HPASharp.HierarchicalMap.GetHeuristic C# (CSharp) Method

        public int GetHeuristic(int startNodeId, int targetNodeId)
        {
            var startPos = AbstractGraph.GetNodeInfo(startNodeId).Position;
            var targetPos = AbstractGraph.GetNodeInfo(targetNodeId).Position;
            var diffY = Math.Abs(startPos.Y - targetPos.Y);
            var diffX = Math.Abs(startPos.X - targetPos.X);

            switch (Type)
            {
                case AbsType.ABSTRACT_TILE:
					// Manhattan distance
                    return (diffY + diffX) * Constants.COST_ONE;
                case AbsType.ABSTRACT_OCTILE:
					// Diagonal distance
                    {
                        var diag = Math.Min(diffX, diffY);
                        var straight = diffX + diffY;

                        // According to the information link, this is the shape of the function.
                        // We just extract factors to simplify.
                        // Possible simplification: var h = Constants.CellCost * (straight + (Constants.Sqrt2 - 2) * diag);
                        return Constants.COST_ONE * straight + (Constants.COST_ONE * 34 / 24 - 2 * Constants.COST_ONE) * diag;
                    }
                default:
                    return 0;
            }
        }