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 /* refractive fisheye, not logarithmic */
 5 28994509 2004-04-21 devnull 
 6 28994509 2004-04-21 devnull static double n;
 7 28994509 2004-04-21 devnull 
 8 28994509 2004-04-21 devnull static int
 9 28994509 2004-04-21 devnull Xfisheye(struct place *place, double *x, double *y)
10 28994509 2004-04-21 devnull {
11 28994509 2004-04-21 devnull 	double r;
12 28994509 2004-04-21 devnull 	double u = sin(PI/4-place->nlat.l/2)/n;
13 28994509 2004-04-21 devnull 	if(fabs(u) > .97)
14 28994509 2004-04-21 devnull 		return -1;
15 28994509 2004-04-21 devnull 	r = tan(asin(u));
16 28994509 2004-04-21 devnull 	*x = -r*place->wlon.s;
17 28994509 2004-04-21 devnull 	*y = -r*place->wlon.c;
18 28994509 2004-04-21 devnull 	return 1;
19 28994509 2004-04-21 devnull }
20 28994509 2004-04-21 devnull 
21 28994509 2004-04-21 devnull proj
22 28994509 2004-04-21 devnull fisheye(double par)
23 28994509 2004-04-21 devnull {
24 28994509 2004-04-21 devnull 	n = par;
25 28994509 2004-04-21 devnull 	return n<.1? 0: Xfisheye;
26 28994509 2004-04-21 devnull }