X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=mgraph.h;h=06c53e214ec1f5cac09a151f827b8caaf7344b77;hb=cf1b738d035a22d539a44ca50925fb23cdb7588c;hp=22f5d92a37e979b52b4779feb16b8837a704eddc;hpb=b462f455cbaa1d716ff6d7b83ae4e1092ba3092a;p=moebius2.git

diff --git a/mgraph.h b/mgraph.h
index 22f5d92..06c53e2 100644
--- a/mgraph.h
+++ b/mgraph.h
@@ -4,41 +4,45 @@
 /*
  * Vertices in strip are numbered as follows:
  *
- *			  |
+ *                          :axis of symmetry
+ *			  | :
+ *			  | :
  *     ___ X-2 ___ X-1 ___| 0  ___  1  ___  2  ___  3  ___  4  __
- *         Y-1     Y-1    |0       0       0       0       0
- *        /  \    /  \    /  \    /  \    /  \    /  \    /  \
- *       /    \  /    \  /|   \  /    \  /    \  /    \  /    \
+ *         Y-1     Y-1    |0:      0       0       0       0
+ *        /  \    /  \    / :\    /  \    /  \    /  \    /  \
+ *       /    \  /    \  /| : \  /    \  /    \  /    \  /    \
  *     X-3 ___ X-2 ___ X-1|___  0  ___  1  ___  2  ___  3  ___  4
- *     Y-2     Y-2     Y-2|    1       1       1       1       1
- *       \    /  \    /  \|   /  \    /  \    /  \    /  \    /
- *        \  /    \  /    \  /    \  /    \  /    \  /    \  /
+ *     Y-2     Y-2     Y-2| :  1       1       1       1       1
+ *       \    /  \    /  \| : /  \    /  \    /  \    /  \    /
+ *        \  /    \  /    \ :/    \  /    \  /    \  /    \  /
  *     ___ X-2 ___ X-1 ___| 0  ___  1  ___  2  ___  3  __   4 ___
- *         Y-3     Y-3    |2       2       2       2 	   2
- *        /  \    /  \    /  \    /  \    /  \    /  \    /  \
- *       /    \  /    \  /|   \  /    \  /    \  /    \  /    \
+ *         Y-3     Y-3    |2:      2       2       2 	   2
+ *        /  \    /  \    / :\    /  \    /  \    /  \    /  \
+ *       /    \  /    \  /| : \  /    \  /    \  /    \  /    \
  *     X-3 ___ X-2 ___ X-1|___  0  ___  1  ___  2  ___  3  ___  4
- *     Y-4     Y-4     Y-4|    3       3       3       3       3
- *			  |
- *       .   .   .   .   .|  .   .   .   .   .   .   .   .   .   .
- *			  |
+ *     Y-4     Y-4     Y-4| :  3       3       3       3       3
+ *			  | :
+ *       .   .   .   .   .| :.   .   .   .   .   .   .   .   .   .
+ *			  | :
  *     ___ X-2 ___ X-1 ___| 0  ___  1  ___  2  ___  3  ___  4 ___
  *         2       2      |Y-3     Y-3     Y-3     Y-3     Y-3
- *        /  \    /  \    /  \    /  \    /  \    /  \    /  \
- *       /    \  /    \  /|   \  /    \  /    \  /    \  /    \
+ *        /  \    /  \    / :\    /  \    /  \    /  \    /  \
+ *       /    \  /    \  /| : \  /    \  /    \  /    \  /    \
  *          __ X-2 ___ X-1|___  0  ___  1  ___  2  ___  3  ___  3  ___  4
- *             1       1  |    Y-2     Y-2     Y-2     Y-2     Y-2     Y-2
- *    /  \    /  \    /  \|   /  \    /  \    /	 \    /  \    /
- *   /    \  /    \  /    \  /    \  /    \  /	  \  /    \  /
+ *             1       1  | :  Y-2     Y-2     Y-2     Y-2     Y-2     Y-2
+ *    /  \    /  \    /  \| : /  \    /  \    /	 \    /  \    /
+ *   /    \  /    \  /    \ :/    \  /    \  /	  \  /    \  /
  *  -3 ___ X-2 ___ X-1 ___| 0  ___  1  ___  2  ___  3  ___  4 ___
  *  0      0       0      |Y-1     Y-1     Y-1     Y-1     Y-1
+ *			  | :
+ *			  | :
  *			  |
  *                        ^ join, where there is
  *                           a discontinuity in numbering
  *
  * Node x,y for
  *   0 <= x < X = 2^XBITS     x = distance along
- *   0 <= y < Y = 2^YBITS-1     y = distance across
+ *   0 <= y < Y = 2^YBITS-1   y = distance across
  *
  * Vertices are in reading order from diagram above ie x varies fastest.
  *
@@ -55,6 +59,9 @@
  *		  3    1   0
  *		     /  \
  *		   4/   5\
+ *
+ * vertex number:   0000 | y      | x
+ *                        (YBITS)   XBITS
  */
 
