From c22aeedde9fd800823785afa41eaa2a40142a2c5 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Mon, 17 Jun 2024 23:10:09 +0200
Subject: [PATCH] fixed_yz now works in all geometries where it makes sense

---
 config.cpp   |  2 +-
 hypgraph.cpp | 18 ++++++++++++++++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/config.cpp b/config.cpp
index c805a1f6..25541394 100644
--- a/config.cpp
+++ b/config.cpp
@@ -3003,7 +3003,7 @@ EX void show3D() {
       });
     }
 
-  if(mproduct || embedded_plane)
+  if(has_fixed_yz())
     dialog::addBoolItem_action(XLAT("fixed Y/Z rotation"), vid.fixed_yz, 'Z');
 
   if(WDIM == 2 && GDIM == 3) {
diff --git a/hypgraph.cpp b/hypgraph.cpp
index c7b9cc66..b69b2dce 100644
--- a/hypgraph.cpp
+++ b/hypgraph.cpp
@@ -2020,8 +2020,12 @@ void hrmap_standard::draw_at(cell *at, const shiftmatrix& where) {
     }
   }
 
+EX bool has_fixed_yz() {
+  return (embedded_plane || mhybrid || nil || euclid || sol || nih || (cgflags & qSTRETCHABLE) || (hyperbolic && bt::in()));
+  }
+
 EX bool keep_vertical() {
-  if((WDIM == 2 || gproduct) && GDIM == 3 && vid.fixed_yz) return !CAP_ORIENTATION;
+  if(vid.fixed_yz && has_fixed_yz()) return !CAP_ORIENTATION;
   if(downseek.qty) return true;
   return false;
   }
@@ -2033,9 +2037,19 @@ EX hyperpoint vertical_vector() {
     if(gproduct) Rot = NLP * Rot;
     return Rot * lztangent(vid.wall_height);
     }
-  if(gproduct && vid.fixed_yz) {
+  if(mproduct && vid.fixed_yz) {
     return get_view_orientation() * lztangent(1);
     }
+  if(((cgflags & qSTRETCHABLE) || (mtwisted && sphere)) && vid.fixed_yz) {
+    return stretch::itranslate(View * C0) * View * lztangent(1);
+    }
+  if((nil || euclid || sol || nih) && vid.fixed_yz) {
+    return View * lztangent(1);
+    }
+  if(hyperbolic && bt::in() && vid.fixed_yz) {
+    hyperpoint h = inverse(View) * C0;
+    return View * parabolic13_at(deparabolic13(h)) * xtangent(1);
+    }
   if(ds.qty && gproduct)
     return get_view_orientation() * product::inverse_exp(ds.point);
   if(ds.qty)