X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=moebius2.git;a=blobdiff_plain;f=mgraph.h;h=2267fdbda1ffcf59bbf7a9919c651bee46ffa6b0;hp=a5eb61127f6e6cc3fbbf0493d5b53c0fe565d3a1;hb=f67c0e9702cec922ccd0d3149f48bc881b42222b;hpb=75293637fe7efbce3f2e873cc792da3bff577fef

diff --git a/mgraph.h b/mgraph.h
index a5eb611..2267fdb 100644
--- a/mgraph.h
+++ b/mgraph.h
@@ -87,24 +87,35 @@
 #define Y1 (1 << YSHIFT)
 
 #define V6 6
+#define V3 3
 
-#define FOR_VERTEX(v) \
-  for ((v)=0; (v)<N; (v)++)
 
-#define FOR_VPEDGE(v,e) \
+/* Loop constructors are macros of the form
+ *    LOOP(v,zero,n, precomp)
+ * which work much like this one:
+ */
+#define INNER(v,zero,n, precomp)  \
+  for ((v)=(zero); precomp, (v)<(n); (v)++)
+
+#define FOR_VERTEX(v,loop) \
+  loop ((v), 0, N, NOTHING)
+
+#define FOR_VPEDGE(e) \
   for ((e)=0; (e)<V6; (e)++)
 
-int edge_end2(unsigned v1, int e);
-#define EDGE_END2 edge_end2
+extern short edge_end2_memo[][V6];
+#define EDGE_END2(v1,e) edge_end2_memo[v1][e]
 
 /* 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
@@ -114,15 +125,19 @@ int edge_reverse(int v1, int e);
 #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, loop)			\
+  FOR_VERTEX((v1), loop)			\
     FOR_VEDGE((v1),(e),(v2))
 
-#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)++)
+#define FOR_RIM_VERTEX(vy,vx,v, loop)		\
+  for ((vy)=0; (vy)<Y; (vy)+=Y-1)		\
+    loop ((vx), 0, X, (v)= (vy)<<YSHIFT | (vx))
+
+int vertices_span_join_p(int v0, int v1);
 
 typedef double Vertices[N][D3];
 struct Vertices { Vertices a; };
 
+void mgraph_prepare(void);
+
 #endif /*MGRAPH_H*/