TetrisGameState SetCurrentPiece(PieceInstance currentPiece, bool autoSolidify)
{
if (ValidPosition(currentPiece, Grid))
return new TetrisGameState(PieceGenerator, Rows, Points, currentPiece, NextPiece, Grid);
if (autoSolidify)
return SolidifyCurrentPiece(Grid);
return this;
}
static bool ValidPosition(PieceInstance livePiece, Color[,] grid)
{
var shape = livePiece.Shape.Data;
for (int l = 0; l < 4; l++)
{
int checkY = livePiece.Position.Y + l - 1;
for (int c = 0; c < 4; c++)
{
int checkX = livePiece.Position.X + c - 2;
if (checkY < 0)
continue;
if (shape[l, c] && (checkX < 0 || checkX >= 10 || checkY < 0 || checkY >= 20 || grid[checkY, checkX] != Color.Transparent))
return false;
}
}
return true;
}
public TetrisGameState Tick()
{
var nextPiece = new PieceInstance(CurrentPiece.Piece, CurrentPiece.Rotation,
new Point(CurrentPiece.Position.X, CurrentPiece.Position.Y + 1));
return SetCurrentPiece(nextPiece, true);
}
public TetrisGameState RotateCounterClockwise()
{
var nextRotation = (CurrentPiece.Rotation + 1) % CurrentPiece.Piece.Shapes.Length;
var nextPiece = new PieceInstance(CurrentPiece.Piece, nextRotation, CurrentPiece.Position);
return SetCurrentPiece(nextPiece, false);
}
public TetrisGameState MoveRight()
{
var nextPiece = new PieceInstance(CurrentPiece.Piece, CurrentPiece.Rotation,
new Point(CurrentPiece.Position.X + 1, CurrentPiece.Position.Y));
return SetCurrentPiece(nextPiece, false);
}
public TetrisGameState(IPieceGenerator generator, int rows, int points, PieceInstance current, Piece next, Color[,] grid)
{
PieceGenerator = generator;
Level = rows / 10;
Rows = rows;
Points = points;
CurrentPiece = current;
NextPiece = next;
Grid = grid;
IsFinished = !ValidPosition(current, grid);
}