/// <summary>
/// Calculates the shortest path between grid node <paramref name="i"/>
/// and <paramref name="j"/>.
/// </summary>
private void calcShortestPath(int i, int j)
{
Queue <int> fifo_i, fifo_j, dist;
fifo_i = new Queue <int>();
fifo_j = new Queue <int>();
dist = new Queue <int>();
int sourceNode = gridNodeLabel[i, j];
// init found vector
Utilities.Populate <bool>(found, false);
fifo_i.Enqueue(i);
fifo_j.Enqueue(j);
dist.Enqueue(0);
found[sourceNode] = true;
while (fifo_i.Count > 0)
{
int curr_i = fifo_i.Dequeue();
int curr_j = fifo_j.Dequeue();
int currNode = gridNodeLabel[curr_i, curr_j];
int currDist = dist.Dequeue();
shortestPath[sourceNode, currNode] = currDist;
for (GameConstants.actions k = GameConstants.actions.east;
k <= GameConstants.actions.north; k++)
{
// k = 0 is noop move
if (gridNodeLabel[curr_i + GameConstants.RelativeDirX[(int)k], curr_j +
GameConstants.RelativeDirY[(int)k]] >= 0)
{
int neighbour = gridNodeLabel[curr_i + GameConstants.RelativeDirX[(int)k], curr_j
+ GameConstants.RelativeDirY[(int)k]];
if (!found[neighbour])
{
found[neighbour] = true;
fifo_i.Enqueue(curr_i + GameConstants.RelativeDirX[(int)k]);
fifo_j.Enqueue(curr_j + GameConstants.RelativeDirY[(int)k]);
dist.Enqueue(currDist + 1);
}
}
}
}
}
/// <summary>
/// Returns valid actions at point <paramref name="xCoord"/>, <paramref name="yCoord"/>.
/// </summary>
/// <param name='actions'>
/// Returned list of valid actions.
/// </param>
public void getValidActions(List <int> actions, int xCoord, int yCoord)
{
actions.Clear();
// nochanged is always a valid action
actions.Add((int)GameConstants.actions.unchanged);
// check the movement actions
for (GameConstants.actions i = GameConstants.actions.east; i <= GameConstants.actions.north; i++)
{
//if (levelData.map[xCoord + GameConstants.RelativeDirX[(int)i], yCoord + GameConstants.RelativeDirY[(int)i]]
// > GameConstants.Wall)
if (isFreeSpace(xCoord + GameConstants.RelativeDirX[(int)i], yCoord + GameConstants.RelativeDirY[(int)i]))
{
actions.Add((int)i);
}
}
}
/// <summary>
/// Returns valid actions at point <paramref name="xCoord"/>, <paramref name="yCoord"/>
/// that do not move into the point <paramref name="exX"/>, <paramref name="exY"/>.
/// </summary>
/// <param name='actions'>
/// Returned list of valid actions.
/// </param>
public void getValidActionsExcludePoint(List <int> actions,
int xCoord, int yCoord,
int exX, int exY)
{
actions.Clear();
// nochanged is always a valid action
actions.Add((int)GameConstants.actions.unchanged);
// check the movement actions
for (GameConstants.actions i = GameConstants.actions.east; i <= GameConstants.actions.north; i++)
{
if (isFreeSpace(xCoord + GameConstants.RelativeDirX[(int)i], yCoord + GameConstants.RelativeDirY[(int)i]) &&
(xCoord + GameConstants.RelativeDirX[(int)i] != exX || yCoord + GameConstants.RelativeDirY[(int)i] != exY))
{
actions.Add((int)i);
}
}
}
