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);
}
