From d3d1d689fa94fc1ce18e46718ccef89b2b696b0a Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Fri, 27 Dec 2019 23:34:41 +0100
Subject: [PATCH] arb:: pattern Sublines

---
 arbitrile.cpp | 19 +++++++++++++++++++
 pattern2.cpp  | 10 +++++++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/arbitrile.cpp b/arbitrile.cpp
index 595be4c3..c58dda9b 100644
--- a/arbitrile.cpp
+++ b/arbitrile.cpp
@@ -23,6 +23,7 @@ struct shape {
   vector<tuple<int, int, int>> connections;
   int size() const { return isize(vertices); }
   void build_from_angles_edges();
+  vector<pair<int, int> > sublines;
   };
 
 struct arbi_tiling {
@@ -210,6 +211,24 @@ void load(const string& fname) {
       c.shapes[ai].connections[as] = make_tuple(bi, bs, m);
       c.shapes[bi].connections[bs] = make_tuple(ai, as, m);
       }
+    else if(ep.eat("subline(")) {
+      int ai = ep.iparse(); verify_index(ai, c.shapes); ep.force_eat(",");
+      int as = ep.iparse(); verify_index(as, c.shapes[ai]); ep.force_eat(",");
+      int bs = ep.iparse(); verify_index(bs, c.shapes[ai]); ep.force_eat(")");
+      c.shapes[ai].sublines.emplace_back(as, bs);
+      }
+    else if(ep.eat("sublines(")) {
+      int d = ep.rparse(); ep.force_eat(")");
+      for(auto& sh: c.shapes) {
+        for(int i=0; i<isize(sh.vertices); i++)
+        for(int j=0; j<isize(sh.vertices); j++)
+          if(j != i+1 && i != j+1 && !(i==0 && j == isize(sh.vertices)-1) && !(j==0 && i == isize(sh.vertices)-1))
+            if(abs(hdist(sh.vertices[i], sh.vertices[j]) - distunit * d) < 1e-6) {
+              sh.sublines.emplace_back(i, j);
+              println(hlog, "add subline ", i, "-", j);
+              }
+        }
+      }
     else throw hr_parse_exception("expecting command");
     }
   }
diff --git a/pattern2.cpp b/pattern2.cpp
index 975aa5d1..9529aebc 100644
--- a/pattern2.cpp
+++ b/pattern2.cpp
@@ -2686,6 +2686,14 @@ EX namespace linepatterns {
         }
       )
     );
+  linepattern patSublines("sub-lines", 0xFFFFFF00, arb::in,
+    ALLCELLS(
+      int i = arb::id_of(c->master);
+      auto& sh = arb::current.shapes[i];
+      for(auto p: sh.sublines)
+        gridlinef(V, sh.vertices[p.first], sh.vertices[p.second], col, 2 + vid.linequality);
+      )
+    );
   
   #if HDR
   extern linepattern patTriTree, patTriRings, patTriOther;
@@ -2698,7 +2706,7 @@ EX namespace linepatterns {
     &patVine, &patPalacelike, &patPalace, &patPower, &patHorocycles,
     &patTriRings, &patTriTree, &patTriOther,
     &patGoldbergTree, &patIrregularMaster, &patGoldbergSep, &patHeawood, &patArcm,
-    &patCircles, &patRadii, &patMeridians, &patParallels
+    &patCircles, &patRadii, &patMeridians, &patParallels, &patSublines
     };
 
   EX void clearAll() {