private void FetchTraverseMap(ParcelBot bot, ref int[,] traverseMap)
{
//loop over every cell
for (int i = 0; i < BoardData.height; i++)
{
for (int j = 0; j < BoardData.width; j++)
{
BoardData.CellType staticCell = BoardData.instance.GetCellType(i, j);
//if the cell is parcel hole, the value will be -2 else -1
//-2 means blocked
//-1 means walkable
traverseMap[i, j] = staticCell == BoardData.CellType.ParcelHole ? -2 : -1;
}
}
//loop over everybot except current bot that we are going to assign direction
foreach (ParcelBot b in BoardData.instance.GetBots())
{
if (b == bot)
{
continue;
}
//set value -2 to the cell that each bot is standing or stepping to
Vector2Int bCurrent = b.GetCurrent();
Vector2Int bNextStep = b.GetNextStep();
traverseMap[bCurrent.y, bCurrent.x] = -2;
traverseMap[bNextStep.y, bNextStep.x] = -2;
}
}
public IEnumerator RequestNextStep(ParcelBot bot)
{
Vector2Int target = bot.GetTarget();
Vector2Int current = bot.GetCurrent();
//start the algorithm
yield return(StartCoroutine(CalculateNextStep(bot, current, target)));
}
public void Start()
{
BoardData.instance.ClearAllBots();
//create bots object. the amount is according to BoardData.botNum
for (int i = 0; i < BoardData.botNum; i++)
{
ParcelBot bot = Instantiate(prefab) as ParcelBot;
bot.transform.parent = transform;
bot.Initialize(i);
BoardData.instance.AddBot(bot);
}
}
public void AddBot(ParcelBot b)
{
//add new bot b to bot list
bots.Add(b);
}
//this method will be called when clicked
private void OnMouseDown()
{
//find the bot with the minimum load
//find the block with minimum load
ParcelBot responsibleBot = null;
List <ParcelBot> allBots = BoardData.instance.GetBots();
List <Vector2Int> availableBlocks = new List <Vector2Int>(nearbyBlocks);
int minLoad = 999999;
ParcelBot minBot = null;
foreach (ParcelBot bot in allBots)
{
//int load = bot.GetLoadCount();
int load = bot.GetLoadCount() + Mathf.Abs(bot.GetId() - x) + Mathf.Abs(y);
if (bot.IsFree() == false)
{
load += 100;
}
//float load = (float)(bot.GetLoadCount() + Mathf.Abs(bot.GetCurrent().x - x) + Mathf.Abs(bot.GetCurrent().y - y));
//print(bot.GetCurrent());
//print(x +" " + y);
//print(load);
//print("");
if (load < minLoad)
{
responsibleBot = bot;
minLoad = load;
minBot = bot;
}
if (responsibleBot == null && bot.IsFree())
{
responsibleBot = bot;
}
if (availableBlocks.Contains(bot.GetTarget()))
{
availableBlocks.Remove(bot.GetTarget());
}
}
//forget what this condition does but don't dare to remove it ;-)
if (responsibleBot == null)
{
responsibleBot = minBot;
}
//no bot with enough battery available
if (responsibleBot == null)
{
return;
}
//if there is no available nearby block that is currently free
//just pick one randomly
if (availableBlocks.Count == 0)
{
availableBlocks.Add(nearbyBlocks[Random.Range(0, 3)]);
}
//assign the bot to move to the nearby block with minimum load
responsibleBot.AssignNextParcelPoint(availableBlocks[0], id);
}
private IEnumerator CalculateNextStep(ParcelBot bot, Vector2Int current, Vector2Int target)
{
//create temp map arrays and traverse queue for calculation
int[,] traverseMap = new int[BoardData.height, BoardData.width];
Queue <Vector2Int> traverseQueue = new Queue <Vector2Int>();
//fill values into map arrays
FetchTraverseMap(bot, ref traverseMap);
//if the target cell is not available (not empty)
if (traverseMap[target.y, target.x] == -2)
{
//stop bot movement
bot.SetNextStep(current);
yield break;
}
//initialize first value in the queue
traverseMap[current.y, current.x] = 0;
traverseQueue.Clear();
traverseQueue.Enqueue(current);
//while the queue is not empty
while (traverseQueue.Count > 0)
{
Vector2Int now = traverseQueue.Dequeue();
//add nearby cell's position that bot can walk to to the queue for next round of calculation
AddPossibleNextStepToQueue(now, target, ref traverseMap, ref traverseQueue);
//get the shortest cost to travel from 'current' to 'now'
traverseMap[now.y, now.x] = GetBestValueFromAround(now, ref traverseMap) + 1;
//stop loop when reached target cell
if (traverseMap[target.y, target.x] != -1)
{
break;
}
}
//DebugTraverseMap();
//if the target is not reached
if (traverseMap[target.y, target.x] < 0)
{
//stop bot movement
bot.SetNextStep(current);
yield break;
}
//initialize values to finc next step from calculated map
Vector2Int tracker = target; //stat from target cell
Vector2Int prev = tracker; //this var is to temporarily keep tracking position
//do the block until tracker reached start cell
while (tracker != current)
{
prev = tracker;
//move tracker one step closer to start point
tracker = GetNextBackStep(tracker, ref traverseMap);
}
//tell bot to move to the cell before the tracker reached bot
bot.SetNextStep(prev);
}
