From d2564d07ee503b309cf20796e897127a51e40c66 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Fri, 17 Apr 2026 18:23:59 +0200
Subject: [PATCH] zebra patterns: binary-tiling (parity), oox3 (random)

---
 landgen.cpp  | 8 +++++++-
 landlock.cpp | 4 ++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/landgen.cpp b/landgen.cpp
index 9f11f297..7bdb57b2 100644
--- a/landgen.cpp
+++ b/landgen.cpp
@@ -229,9 +229,15 @@ EX bool is_zebra_trapdoor(cell *c) {
     return (y&1);
     }
   #if CAP_ARCM
-  else 
+  else
     if(arcm::in()) return hrand(2);
   #endif
+  else
+    if(S3 >= OINF) return hrand(2);
+  #if CAP_BT
+  else
+    if(bt::in()) return c->master->distance & 1;
+  #endif
   else
     return (randomPatternsMode ? RANDPAT : (zebra40(c)&2));
   }
diff --git a/landlock.cpp b/landlock.cpp
index 7d156e8c..92be66de 100644
--- a/landlock.cpp
+++ b/landlock.cpp
@@ -1550,6 +1550,10 @@ EX land_validity_t& land_validity(eLand l) {
   if(l == laCrossroads4 && quotient)
     return some0;
 
+  if(l == laZebra && bt::in()) return pattern_defined;
+
+  if(l == laZebra && S3 >= OINF) return pattern_not_implemented_random;
+
   if(among(l, laZebra, laFrog) && quotient && geometry != gZebraQuotient && !randomPatternsMode)
     return pattern_incompatibility;