1 #include "map.h" 2 3 static struct coord stdp0, stdp1; 4 static double k; 5 6 static int 7 Xlambert(struct place *place, double *x, double *y) 8 { 9 double r; 10 if(place->nlat.l < -80.*RAD) 11 return(-1); 12 if(place->nlat.l > 89.*RAD) 13 r = 0; /* slovenly */ 14 else 15 r = stdp0.c*exp(0.5*k*log( 16 (1+stdp0.s)*(1-place->nlat.s)/((1-stdp0.s)*(1+place->nlat.s)))); 17 if(stdp1.l<0.) 18 r = -r; 19 *x = - r*sin(k * place->wlon.l); 20 *y = - r*cos(k * place->wlon.l); 21 return(1); 22 } 23 24 proj 25 lambert(double par0, double par1) 26 { 27 double temp; 28 if(fabs(par0)>fabs(par1)){ 29 temp = par0; 30 par0 = par1; 31 par1 = temp; 32 } 33 deg2rad(par0, &stdp0); 34 deg2rad(par1, &stdp1); 35 if(fabs(par1+par0)<.1) 36 return(mercator()); 37 if(fabs(par1-par0)<.1) 38 return(perspective(-1.)); 39 if(fabs(par0)>89.5||fabs(par1)>89.5) 40 return(0); 41 k = 2*log(stdp1.c/stdp0.c)/log( 42 (1+stdp0.s)*(1-stdp1.s)/((1-stdp0.s)*(1+stdp1.s))); 43 return(Xlambert); 44 } 45