicDelegate tHeuristic = iParam.HeuristicFunc;
IntervalHeap <Node> tOpenList = iParam.openList;
int tEndX = iParam.EndNode.x;
int tEndY = iParam.EndNode.y;
GridPos tNeighbor;
GridPos tJumpPoint;
Node tJumpNode;
List <GridPos> tNeighbors = findNeighbors(iParam, iNode);
for (int i = 0; i < tNeighbors.Count; i++)
{
tNeighbor = tNeighbors[i];
if (iParam.CurIterationType == IterationType.RECURSIVE)
{
tJumpPoint = jump(iParam, tNeighbor.x, tNeighbor.y, iNode.x, iNode.y);
}
else
{
tJumpPoint = jumpLoop(iParam, tNeighbor.x, tNeighbor.y, iNode.x, iNode.y);
}
if (tJumpPoint != null)
{
tJumpNode = iParam.SearchGrid.GetNodeAt(tJumpPoint.x, tJumpPoint.y);
if (tJumpNode == null)
{
if (iParam.EndNode.x == tJumpPoint.x && iParam.EndNode.y == tJumpPoint.y)
{
tJumpNode = iParam.SearchGrid.GetNodeAt(tJumpPoint);
}
}
if (tJumpNode.isClosed)
{
continue;
}
// include distance, as parent may not be immediately adjacent:
float tCurNodeToJumpNodeLen = tHeuristic(Math.Abs(tJumpPoint.x - iNode.x), Math.Abs(tJumpPoint.y - iNode.y));
float tStartToJumpNodeLen = iNode.startToCurNodeLen + tCurNodeToJumpNodeLen; // next `startToCurNodeLen` value
if (!tJumpNode.isOpened || tStartToJumpNodeLen < tJumpNode.startToCurNodeLen)
{
tJumpNode.startToCurNodeLen = tStartToJumpNodeLen;
tJumpNode.heuristicCurNodeToEndLen = (tJumpNode.heuristicCurNodeToEndLen == null ? tHeuristic(Math.Abs(tJumpPoint.x - tEndX), Math.Abs(tJumpPoint.y - tEndY)) : tJumpNode.heuristicCurNodeToEndLen);
tJumpNode.heuristicStartToEndLen = tJumpNode.startToCurNodeLen + tJumpNode.heuristicCurNodeToEndLen.Value;
tJumpNode.parent = iNode;
if (!tJumpNode.isOpened)
{
tOpenList.Add(tJumpNode);
tJumpNode.isOpened = true;
}
}
}
}
}
public JumpPointParam(JumpPointParam b) : base(b)
{
m_heuristic = b.m_heuristic;
CurEndNodeUnWalkableTreatment = b.CurEndNodeUnWalkableTreatment;
openList = new IntervalHeap <Node>();
openList.AddAll(b.openList);
CurIterationType = b.CurIterationType;
}
public static List <GridPos> FindPath(JumpPointParam iParam)
{
IntervalHeap <Node> tOpenList = iParam.openList;
Node tStartNode = iParam.StartNode;
Node tEndNode = iParam.EndNode;
Node tNode;
bool revertEndNodeWalkable = false;
// set the `g` and `f` value of the start node to be 0
tStartNode.startToCurNodeLen = 0;
tStartNode.heuristicStartToEndLen = 0;
// push the start node into the open list
tOpenList.Add(tStartNode);
tStartNode.isOpened = true;
if (iParam.CurEndNodeUnWalkableTreatment == EndNodeUnWalkableTreatment.ALLOW && !iParam.SearchGrid.IsWalkableAt(tEndNode.x, tEndNode.y))
{
iParam.SearchGrid.SetWalkableAt(tEndNode.x, tEndNode.y, true);
revertEndNodeWalkable = true;
}
// while the open list is not empty
while (tOpenList.Count > 0)
{
// pop the position of node which has the minimum `f` value.
tNode = tOpenList.DeleteMin();
tNode.isClosed = true;
if (tNode.Equals(tEndNode))
{
if (revertEndNodeWalkable)
{
iParam.SearchGrid.SetWalkableAt(tEndNode.x, tEndNode.y, false);
}
return(Node.Backtrace(tNode)); // rebuilding path
}
identifySuccessors(iParam, tNode);
}
if (revertEndNodeWalkable)
{
iParam.SearchGrid.SetWalkableAt(tEndNode.x, tEndNode.y, false);
}
// fail to find the path
return(new List <GridPos>());
}
private static List <GridPos> findNeighbors(JumpPointParam iParam, Node iNode)
{
Node tParent = (Node)iNode.parent;
//var diagonalMovement = Util.GetDiagonalMovement(iParam.CrossCorner, iParam.CrossAdjacentPoint);
int tX = iNode.x;
int tY = iNode.y;
int tPx, tPy, tDx, tDy;
List <GridPos> tNeighbors = new List <GridPos>();
List <Node> tNeighborNodes;
Node tNeighborNode;
// directed pruning: can ignore most neighbors, unless forced.
