I can validate that a map is pathable, but can't fix it.

src/algos/maze.cpp

@@ -7,7 +7,6 @@
 using std::string;
 using matrix::Matrix;
 
-
 namespace maze {
   inline size_t rand(size_t i, size_t j) {
     if(i < j) {
@@ -94,7 +93,7 @@ namespace maze {
     dbc::sentinel("failed to find coord?");
   }
 
-  bool Builder::room_should_exist(Room& room) {
+  bool Builder::room_should_exist(Room& room, bool allow_dupes) {
     if(!matrix::inbounds($walls, room.x, room.y) ||
       !matrix::inbounds($walls, room.x + room.width, room.y + room.height))
     {
@@ -106,7 +105,11 @@ namespace maze {
     }
 
     for(auto& other : $rooms) {
-      if(room.overlaps(other)) return false;
+      bool is_duped = allow_dupes ? room == other : room != other;
+
+      if(is_duped && room.overlaps(other)) {
+        return false;
+      }
     }
 
     // it's in the map and doesn't collide with another room
@@ -181,8 +184,6 @@ namespace maze {
         on = nb;
       }
     }
-
-    enclose();
   }
 
   void Builder::place_rooms() {
@@ -191,8 +192,6 @@ namespace maze {
         $walls[it.y][it.x] = 0;
       }
     }
-
-    enclose();
   }
 
   void Builder::inner_donut(float outer_rad, float inner_rad) {
@@ -245,7 +244,11 @@ namespace maze {
     // mark dead ends
     for(auto at : $dead_ends) {
       // don't mark dead ends if there's something else there
-      wall_copy[at.y][at.x]=32;
+      wall_copy[at.y][at.x] = 32;
+    }
+
+    for(auto [at, _] : $doors) {
+      wall_copy[at.y][at.x] = 0xd;
     }
 
     matrix::dump(msg, wall_copy);
@@ -273,7 +276,9 @@ namespace maze {
     size_t height = matrix::height($walls);
 
     perimeter(0, 0, width, height, [&](size_t x, size_t y) {
-      $walls[y][x] = 1;
+      $walls[y][x] = WALL_VALUE;
+      Point at{x,y};
+      if($doors.contains(at)) $doors.erase(at);
     });
   }
 
@@ -303,20 +308,35 @@ namespace maze {
 
   void Builder::make_doors() {
     for(auto room : $rooms) {
-      // BUG: still makes rooms without doors, so detect if no door added and brute force one in
-      perimeter(room.x, room.y, room.width, room.height, [&](auto x, auto y) {
+      // walk the outer wall looking for an emergent door
+      int has_door = 0;
+      Point last_door{0,0};
+
+      perimeter(room.x - 1, room.y - 1, room.width + 2, room.height + 2, [&](size_t x, size_t y) {
+          if($walls[y][x] == SPACE_VALUE) {
+            last_door = {x, y};
+            has_door++;
+          }
+      });
+
+      // if only found one then make that an actual door
+      if(has_door == 1) {
+        $doors.insert_or_assign(last_door, true);
+      }
+
+      // no emergent door found, punch out one
+      perimeter(room.x, room.y, room.width, room.height, [&](size_t x, size_t y) {
         if($ends_map.contains({x, y})) {
           for(matrix::compass door_at{$walls, x, y}; door_at.next();) {
             if($walls[door_at.y][door_at.x] == WALL_VALUE) {
               $walls[door_at.y][door_at.x] = SPACE_VALUE;
+              $doors.insert_or_assign({size_t(door_at.x), size_t(door_at.y)}, true);
               break;
             }
           }
         }
       });
     }
-
-    enclose();
   }
 
   void Builder::inner_box(size_t outer_size, size_t inner_size) {
@@ -338,10 +358,51 @@ namespace maze {
   }
 
   void Builder::add_dead_end(Point at) {
+    // doing this ensures no dupes, if it's !inserted then it already existed
     auto [_, inserted] = $ends_map.insert_or_assign(at, true);
 
+    // so skip it, it isn't new
     if(inserted) {
       $dead_ends.push_back(at);
     }
   }
+
+  bool Builder::validate() {
+    size_t width = matrix::width($walls);
+    size_t height = matrix::height($walls);
+
+    // no rooms can overlap
+    for(auto& room : $rooms) {
+      if(!room_should_exist(room)) return false;
+    }
+
+    bool bad_perimeter = false;
+    // BUG: this is dogshit, get rid of perimeter, I can't even spell it right it's so bad
+    perimeter(0, 0, width, height, [&](size_t x, size_t y) {
+      if($ends_map.contains({x, y})) bad_perimeter = true;
+      if($doors.contains({x, y})) bad_perimeter = true;
+    });
+
+    if(bad_perimeter) return false;
+
+    if($rooms.size() == 1) return true;
+
+    // initial path test can just use one room then look for
+    // any cells that are empty in the walls map but unpathed in the paths
+    Room test_room = $rooms.at(0);
+    Point test{test_room.x, test_room.y};
+    $paths.set_target(test);
+    $paths.compute_paths($walls);
+    $paths.dump("AFTER COMPUTE");
+    $paths.clear_target(test);
+
+    for(matrix::each_cell it{$walls}; it.next();) {
+      if($walls[it.y][it.x] == SPACE_VALUE &&
+          $paths.$paths[it.y][it.x] == WALL_PATH_LIMIT) {
+        return false;
+      }
+    }
+
+    return true;
+  }
 }

src/algos/maze.hpp

@@ -11,10 +11,17 @@ namespace maze {
     std::vector<Point>& $dead_ends;
     std::unordered_map<Point, bool> $ends_map;
     Room $no_rooms_region{0,0,0,0};
+    // BUG: instead of bool map it to the room?
+    std::unordered_map<Point, bool> $doors;
+    Pathing $paths;
 
     Builder(Map& map) :
-      $walls(map.$walls), $rooms(map.$rooms), $dead_ends(map.$dead_ends)
+      $walls(map.$walls), $rooms(map.$rooms), $dead_ends(map.$dead_ends),
+      $paths{matrix::width(map.$walls), matrix::height(map.$walls)}
     {
+      dbc::check(map.$width % 2 == 1, "map width not an ODD number (perimter dead ends bug)");
+      dbc::check(map.$height % 2 == 1, "map height not an ODD number (perimter dead ends bug)");
+
       clear();
     }
 
@@ -31,7 +38,8 @@ namespace maze {
     void perimeter(size_t x, size_t y, size_t width, size_t height, std::function<void(size_t x, size_t y)> cb);
     void open_box(size_t outer_size);
     void add_dead_end(Point at);
-    bool room_should_exist(Room& room);
+    bool room_should_exist(Room& room, bool allow_dupes=false);
     void make_doors();
+    bool validate();
   };
 }

src/algos/pathing.cpp

@@ -132,3 +132,7 @@ bool Pathing::INVARIANT() {
 
   return true;
 }
+
+void Pathing::dump(const std::string& msg) {
+  matrix::dump(msg, $paths);
+}

src/algos/pathing.hpp

@@ -37,4 +37,5 @@ public:
   PathingResult find_path(Point &out, int direction, bool diag);
 
   bool INVARIANT();
+  void dump(const std::string& msg);
 };