 #ifndef MGRAPH_H
@@ -62,40 +69,45 @@
 
 #include "common.h"
 
-#define DIMBITS 4
-
-#define XBITS DIMBITS
-#define X (1<<XBITS)
-#define YBITS DIMBITS
+#ifndef DEFSZ /* DEFSZ may be (Y/2-1)*10 + XBITS ie Y is 2*<tens>+1 */
+#define XBITS 3
+#define YBITS 3
 #define Y ((1<<YBITS) - 1)
+#define YMASK (Y << YSHIFT)
+#else
+#define XBITS  (DEFSZ % 10)
+#define Y      ((DEFSZ / 10)*2+1)
+#endif
 
-/* vertex number:   0000 | y     | x
- *                        YBITS   XBITS
- */
+#define X (1<<XBITS)
 
 #define N (X*Y)
 #define XMASK (X-1)
 #define YSHIFT XBITS
 #define Y1 (1 << YSHIFT)
-#define YMASK (Y << YSHIFT)
-
-#define DIM (N*D3)
 
 #define V6 6
+#define V3 3
 
 #define FOR_VERTEX(v) \
   for ((v)=0; (v)<N; (v)++)
 
-#define FOR_VPEDGE(v,e) \
+#define FOR_VPEDGE(e) \
   for ((e)=0; (e)<V6; (e)++)
 
-extern int edge_end2(unsigned v1, int e);
+int edge_end2(unsigned v1, int e);
 #define EDGE_END2 edge_end2
 
-#define RIM_VERTEX_P(v) (((v) & YMASK) == 0 || ((v) & YMASK) == (Y-1)*Y1)
+/* given    v1,e     s.t.  v2==EDGE_END2(v1,e) >= 0,
+ * returns  eprime   s.t.  v1==EDGE_END2(v2,eprime) */
+int edge_reverse(int v1, int e);
+
+#define EDGE_OPPOSITE(e) (((e)+V3) % V6)
+
+#define RIM_VERTEX_P(v) (((v) & ~XMASK) == 0 || ((v) & ~XMASK) == (Y-1)*Y1)
 
 #define FOR_VEDGE_X(v1,e,v2,init,otherwise)	\
-  FOR_VPEDGE((v1),(e))				\
+  FOR_VPEDGE((e))				\
     if (((v2)= EDGE_END2((v1),(e)),		\
 	 (init),				\
 	 (v2)) < 0) { otherwise; } else
@@ -113,6 +125,9 @@ extern int edge_end2(unsigned v1, int e);
   for ((vy)=0; (vy)<Y; (vy)+=Y-1)				\
     for ((vx)=0; (v)= (vy)<<YSHIFT | (vx), (vx)<X; (vx)++)
 
+int vertices_span_join_p(int v0, int v1);
+
 typedef double Vertices[N][D3];
+struct Vertices { Vertices a; };
 
 #endif /*MGRAPH_H*/