PJ_august.c
552 Bytes
#define PJ_LIB__
#include <projects.h>
PROJ_HEAD(august, "August Epicycloidal") "\n\tMisc Sph, no inv.";
#define M 1.333333333333333
FORWARD(s_forward); /* spheroid */
double t, c1, c, x1, x12, y1, y12;
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);
}
FREEUP; if (P) pj_dalloc(P); }
ENTRY0(august) P->inv = 0; P->fwd = s_forward; P->es = 0.; ENDENTRY(P)