/// <summary>
/// Move a <see cref="Tetrimino" /> towards a <see cref="MoveDirection" /> if permits.
/// The <see cref="Tetrimino" /> will not be changed if the operation fails.
/// </summary>
/// <param name="collisionChecker">
/// A <see cref="Func{Block, bool}" /> which returns <see cref="true" />
/// when the block will collide
/// </param>
/// <returns>Whether the <see cref="TryMove" /> step succeeds</returns>
public bool TryMove(MoveDirection direction, Func <Block, bool> collisionChecker)
{
var position = Position;
if (direction == MoveDirection.Down)
{
var row = position.Y + 1;
position = new Position(position.X, row);
}
else
{
var delta = direction == MoveDirection.Right ? 1 : -1;
var column = position.X + delta;
position = new Position(column, position.Y);
}
var blocks = TetriminoHelper.CreateOffsetedBlocks(Kind, position, FacingDirection);
if (blocks.Any(collisionChecker))
{
return(false);
}
Position = position;
Blocks = blocks;
return(true);
}
public Tetrimino(TetriminoKind kind)
{
Kind = kind;
Position = TetriminoHelper.GetInitialPositionByKind(kind);
Blocks = TetriminoHelper.CreateOffsetedBlocks(kind, Position);
FacingDirection = Direction.Up;
}
/// <summary>
/// Rotate a <see cref="Tetrimino" /> towards a <see cref="RotationDirection" /> if permits.
/// The <see cref="Tetrimino" /> will not be changed if the operation fails.
/// </summary>
/// <param name="collisionChecker">
/// A <see cref="Func{Block, bool}" /> which returns <see cref="true" /> when the block will
/// collide
/// </param>
/// <returns>Whether the <see cref="TryRotate" /> step succeeds</returns>
public bool TryRotate(RotationDirection rotationDirection, Func <Block, bool> collisionChecker)
{
var count = Enum.GetValues(typeof(Direction)).Length;
var delta = rotationDirection == RotationDirection.Right ? 1 : -1;
var direction = (int)FacingDirection + delta;
if (direction < 0)
{
direction += count;
}
if (direction >= count)
{
direction %= count;
}
var adjustPattern = Kind == TetriminoKind.Linear
? new[] { 0, 1, -1, 2, -2 }
: new[] { 0, 1, -1 };
foreach (var adjust in adjustPattern)
{
var position = new Position(Position.X + adjust, Position.Y);
var blocks = TetriminoHelper.CreateOffsetedBlocks(Kind, position, (Direction)direction);
if (!blocks.Any(collisionChecker))
{
FacingDirection = (Direction)direction;
Position = position;
Blocks = blocks;
return(true);
}
}
return(false);
}