private static bool CheckDirection(GridModel grid, Direction direction)
{
var vector = Vector.FromDirection(direction);
foreach (int x in grid.TraversalsX(direction))
{
foreach (int y in grid.TraversalsY(direction))
{
var cell1 = grid[x, y];
var cell2 = grid[x + vector.x, y + vector.y];
if (cell1 != null && cell2 != null)
{
if (cell1.IsOccupied && cell2.IsAvailable)
{
return true;
}
if (cell1.IsOccupied && cell2.IsOccupied)
{
if (cell1.Tile.Value == cell2.Tile.Value)
return true;
}
}
}
}
return false;
}
public bool Move(GridModel grid, Direction direction, out int score)
{
score = 0;
if (direction == Direction.None)
return false;
var vector = Vector.FromDirection(direction);
var moved = false;
var alreadyMerged = new List<TileModel>();
// Traverse the grid in the right direction and move tiles
foreach (int x in grid.TraversalsX(direction))
{
foreach (int y in grid.TraversalsY(direction))
{
CellModel cell = grid[x, y];
if (cell.IsOccupied)
{
TileModel tile = cell.Tile;
CellModel nextCell;
CellModel farthestCell = grid.FindFarthestPosition(cell, vector, out nextCell);
TileModel nextTile = (nextCell == null) ? null : nextCell.Tile;
// Only one merger per row traversal?
if (nextTile != null && nextTile.Value == tile.Value && !alreadyMerged.Contains(nextTile))
{
var merged = new TileModel(tile, nextTile);
alreadyMerged.Add(merged);
tile.Position = null;
nextTile.Position = null;
merged.Position = nextCell;
moved = true;
// Update the score
score += (int)Math.Pow(2, merged.Value);
}
else
{
var oldPosition = tile.Position;
tile.Position = farthestCell;
if ((oldPosition.PosX != tile.Position.PosX)
|| (oldPosition.PosY != tile.Position.PosY))
moved = true;
}
}
}
}
return moved;
}
private int CountMerges(Direction direction, GridModel grid)
{
var vector = Vector.FromDirection(direction);
int merges = 0;
foreach (int x in grid.TraversalsX(direction))
{
foreach (int y in grid.TraversalsY(direction))
{
var cell1 = grid[x, y];
var cell2 = grid[x + vector.x, y + vector.y];
if (cell1 != null && cell2 != null)
{
if (cell1.IsOccupied && cell2.IsOccupied)
{
if (cell1.Tile.Value == cell2.Tile.Value)
merges++;
}
}
}
}
return merges;
}