Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include "map.h"

static double r0, a;

static int
Xsimpleconic(struct place *place, double *x, double *y)
{
        double r = r0 - place->nlat.l;
        double t = a*place->wlon.l;
        *x = -r*sin(t);
        *y = -r*cos(t);
        return 1;
}

proj
simpleconic(double par0, double par1)
{
        struct coord lat0;
        struct coord lat1;
        deg2rad(par0,&lat0);
        deg2rad(par1,&lat1);
        if(fabs(lat0.l+lat1.l)<.01)
                return rectangular(par0);
        if(fabs(lat0.l-lat1.l)<.01) {
                a = lat0.s/lat0.l;
                r0 = lat0.c/lat0.s + lat0.l;
        } else {
                a = (lat1.c-lat0.c)/(lat0.l-lat1.l);
                r0 = ((lat0.c+lat1.c)/a + lat1.l + lat0.l)/2;
        }
        return Xsimpleconic;
}