From 4c3a348666b1a58a5aa855687d6de58daad45a01 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Sun, 16 Jun 2024 17:59:04 +0200
Subject: [PATCH] twisted product now actually appears for spherical space, and
 automatically sets csteps if it was illegal

---
 geom-exp.cpp     | 9 +++++++--
 nonisotropic.cpp | 8 ++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/geom-exp.cpp b/geom-exp.cpp
index 397108c9..a54fd44e 100644
--- a/geom-exp.cpp
+++ b/geom-exp.cpp
@@ -262,7 +262,7 @@ bool forced_quotient() { return quotient && !(cgflags & qOPTQ); }
 EX geometry_filter gf_hyperbolic = {"hyperbolic", 'h', [] { return (arcm::in() || arb::in() || hyperbolic) && !forced_quotient(); }};
 EX geometry_filter gf_spherical = {"spherical", 's', [] { return (arcm::in() || arb::in() || sphere) && !forced_quotient(); }};
 EX geometry_filter gf_euclidean = {"Euclidean", 'e', [] { return (arcm::in() || arb::in() || euclid) && !forced_quotient(); }};
-EX geometry_filter gf_other = {"non-isotropic", 'n', [] { return mproduct || nonisotropic; }};
+EX geometry_filter gf_other = {"non-isotropic", 'n', [] { return mproduct || mtwisted || nonisotropic; }};
 EX geometry_filter gf_regular_2d = {"regular 2D tesselations", 'r', [] { 
   return standard_tiling() && WDIM == 2 && !forced_quotient();
   }};
@@ -314,6 +314,7 @@ void set_or_configure_geometry(eGeometry g) {
   else if(g == gArbitrary)
     arb::choose();
   else {
+    bool quo = false;
     if(among(g, gProduct, gTwistedProduct)) {
       if(WDIM == 3 || (g == gTwistedProduct && euclid)) {
         addMessage(
@@ -325,6 +326,7 @@ void set_or_configure_geometry(eGeometry g) {
         }
       if(g == gTwistedProduct) {
         bool ok = true;
+        quo = sphere || quotient;
         if(arcm::in()) ok = PURE;
         else if(bt::in() || aperiodic) ok = false;
         else ok = PURE || BITRUNCATED;
@@ -343,7 +345,10 @@ void set_or_configure_geometry(eGeometry g) {
         #endif
         }
       }
-    dual::may_split_or_do([g] { set_geometry(g); });
+    dual::may_split_or_do([g, quo] {
+      set_geometry(g);
+      if(quo) hybrid::fixup_csteps();
+      });
     start_game();
     }
   }
diff --git a/nonisotropic.cpp b/nonisotropic.cpp
index b4c811e3..1ec13b55 100644
--- a/nonisotropic.cpp
+++ b/nonisotropic.cpp
@@ -1249,6 +1249,14 @@ EX namespace hybrid {
       }
     }
 
+  EX void fixup_csteps() {
+    check_cgi(); cgi.require_basics();
+    if(!hybrid::csteps || gmod(cgi.psl_steps, hybrid::csteps)) {
+      hybrid::csteps = cgi.psl_steps;
+      hybrid::reconfigure();
+      }
+    }
+
   EX hrmap *pmap;
   EX geometry_information *pcgip;
   EX eGeometry actual_geometry;