Vault/BSP based level generator, part 1

lib/assets.dart

@@ -1,7 +1,6 @@
 import 'dart:ui' as ui;
 
-import 'package:dartterm/wfc/template.dart';
+import 'package:dartterm/gen/generator.dart';
-import 'package:dartterm/world/level.dart';
 import 'package:flutter/services.dart';
 
 class Assets {
@@ -14,15 +13,14 @@ class Assets {
     return image;
   });
 
-  final _Table<WfcTemplate<LevelTile>> _wfcLevelTemplates =
+  final _Table<Vaults> _vaults = _Table(Vaults.load);
-      _Table(loadLevelWfcAsync);
 
   ui.Image? getImageIfAvailable(String name) {
     return _images.getIfAvailable(name);
   }
 
-  WfcTemplate<LevelTile>? getWfcLevelTemplateIfAvailable(String name) {
+  Vaults? getVaultsIfAvailable(String name) {
-    return _wfcLevelTemplates.getIfAvailable(name);
+    return _vaults.getIfAvailable(name);
   }
 }
 
@@ -53,6 +51,6 @@ ui.Image? getImageIfAvailable(String name) {
   return assets.getImageIfAvailable(name);
 }
 
-WfcTemplate<LevelTile>? getWfcLevelTemplateIfAvailable(String name) {
+Vaults? getVaultsIfAvailable(String name) {
-  return assets.getWfcLevelTemplateIfAvailable(name);
+  return assets.getVaultsIfAvailable(name);
 }

lib/game.dart

@@ -1,41 +1,48 @@
 import 'dart:developer';
-
+import 'dart:math' as math;
 import 'package:dartterm/assets.dart';
 import 'package:dartterm/colors.dart';
+import 'package:dartterm/gen/generator.dart';
 import 'package:dartterm/terminal.dart';
-import 'package:dartterm/wfc/template.dart';
 import 'package:dartterm/world/level.dart';
 
 void main() async {
-  WfcTemplate<LevelTile> template;
+  Vaults vaults;
   while (true) {
     log("about to load template");
     at(0, 0).clear();
     at(0, 0).puts("Loading template!");
-    WfcTemplate<LevelTile>? maybeTemplate =
+    Vaults? maybeVaults =
-        getWfcLevelTemplateIfAvailable("assets/images/wfc/bighouse2.png");
+        getVaultsIfAvailable("assets/images/wfc/bighouse2.png");
 
-    if (maybeTemplate != null) {
+    if (maybeVaults != null) {
       log("wasn't null!");
-      template = maybeTemplate;
+      vaults = maybeVaults;
       break;
     }
     await zzz(0.1);
   }
 
   at(0, 0).clear();
-  at(0, 0).puts("Loaded! $template");
+  at(0, 0).puts("Loaded! $vaults");
 
-  var W = 16;
+  Vault output = vaults.generateBoxed(
-  var H = 16;
+      math.Random(2),
-
+      Requirement(
-  var wfc = Wfc(template, W, H);
+          16,
-  wfc.run(1, -1);
+          16,
-  var output = wfc.extractPartial();
+          DirectionSet({
-  for (var y = 0; y < W; y++) {
+            Direction.up,
-    for (var x = 0; x < H; x++) {
+            Direction.left,
+            Direction.right,
+            Direction.down
+          })));
+  var w = output.vx;
+  var h = output.vy;
+  for (var y = 0; y < w; y++) {
+    for (var x = 0; x < h; x++) {
       var cursor = at(x * 2, y * 2).big();
-      switch (output[x + y * W]) {
+      switch (output.tiles[x + y * w]) {
         case LevelTile.floor:
           cursor.puts(" ");
         case LevelTile.door:
@@ -44,8 +51,6 @@ void main() async {
           cursor.puts("#");
         case LevelTile.exit:
           cursor.puts("X");
-        case null:
-          cursor.puts("?");
       }
     }
   }

