public QuantumPiece GetQuantumPiece(Position pos)
{
Piece?piece = null;
ulong filled = 0, empty = 0;
foreach (QuantumHarmonic harmonic in Harmonics_)
{
Piece?classical = harmonic.Board[pos];
if (classical.HasValue)
{
AssertionException.Assert(piece == null || piece == classical,
$"The square {pos} appears in a superposition of two pieces");
piece = classical;
filled += harmonic.Degeneracy;
}
else
{
empty += harmonic.Degeneracy;
}
}
if (piece.HasValue)
{
return(new QuantumPiece(piece, MeasurementUtils.Probability(filled, filled + empty)));
}
else
{
return(new QuantumPiece(null, 1.0));
}
}
private void UpdateGameState()
{
if (GameState_ != GameState.GameStillGoing)
{
return;
}
if (Harmonics_.All((h) => h.Board.GameState != GameState.GameStillGoing))
{
ulong white_victory_degeneracy = Harmonics_
.Where((h) => h.Board.GameState == GameState.WhiteVictory)
.Select((h) => h.Degeneracy)
.Aggregate(0ul, (a, b) => a + b);
ulong black_victory_degeneracy = Harmonics_
.Where((h) => h.Board.GameState == GameState.BlackVictory)
.Select((h) => h.Degeneracy)
.Aggregate(0ul, (a, b) => a + b);
ulong tie_degeneracy = Harmonics_
.Where((h) => h.Board.GameState == GameState.Tie)
.Select((h) => h.Degeneracy)
.Aggregate(0ul, (a, b) => a + b);
ulong total_degeneracy = white_victory_degeneracy + black_victory_degeneracy + tie_degeneracy;
if (!MeasurementUtils.Decide(tie_degeneracy, total_degeneracy))
{
total_degeneracy -= tie_degeneracy;
if (MeasurementUtils.Decide(white_victory_degeneracy, total_degeneracy))
{
GameState_ = GameState.WhiteVictory;
}
else
{
GameState_ = GameState.BlackVictory;
}
}
else
{
GameState_ = GameState.Tie;
}
}
}
private void PerformMeasurement(Position pos)
{
var piece_degeneracies = new Dictionary <Piece, ulong>();
ulong overall_degeneracy = 0;
foreach (QuantumHarmonic harmonic in Harmonics_)
{
Piece?square = harmonic.Board[pos];
if (square.HasValue)
{
if (!piece_degeneracies.ContainsKey(square.Value))
{
piece_degeneracies[square.Value] = 0;
}
piece_degeneracies[square.Value] += harmonic.Degeneracy;
overall_degeneracy += harmonic.Degeneracy;
}
}
if (piece_degeneracies.Count <= 1)
{
// No measurement is needed
return;
}
foreach (Piece piece in piece_degeneracies.Keys)
{
ulong degeneracy = piece_degeneracies[piece];
if (MeasurementUtils.Decide(degeneracy, overall_degeneracy))
{
// Removing all the harmonics with another piece
FilterBy((h) => h.Board[pos] == null || h.Board[pos] == piece);
return;
}
else
{
overall_degeneracy -= degeneracy;
}
}
AssertionException.Assert(false, "One of the pieces has to be chosen");
}
private void PerformSpontaneousMeasurement()
{
ulong total_degeneracy = 0;
foreach (QuantumHarmonic harmonic in Harmonics_)
{
total_degeneracy += harmonic.Degeneracy;
}
foreach (QuantumHarmonic harmonic in Harmonics_)
{
if (MeasurementUtils.Decide(harmonic.Degeneracy, total_degeneracy))
{
var new_harmonics = new List <QuantumHarmonic>();
new_harmonics.Add(harmonic);
Harmonics_ = new_harmonics;
return;
}
total_degeneracy -= harmonic.Degeneracy;
}
}