public static IReadOnlyList <TetriminoNode> GetTetriminoDependencyGraph(IReadOnlyList <Tetrimino> tetriminos,
int playAreaWidth, int playAreaHeight)
{
// Build block map
var tetriminoNodes = new List <TetriminoNode>(tetriminos.Count);
var memoizedMap = new MemoizedBlock[playAreaHeight, playAreaWidth];
foreach (var tetrimino in tetriminos)
{
var tetriminoNode = new TetriminoNode(tetrimino.Kind,
tetrimino.Position,
GeneratorHelper.GetFirstBlockPositionByPosition(tetrimino.Position, tetrimino.Kind,
tetrimino.FacingDirection),
tetrimino.FacingDirection
);
tetriminoNode.Blocks = tetriminoNode.MemoizedBlocks =
GetMemoizedBlocksForTetriminoNode(tetriminoNode, tetrimino);
foreach (var block in tetriminoNode.MemoizedBlocks)
{
memoizedMap[block.Position.Y, block.Position.X] = block;
}
tetriminoNodes.Add(tetriminoNode);
}
// Get dependency relationship
foreach (var tetriminoNode in tetriminoNodes)
{
foreach (var block in tetriminoNode.MemoizedBlocks)
{
// if a blocker under the current block is occupied then
// this tetrimino can not be placed until the underlying block's
// owner is placed, i.e., this tetrimino depends on the underlying
// block's owner.
var dependedBlockRow = block.Position.Y + 1;
var dependedBlockCol = block.Position.X;
if (!TryGetOccupiedTetriminoNode(
memoizedMap,
dependedBlockRow, dependedBlockCol,
playAreaWidth, playAreaHeight,
out var dependOn
) || dependOn == tetriminoNode)
{
continue;
}
dependOn.DependedBy.Add(tetriminoNode);
tetriminoNode.Depending.Add(dependOn);
}
}
return(tetriminoNodes);
}
private static bool TryGetOccupiedTetriminoNode(MemoizedBlock[,] map,
int row, int col,
int playAreaWidth, int playAreaHeight,
out TetriminoNode result)
{
if (row < 0 || row >= playAreaHeight || col < 0 || col >= playAreaWidth)
{
result = null;
return(false);
}
var cell = map[row, col];
if (cell == null ||
cell.FilledBy == TetriminoKind.AvailableToFill ||
cell.FilledBy == TetriminoKind.UnavailableToFill)
{
result = null;
return(false);
}
result = cell.Owner;
return(true);
}
private static IReadOnlyList <MemoizedBlock> GetMemoizedBlocksForTetriminoNode(TetriminoNode node,
Tetrimino tetrimino)
{
return(tetrimino.Blocks.Select(
block => new MemoizedBlock(block.FilledBy, block.Position, node, block.AtomicNumber, block.Identifier)
).ToList());
}
public MemoizedBlock(TetriminoKind filledBy, Position position, TetriminoNode owner, int atomicNumber = 0,
int identifier = 0)
: base(filledBy, position, atomicNumber, identifier)
{
Owner = owner;
}