lib/gen/generator.dart

@@ -0,0 +1,301 @@
+import 'dart:developer';
+import 'dart:math' as math;
+
+import 'package:dartterm/world/level.dart';
+
+enum Direction {
+  up,
+  left,
+  down,
+  right,
+}
+
+class Vaults {
+  List<Vault> _primitive = [];
+
+  static Future<Vaults> load(String filename) async {
+    // TODO
+    return Vaults();
+  }
+
+  Vault generateBoxed(math.Random random, Requirement req) {
+    var vx = req.vx;
+    var vy = req.vy;
+
+    var tiles = [
+      for (var y = 0; y < vy; y++)
+        for (var x = 0; x < vx; x++) LevelTile.wall
+    ];
+    var v = Vault(tiles, vx, vy, req.smooth);
+
+    if (req.vx < 2 || req.vy < 2) {
+      return v;
+    }
+    var req2 = Requirement(vx - 2, vy - 2, req.smooth);
+    var inner = generate(random, req2);
+    v.blitFrom(inner, 1, 1);
+    return v;
+  }
+
+  Vault generate(math.Random random, Requirement requirement) {
+    // TODO: Pick a relevant vault from the vaults file if possible
+    //
+
+    // First of all: randomize orientation.
+    // This way we only have to consider one kind of spilt
+    var orientation = randomOrientation(random);
+
+    // Try to make vx the long axis if possible
+    var req2 = requirement.unReorient(orientation);
+    if (req2.vy > (req2.vx - 2) * 3 / 2) {
+      orientation = (orientation + 2) % 8; // rotate once more
+    }
+    req2 = requirement.unReorient(orientation);
+
+    var out2 = _generate(random, req2);
+    var out1 = out2.reorient(orientation);
+
+    log("$orientation ${requirement.vx} ${requirement.vy} ${req2.vx} ${req2.vy} ${out2.vx} ${out2.vy} ${out1.vx} ${out1.vy}");
+    assert(out1.vx == requirement.vx);
+    assert(out1.vy == requirement.vy);
+    return out1;
+  }
+
+  Vault _generate(math.Random random, Requirement req) {
+    var vx = req.vx;
+    var vy = req.vy;
+
+    var tiles = [
+      for (var y = 0; y < vy; y++)
+        for (var x = 0; x < vx; x++) LevelTile.wall
+    ];
+    var v = Vault(tiles, vx, vy, req.smooth);
+
+    if (vx < 3 || vx * vy < 10) {
+      v.clear(LevelTile.floor);
+    } else {
+      // pick a split point
+      var splitVx = random.nextInt(vx - 2) + 1;
+
+      var reqLeft = Requirement(splitVx, vy, req.smooth.clone());
+      reqLeft.smooth.directions.add(Direction.right);
+      var reqRight = Requirement((vx - splitVx - 1), vy, req.smooth.clone());
+      reqRight.smooth.directions.add(Direction.left);
+
+      var vaultLeft = generate(random, reqLeft);
+      var vaultRight = generate(random, reqRight);
+      v.blitFrom(vaultLeft, 0, 0);
+      v.blitFrom(vaultRight, splitVx + 1, 0);
+    }
+
+    return v;
+  }
+}
+
+// TODO: There are many more efficient ways to do this
+class DirectionSet {
+  final Set<Direction> directions;
+
+  DirectionSet(this.directions);
+
+  DirectionSet flip() {
+    var ds2 = DirectionSet({});
+    for (var i in directions) {
+      switch (i) {
+        case Direction.up:
+          ds2.directions.add(Direction.up);
+        case Direction.left:
+          ds2.directions.add(Direction.right);
+        case Direction.down:
+          ds2.directions.add(Direction.down);
+        case Direction.right:
+          ds2.directions.add(Direction.left);
+      }
+    }
+    return ds2;
+  }
+
+  DirectionSet rotateLeft() {
+    var ds2 = DirectionSet({});
+    for (var i in directions) {
+      switch (i) {
+        case Direction.up:
+          ds2.directions.add(Direction.left);
+        case Direction.left:
+          ds2.directions.add(Direction.down);
+        case Direction.down:
+          ds2.directions.add(Direction.right);
+        case Direction.right:
+          ds2.directions.add(Direction.up);
+      }
+    }
+    return ds2;
+  }
+
+  DirectionSet rotateRight() {
+    var ds2 = DirectionSet({});
