1 28994509 2004-04-21 devnull #include <u.h>
 2 28994509 2004-04-21 devnull #include <libc.h>
 3 28994509 2004-04-21 devnull #include "map.h"
 4 28994509 2004-04-21 devnull 
 5 28994509 2004-04-21 devnull static int
 6 28994509 2004-04-21 devnull Xmercator(struct place *place, double *x, double *y)
 7 28994509 2004-04-21 devnull {
 8 28994509 2004-04-21 devnull 	if(fabs(place->nlat.l) > 80.*RAD)
 9 28994509 2004-04-21 devnull 		return(-1);
10 28994509 2004-04-21 devnull 	*x = -place->wlon.l;
11 28994509 2004-04-21 devnull 	*y = 0.5*log((1+place->nlat.s)/(1-place->nlat.s));
12 28994509 2004-04-21 devnull 	return(1);
13 28994509 2004-04-21 devnull }
14 28994509 2004-04-21 devnull 
15 28994509 2004-04-21 devnull proj
16 28994509 2004-04-21 devnull mercator(void)
17 28994509 2004-04-21 devnull {
18 28994509 2004-04-21 devnull 	return(Xmercator);
19 28994509 2004-04-21 devnull }
20 28994509 2004-04-21 devnull 
21 28994509 2004-04-21 devnull static double ecc = ECC;
22 28994509 2004-04-21 devnull 
23 28994509 2004-04-21 devnull static int
24 28994509 2004-04-21 devnull Xspmercator(struct place *place, double *x, double *y)
25 28994509 2004-04-21 devnull {
26 28994509 2004-04-21 devnull 	if(Xmercator(place,x,y) < 0)
27 28994509 2004-04-21 devnull 		return(-1);
28 28994509 2004-04-21 devnull 	*y += 0.5*ecc*log((1-ecc*place->nlat.s)/(1+ecc*place->nlat.s));
29 28994509 2004-04-21 devnull 	return(1);
30 28994509 2004-04-21 devnull }
31 28994509 2004-04-21 devnull 
32 28994509 2004-04-21 devnull proj
33 28994509 2004-04-21 devnull sp_mercator(void)
34 28994509 2004-04-21 devnull {
35 28994509 2004-04-21 devnull 	return(Xspmercator);
36 28994509 2004-04-21 devnull }