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;
if (iParam.DiagonalMovement == DiagonalMovement.Always || iParam.DiagonalMovement == DiagonalMovement.IfAtLeastOneWalkable)
{
// 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.tDx, currentSnapshot.iY)) ||
(iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY - currentSnapshot.tDy) && !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.tDx, currentSnapshot.iY + 1) && !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)))
{
retVal = new GridPos(currentSnapshot.iX, currentSnapshot.iY);
continue;
}
}
else
{
if ((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) && !iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX - 1, currentSnapshot.iY)))
{
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 = 1;
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 one of the vertical/horizontal
// neighbors is open to allow the path
// 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;
}
else if (iParam.DiagonalMovement == DiagonalMovement.Always)
{
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;
}
}
else if (iParam.DiagonalMovement == DiagonalMovement.OnlyWhenNoObstacles)
{
// 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;
}
}
else // if(iParam.DiagonalMovement == DiagonalMovement.Never)
{
if (currentSnapshot.tDx != 0)
{
// moving along x
if (!iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX + currentSnapshot.tDx, currentSnapshot.iY))
{
retVal = new GridPos(iX, iY);
continue;
}
}
else
{
if (!iParam.SearchGrid.IsWalkableAt(currentSnapshot.iX, currentSnapshot.iY + currentSnapshot.tDy))
{
retVal = new GridPos(iX, iY);
continue;
}
}
// must check for perpendicular jump points
if (currentSnapshot.tDx != 0)
{
currentSnapshot.stage = 5;
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);
continue;
}
else // tDy != 0
{
currentSnapshot.stage = 6;
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);
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;
}
else if (iParam.DiagonalMovement == DiagonalMovement.Always)
{
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);
}
internal override void _reset(GridPos iStartPos, GridPos iEndPos, BaseGrid iSearchGrid = null)
{
openList = new IntervalHeap <Node>();
//openList.Clear();
}
public override Node GetNodeAt(GridPos blockPos)
{
return(GetNodeAt(blockPos.x, blockPos.y));
}