src/aasincos.c


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/* arc sin, cosine, tan2 and sqrt that will NOT fail */

#include <math.h>

#include "projects.h"

#define ONE_TOL	 1.00000000000001
#define ATOL 1e-50

        double
aasin(projCtx ctx,double v) {
        double av;

        if ((av = fabs(v)) >= 1.) {
                if (av > ONE_TOL)
                        pj_ctx_set_errno( ctx, PJD_ERR_ACOS_ASIN_ARG_TOO_LARGE );
                return (v < 0. ? -M_HALFPI : M_HALFPI);
        }
        return asin(v);
}

        double
aacos(projCtx ctx, double v) {
        double av;

        if ((av = fabs(v)) >= 1.) {
                if (av > ONE_TOL)
                        pj_ctx_set_errno( ctx, PJD_ERR_ACOS_ASIN_ARG_TOO_LARGE );
                return (v < 0. ? M_PI : 0.);
        }
        return acos(v);
}
        double
asqrt(double v) { return ((v <= 0) ? 0. : sqrt(v)); }
        double
aatan2(double n, double d) {
        return ((fabs(n) < ATOL && fabs(d) < ATOL) ? 0. : atan2(n,d));
}