| #include <u.h> |
| #include <libc.h> |
| #include "map.h" |
| |
| static int |
| Xmercator(struct place *place, double *x, double *y) |
| { |
| if(fabs(place->nlat.l) > 80.*RAD) |
| return(-1); |
| *x = -place->wlon.l; |
| *y = 0.5*log((1+place->nlat.s)/(1-place->nlat.s)); |
| return(1); |
| } |
| |
| proj |
| mercator(void) |
| { |
| return(Xmercator); |
| } |
| |
| static double ecc = ECC; |
| |
| static int |
| Xspmercator(struct place *place, double *x, double *y) |
| { |
| if(Xmercator(place,x,y) < 0) |
| return(-1); |
| *y += 0.5*ecc*log((1-ecc*place->nlat.s)/(1+ecc*place->nlat.s)); |
| return(1); |
| } |
| |
| proj |
| sp_mercator(void) |
| { |
| return(Xspmercator); |
| } |
