onLinesCleared method

ScoreState onLinesCleared(ScoreState state, int linesCleared, int level, { TSpinType tSpin = TSpinType.none, bool perfectClear = false, })

Returns a new ScoreState after a piece locks and clears linesCleared lines. level is used for point multipliers.

tSpin awards T-Spin points, and perfectClear adds the perfect clear bonus when the board is left empty.

Back-to-back is kept alive by consecutive "difficult" clears (Tetrises and T-Spin line clears) and is only broken by an ordinary line clear; placing a piece that clears nothing does not break it.

Implementation

ScoreState onLinesCleared(
  ScoreState state,
  int linesCleared,
  int level, {
  TSpinType tSpin = TSpinType.none,
  bool perfectClear = false,
}) {
  if (linesCleared == 0) {
    // A T-Spin with no lines still scores, but ends any combo.
    return state.copyWith(
      score: state.score + _tSpinPoints(tSpin, 0) * level,
      combo: 0,
    );
  }

  final difficult = linesCleared == 4 || tSpin != TSpinType.none;
  final b2b = difficult && state.backToBack;

  var base =
      (tSpin == TSpinType.none
          ? _basePoints(linesCleared)
          : _tSpinPoints(tSpin, linesCleared)) *
      level;
  if (b2b) base = (base * 1.5).toInt();

  var comboBonus = 0;
  if (state.combo > 0) comboBonus = 50 * state.combo * level;

  var pcBonus = 0;
  if (perfectClear) {
    pcBonus =
        (linesCleared == 4 && b2b
            ? 3200
            : _perfectClearPoints(linesCleared)) *
        level;
  }

  return state.copyWith(
    score: state.score + base + comboBonus + pcBonus,
    combo: state.combo + 1,
    backToBack: difficult,
  );
}