Move the random gen to a global for now.

map.cpp

@@ -5,6 +5,10 @@
 #include <random>
 #include <utility>
 
+
+std::random_device g_rng;
+std::mt19937 g_generator(g_rng());
+
 using std::vector, std::pair;
 using namespace fmt;
 
@@ -105,7 +109,7 @@ void Map::make_room(size_t origin_x, size_t origin_y, size_t w, size_t h) {
   }
 }
 
-inline int make_split(std::mt19937 &gen, Room &cur, bool horiz) {
+inline int make_split(Room &cur, bool horiz) {
   println("MAKE SPLIT horiz={}, y={}, w={}, h={}", horiz,
         cur.y, cur.width, cur.height);
   size_t dimension = horiz ? cur.height : cur.width;
@@ -113,10 +117,10 @@ inline int make_split(std::mt19937 &gen, Room &cur, bool horiz) {
   int max = dimension - min;
   println("dimension={}, min={}, max={}", dimension, min, max);
   std::uniform_int_distribution<int> rand_dim(min, max);
-  return rand_dim(gen);
+  return rand_dim(g_generator);
 }
 
-void Map::partition_map(std::mt19937 &gen, Room &cur, int depth) {
+void Map::partition_map(Room &cur, int depth) {
 
   if(cur.width >= 5 && cur.width <= 10 &&
       cur.height >= 5 && cur.height <= 10) {
@@ -126,7 +130,7 @@ void Map::partition_map(std::mt19937 &gen, Room &cur, int depth) {
 
   std::uniform_int_distribution<int> rsplit(0, 1);
   bool horiz = cur.width > cur.height ? false : true;
-  int split = make_split(gen, cur, horiz);
+  int split = make_split(cur, horiz);
   Room left = cur;
   Room right = cur;
 
@@ -146,11 +150,11 @@ void Map::partition_map(std::mt19937 &gen, Room &cur, int depth) {
   }
 
   if(depth > 0  && left.width > 5 && left.height > 5) {
-    partition_map(gen, left, depth-1);
+    partition_map(left, depth-1);
   }
 
   if(depth > 0 && right.width > 5 && right.height > 5) {
-    partition_map(gen, right, depth-1);
+    partition_map(right, depth-1);
   }
 }
 
@@ -161,9 +165,6 @@ void Map::draw_map(Room &cur) {
 }
 
 void Map::generate() {
-  std::random_device rd;
-  std::mt19937 gen(rd());
-
   Room root{
     .x = 0,
     .y = 0,
@@ -171,7 +172,7 @@ void Map::generate() {
     .height = height()
   };
 
-  partition_map(gen, root, 6);
+  partition_map(root, 6);
   draw_map(root); // left
 }
 

map.hpp

@@ -59,6 +59,6 @@ public:
   void generate();
   void draw_map(Room &root);
   void make_paths();
-  void partition_map(std::mt19937 &gen, Room &cur, int depth);
+  void partition_map(Room &cur, int depth);
   void dump();
 };