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30 lines
578 B
C
30 lines
578 B
C
#include <u.h>
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#include <libc.h>
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#include "map.h"
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static struct coord stdpar0, stdpar1;
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static double k;
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static double yeq;
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static int
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Xtrapezoidal(struct place *place, double *x, double *y)
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{
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*y = yeq + place->nlat.l;
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*x = *y*k*place->wlon.l;
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return 1;
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}
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proj
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trapezoidal(double par0, double par1)
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{
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if(fabs(fabs(par0)-fabs(par1))<.1)
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return rectangular(par0);
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deg2rad(par0,&stdpar0);
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deg2rad(par1,&stdpar1);
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if(fabs(par1-par0) < .1)
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k = stdpar1.s;
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else
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k = (stdpar1.c-stdpar0.c)/(stdpar0.l-stdpar1.l);
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yeq = -stdpar1.l - stdpar1.c/k;
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return Xtrapezoidal;
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}
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