+    for (var i in directions) {
+      switch (i) {
+        case Direction.up:
+          ds2.directions.add(Direction.right);
+        case Direction.right:
+          ds2.directions.add(Direction.down);
+        case Direction.down:
+          ds2.directions.add(Direction.left);
+        case Direction.left:
+          ds2.directions.add(Direction.up);
+      }
+    }
+    return ds2;
+  }
+
+  DirectionSet clone() {
+    var ds2 = DirectionSet({});
+    ds2.directions.addAll(directions);
+    return ds2;
+  }
+}
+
+class Requirement {
+  final int vx, vy;
+  final DirectionSet smooth;
+
+  Requirement(this.vx, this.vy, this.smooth);
+
+  Requirement flip() {
+    return Requirement(vx, vy, smooth.flip());
+  }
+
+  Requirement rotateLeft() {
+    return Requirement(vy, vx, smooth.rotateLeft());
+  }
+
+  Requirement rotateRight() {
+    return Requirement(vy, vx, smooth.rotateRight());
+  }
+
+  Requirement unReorient(int r) {
+    assert(r >= 0 && r < 8);
+    Requirement o = this;
+    if (r % 2 == 1) {
+      o = o.flip();
+      r -= 1;
+    }
+    while (r >= 2) {
+      o = o.rotateLeft();
+      r -= 2;
+    }
+    return o;
+  }
+}
+
+class Vault {
+  final List<LevelTile> tiles;
+  final int vx, vy;
+  final DirectionSet smooth;
+
+  Vault(this.tiles, this.vx, this.vy, this.smooth) {
+    assert(tiles.length == vx * vy);
+  }
+
+  static Vault fromVaultData(List<LevelTile> tiles, int vx, int vy) {
+    assert(tiles.length == vx * vy);
+    var smooth = {
+      Direction.up,
+      Direction.left,
+      Direction.down,
+      Direction.right
+    };
+    for (var x = 0; x < vx; x++) {
+      if (tiles[x + 0 * vx] == LevelTile.wall) {
+        smooth.remove(Direction.up);
+        break;
+      }
+    }
+    for (var x = 0; x < vx; x++) {
+      if (tiles[x + (vy - 1) * vx] == LevelTile.wall) {
+        smooth.remove(Direction.down);
+        break;
+      }
+    }
+    for (var y = 0; y < vy; y++) {
+      if (tiles[0 + y * vx] == LevelTile.wall) {
+        smooth.remove(Direction.left);
+        break;
+      }
+    }
+    for (var y = 0; y < vy; y++) {
+      if (tiles[vx - 1 + y * vx] == LevelTile.wall) {
+        smooth.remove(Direction.right);
+        break;
+      }
+    }
+
+    return Vault(tiles, vx, vy, DirectionSet(smooth));
+  }
+
+  void clear(LevelTile lt) {
+    for (var y = 0; y < vy; y++) {
+      for (var x = 0; x < vx; x++) {
+        tiles[y * vx + x] = lt;
+      }
+    }
+  }
+
+  void blitFrom(Vault other, int dx, int dy) {
+    assert(dx >= 0);
+    assert(dy >= 0);
+    assert(dx + other.vx <= vx);
+    assert(dy + other.vy <= vy);
+    for (var x = 0; x < other.vx; x++) {
+      for (var y = 0; y < other.vy; y++) {
+        tiles[(y + dy) * vx + x + dx] = other.tiles[y * other.vx + x];
+      }
+    }
+  }
+
+  Vault flip() {
+    List<LevelTile> tiles2 = [
+      for (var y = 0; y < vy; y++)
+        for (var x = vx - 1; x >= 0; x--) tiles[y * vx + x]
+    ];
+
+    return Vault(tiles2, vx, vy, smooth.flip());
+  }
+
+  Vault rotateRight() {
+    List<LevelTile> tiles2 = [
+      for (var x = 0; x < vx; x++)
+        for (var y = 0; y < vy; y++) tiles[y * vx + x]
+    ];
+
+    return Vault(tiles2, vy, vx, smooth.rotateRight());
+  }
+
+  Vault rotateLeft() {
+    List<LevelTile> tiles2 = [
+      for (var x = vx - 1; x >= 0; x++)
+        for (var y = vy - 1; y >= 0; y++) tiles[y * vx + x]
+    ];
+
+    return Vault(tiles2, vy, vx, smooth.rotateLeft());
+  }
+
+  Vault reorient(int r) {
+    assert(r >= 0 && r < 8);
+    Vault o = this;
+    while (r >= 2) {
+      o = o.rotateRight();
+      r -= 2;
+    }
+    if (r == 1) {
+      o = o.flip();
+      r -= 1;
+    }
+    return o;
+  }
+}
+
+int randomOrientation(math.Random random) {
+  return random.nextInt(8);
+}

