From e6dd27f5bf2d653aba29c89122e83937a63149d6 Mon Sep 17 00:00:00 2001
From: Zeno Rogue <zeno@attnam.com>
Date: Wed, 16 Jun 2021 11:12:42 +0200
Subject: [PATCH] dice:: now work correctly in non-orientable spaces

---
 complex2.cpp  | 12 ++++++++----
 mapeditor.cpp |  3 +++
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/complex2.cpp b/complex2.cpp
index aebdbc25..2b921d8a 100644
--- a/complex2.cpp
+++ b/complex2.cpp
@@ -963,6 +963,7 @@ EX namespace dice {
     struct die_structure *which;
     int val;
     int dir;
+    bool mirrored;
     int happy();
     };
   #endif
@@ -1113,12 +1114,11 @@ EX namespace dice {
     
     auto& dw = dd.which;
     
-    int si = isize(dw->sides[val]);
+    int si = dw->facesides;
     
     if(t % si) { println(hlog, "error: bad roll"); return dd; }
     
-    int sideid = (rdir - dir) * si / t;
-    if(sideid < 0) sideid += si;
+    int sideid = gmod((rdir - dir) * (dd.mirrored?-1:1) * si / t, si);
     
     int val1 = dw->sides[val][sideid];
     
@@ -1131,10 +1131,13 @@ EX namespace dice {
     
     int rdir1 = mi.rev_dir_force();
     
-    int dir1 = rdir1 - sideid1 * t1 / si1;
+    bool mirror1 = dd.mirrored ^ mi.mirror();
+    
+    int dir1 = rdir1 - (mirror1?-1:1) * sideid1 * t1 / si1;
     
     dir1 = gmod(dir1, t1);
     
+    dd.mirrored = mirror1;
     dd.val = val1;
     dd.dir = dir1;
     return dd;
@@ -1211,6 +1214,7 @@ EX namespace dice {
     #endif
     
     shiftmatrix V1 = V * ddspin(c, dir) * spin(M_PI);
+    if(dd.mirrored) V1 = V1 * MirrorY;
     
     // loop:
 
diff --git a/mapeditor.cpp b/mapeditor.cpp
index 49042f63..e6ecd83f 100644
--- a/mapeditor.cpp
+++ b/mapeditor.cpp
@@ -677,6 +677,7 @@ EX namespace mapstream {
         f.write_char(dice::get_die_id(dat.which));
         f.write_char(dat.val);
         f.write_char(dat.dir);
+        f.write_char(dat.mirrored);
         }
       // f.write_char(c->barleft);
       // f.write_char(c->barright);
@@ -833,6 +834,8 @@ EX namespace mapstream {
         dat.which = dice::get_by_id(f.read_char());
         dat.val = f.read_char();
         dat.dir = fixspin(rspin, f.read_char(), c->type, f.vernum);
+        if(f.vernum >= 0xA902)
+          dat.mirrored = f.read_char();
         }
       // c->barleft = (eLand) f.read_char();
       // c->barright = (eLand) f.read_char();