From 60d0d15dab82c2393149398bd18715b8503902f2 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Sat, 8 Oct 2022 01:54:30 +0200
Subject: [PATCH] tes:: refactored find_connection

---
 arbitrile.cpp | 48 +++++++++++++++++++++++++++++-------------------
 1 file changed, 29 insertions(+), 19 deletions(-)

diff --git a/arbitrile.cpp b/arbitrile.cpp
index a910c02c..3111bec9 100644
--- a/arbitrile.cpp
+++ b/arbitrile.cpp
@@ -1377,6 +1377,28 @@ EX transmatrix get_adj(arbi_tiling& c, int t, int dl) {
   return get_adj(c, t, dl, co.sid, co.eid, co.mirror);
   }
 
+/** Returns if F describes the same tile as T, taking possible symmetries into account. Paramater co is the expected edge (co.sid tells us the tile type); if yes, co may be adjusted */
+EX bool find_connection(const transmatrix& T, const transmatrix& F, connection_t& co) {
+
+  if(!same_point_may_warn(tC0(F), tC0(T))) return false;
+
+  auto& xsh = current.shapes[co.sid];
+  int n = isize(xsh.connections);
+  for(int oth = 0; oth < n; oth++) {
+    int oth1 = gmod(oth+1, n);
+    int eid1 = gmod(co.eid+1, n);
+    if(same_point_may_warn(F * xsh.vertices[oth], T * xsh.vertices[co.eid]) && same_point_may_warn(F * xsh.vertices[oth1], T * xsh.vertices[eid1])) {
+      co.eid = oth;
+      return true;
+      }
+    if(same_point_may_warn(F * xsh.vertices[oth], T * xsh.vertices[eid1]) && same_point_may_warn(F * xsh.vertices[oth1], T * xsh.vertices[co.eid])) {
+      co.eid = oth; co.mirror = !co.mirror;
+      return true;
+      }
+    }
+  return false;
+  }
+
 struct hrmap_arbi : hrmap {
   heptagon *origin;
   heptagon *getOrigin() override { return origin; }
@@ -1433,8 +1455,6 @@ struct hrmap_arbi : hrmap {
     
     auto& co = sh.connections[d];
     
-    auto& xsh = current.shapes[co.sid];
-    
     if(cgflags & qAFFINE) {
       set<heptagon*> visited;
       
@@ -1492,24 +1512,14 @@ struct hrmap_arbi : hrmap {
       alt = (heptagon*) s;
       }
 
-    for(auto& p2: altmap[alt]) if(id_of(p2.first) == co.sid && same_point_may_warn(tC0(p2.second), tC0(T))) {
-      for(int oth=0; oth < p2.first->type; oth++) {
-        int oth1 = gmod(oth+1, p2.first->type);
-        int eid1 = gmod(co.eid+1, p2.first->type);
-        if(same_point_may_warn(p2.second * xsh.vertices[oth], T * xsh.vertices[co.eid]) && same_point_may_warn(p2.second * xsh.vertices[oth1], T * xsh.vertices[eid1])) {
-          if(p2.first->move(oth)) {
-            throw hr_exception("already connected!");
-            }
-          h->c.connect(d, p2.first, oth%p2.first->type, co.mirror);
-          return p2.first;
-          }
-        if(same_point_may_warn(p2.second * xsh.vertices[oth], T * xsh.vertices[eid1]) && same_point_may_warn(p2.second * xsh.vertices[oth1], T * xsh.vertices[co.eid])) {
-          if(p2.first->move(oth)) {
-            throw hr_exception("already connected!");
-            }
-          h->c.connect(d, p2.first, oth%p2.first->type, co.mirror^1);
-          return p2.first;
+    for(auto& p2: altmap[alt]) if(id_of(p2.first) == co.sid) {
+      connection_t co1 = co;
+      if(find_connection(T, p2.second, co1)) {
+        if(p2.first->move(co1.eid)) {
+          throw hr_exception("already connected!");
           }
+        h->c.connect(d, p2.first, co1.eid, co1.mirror);
+        return p2.first;
         }
       }