lib/wfc/model.dart.old

@@ -1,281 +0,0 @@
-import 'dart:math';
-
-abstract class Model {
-  static var dx = [-1, 0, 1, 0];
-  static var dy = [0, 1, 0, -1];
-  static var opposite = [2, 3, 0, 1];
-
-  bool _initialized = false;
-  List<List<bool>> _wave = [];
-  List<List<List<int>>> propagator = [];
-  List<List<List<int>>> _compatible = [];
-  List<int?> _observed = [];
-
-  List<(int, int)> _stack = [];
-  int _stacksize = 0, _observedSoFar = 0;
-
-  int cMx = 0, cMy = 0, cT = 0, cN = 0;
-  bool _periodic = false;
-  bool ground = false;
-
-  List<double> weights = [];
-  List<double> _weightLogWeights = [], _distribution = [];
-
-  List<int> _sumsOfOnes = [];
-  double _sumOfWeights = 0.0,
-      _sumOfWeightLogWeights = 0.0,
-      _startingEntropy = 0.0;
-  List<double> _sumsOfWeights = [],
-      _sumsOfWeightLogWeights = [],
-      _entropies = [];
-
-  Heuristic _heuristic = Heuristic.Entropy;
-
-  Model(int width, int height, int n, bool periodic, Heuristic heuristic) {
-    cMx = width;
-    cMy = height;
-    cN = n;
-    _periodic = periodic;
-    _heuristic = heuristic;
-  }
-
-  void _init() {
-    _initialized = true;
-    _wave = [
-      for (var r = 0; r < cMx * cMy; r++) [for (var t = 0; t < cT; t++) false]
-    ];
-    _compatible = [
-      for (var r = 0; r < cMx * cMy; r++)
-        [
-          for (var t = 0; t < cT; t++) [0, 0, 0, 0]
-        ]
-    ];
-    _distribution = [for (var t = 0; t < cT; t++) 0.0];
-    _observed = [for (var r = 0; r < cMx * cMy; r++) null];
-
-    _weightLogWeights = [
-      for (var t = 0; t < cT; t++) weights[t] * log(weights[t])
-    ];
-    _sumOfWeights = 0;
-    _sumOfWeightLogWeights = 0.0;
-    for (var t = 0; t < cT; t++) {
-      _sumOfWeights += weights[t];
-      _sumOfWeightLogWeights += _weightLogWeights[t];
-    }
-
-    _startingEntropy =
-        log(_sumOfWeights) - _sumOfWeightLogWeights / _sumOfWeights;
-
-    _sumsOfOnes = [for (var r = 0; r < cMx * cMy; r++) 0];
-    _sumsOfWeights = [for (var r = 0; r < cMx * cMy; r++) 0.0];
-    _sumsOfWeightLogWeights = [for (var r = 0; r < cMx * cMy; r++) 0.0];
-    _entropies = [for (var r = 0; r < cMx * cMy; r++) 0.0];
-
-    _stack = [for (var r = 0; r < _wave.length * cT; r++) (0, 0)];
-    _stacksize = 0;
-  }
-
-  bool run(int? seed, int limit) {
-    if (!_initialized) {
-      _init();
-    }
-    clear();
-
-    var random = Random(seed);
-
-    for (var l = 0; l < limit || limit < 0; l++) {
-      var node = _nextUnobservedNode(random);
-      if (node >= 0) {
-        _observe(node, random);
-        var success = _propagate();
-        if (!success) {
-          return false;
-        }
-      } else {
-        for (var i = 0; i < _wave.length; i++) {
-          for (var t = 0; t < cT; t++) {
-            if (_wave[i][t]) {
-              _observed[i] = t;
-              break;
-            }
-          }
-        }
-        return true;
-      }
-    }
-
-    return true;
-  }
-
-  int _nextUnobservedNode(Random random) {
-    if (_heuristic == Heuristic.Scanline) {
-      for (var i = _observedSoFar; i < _wave.length; i++) {
-        if (!_periodic && (i % cMx + cN > cMx || i ~/ cMx + cN > cMy)) {
-          continue;
-        }
-        if (_sumsOfOnes[i] > 1) {
-          _observedSoFar = i + 1;
-          return i;
-        }
-      }
-      return -1;
-    }
-
-    double min = 1E+4;
-    int argmin = -1;
-    for (var i = 0; i < _wave.length; i++) {
-      if (!_periodic && (i % cMx + cN > cMx || i ~/ cMx + cN > cMy)) {
-        continue;
-      }
-      var remainingValues = _sumsOfOnes[i];
