* | :
* ___ X-2 ___ X-1 ___| 0 ___ 1 ___ 2 ___ 3 ___ 4 __
* 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
*
* 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.
*
* / \
* 4/ 5\
*
- * vertex number: 0000 | y | x
- * YBITS XBITS
+ * vertex number: 0000 | y | x
+ * (YBITS) XBITS
*/
#ifndef MGRAPH_H
#include "common.h"
+#ifndef DEFSZ /* DEFSZ may be (Y/2-1)*10 + XBITS ie Y is 2*<tens>+1 */
#define XBITS 3
-#define X (1<<XBITS)
#define YBITS 3
#define Y ((1<<YBITS) - 1)
+#define YMASK (Y << YSHIFT)
+#else
+#define XBITS (DEFSZ % 10)
+#define Y ((DEFSZ / 10)*2+1)
+#endif
+
+#define X (1<<XBITS)
#define N (X*Y)
#define XMASK (X-1)
#define YSHIFT XBITS
#define Y1 (1 << YSHIFT)
-#define YMASK (Y << YSHIFT)
#define V6 6
+#define V3 3
#define FOR_VERTEX(v) \
for ((v)=0; (v)<N; (v)++)
#define FOR_VPEDGE(v,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)) \