From 84afa659c8114437a885f71fc864442ef10a22cc Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Tue, 10 Jul 2018 13:17:55 +0200
Subject: [PATCH] geometry changing now keeps gp:: state if possible -- no
 longer disable when switching to nonorientable or a4

---
 system.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/system.cpp b/system.cpp
index e0bb3140..2d71d957 100644
--- a/system.cpp
+++ b/system.cpp
@@ -1174,7 +1174,13 @@ void switch_game_mode(char switchWhat) {
       else geometry = targetgeometry;
       if(chaosmode && (euclid || sphere || quotient)) chaosmode = false;
       if(nonbitrunc && euclid6) nonbitrunc = false;
-      if(gp::on && (S3 != 3 || elliptic)) gp::on = false;
+      if(gp::on && gp::param == gp::loc(1,1) && S3 == 3) {
+        gp::on = false; nonbitrunc = false;
+        }
+      if(gp::on && nonorientable) {
+        if(gp::param.second && gp::param.second != gp::param.first)
+          gp::param.second = 0;
+        }
   
       need_reset_geometry = true; 
       #if CAP_TEXTURE