diff --git a/crystal.cpp b/crystal.cpp
index 843eeeed..e37826b5 100644
--- a/crystal.cpp
+++ b/crystal.cpp
@@ -24,14 +24,6 @@ bool view_east = false;
 
 bool used_compass_inside;
 
-const int MAXDIM = 7;
-
-typedef array<int, MAXDIM> coord;
-static const coord c0 = {};
-
-typedef array<ld, MAXDIM> ldcoord;
-static const ldcoord ldc0 = {};
-
 ldcoord told(coord c) { ldcoord a; for(int i=0; i<MAXDIM; i++) a[i] = c[i]; return a; }
 // strange number to prevent weird acting in case of precision errors
 coord roundcoord(ldcoord c) { coord a; for(int i=0; i<MAXDIM; i++) a[i] = floor(c[i] + .5136); return a; }
@@ -449,6 +441,10 @@ hrmap_crystal *crystal_map() {
   return (hrmap_crystal*) currentmap;
   } 
 
+heptagon *get_heptagon_at(coord c) { return crystal_map()->get_heptagon_at(c, S7); }
+coord get_coord(heptagon *h) { return crystal_map()->hcoords[h]; }
+ldcoord get_ldcoord(cell *c) { return crystal_map()->get_coord(c); }
+
 bool is_bi(crystal_structure& cs, coord co) {
   for(int i=0; i<cs.dim; i++) if(co[i] & HALFSTEP) return true;
   return false;
diff --git a/hyper.h b/hyper.h
index 1b04dc99..d7010825 100644
--- a/hyper.h
+++ b/hyper.h
@@ -4185,6 +4185,17 @@ namespace arcm {
   }
 
 namespace crystal {
+  static const int MAXDIM = 7;
+  typedef array<int, MAXDIM> coord;
+  static const coord c0 = {};
+  
+  typedef array<ld, MAXDIM> ldcoord;
+  static const ldcoord ldc0 = {};
+
+  heptagon *get_heptagon_at(coord c);
+  coord get_coord(heptagon *h);
+  ldcoord get_ldcoord(cell *c);
+  
   extern colortable coordcolors;
   extern ld compass_probability;
   extern bool view_coordinates;