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#include <u.h>
#include <libc.h>
#include "map.h"
static struct coord stdp0, stdp1;
static double k;
static int
Xlambert(struct place *place, double *x, double *y)
{
double r;
if(place->nlat.l < -80.*RAD)
return(-1);
if(place->nlat.l > 89.*RAD)
r = 0; /* slovenly */
else
r = stdp0.c*exp(0.5*k*log(
(1+stdp0.s)*(1-place->nlat.s)/((1-stdp0.s)*(1+place->nlat.s))));
if(stdp1.l<0.)
r = -r;
*x = - r*sin(k * place->wlon.l);
*y = - r*cos(k * place->wlon.l);
return(1);
}
proj
lambert(double par0, double par1)
{
double temp;
if(fabs(par0)>fabs(par1)){
temp = par0;
par0 = par1;
par1 = temp;
}
deg2rad(par0, &stdp0);
deg2rad(par1, &stdp1);
if(fabs(par1+par0)<.1)
return(mercator());
if(fabs(par1-par0)<.1)
return(perspective(-1.));
if(fabs(par0)>89.5||fabs(par1)>89.5)
return(0);
k = 2*log(stdp1.c/stdp0.c)/log(
(1+stdp0.s)*(1-stdp1.s)/((1-stdp0.s)*(1+stdp1.s)));
return(Xlambert);
}
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