X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=primer.c;fp=primer.c;h=42c4019da42d425e3da33b1f672e04319d97bec4;hb=70df58c53bdd2c2b0de6a93e6c7c480730e6732a;hp=a21dded6765a45618439bbca9ef16de71f7c51cd;hpb=134d36d51a86567bba2a9cfe1b209c4bc7d1a7f0;p=moebius2.git diff --git a/primer.c b/primer.c index a21dded..42c4019 100644 --- a/primer.c +++ b/primer.c @@ -8,21 +8,26 @@ #include "mgraph.h" int main(int argc, const char **argv) { - int v, k; + static const int prec= DBL_DIG+2; + int vi, k; if (argc>1) { fputs("no args please\n",stderr); exit(8); } printf("print %d, %d, %d, %d, %d\n", DIM, N, X, Y, D3); - FOR_VERTEX(v) { - int x= v & XMASK; /* distance along strip */ - int y= v >> YSHIFT; /* distance across strip */ - double u= y * 1.0 / (Y-1); - double v= x * M_PI / (X-1); /* SGT's u runs 0..pi along the strip */ - K printf("print %c%c(%.*g,%.*g)\n", - "+-+"[k], - "xyz"[k], - DBL_DIG+2,u, DBL_DIG+2,v); + FOR_VERTEX(vi) { + 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 * M_PI / X; + + 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); } flushoutput(); return 0;