36 lines
567 B
C
36 lines
567 B
C
#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);
|
|
}
|