public bool Rotate(bool left)
{
int oldX = X, oldY = Y;
IEnumerable <Tuple <int, int> > reindex = new LinkedList <Tuple <int, int> >();
//erase old location
for (int x = 0; x < 4; x++)
{
for (int y = 0; y < 4; y++)
{
if (Structure[x, y])
{
TetrisState.Grid[x + X, y + Y] = Color.Transparent;
((LinkedList <Tuple <int, int> >)reindex).AddLast(Tuple.Create(x + X, y + Y));
}
}
}
bool[,] candidateStructure = Rotate(Structure, left ? 1 : 3);
//check wall collisions, and try to correct for them
//is there a left collision?
int leftBound = FindLeftSurfaces(candidateStructure).Min();
if (X + leftBound < 0)
{
X = -leftBound - 1;
}
int rightBound = FindRightSurfaces(candidateStructure).Max();
if (X + rightBound >= Tetris.Width)
{
X = Tetris.Width - rightBound;
}
int bottomBound = FindBottomSurfaces(candidateStructure).Max();
if (Y + bottomBound >= Tetris.Height)
{
Y = Tetris.Height - bottomBound;
}
//check block intersections
bool failure = false;
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 4; j++)
{
if (candidateStructure[i, j] && TetrisState.Grid[i + X, j + Y] != Color.Transparent)
{
failure = true;
break;
}
}
}
if (!failure)
{
//we have a valid location, put the tetromino there
#if diagnose
Debug.WriteLine("tetra rotating");
#endif
if (oldX != X || oldY != Y)
{
reindex = TetrisState.ReIndexTransitions(reindex, t => Tuple.Create(t.Item1 + (X - oldX), t.Item2 + (Y - oldY)));
TranslationTransition.FromTetromino(TetrisState, this, oldX, oldY, TransitionTime);
}
Structure = candidateStructure;
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 4; j++)
{
if (Structure[i, j])
{
TetrisState.Grid[i + X, j + Y] = Color;
}
}
}
TetrisState.ReIndexTransitions(reindex, t =>
{
Tuple <int, int> transformed = Tetromino.RotationTransform(Tuple.Create(t.Item1 - X, t.Item2 - Y), left ? 1 : 3);
return(Tuple.Create(transformed.Item1 + X, transformed.Item2 + Y));
});
RotationTransition.FromTetromino(TetrisState, this, left ? -1 : 1, TransitionTime);
return(true);
}
else
{
X = oldX;
Y = oldY;
for (int x = 0; x < 4; x++)
{
for (int y = 0; y < 4; y++)
{
if (Structure[x, y])
{
TetrisState.Grid[x + X, y + Y] = Color;
}
}
}
return(false);
}
}