Fix some unguarded bits of CAP_BT and CAP_CRYSTAL.

Found by trying to build with `-DISMINI=0`, not that that
comes even close to working.

binary-tiling.cpp

@@ -9,11 +9,17 @@
 namespace hr {
 
 EX namespace bt {
-#if CAP_BT
 
   /** note: nihsolv and kd3 tilings return bt::in(). They are defined elsewhere, although some of bt:: functions are used for them */
-  EX bool in() { return cgflags & qBINARY; }
+  EX bool in() {
+#if CAP_BT
+    return cgflags & qBINARY;
+#else
+    return false;
+#endif
+    }
   
+#if CAP_BT
   #if HDR
   enum bindir {
     bd_right = 0,

geometry.cpp

@@ -433,16 +433,16 @@ hpcshape
     ld alpha;
     int area;
     };
-  shared_ptr<gpdata_t> gpdata;
+  shared_ptr<gpdata_t> gpdata = nullptr;
   #endif
   
-  int state;
-  int usershape_state;
+  int state = 0;
+  int usershape_state = 0;
 
   /** contains the texture point coordinates for 3D models */
   basic_textureinfo models_texture;
   
-  geometry_information() { last = NULL; state = usershape_state = 0; gpdata = NULL; }
+  geometry_information() { last = NULL; }
   
   void require_basics() { if(state & 1) return; state |= 1; prepare_basics(); }
   void require_shapes() { if(state & 2) return; state |= 2; prepare_shapes(); }

reg3.cpp

@@ -282,6 +282,7 @@ EX namespace reg3 {
     return Id;
     }
     
+#if CAP_CRYSTAL
   int encode_coord(const crystal::coord& co) {
     int c = 0;
     for(int i=0; i<4; i++) c |= ((co[i]>>1) & 3) << (2*i);
@@ -314,6 +315,7 @@ EX namespace reg3 {
         }
       }        
     };
+#endif
 
   struct hrmap_field3 : reg3::hrmap_quotient3 {
   

sysconfig.h

@@ -407,7 +407,6 @@ extern "C" {
 #define CAP_GLEW (CAP_GL && !ISMOBILE && !ISMAC && !ISLINUX && !ISWEB)
 #endif
 
-#if CAP_GL
 #if CAP_GLEW
   #include <GL/glew.h>
 #else
@@ -429,7 +428,6 @@ extern "C" {
     #include <GL/gl.h>
     #include <GL/glu.h>
     #include <GL/glext.h>
-    #endif
   #endif
 #endif