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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
5 28994509 2004-04-21 devnull static struct coord stdp0, stdp1;
6 28994509 2004-04-21 devnull static double k;
7 28994509 2004-04-21 devnull
8 28994509 2004-04-21 devnull static int
9 28994509 2004-04-21 devnull Xlambert(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 if(place->nlat.l < -80.*RAD)
13 28994509 2004-04-21 devnull return(-1);
14 28994509 2004-04-21 devnull if(place->nlat.l > 89.*RAD)
15 28994509 2004-04-21 devnull r = 0; /* slovenly */
16 28994509 2004-04-21 devnull else
17 28994509 2004-04-21 devnull r = stdp0.c*exp(0.5*k*log(
18 28994509 2004-04-21 devnull (1+stdp0.s)*(1-place->nlat.s)/((1-stdp0.s)*(1+place->nlat.s))));
19 28994509 2004-04-21 devnull if(stdp1.l<0.)
20 28994509 2004-04-21 devnull r = -r;
21 28994509 2004-04-21 devnull *x = - r*sin(k * place->wlon.l);
22 28994509 2004-04-21 devnull *y = - r*cos(k * place->wlon.l);
23 28994509 2004-04-21 devnull return(1);
24 28994509 2004-04-21 devnull }
25 28994509 2004-04-21 devnull
26 28994509 2004-04-21 devnull proj
27 28994509 2004-04-21 devnull lambert(double par0, double par1)
28 28994509 2004-04-21 devnull {
29 28994509 2004-04-21 devnull double temp;
30 28994509 2004-04-21 devnull if(fabs(par0)>fabs(par1)){
31 28994509 2004-04-21 devnull temp = par0;
32 28994509 2004-04-21 devnull par0 = par1;
33 28994509 2004-04-21 devnull par1 = temp;
34 28994509 2004-04-21 devnull }
35 28994509 2004-04-21 devnull deg2rad(par0, &stdp0);
36 28994509 2004-04-21 devnull deg2rad(par1, &stdp1);
37 fa325e9b 2020-01-10 cross if(fabs(par1+par0)<.1)
38 28994509 2004-04-21 devnull return(mercator());
39 28994509 2004-04-21 devnull if(fabs(par1-par0)<.1)
40 28994509 2004-04-21 devnull return(perspective(-1.));
41 28994509 2004-04-21 devnull if(fabs(par0)>89.5||fabs(par1)>89.5)
42 28994509 2004-04-21 devnull return(0);
43 28994509 2004-04-21 devnull k = 2*log(stdp1.c/stdp0.c)/log(
44 28994509 2004-04-21 devnull (1+stdp0.s)*(1-stdp1.s)/((1-stdp0.s)*(1+stdp1.s)));
45 28994509 2004-04-21 devnull return(Xlambert);
46 28994509 2004-04-21 devnull }