Use vaults if we have them

lib/algorithms/regionalize.dart

@@ -0,0 +1,66 @@
+import 'dart:math' as math;
+
+class Region {
+  final math.Rectangle<int> rect;
+  final Set<(int, int)> points;
+
+  Region(this.rect, this.points);
+
+  static fromNonEmptySet(Set<(int, int)> s) {
+    assert(s.isNotEmpty);
+    int xMin = s.map<int>((xy) => xy.$1).reduce(math.min);
+    int yMin = s.map<int>((xy) => xy.$2).reduce(math.min);
+    int xMax = s.map<int>((xy) => xy.$1).reduce(math.max);
+    int yMax = s.map<int>((xy) => xy.$2).reduce(math.max);
+    var rect = math.Rectangle.fromPoints(
+        math.Point(xMin, yMin), math.Point(xMax, yMax));
+    Region(rect, s);
+  }
+}
+
+List<Region> regionalize(
+    math.Rectangle<int> rect, bool Function(int, int) isAccessible) {
+  int nextRegion = 0;
+  Map<(int, int), int> regions = {};
+
+  void floodfill(int x, int y, region) {
+    if (!rect.containsPoint(math.Point(x, y))) {
+      return;
+    }
+    if (regions[(x, y)] != null) {
+      return;
+    }
+    if (!isAccessible(x, y)) {
+      return;
+    }
+
+    regions[(x, y)] = region;
+    floodfill(x - 1, y, region);
+    floodfill(x + 1, y, region);
+    floodfill(x, y - 1, region);
+    floodfill(x, y + 1, region);
+  }
+
+  // TODO: This can be done more efficiently with a union/find data structure
+  // But this is an easy implementation to understand
+  for (var y = rect.top; y < rect.bottom; y++) {
+    for (var x = rect.left; x < rect.right; x++) {
+      if (regions[(x, y)] == null) {
+        floodfill(x, y, nextRegion);
+        nextRegion += 1;
+      }
+    }
+  }
+  return _toExplicit(regions);
+}
+
+List<Region> _toExplicit(Map<(int, int), int> regions) {
+  List<Set<(int, int)>> pointsOut = [
+    for (var i = 0; i < regions.length; i++) Set()
+  ];
+  for (var MapEntry(key: (x, y), value: id_) in regions.entries) {
+    pointsOut[id_].add((x, y));
+  }
+
+  return [for (var s in pointsOut) Region.fromNonEmptySet(s)];
+}

lib/gen/generator.dart

@@ -10,9 +10,12 @@ part 'requirement.dart';
 part 'vault.dart';
 part 'vaults.dart';
 
+const vaultTries = 10;
+
 class Generator {
   final math.Random _random;
   final Vaults _vaults;
+  List<Vault> _queue = [];
 
   Generator(this._random, this._vaults);
 
@@ -32,7 +35,10 @@ class Generator {
   }
 
   Vault generate(Requirement requirement) {
-    // TODO: Pick a relevant vault from the vaults file if possible
+    Vault? suggested = _suggest(vaultTries, requirement);
+    if (suggested != null) {
+      return suggested;
+    }
 
     // First of all: randomize orientation
     // This way we only have to consider one kind of spilt
@@ -78,4 +84,74 @@ class Generator {
 
     return v;
   }
+
+  Vault? _suggest(int tries, Requirement req) {
+    for (var i = 0; i < tries; i++) {
+      var sugg = _popSuggestion();
+      if (sugg == null) {
+        return null;
+      }
+
+      sugg = reorientVault(sugg, randomOrientation(_random));
+      sugg = _tidy(sugg, req);
+      if (sugg != null) {
+        return sugg;
+      }
+    }
+    return null;
+  }
+
+  Vault? _popSuggestion() {
+    if (_queue.isEmpty) {
+      _queue = _vaults.randomFlight(_random);
+    }
+    if (_queue.isEmpty) {
+      return null;
+    }
+    return _queue.removeLast();
+  }
+
+  Vault? _tidy(Vault vault, Requirement req) {
+    if (vault.vx > req.vx || vault.vy > req.vy) {
+      return null;
+    }
+    if (vault.vx < req.vx / 2 || vault.vy < req.vy / 2) {
+      return null;
+    }
+
+    var rsd = req.smooth.directions;
+    bool mustFillX =
+        rsd.contains(Direction.left) && rsd.contains(Direction.right);
+    if (vault.vx != req.vx && mustFillX) {
+      return null;
+    }
+    bool mustFillY =
+        rsd.contains(Direction.left) && rsd.contains(Direction.right);
+    if (vault.vy != req.vy && mustFillY) {
+      return null;
+    }
+
+    Vault full = Vault.blank(req.vx, req.vy, req.smooth, LevelTile.wall);
+    int vx = vault.vx;
+    int dx;
+    if (rsd.contains(Direction.left)) {
+      dx = 0;
+    } else if (rsd.contains(Direction.right)) {
+      dx = req.vx - vx;
+    } else {
+      dx = _random.nextInt(req.vx - vx);
+    }
+
+    int vy = vault.vy;
+    int dy;
+    if (rsd.contains(Direction.up)) {
+      dy = 0;
+    } else if (rsd.contains(Direction.down)) {
+      dy = req.vy - vy;
+    } else {
+      dy = _random.nextInt(req.vx - vx);
+    }
+    full.blitFrom(vault, dx, dy);
+    return full;
+  }
 }

lib/gen/vaults.dart

@@ -7,4 +7,12 @@ class Vaults {
     // TODO
     return Vaults();
   }
+
+  List<Vault> randomFlight(math.Random rng) {
+    // TODO: There are many more efficient ways to do this!
+    List<Vault> list2 = [];
+    list2.addAll(_primitive);
+    list2.shuffle(rng);
+    return list2;
+  }
 }

pubspec.yaml

@@ -62,6 +62,7 @@ flutter:
   assets:
     - assets/images/fonts/
     - assets/images/wfc/
+    - assets/images/vaults/
   #   - images/a_dot_burr.jpeg
   #   - images/a_dot_ham.jpeg