public override void Think()
{
// TODO: algorithm is not optimal because when returning from child to parent, child nodes will be listed again (not so big problem, but it something to improve)
// timing
double currentTime = DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond;
double mspa = 1000 / aiSpeed;
if (!IgnoreSpeed)
{
if ((currentTime - lastActionTime) < mspa)
{
return;
}
}
Map.Map map = Position.ParentMap;
// if the stack is empty AI may be in dead end
// put its current position to the stack and run the DFS again
if (blockStack.Count == 0)
{
blockStack.Push(new VisitedBlock(Position));
}
// get current node and his neighbours
VisitedBlock currVisitedBlock = blockStack.Peek();
currVisitedBlock.state = BlockState.OPEN;
visitedBlocks.Add(currVisitedBlock);
MapBlock curr = map.Grid[currVisitedBlock.x, currVisitedBlock.y];
List <MapBlock> neighbours = curr.AccessibleNeighbours();
// choose the next neighbour to go to
// those neighbours must not be in CLOSED state and should not contain monster
MapBlock nextBlock = null;
foreach (MapBlock neighbour in neighbours)
{
// check if the neighbour wasn't already visited and is not occupied
// visited block hash code is calculated only by its coordinates so this can be used
VisitedBlock neighbourVb = new VisitedBlock(neighbour);
if (!visitedBlocks.Contains(neighbourVb) && !neighbour.Occupied)
{
// get the last not-visited, unoccupied neighbour
// add it to the stack later
nextBlock = neighbour;
}
}
// if some neighbours were found, create move action to the last block on the stack
if (nextBlock != null)
{
blockStack.Push(new VisitedBlock(nextBlock));
Direction nextDirection = DirectionMethods.GetDirection(Position, nextBlock);
NextAction = new Move()
{
Actor = this, Direction = nextDirection
};
}
else
{
// no possible neighbours were found
// this opens up two possibilities
// 1. assume current block is a dead end
// 2. check if there are monster to fight in neighbour blocks and try to fight them
// for now lets just pick the first one
// mark current block as closed and pop it from the stack
currVisitedBlock.state = BlockState.CLOSED;
blockStack.Pop();
// move one step back
if (blockStack.Count > 0)
{
VisitedBlock prevBlock = blockStack.Peek();
nextBlock = map.Grid[prevBlock.x, prevBlock.y];
NextAction = new Move()
{
Actor = this, Direction = DirectionMethods.GetDirection(Position, nextBlock)
};
}
}
lastActionTime = currentTime;
}