//returns available node which is closest to goal (using manhattan distance)
public FieldNode getClosestNext(FieldNode node, FieldNode goal)
{
//if the goal is a neighbor
if (Math.Abs(node.x - goal.x) == 1 || Math.Abs(node.y - goal.y) == 1)
{
//if the only item in the goal space is the hiding spot, return it
if (map[goal.x, goal.y] == 1)
return goal;
//otherwise, need to find a new hiding spot
else
throw new SpotTakenException();
}
int x = node.x;
int y = node.y;
if (x >= sizeX || y >= sizeY || x < 0 || y < 0)
return null;
//go through all neighbors and find the one which is closest to the hiding spot, using Manhattan distancea
FieldNode best = null;
double bestVal = 300;
if (y + 1 < sizeY && map[x, y + 1] <= 0)
{
FieldNode next = new FieldNode(x, y + 1);
double val = next.EuclideanDist(goal);
if (val < bestVal)
{
bestVal = val;
best = next;
}
}
if (x + 1 < sizeX && y + 1 < sizeY && map[x + 1, y + 1] <= 0)
{
FieldNode next = new FieldNode(x + 1, y + 1);
double val = next.EuclideanDist(goal);
if (val < bestVal)
{
bestVal = val;
best = next;
}
}
if (x + 1 < sizeX && map[x + 1, y] <= 0)
{
FieldNode next = new FieldNode(x + 1, y);
double val = next.EuclideanDist(goal);
if (val < bestVal)
{
bestVal = val;
best = next;
}
}
if (x + 1 < sizeX && y - 1 >= 0 && map[x + 1, y - 1] <= 0)
{
FieldNode next = new FieldNode(x + 1, y - 1);
double val = next.EuclideanDist(goal);
if (val < bestVal)
{
bestVal = val;
best = next;
}
}
if (y - 1 >= 0 && map[x, y - 1] <= 0)
{
FieldNode next = new FieldNode(x, y - 1);
double val = next.EuclideanDist(goal);
if (val < bestVal)
{
bestVal = val;
best = next;
}
}
if (x - 1 >= 0 && y - 1 >= 0 && map[x - 1, y - 1] <= 0)
{
FieldNode next = new FieldNode(x - 1, y - 1);
double val = next.EuclideanDist(goal);
if (val < bestVal)
{
bestVal = val;
best = next;
}
}
if (x - 1 >= 0 && map[x - 1, y] <= 0)
{
FieldNode next = new FieldNode(x - 1, y);
double val = next.EuclideanDist(goal);
if (val < bestVal)
{
bestVal = val;
best = next;
}
}
if (x - 1 >= 0 && y + 1 < sizeY && map[x - 1, y + 1] <= 0)
{
FieldNode next = new FieldNode(x - 1, y + 1);
double val = next.EuclideanDist(goal);
if (val < bestVal)
{
bestVal = val;
best = next;
}
}
return best;
}
