public bool CollapseLocation(int x, int y)
{
Debug.Assert(y < solution.Count);
List <TilePossibilities> row = solution[y];
Debug.Assert(x < row.Count);
TilePossibilities location = row[x];
UpdateFromNeighbours(x, y);
if (!location.HasPossibilities)
{
return(false);
}
location.Collapse();
Debug.Assert(location.HasCollapsed, "Invalid number of possible tiles after collapse");
Debug.Log(string.Format("Location {0}, {1} collapsed to {2}", x, y, location.possibleTiles[0]));
UpdateNeighbours(x, y, location.possibleTiles[0]);
// If any of them end up with no possibilities this was a bad choice
// OPTIMIZATION: Possibility to backtrack here and do another choice
return(DoAllNeighboursHavePossibilities(x, y));
}
private void UpdateFromNeighbours(int x, int y)
{
Debug.Assert(y < solution.Count);
List <TilePossibilities> row = solution[y];
Debug.Assert(x < row.Count);
TilePossibilities location = row[x];
// Check left
{
if (x == 0)
{
location.RemoveUnsupportedPossibilitiesFor(null, Direction.Left);
}
else if (row[x - 1].HasCollapsed)
{
location.RemoveUnsupportedPossibilitiesFor(row[x - 1].possibleTiles[0], Direction.Left);
}
}
// Check Right
{
if (x == row.Count - 1)
{
location.RemoveUnsupportedPossibilitiesFor(null, Direction.Right);
}
else if (row[x + 1].HasCollapsed)
{
location.RemoveUnsupportedPossibilitiesFor(row[x + 1].possibleTiles[0], Direction.Right);
}
}
// Check Bottom
{
if (y == 0)
{
location.RemoveUnsupportedPossibilitiesFor(null, Direction.Bottom);
}
else if (solution[y - 1][x].HasCollapsed)
{
location.RemoveUnsupportedPossibilitiesFor(solution[y - 1][x].possibleTiles[0], Direction.Bottom);
}
}
// Check Top
{
if (y == solution.Count - 1)
{
location.RemoveUnsupportedPossibilitiesFor(null, Direction.Top);
}
else if (solution[y + 1][x].HasCollapsed)
{
location.RemoveUnsupportedPossibilitiesFor(solution[y + 1][x].possibleTiles[0], Direction.Top);
}
}
}
private int CollapsedLocationCount()
{
int count = 0;
for (int row = 0; row < rows; ++row)
{
List <TilePossibilities> rowPossibilities = solution[row];
for (int column = 0; column < columns; ++column)
{
TilePossibilities location = rowPossibilities[column];
if (location.HasCollapsed)
{
++count;
}
}
}
return(count);
}
private Vector2 NextLocation()
{
int x = 0, y = 0;
int currentPossibilityCount = int.MaxValue;
for (int row = 0; row < rows; ++row)
{
List <TilePossibilities> rowPossibilities = solution[row];
for (int column = 0; column < columns; ++column)
{
TilePossibilities location = rowPossibilities[column];
if (!location.HasCollapsed && location.HasPossibilities && location.possibleTiles.Count < currentPossibilityCount)
{
x = column;
y = row;
currentPossibilityCount = location.possibleTiles.Count;
}
}
}
return(new Vector2(x, y));
}