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#define PJ_LIB__
#include <math.h>
#include "projects.h"
PROJ_HEAD(august, "August Epicycloidal") "\n\tMisc Sph, no inv";
#define M 1.333333333333333
static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */
XY xy = {0.0,0.0};
double t, c1, c, x1, x12, y1, y12;
(void) P;
t = tan(.5 * lp.phi);
c1 = sqrt(1. - t * t);
c = 1. + c1 * cos(lp.lam *= .5);
x1 = sin(lp.lam) * c1 / c;
y1 = t / c;
xy.x = M * x1 * (3. + (x12 = x1 * x1) - 3. * (y12 = y1 * y1));
xy.y = M * y1 * (3. + 3. * x12 - y12);
return (xy);
}
PJ *PROJECTION(august) {
P->inv = nullptr;
P->fwd = s_forward;
P->es = 0.;
return P;
}
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