if (tParent != null)
{
tPx = tParent.x;
tPy = tParent.y;
// get the normalized direction of travel
tDx = (tX - tPx) / Math.Max(Math.Abs(tX - tPx), 1);
tDy = (tY - tPy) / Math.Max(Math.Abs(tY - tPy), 1);
// search diagonally
if (tDx != 0 && tDy != 0)
{
if (iParam.SearchGrid.IsWalkableAt(tX, tY + tDy))
{
tNeighbors.Add(new GridPos(tX, tY + tDy));
}
if (iParam.SearchGrid.IsWalkableAt(tX + tDx, tY))
{
tNeighbors.Add(new GridPos(tX + tDx, tY));
}
if (iParam.SearchGrid.IsWalkableAt(tX + tDx, tY + tDy))
{
if (iParam.SearchGrid.IsWalkableAt(tX, tY + tDy) && iParam.SearchGrid.IsWalkableAt(tX + tDx, tY))
{
tNeighbors.Add(new GridPos(tX + tDx, tY + tDy));
}
}
if (iParam.SearchGrid.IsWalkableAt(tX - tDx, tY + tDy))
{
if (iParam.SearchGrid.IsWalkableAt(tX, tY + tDy) && iParam.SearchGrid.IsWalkableAt(tX - tDx, tY))
{
tNeighbors.Add(new GridPos(tX - tDx, tY + tDy));
}
}
if (iParam.SearchGrid.IsWalkableAt(tX + tDx, tY - tDy))
{
if (iParam.SearchGrid.IsWalkableAt(tX, tY - tDy) && iParam.SearchGrid.IsWalkableAt(tX + tDx, tY))
{
tNeighbors.Add(new GridPos(tX + tDx, tY - tDy));
}
}
}
// search horizontally/vertically
else
{
if (tDx != 0)
{
if (iParam.SearchGrid.IsWalkableAt(tX + tDx, tY))
{
tNeighbors.Add(new GridPos(tX + tDx, tY));
if (iParam.SearchGrid.IsWalkableAt(tX + tDx, tY + 1) && iParam.SearchGrid.IsWalkableAt(tX, tY + 1))
{
tNeighbors.Add(new GridPos(tX + tDx, tY + 1));
}
if (iParam.SearchGrid.IsWalkableAt(tX + tDx, tY - 1) && iParam.SearchGrid.IsWalkableAt(tX, tY - 1))
{
tNeighbors.Add(new GridPos(tX + tDx, tY - 1));
}
}
if (iParam.SearchGrid.IsWalkableAt(tX, tY + 1))
{
tNeighbors.Add(new GridPos(tX, tY + 1));
}
if (iParam.SearchGrid.IsWalkableAt(tX, tY - 1))
{
tNeighbors.Add(new GridPos(tX, tY - 1));
}
}
else
{
if (iParam.SearchGrid.IsWalkableAt(tX, tY + tDy))
{
tNeighbors.Add(new GridPos(tX, tY + tDy));
if (iParam.SearchGrid.IsWalkableAt(tX + 1, tY + tDy) && iParam.SearchGrid.IsWalkableAt(tX + 1, tY))
{
tNeighbors.Add(new GridPos(tX + 1, tY + tDy));
}
if (iParam.SearchGrid.IsWalkableAt(tX - 1, tY + tDy) && iParam.SearchGrid.IsWalkableAt(tX - 1, tY))
{
tNeighbors.Add(new GridPos(tX - 1, tY + tDy));
}
}
if (iParam.SearchGrid.IsWalkableAt(tX + 1, tY))
{
tNeighbors.Add(new GridPos(tX + 1, tY));
}
if (iParam.SearchGrid.IsWalkableAt(tX - 1, tY))
{
tNeighbors.Add(new GridPos(tX - 1, tY));
}
}
}
}
// return all neighbors
else
{
tNeighborNodes = iParam.SearchGrid.GetNeighbors(iNode);
for (int i = 0; i < tNeighborNodes.Count; i++)
{
tNeighborNode = tNeighborNodes[i];
tNeighbors.Add(new GridPos(tNeighborNode.x, tNeighborNode.y));
}
}
return(tNeighbors);
}
private static GridPos jump(JumpPointParam iParam, int iX, int iY, int iPx, int iPy)
{
if (!iParam.SearchGrid.IsWalkableAt(iX, iY))
{
return(null);
}
else if (iParam.SearchGrid.GetNodeAt(iX, iY).Equals(iParam.EndNode))
{
return(new GridPos(iX, iY));
}
int tDx = iX - iPx;
int tDy = iY - iPy;
// check for forced neighbors
// along the diagonal
if (tDx != 0 && tDy != 0)
{
if (iParam.SearchGrid.IsWalkableAt(iX + tDx, iY + tDy) && (!iParam.SearchGrid.IsWalkableAt(iX, iY + tDy) || !iParam.SearchGrid.IsWalkableAt(iX + tDx, iY)))
{
return(new GridPos(iX, iY));
}
}
// horizontally/vertically
else
{
if (tDx != 0)
{
// moving along x
if ((iParam.SearchGrid.IsWalkableAt(iX, iY + 1) && !iParam.SearchGrid.IsWalkableAt(iX - tDx, iY + 1)) ||
(iParam.SearchGrid.IsWalkableAt(iX, iY - 1) && !iParam.SearchGrid.IsWalkableAt(iX - tDx, iY - 1)))
{
return(new GridPos(iX, iY));
}
}
else
{
if ((iParam.SearchGrid.IsWalkableAt(iX + 1, iY) && !iParam.SearchGrid.IsWalkableAt(iX + 1, iY - tDy)) ||
(iParam.SearchGrid.IsWalkableAt(iX - 1, iY) && !iParam.SearchGrid.IsWalkableAt(iX - 1, iY - tDy)))
{
return(new GridPos(iX, iY));
}
}
}
