From e466ed8e2258022d1351497fb5bd560ba9db5127 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Sun, 26 Dec 2021 17:31:42 +0100
Subject: [PATCH] Revert "rulegen:: trace_rootpath changed to beats_exhaustive"

This reverts commit 81e8a1f113f82f5cf4998960f3ffec68b736c490.
---
 rulegen.cpp | 60 +++++++++++++++++++++++++++++++++--------------------
 1 file changed, 38 insertions(+), 22 deletions(-)

diff --git a/rulegen.cpp b/rulegen.cpp
index f1e645b4..5e1d6534 100644
--- a/rulegen.cpp
+++ b/rulegen.cpp
@@ -814,29 +814,38 @@ EX void ensure_shorter(twalker cw) {
     }
   }
 
-EX bool beats_exhaustive(twalker w1, twalker w2) {
-  int iter = 0;
-  while(true) { iter++;
-    w1 += wstep;
-    w2 += wstep;
+void trace_root_path(vector<int>& rp, twalker cw) {
+  auto d = cw.peek()->dist;
+  cw += wstep; auto scw = cw;
 
-    if(w1.at->dist == 0)
-      return w1.spin > w2.spin;
+  bool side = (flags & w_parent_side);
 
-    be_solid(w1.at);
-    be_solid(w2.at);
+  next:
+  if(d > 0) {
+    ufind(cw);
     handle_distance_errors();
-
-    auto sw1 = get_parent_dir(w1);
-    auto sw2 = get_parent_dir(w2);
-
-    int d1 = w1.to_spin(sw1.spin);
-    int d2 = w2.to_spin(sw2.spin);
-    if(d1 != d2) return d1 < d2;
-
-    w1 = sw1;
-    w2 = sw2;
+    auto cwd = get_parent_dir(cw);
+    for(int i=0; i<cw.at->type; i++) {
+      if((!side) && (cw+i) != cwd) continue;
+      tcell *c1 = cwd.peek();
+      if(!c1) continue;
+      be_solid(c1);
+      handle_distance_errors();
+      if(c1->dist < d) {
+        rp.push_back(i);
+        cw += i;
+        cw += wstep;
+        d--;
+        goto next;
+        }
+      }
     }
+  if(d > 0) {
+    debuglist = {scw};
+    throw rulegen_failure("should not happen [trace]");
+    }
+  rp.push_back(cw.to_spin(0));
+  if(flags & w_parent_reverse) reverse(rp.begin(), rp.end());
   }
 
 EX int parent_updates;
@@ -904,10 +913,17 @@ EX twalker get_parent_dir(twalker& cw) {
 
       resolve:
       hard_parents++;
-      bestd = nearer[0];
+      vector<int> best;
+      int bestfor = nearer[0];
+      trace_root_path(best, twalker(c, nearer[0]));
 
-      for(auto ne1: nearer) if(ne1 != bestd && beats_exhaustive(twalker(c, ne1), twalker(c, bestd)))
-        bestd = ne1;
+      for(auto ne1: nearer) {
+        vector<int> other;
+        trace_root_path(other, twalker(c, ne1));
+        if(other < best) best = other, bestfor = ne1;
+        }
+
+      bestd = bestfor;
       }
 
     if(bestd == -1) {