-      double entropy = _heuristic == Heuristic.Entropy
-          ? _entropies[i]
-          : remainingValues.toDouble();
-      if (remainingValues > 1 && entropy <= min) {
-        double noise = 1E-6 * random.nextDouble();
-        if (entropy + noise < min) {
-          min = entropy + noise;
-          argmin = i;
-        }
-      }
-    }
-    return argmin;
-  }
-
-  void _observe(int node, Random random) {
-    var w = _wave[node];
-    for (var t = 0; t < cT; t++) {
-      _distribution[t] = w[t] ? weights[t] : 0.0;
-    }
-    int r = _chooseRandom(random, _distribution);
-    for (var t = 0; t < cT; t++) {
-      if (w[t] != (t == r)) {
-        _ban(node, t);
-      }
-    }
-  }
-
-  bool _propagate() {
-    while (_stacksize > 0) {
-      int i1, t1;
-      (i1, t1) = _stack[_stacksize - 1];
-      _stacksize--;
-
-      int x1 = i1 % cMx;
-      int y1 = i1 % cMy;
-
-      for (int d = 0; d < 4; d++) {
-        int x2 = x1 + dx[d];
-        int y2 = y1 + dy[d];
-
-        if (!_periodic &&
-            (x2 < 0 || y2 < 0 || x2 + cN > cMx || y2 + cN > cMy)) {
-          continue;
-        }
-
-        if (x2 < 0) {
-          x2 += cMx;
-        } else if (x2 >= cMx) {
-          x2 -= cMx;
-        }
-
-        if (y2 < 0) {
-          y2 += cMy;
-        } else if (y2 >= cMy) {
-          y2 -= cMy;
-        }
-
-        int i2 = x2 + y2 * cMx;
-        var p = propagator[d][t1];
-        var compat = _compatible[i2];
-
-        for (var l = 0; l < p.length; l++) {
-          var t2 = p[l];
-          var comp = compat[t2];
-          comp[d]--;
-          if (comp[d] == 0) {
-            _ban(i2, t2);
-          }
-        }
-      }
-    }
-
-    return _sumsOfOnes[0] > 0;
-  }
-
-  void _ban(int i, int t) {
-    _wave[i][t] = false;
-
-    var comp = _compatible[i][t];
-    for (var d = 0; d < 4; d++) {
-      comp[d] = 0;
-    }
-    _stack[_stacksize] = (i, t);
-    _stacksize++;
-
-    _sumsOfOnes[i] -= 1;
-    _sumsOfWeights[i] -= weights[t];
-    _sumsOfWeightLogWeights[i] -= _weightLogWeights[t];
-
-    var sum = _sumsOfWeights[i];
-    _entropies[i] = log(sum) - _sumsOfWeightLogWeights[i] / sum;
-  }
-
-  void clear() {
-    for (var i = 0; i < _wave.length; i++) {
-      for (var t = 0; t < cT; t++) {
-        _wave[i][t] = true;
-        for (var d = 0; d < 4; d++) {
-          _compatible[i][t][d] = propagator[opposite[d]][t].length;
-        }
-      }
-
-      _sumsOfOnes[i] = weights.length;
-      _sumsOfWeights[i] = _sumOfWeights;
-      _sumsOfWeightLogWeights[i] = _sumOfWeightLogWeights;
-      _entropies[i] = _startingEntropy;
-      _observed[i] = -1;
-    }
-    _observedSoFar = 0;
-
-    if (ground) {
-      for (var x = 0; x < cMx; x++) {
-        for (var t = 0; t < cT - 1; t++) {
-          _ban(x + (cMy - 1) * cMx, t);
-        }
-        for (var y = 0; y < cMy - 1; y++) {
-          _ban(x + y * cMx, cT - 1);
-        }
-      }
-      _propagate();
-    }
-  }
-}
-
-int _chooseRandom(Random rand, List<double> distribution) {
-  if (distribution.isEmpty) {
-    throw Exception("can't sample empty distribution");
-  }
-  var sum = 0.0;
-  for (var i = 0; i < distribution.length; i++) {
-    sum += distribution[i];
-  }
-
-  if (sum == 0.0) {
-    return rand.nextInt(distribution.length);
-  }
-
-  var rnd = rand.nextDouble() * sum;
-
-  var i = 0;
-  while (rnd > 0) {
-    rnd -= distribution[i];
-    if (rnd < 0) {
-      return i;
-    }
-    i += 1;
-  }
-  return distribution.length - 1;
-}
-
-enum Heuristic { Entropy, MRV, Scanline }

