From 9bfc3ba400f17df6240193b174c05a8ee8c17e7c Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Thu, 16 Apr 2026 19:02:07 +0200
Subject: [PATCH] stuff affected by on_dim_change now implements the
 dim_listener interface

---
 aperiodic-hat.cpp |  2 +-
 cell.cpp          |  7 ++++---
 fake.cpp          |  4 ++--
 geometry.cpp      | 21 ++++++++++++++++++++-
 shmup.cpp         | 12 ++++--------
 sphere.cpp        |  6 ++++--
 6 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/aperiodic-hat.cpp b/aperiodic-hat.cpp
index e3fb562e..f3cdc128 100644
--- a/aperiodic-hat.cpp
+++ b/aperiodic-hat.cpp
@@ -784,7 +784,7 @@ vector<rule_recursive> spectre_rules_recursive = { rule_recursive
 EX ld hat_param = 1;
 EX ld hat_param_imag = 0;
 
-struct hrmap_hat : hrmap {
+struct hrmap_hat : hrmap, dim_listener {
 
   // always generate the same way
   std::mt19937 hatrng;
diff --git a/cell.cpp b/cell.cpp
index 2a9b7e88..3330f09a 100644
--- a/cell.cpp
+++ b/cell.cpp
@@ -29,7 +29,6 @@ struct hrmap {
   virtual ~hrmap() { }
   virtual vector<cell*>& allcells();
   virtual void verify() { }
-  virtual void on_dim_change() { }
   virtual bool link_alt(heptagon *h, heptagon *alt, hstate firststate, int dir);
   virtual void extend_altmap(heptagon *h, int levs = default_levs(), bool link_cdata = true);
   heptagon *may_create_step(heptagon *h, int direction) {
@@ -37,6 +36,8 @@ struct hrmap {
     return create_step(h, direction);
     }
   virtual heptagon *create_step(heptagon *h, int direction);
+  /** reinitialize the map after swapping dimensions */
+  virtual void reinit() {}
 protected:
   virtual transmatrix relative_matrixh(heptagon *h2, heptagon *h1, const hyperpoint& hint);
   virtual transmatrix relative_matrixc(cell *c2, cell *c1, const hyperpoint& hint);
@@ -103,7 +104,7 @@ public:
  *  Liskov substitution warning: maps which produce both tiling like above and 3D tilings
  *  (e.g. Euclidean and Crystal) also inherit from hrmap_standard
  **/
-struct hrmap_standard : hrmap {
+struct hrmap_standard : hrmap, dim_listener {
   void draw_at(cell *at, const shiftmatrix& where) override;
   transmatrix relative_matrixh(heptagon *h2, heptagon *h1, const hyperpoint& hint) override;
   transmatrix relative_matrixc(cell *c2, cell *c1, const hyperpoint& hint) override;
@@ -592,7 +593,7 @@ EX void initcells() {
     check_cgi();
     geom3::swap_direction = +1;
     for(auto& m: cgi.heptmove) swapmatrix(m);
-    currentmap->on_dim_change();
+    currentmap->reinit();
     return;
     }
 
diff --git a/fake.cpp b/fake.cpp
index 78c32628..c9b3d132 100644
--- a/fake.cpp
+++ b/fake.cpp
@@ -25,8 +25,8 @@ EX namespace fake {
 
   EX bool in_ext() { return in() || (mhybrid && PIU(in())); }
 
-  EX void on_dim_change() { pmap->on_dim_change(); }
-  
+  EX void reinit() override { pmap->reinit(); }
+
   /** like in() but takes slided arb into account */
   EX bool split() { return in() || arb::in_slided(); }
   
diff --git a/geometry.cpp b/geometry.cpp
index 663a0cda..22982dad 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -986,6 +986,25 @@ void geometry_information::prepare_basics() {
 
 EX purehookset hooks_swapdim;
 
+#if HDR
+extern struct dim_listener *dl_list;
+
+struct dim_listener {
+  dim_listener *next, **prev;
+  dim_listener() {
+    dl_list->prev = &next;
+    next = dl_list;
+    dl_list = this;
+    }
+  ~dim_listener() {
+    *prev = next; next->prev = prev;
+    }
+  virtual void on_dim_change() {}
+  };
+#endif
+
+dim_listener *dl_list;
+
 EX hookset<void(geometry_information*)> hooks_scalefactor;
 
 EX namespace geom3 {
@@ -1210,7 +1229,7 @@ EX namespace geom3 {
     swapmatrix_view(NLP, View);
     swapmatrix_view(NLP, current_display->which_copy);
     callhooks(hooks_swapdim);
-    for(auto m: allmaps) m->on_dim_change();
+    auto dl = dl_list; while(dl) { dl->on_dim_change(); dl = dl->next; }
     }
 
   #if MAXMDIM >= 4
diff --git a/shmup.cpp b/shmup.cpp
index ee0f8169..8c327369 100644
--- a/shmup.cpp
+++ b/shmup.cpp
@@ -34,7 +34,8 @@ ld sqdist(shiftpoint a, shiftpoint b) {
 EX namespace shmup {
 
 #if HDR
-struct monster {
+
+struct monster : dim_listener {
   eMonster type;
   cell *base;      ///< on which base cell this monster currently is
   cell *torigin;   ///< tortoises: origin, butterflies: last position
@@ -92,7 +93,8 @@ struct monster {
     parent->refs++;
     }
 
-  };  
+  void on_dim_change() override { swapmatrix(at); }
+  };
 #endif
 
 void monster::reset() {
@@ -3056,12 +3058,6 @@ EX void switch_shmup() {
   start_game();
   }
 
-#if MAXMDIM >= 4
-auto hooksw = addHook(hooks_swapdim, 100, [] {
-  for(auto& p: monstersAt) swapmatrix(p.second->at);
-  });
-#endif
-    
 EX shiftmatrix at_missile_level(const shiftmatrix& T) {
   if(WDIM == 3) return T;
   if(GDIM == 3) return orthogonal_move(T, cgi.BODY);
diff --git a/sphere.cpp b/sphere.cpp
index d66617e6..104a706b 100644
--- a/sphere.cpp
+++ b/sphere.cpp
@@ -172,11 +172,13 @@ struct hrmap_spherical : hrmap_standard {
     return Id;
     }
   
-  void on_dim_change() override {
-    hrmap_standard::on_dim_change();
+  void reinit() override {
+    hrmap_standard::reinit();
     where.clear();
     }
 
+  void on_dim_change() override { reinit(); }
+
   transmatrix relative_matrixc(cell *c2, cell *c1, const hyperpoint& hint) override {
     if(IRREGULAR) return relative_matrix_via_masters(c2, c1, hint);
     transmatrix T = iso_inverse(get_where(c1)) * get_where(c2);