// when moving diagonally, must check for vertical/horizontal jump points
if (tDx != 0 && tDy != 0)
{
if (jump(iParam, iX + tDx, iY, iX, iY) != null)
{
return(new GridPos(iX, iY));
}
if (jump(iParam, iX, iY + tDy, iX, iY) != null)
{
return(new GridPos(iX, iY));
}
}
// moving diagonally, must make sure both of the vertical/horizontal
// neighbors is open to allow the path
if (iParam.SearchGrid.IsWalkableAt(iX + tDx, iY) && iParam.SearchGrid.IsWalkableAt(iX, iY + tDy))
{
return(jump(iParam, iX + tDx, iY + tDy, iX, iY));
}
else
{
return(null);
}
}
private static GridPos jumpLoop(JumpPointParam iParam, int iX, int iY, int iPx, int iPy)
{
GridPos retVal = null;
Stack <JumpSnapshot> stack = new Stack <JumpSnapshot>();
JumpSnapshot currentSnapshot = new JumpSnapshot();
JumpSnapshot newSnapshot = null;
currentSnapshot.iX = iX;
currentSnapshot.iY = iY;
currentSnapshot.iPx = iPx;
currentSnapshot.iPy = iPy;
currentSnapshot.stage = 0;
stack.Push(currentSnapshot);
while (stack.Count != 0)
{
currentSnapshot = stack.Pop();
switch (currentSnapshot.stage)
{
case 0:
if (!iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY))
{
retVal = null;
continue;
}
else if (iParam.SearchGrid.GetNodeAt(currentSnapshot.iX, currentSnapshot.iY).Equals(iParam.EndNode))
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
currentSnapshot.tDx = currentSnapshot.iX - currentSnapshot.iPx;
currentSnapshot.tDy = currentSnapshot.iY - currentSnapshot.iPy;
// check for forced neighbors
// along the diagonal
if (currentSnapshot.tDx != 0 && currentSnapshot.tDy != 0)
{
if ((iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY + currentSnapshot.tDy) && iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY + currentSnapshot.tDy) && !iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY)) ||
(iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY + currentSnapshot.tDy) && iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY) && !iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY + currentSnapshot.tDy)))
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
}
// horizontally/vertically
else
{
if (currentSnapshot.tDx != 0)
{
// moving along x
if ((iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY + 1) && !iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX - currentSnapshot.tDx, currentSnapshot.iY + 1)) ||
(iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY - 1) && !iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX - currentSnapshot.tDx, currentSnapshot.iY - 1)))
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
}
else
{
if ((iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + 1, currentSnapshot.iY) && !iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + 1, currentSnapshot.iY - currentSnapshot.tDy)) ||
(iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX - 1, currentSnapshot.iY) && !iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX - 1, currentSnapshot.iY - currentSnapshot.tDy)))
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
}
}
// when moving diagonally, must check for vertical/horizontal jump points
if (currentSnapshot.tDx != 0 && currentSnapshot.tDy != 0)
{
currentSnapshot.stage = 3;
stack.Push(currentSnapshot);
newSnapshot = new JumpSnapshot();
newSnapshot.iX = currentSnapshot.iX + currentSnapshot.tDx;
newSnapshot.iY = currentSnapshot.iY;
newSnapshot.iPx = currentSnapshot.iX;
newSnapshot.iPy = currentSnapshot.iY;
newSnapshot.stage = 0;
stack.Push(newSnapshot);
continue;
}
// moving diagonally, must make sure both of the vertical/horizontal
// neighbors is open to allow the path
if (iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY) && iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY + currentSnapshot.tDy))
{
newSnapshot = new JumpSnapshot();
