gistfile1.js

  // Neighbours functions, used by findNeighbours function
	// to locate adjacent available cells that aren't blocked

	// Returns every available North, South, East or West
	// cell that is empty. No diagonals,
	// unless distanceFunction function is not Manhattan
	function Neighbours(x, y)
	{
		var	N = y - 1,
		S = y + 1,
		E = x + 1,
		W = x - 1,
		myN = N > -1 && canWalkHere(x, N),
		myS = S < worldHeight && canWalkHere(x, S),
		myE = E < worldWidth && canWalkHere(E, y),
		myW = W > -1 && canWalkHere(W, y),
		result = [];
		if(myN)
		result.push({x:x, y:N});
		if(myE)
		result.push({x:E, y:y});
		if(myS)
		result.push({x:x, y:S});
		if(myW)
		result.push({x:W, y:y});
		findNeighbours(myN, myS, myE, myW, N, S, E, W, result);
		return result;
	}

	// returns every available North East, South East,
	// South West or North West cell - no squeezing through
	// "cracks" between two diagonals
	function DiagonalNeighbours(myN, myS, myE, myW, N, S, E, W, result)
	{
		if(myN)
		{
			if(myE && canWalkHere(E, N))
			result.push({x:E, y:N});
			if(myW && canWalkHere(W, N))
			result.push({x:W, y:N});
		}
		if(myS)
		{
			if(myE && canWalkHere(E, S))
			result.push({x:E, y:S});
			if(myW && canWalkHere(W, S))
			result.push({x:W, y:S});
		}
	}

	// returns every available North East, South East,
	// South West or North West cell including the times that
	// you would be squeezing through a "crack"
	function DiagonalNeighboursFree(myN, myS, myE, myW, N, S, E, W, result)
	{
		myN = N > -1;
		myS = S < worldHeight;
		myE = E < worldWidth;
		myW = W > -1;
		if(myE)
		{
			if(myN && canWalkHere(E, N))
			result.push({x:E, y:N});
			if(myS && canWalkHere(E, S))
			result.push({x:E, y:S});
		}
		if(myW)
		{
			if(myN && canWalkHere(W, N))
			result.push({x:W, y:N});
			if(myS && canWalkHere(W, S))
			result.push({x:W, y:S});
		}
	}