X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=moebius2.git;a=blobdiff_plain;f=mgraph.h;h=3995d463ed0bda1160791fa997d2da40fde6ea66;hp=ae341fae532786f45a2b53c779802eeb47ab0f25;hb=2a4bf2376456c0650ffea5d89e4b4cf4763af1ad;hpb=8ff2e481a33d24276b85600c4f3fd7bc9cbf5a18

diff --git a/mgraph.h b/mgraph.h
index ae341fa..3995d46 100644
--- a/mgraph.h
+++ b/mgraph.h
@@ -1,3 +1,6 @@
+/*
+ * Graph topology
+ */
 /*
  * Vertices in strip are numbered as follows:
  *
@@ -32,23 +35,19 @@
  *
  * We label edges as follows:
  *
- *			    \0   /1
+ *		e:	    \2   /1
  *			     \  /
  *			  ___ 0   __
- *			  2    1   3
+ *			  3    1   0
  *			     /  \
  *			   4/   5\
- *
- * (This numbering permits the order-4 nodes at the strip's edge
- *  to have a contiguous edge numbering 2..5 or 0..3.)
- *
- * When we iterate over edges, we iterate first over vertices and then
- * over edges 0 to 2, disregarding edges 3 to 5.
  */
 
 #ifndef MGRAPH_H
 #define MGRAPH_H
 
+#include "common.h"
+
 #define XBITS 4
 #define X (1<<XBITS)
 #define YBITS 4
@@ -62,49 +61,40 @@
 #define XMASK (X-1)
 #define YSHIFT XBITS
 #define Y1 (1 << YSHIFT)
-#define YMASK (Y-1 << YSHIFT)
+#define YMASK ((Y-1) << YSHIFT)
 
-#define V6 6
+#define DIM (N*D3)
 
-#define D3 3
+#define V6 6
 
 #define FOR_VERTEX(v) \
   for ((v)=0; (v)<N; (v)++)
 
-#define VE_MIN(v) ((v) & YMASK ? 0 : 2)
-#define VE_MAX(v) (~(v) & YMASK ? V6 : 4)
-
 #define FOR_VPEDGE(v,e) \
-  for ((e)=VE_MIN(v); (e)<VE_MAX(v); (e)++)
+  for ((e)=0; (e)<V6; (e)++)
 
 extern int edge_end2(unsigned v1, int e);
 #define EDGE_END2 edge_end2
 
-#define FOR_VEDGE_X(v1,e,init,otherwise)	\
+#define FOR_VEDGE_X(v1,e,v2,init,otherwise)	\
   FOR_VPEDGE((v1),(e))				\
     if (((v2)= EDGE_END2((v1),(e)),		\
 	 (init),				\
-	 (v2)) < 0) { otherwise } else
+	 (v2)) < 0) { otherwise; } else
 
 #define NOTHING ((void)0)
 
-#define FOR_VEDGE(v1,e) \
-  FOR_VEDGE_X(v1,e,NOTHING,NOTHING)
+#define FOR_VEDGE(v1,e,v2)			\
+  FOR_VEDGE_X(v1,e,v2,NOTHING,NOTHING)
 
-#define FOR_EDGE(v1,e,v2) \
-  FOR_VERTEX((v1)) \
+#define FOR_EDGE(v1,e,v2)			\
+  FOR_VERTEX((v1))				\
     FOR_VEDGE((v1),(e),(v2))
 
-#define FOR_COORD(k) \
-  for ((k)=0; (k)<D3; (k)++)
-
-#define K FOR_COORD(k)
-
-typedef struct {
-  double v[N][D3];
-} Layout;
+#define FOR_RIM_VERTEX(vy,vx,v)					\
+  for ((vy)=0; (vy)<Y; (vy)+=Y-1)				\
+    for ((vx)=0; (v)= (vy)<<YSHIFT | (vx), (vx)<X; (vx)++)
 
-double hypotD(const double p[D3], const double q[D3]);
-double hypotD2(const double p[D3], const double q[D3]);
+typedef double Vertices[N][D3];
 
 #endif /*MGRAPH_H*/