newSnapshot.iX = currentSnapshot.iX + currentSnapshot.tDx;
newSnapshot.iY = currentSnapshot.iY + currentSnapshot.tDy;
newSnapshot.iPx = currentSnapshot.iX;
newSnapshot.iPy = currentSnapshot.iY;
newSnapshot.stage = 0;
stack.Push(newSnapshot);
continue;
}
retVal = null;
break;
case 1:
if (retVal != null)
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
currentSnapshot.stage = 2;
stack.Push(currentSnapshot);
newSnapshot = new JumpSnapshot();
newSnapshot.iX = currentSnapshot.iX;
newSnapshot.iY = currentSnapshot.iY + currentSnapshot.tDy;
newSnapshot.iPx = currentSnapshot.iX;
newSnapshot.iPy = currentSnapshot.iY;
newSnapshot.stage = 0;
stack.Push(newSnapshot);
break;
case 2:
if (retVal != null)
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
// moving diagonally, must make sure one of the vertical/horizontal
// neighbors is open to allow the path
if (iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY) || iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY + currentSnapshot.tDy))
{
newSnapshot = new JumpSnapshot();
newSnapshot.iX = currentSnapshot.iX + currentSnapshot.tDx;
newSnapshot.iY = currentSnapshot.iY + currentSnapshot.tDy;
newSnapshot.iPx = currentSnapshot.iX;
newSnapshot.iPy = currentSnapshot.iY;
newSnapshot.stage = 0;
stack.Push(newSnapshot);
continue;
}
retVal = null;
break;
case 3:
if (retVal != null)
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
currentSnapshot.stage = 4;
stack.Push(currentSnapshot);
newSnapshot = new JumpSnapshot();
newSnapshot.iX = currentSnapshot.iX;
newSnapshot.iY = currentSnapshot.iY + currentSnapshot.tDy;
newSnapshot.iPx = currentSnapshot.iX;
newSnapshot.iPy = currentSnapshot.iY;
newSnapshot.stage = 0;
stack.Push(newSnapshot);
break;
case 4:
if (retVal != null)
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
// moving diagonally, must make sure both of the vertical/horizontal
// neighbors is open to allow the path
if (iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY) && iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY + currentSnapshot.tDy))
{
newSnapshot = new JumpSnapshot();
newSnapshot.iX = currentSnapshot.iX + currentSnapshot.tDx;
newSnapshot.iY = currentSnapshot.iY + currentSnapshot.tDy;
newSnapshot.iPx = currentSnapshot.iX;
newSnapshot.iPy = currentSnapshot.iY;
newSnapshot.stage = 0;
stack.Push(newSnapshot);
continue;
}
retVal = null;
break;
case 5:
if (retVal != null)
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
currentSnapshot.stage = 7;
stack.Push(currentSnapshot);
newSnapshot = new JumpSnapshot();
newSnapshot.iX = currentSnapshot.iX;
newSnapshot.iY = currentSnapshot.iY - 1;
newSnapshot.iPx = currentSnapshot.iX;
newSnapshot.iPy = currentSnapshot.iY;
newSnapshot.stage = 0;
stack.Push(newSnapshot);
break;
case 6:
if (retVal != null)
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
currentSnapshot.stage = 7;
stack.Push(currentSnapshot);
newSnapshot = new JumpSnapshot();
newSnapshot.iX = currentSnapshot.iX - 1;
newSnapshot.iY = currentSnapshot.iY;
newSnapshot.iPx = currentSnapshot.iX;
newSnapshot.iPy = currentSnapshot.iY;
newSnapshot.stage = 0;
stack.Push(newSnapshot);
break;
case 7:
if (retVal != null)
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
// keep going
if (iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY) && iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY + currentSnapshot.tDy))
{
newSnapshot = new JumpSnapshot();
newSnapshot.iX = currentSnapshot.iX + currentSnapshot.tDx;
newSnapshot.iY = currentSnapshot.iY + currentSnapshot.tDy;
newSnapshot.iPx = currentSnapshot.iX;
newSnapshot.iPy = currentSnapshot.iY;
newSnapshot.stage = 0;
stack.Push(newSnapshot);
continue;
}
retVal = null;
break;
}
}
return(retVal);
}