1 #include <u.h>
2 #include <libc.h>
3 #include "map.h"
4 
5 static double r0, a;
6 
7 static int
8 Xsimpleconic(struct place *place, double *x, double *y)
9 {
10 	double r = r0 - place->nlat.l;
11 	double t = a*place->wlon.l;
12 	*x = -r*sin(t);
13 	*y = -r*cos(t);
14 	return 1;
15 }
16 
17 proj
18 simpleconic(double par0, double par1)
19 {
20 	struct coord lat0;
21 	struct coord lat1;
22 	deg2rad(par0,&lat0);
23 	deg2rad(par1,&lat1);
24 	if(fabs(lat0.l+lat1.l)<.01)
25 		return rectangular(par0);
26 	if(fabs(lat0.l-lat1.l)<.01) {
27 		a = lat0.s/lat0.l;
28 		r0 = lat0.c/lat0.s + lat0.l;
29 	} else {
30 		a = (lat1.c-lat0.c)/(lat0.l-lat1.l);
31 		r0 = ((lat0.c+lat1.c)/a + lat1.l + lat0.l)/2;
32 	}
33 	return Xsimpleconic;
34 }