lib/wfc/template.dart

@@ -1,467 +0,0 @@
-import 'dart:developer';
-import 'dart:math' as math;
-import 'dart:typed_data';
-import 'dart:ui' as ui;
-import 'dart:ui';
-
-import 'package:flutter/services.dart';
-
-class Wfc<T> {
-  // parameters
-  final WfcTemplate<T> _template;
-  final int _mx, _my;
-
-  // constants
-  int get _n => _mx * _my;
-  int get _nShingles => _template._shingles.n;
-  int get _order => _template._order;
-  double _weight(int shingleIx) =>
-      _template._shingles._shingleWeights[shingleIx];
-
-  // overall algo state
-  List<List<bool>> _wave = [];
-  List<List<List<int>>> _compatible = [];
-  List<int?> _observed = [];
-
-  // computationally expensive stuff that we keep in an incremental way
-  List<int> _sumsOfOnes = [];
-
-  // temporaries
-  List<double> _distribution = [];
-  List<(int, int)> _stack = [];
-  int _stacksize = 0;
-
-  Wfc(this._template, this._mx, this._my) {
-    _wave = [
-      for (var r = 0; r < _n; r++) [for (var t = 0; t < _nShingles; t++) false]
-    ];
-
-    _compatible = [
-      for (var r = 0; r < _n; r++)
-        [
-          for (var t = 0; t < _nShingles; t++) [0, 0, 0, 0]
-        ]
-    ];
-
-    _distribution = [for (var t = 0; t < _nShingles; t++) 0.0];
-    _observed = [for (var r = 0; r < _n; r++) null];
-
-    _sumsOfOnes = [for (var r = 0; r < _n; r++) 0];
-
-    _stack = [for (var r = 0; r < _n * _nShingles; r++) (0, 0)];
-    _stacksize = 0;
-  }
-
-  void clear() {
-    for (var i = 0; i < _wave.length; i++) {
-      for (var t = 0; t < _nShingles; t++) {
-        _wave[i][t] = true;
-        for (var d = 0; d < 4; d++) {
-          _compatible[i][t][d] = _template
-              ._shingles._metadata._propagators[_opposite[d]][t].length;
-        }
-      }
-
-      _sumsOfOnes[i] = _nShingles;
-      _observed[i] = null;
-    }
-  }
-
-  bool run(int? seed, int limit) {
-    clear();
-
-    var random = math.Random(seed);
-    for (var l = 0; l < limit || limit < 0; l++) {
-      var node = _nextUnobservedNode(random);
-      if (node != null) {
-        _observe(node, random);
-        var success = _propagate();
-        if (!success) {
-          return false;
-        }
-      } else {
-        for (var i = 0; i < _n; i++) {
-          for (var t = 0; t < _nShingles; t++) {
-            if (_wave[i][t]) {
-              _observed[i] = t;
-              break;
-            }
-          }
-        }
-        return true;
-      }
-    }
-
-    return true;
-  }
-
-  List<T>? extract() {
-    var partial = extractPartial();
-    List<T> out = [];
-    for (var i in partial) {
-      if (i == null) {
-        return null;
-      }
-      out.add(i);
-    }
-    return out;
-  }
-
-  List<T?> extractPartial() {
-    List<T?> result = [];
-    for (int i = 0; i < _n; i++) {
-      result.add(null);
-    }
-
-    for (int y = 0; y < _my; y++) {
-      var dy = y < _my - _order + 1 ? 0 : _order - 1;
-      for (int x = 0; x < _mx; x++) {
-        var dx = x < _mx - _order + 1 ? 0 : _order - 1;
-        var shingleIx = _observed[x - dx + (y - dy) * _mx];
-        if (shingleIx != null) {
-          var shingle = _template._shingles._shingleValues[shingleIx];
-          var content = shingle.content[dx + dy * _order];
-          var real = _template._embedding.decode(content);
-
-          result[x + y * _mx] = real;
-        }
-      }
-    }
-
-    return result;
-  }
-
-  int? _nextUnobservedNode(math.Random random) {
-    double min = 1E+10;
-    int? argmin;
-    for (var i = 0; i < _n; i++) {
-      if (i % _mx + _order > _mx || i ~/ _mx + _order > _my) {
-        continue;
-      }
-      var remainingValues = _sumsOfOnes[i];
-      double entropy = remainingValues.toDouble();
-      if (remainingValues > 1 && entropy <= min) {
-        double noise = 1E-6 * random.nextDouble();
-        if (entropy + noise < min) {
-          min = entropy + noise;
-          argmin = i;
-        }
-      }
-    }
-    return argmin;
-  }
-
-  void _observe(int node, math.Random random) {
-    var w = _wave[node];
-    for (var t = 0; t < _nShingles; t++) {
-      _distribution[t] = w[t] ? _weight(t) : 0.0;
-    }
-
-    int r = _chooseRandom(random, _distribution);
-    for (var t = 0; t < _nShingles; t++) {
-      if (w[t] != (t == r)) {
-        _ban(node, t);
-      }
-    }
-  }
-
-  bool _propagate() {
-    while (_stacksize > 0) {
-      int i1, t1;
-      (i1, t1) = _stack[_stacksize - 1];
-      _stacksize--;
-
-      int x1 = i1 % _mx;
-      int y1 = i1 ~/ _mx;
-
-      for (int d = 0; d < 4; d++) {
-        var x2 = x1 + _dx[d];
-        var y2 = y1 + _dy[d];
-
-        if (x2 < 0 || y2 < 0 || x2 + _order > _mx || y2 + _order > _my) {
-          continue;
-        }
-
-        int i2 = x2 + y2 * _mx;
-        var p = _template._shingles._metadata._propagators[d][t1];
-        var compat = _compatible[i2];
-
-        for (var t2 in p) {
-          var comp = compat[t2];
-          comp[d]--;
-          if (comp[d] == 0) {
-            _ban(i2, t2);
-          }
-        }
-      }
-    }
-
-    return _sumsOfOnes[0] > 0;
-  }
-
-  void _ban(int i, int t) {
-    _wave[i][t] = false;
-
-    var comp = _compatible[i][t];
-    for (var d = 0; d < 4; d++) {
-      comp[d] = 0;
-    }
-    _stack[_stacksize] = (i, t);
-    _stacksize++;
-
-    _sumsOfOnes[i] -= 1;
-  }
-}
-
-class WfcTemplate<T> {
-  final Shingles _shingles;
-  final Embedding<T> _embedding;
-  final int _order;
-
-  WfcTemplate(this._shingles, this._embedding, this._order);
-
-  static Future<WfcTemplate<T>> loadAsync<T>(
-      String name, int order, T Function(int) cb) async {
-    final assetImageByteData = await rootBundle.load(name);
-    final codec =
-        await ui.instantiateImageCodec(assetImageByteData.buffer.asUint8List());
