ref: 88b386a4a15654bcc9d34a534812f1ec9c77e069
dir: /sys/src/cmd/map/libmap/conic.c/
#include <u.h> #include <libc.h> #include "map.h" static struct coord stdpar; static int Xconic(struct place *place, double *x, double *y) { double r; if(fabs(place->nlat.l-stdpar.l) > 80.*RAD) return(-1); r = stdpar.c/stdpar.s - tan(place->nlat.l - stdpar.l); *x = - r*sin(place->wlon.l * stdpar.s); *y = - r*cos(place->wlon.l * stdpar.s); if(r>3) return(0); return(1); } proj conic(double par) { if(fabs(par) <.1) return(Xcylindrical); deg2rad(par, &stdpar); return(Xconic); }