X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=moebius2.git;a=blobdiff_plain;f=primer.c;h=76939a6356b9911dc59e29913603cf8af5ee671b;hp=3d9244a60f0b497a7cbe775b28ed2eebe1ed2de0;hb=c87e982d2102c4276f22429a47d09c59b993f41e;hpb=62f97dcbc53754ef8a81add86946e54825c4c096

diff --git a/primer.c b/primer.c
index 3d9244a..76939a6 100644
--- a/primer.c
+++ b/primer.c
@@ -9,25 +9,30 @@
 
 int main(int argc, const char **argv) {
   static const int prec= DBL_DIG+2;
-  int vi, k;
+  int vi;
   
-  if (argc>1) { fputs("no args please\n",stderr); exit(8); }
+  if (argc!=1) { fputs("need no args\n",stderr); exit(8); }
 
-  printf("print %d, %d, %d, %d, %d\n", DIM, N, X, Y, D3);
-  
-  FOR_VERTEX(vi) {
+  printf("%d %d %d %d %d\n%%-%d.%dg\n",
+	 X*Y, N, X, Y, D3,
+	 prec+5,prec);
+
+  FOR_VERTEX(vi, INNER) {
     int x= vi & XMASK; /* distance along strip */
     int y= vi >> YSHIFT; /* distance across strip */
     double u= y * 1.0 / (Y-1); /* SGT's u runs 0..1 across the strip */
 
     /* SGT's v runs 0..pi along the strip, where the join is at 0==pi.
-     * So that corresponds to 0..X (since 0==X in our scheme). */
-    double v= (x*2 + (y&1)) * M_PI / (X*2);
+     * So that corresponds to 0..X (since 0==X in our scheme).
+     * Vertices with odd y coordinate are halfway to the next x coordinate.
+     */
+    double v= (x*2 + (y&1)) * 1.0 / (X*2);
+    v += 0.5;
+    v *= M_PI;
 
-    K printf("print %c%c( %-*.*g, %-*.*g);  # %03x %2d %2d\n",
-	     "+-+"[k], "xyz"[k],
-	     prec+5,prec,u, prec+5,prec,v,
-	     vi, x, y);
+    printf("%-*.*g %-*.*g # %03x %2d %2d\n",
+	   prec+5,prec,u, prec+5,prec,v,
+	   vi, x, y);
   }
   flushoutput();
   return 0;