-    final image = (await codec.getNextFrame()).image;
-
-    final bytedata =
-        (await image.toByteData(format: ImageByteFormat.rawStraightRgba))!;
-
-    final sx = image.width;
-    final sy = image.height;
-
-    final List<T> bitmap = [];
-    for (var i = 0; i < sx * sy; i++) {
-      var pixel = bytedata.getUint32(i * 4, Endian.little);
-      bitmap.add(cb(pixel));
-    }
-
-    return loadBitmap(bitmap, sx, sy, order);
-  }
-
-  static WfcTemplate<T> loadBitmap<T>(
-      List<T> bitmap, int sx, int sy, int order) {
-    if (bitmap.length != sx * sy) {
-      throw Exception("malformed bitmap");
-    }
-    var embedding = Embedding<T>();
-    List<int> sample = [
-      for (var i = 0; i < bitmap.length; i++) embedding.encode(bitmap[i])
-    ];
-    embedding.freeze();
-
-    var shingles = Shingles();
-    var xmax = sx - order + 1;
-    var ymax = sy - order + 1;
-    for (var y = 0; y < ymax; y++) {
-      for (var x = 0; x < xmax; x++) {
-        var ps = [
-          Shingle(order, embedding.c,
-              (dx, dy) => sample[(x + dx) % sx + (y + dy) % sy * sx])
-        ];
-        ps.add(ps[0].reflect());
-        ps.add(ps[0].rotate());
-        ps.add(ps[2].reflect());
-        ps.add(ps[2].rotate());
-        ps.add(ps[4].reflect());
-        ps.add(ps[4].rotate());
-        ps.add(ps[6].reflect());
-        for (var p in ps) {
-          shingles.observe(p, 1.0);
-        }
-      }
-    }
-    shingles.freeze();
-
-    return WfcTemplate(shingles, embedding, order);
-  }
-}
-
-class Shingles {
-  bool _frozen = false;
-  final Map<int, int> _shingleIndices = {};
-  final List<Shingle> _shingleValues = [];
-  final List<double> _shingleWeights = [];
-
-  late ShingleMetadata _metadata;
-
-  int get n {
-    if (!_frozen) {
-      throw StateError("can't use Shingles#get n until frozen");
-    }
-    return _shingleValues.length;
-  }
-
-  void freeze() {
-    if (_frozen) {
-      throw StateError("can't freeze when already frozen");
-    }
-    _frozen = true;
-
-    _metadata = ShingleMetadata(this);
-  }
-
-  void observe(Shingle s, double n) {
-    if (_frozen) {
-      throw StateError("can't observe when already frozen");
-    }
-
-    // double n: weights can be fractional
-    var index = _shingleIndices[s.hashCode];
-    if (index == null) {
-      index = _shingleValues.length;
-      _shingleValues.add(s);
-      _shingleWeights.add(n);
-    } else {
-      _shingleWeights[index] += n;
-    }
-  }
-}
-
-class ShingleMetadata {
-  // [direction][source] => list of agreeing items
-  List<List<List<int>>> _propagators = [];
-
-  ShingleMetadata(Shingles s) {
-    _propagators = [
-      for (var d = 0; d < 4; d++)
-        [
-          for (var t = 0; t < s.n; t++)
-            [
-              for (var t2 = 0; t2 < s.n; t2++)
-                if (s._shingleValues[t]
-                    .agrees(s._shingleValues[t2], _dx[d], _dy[d]))
-                  t2
-            ]
-        ]
-    ];
-  }
-}
-
-class Shingle {
-  int order;
-  int c;
-  List<int> content = [];
-
-  @override
-  int hashCode = 0;
-
-  Shingle(this.order, this.c, int Function(int, int) f) {
-    content = [
-      for (var y = 0; y < order; y++)
-        for (var x = 0; x < order; x++) f(x, y)
-    ];
-
-    int result = 0, power = 1;
-    for (var i = 0; i < content.length; i++) {
-      result += content[content.length - 1 - i] * power;
-      power *= c;
-    }
-    hashCode = result;
-  }
-
-  Shingle rotate() {
-    return Shingle(order, c, (x, y) => content[order - 1 - y + x * order]);
-  }
-
-  Shingle reflect() {
-    return Shingle(order, c, (x, y) => content[order - 1 - x + y * order]);
-  }
-
-  bool agrees(Shingle other, int dx, int dy) {
-    var p1 = content;
-    var p2 = other.content;
-    var n = order;
-
-    int xmin = dx < 0 ? 0 : dx;
-    int xmax = dx < 0 ? dx + n : n;
-    int ymin = dy < 0 ? 0 : dy;
-    int ymax = dy < 0 ? dy + n : n;
-    for (var y = ymin; y < ymax; y++) {
-      for (var x = xmin; x < xmax; x++) {
-        if (p1[x + n * y] != p2[x - dx + n * (y - dy)]) {
-          return false;
-        }
-      }
-    }
-    return true;
-  }
-
-  @override
-  bool operator ==(Object other) {
-    return (other is Shingle) &&
-        other.hashCode == hashCode &&
-        other.order == order &&
-        other.c == c;
-  }
-}
-
-class Embedding<T> {
-  bool _frozen = false;
-  final List<T> _colorOf = [];
-  final Map<T, int> _codeOf = {};
-
-  void freeze() {
-    if (_frozen) {
-      throw StateError("can't freeze when already frozen");
-    }
-    _frozen = true;
-  }
-
-  int get c {
-    if (!_frozen) {
-      throw StateError("can't use Embedding#get c until frozen");
-    }
-    return _colorOf.length;
-  }
-
-  int encode(T t) {
-    var code = _codeOf[t];
-    if (code == null) {
-      if (_frozen) {
-        throw StateError("can't create new code when frozen");
-      }
-      code = _colorOf.length;
-      _codeOf[t] = code;
-      _colorOf.add(t);
-    }
-    return code;
-  }
-
-  T decode(int i) {
-    return _colorOf[i]!;
-  }
-}
-
-int _chooseRandom(math.Random rand, List<double> distribution) {
-  if (distribution.isEmpty) {
-    throw Exception("can't sample empty distribution");
-  }
-  var sum = 0.0;
-  for (var i = 0; i < distribution.length; i++) {
-    sum += distribution[i];
-  }
-
-  if (sum == 0.0) {
-    return rand.nextInt(distribution.length);
-  }
-
-  var rnd = rand.nextDouble() * sum;
-
-  var i = 0;
-  while (rnd > 0) {
-    rnd -= distribution[i];
-    if (rnd < 0) {
-      return i;
-    }
-    i += 1;
-  }
-  return distribution.length - 1;
-}
-
-final List<int> _dx = [-1, 0, 1, 0];
-final List<int> _dy = [0, 1, 0, -1];
-final List<int> _opposite = [2, 3, 0, 1];

