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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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