Add pure-Dart engine core: RNG, grid, placement, line clear, scoring, piece generator

PCG32 seeded RNG; immutable 8x8 GridState with occupancy bitmask; placement legality + anyPlacementExists; simultaneous row/col clears with single-count gem credit; combo scoring with one-move grace; weighted-bag generator with pity bias and depth-3 solvability nudge. All TDD, 51 tests green. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-06-11 13:05:55 +09:00
parent 40528238b2
commit 0210c14858
19 changed files with 1408 additions and 0 deletions
@@ -0,0 +1,56 @@
+import '../models/cell.dart';
+import '../models/grid.dart';
+
+class ClearResult {
+  const ClearResult({
+    required this.grid,
+    required this.clearedRows,
+    required this.clearedCols,
+    required this.gemsCleared,
+  });
+
+  final GridState grid;
+  final List<int> clearedRows;
+  final List<int> clearedCols;
+  final int gemsCleared;
+
+  int get linesCleared => clearedRows.length + clearedCols.length;
+}
+
+/// Detects all simultaneously full rows/columns and clears them in one pass.
+ClearResult detectAndClear(GridState grid) {
+  final rows = <int>[];
+  final cols = <int>[];
+  for (var y = 0; y < GridState.size; y++) {
+    if (grid.isRowFull(y)) rows.add(y);
+  }
+  for (var x = 0; x < GridState.size; x++) {
+    if (grid.isColFull(x)) cols.add(x);
+  }
+  if (rows.isEmpty && cols.isEmpty) {
+    return ClearResult(
+      grid: grid,
+      clearedRows: const [],
+      clearedCols: const [],
+      gemsCleared: 0,
+    );
+  }
+
+  final rowSet = rows.toSet();
+  final colSet = cols.toSet();
+  var gems = 0;
+  var next = grid;
+  for (var y = 0; y < GridState.size; y++) {
+    for (var x = 0; x < GridState.size; x++) {
+      if (!rowSet.contains(y) && !colSet.contains(x)) continue;
+      if (grid.cellAt(x, y).type == CellType.gem) gems++;
+      next = next.withCell(x, y, Cell.empty);
+    }
+  }
+  return ClearResult(
+    grid: next,
+    clearedRows: rows,
+    clearedCols: cols,
+    gemsCleared: gems,
+  );
+}