lib/world/level.dart

@@ -1,5 +1,3 @@
-import 'package:dartterm/wfc/template.dart';
-
 enum LevelTile {
   exit,
   door,
@@ -11,23 +9,21 @@ class Level {
   Set<(int, int)> openCells = {};
 }
 
-Future<WfcTemplate<LevelTile>> loadLevelWfcAsync(String name) async {
+LevelTile colorToTile(int c) {
-  return WfcTemplate.loadAsync(name, 3, (c) {
+  switch (c) {
-    switch (c) {
+    // ABGR
-      // ABGR
+    case 0xFF000000:
-      case 0xFF000000:
+    case 0xFF707070:
-      case 0xFF707070:
+      return LevelTile.wall;
-        return LevelTile.wall;
+    case 0xFFFFFFFF:
-      case 0xFFFFFFFF:
+    case 0xFF00FFFF:
-      case 0xFF00FFFF:
+    case 0xFFFF00FF:
-      case 0xFFFF00FF:
+      return LevelTile.floor;
-        return LevelTile.floor;
+    case 0xFFFF8700:
-      case 0xFFFF8700:
+      return LevelTile.door;
-        return LevelTile.door;
+    case 0xFF0000FF:
-      case 0xFF0000FF:
+      return LevelTile.exit;
-        return LevelTile.exit;
+    default:
-      default:
+      throw Exception("unrecognized pixel: $c");
-        throw Exception("unrecognized pixel: $c");
+  }
-    }
-  });
 }