svn-gvsig-desktop / trunk / libraries / libjni-proj4 / src / PJ_collg.c @ 7098
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#ifndef lint
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static const char SCCSID[]="@(#)PJ_collg.c 4.1 94/02/15 GIE REL"; |
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#endif
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#define PJ_LIB__
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# include <projects.h> |
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PROJ_HEAD(collg, "Collignon") "\n\tPCyl, Sph."; |
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#define FXC 1.12837916709551257390 |
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#define FYC 1.77245385090551602729 |
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#define ONEEPS 1.0000001 |
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FORWARD(s_forward); /* spheroid */
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if ((xy.y = 1. - sin(lp.phi)) <= 0.) |
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xy.y = 0.;
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else
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xy.y = sqrt(xy.y); |
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xy.x = FXC * lp.lam * xy.y; |
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xy.y = FYC * (1. - xy.y);
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return (xy);
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} |
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INVERSE(s_inverse); /* spheroid */
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lp.phi = xy.y / FYC - 1.;
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if (fabs(lp.phi = 1. - lp.phi * lp.phi) < 1.) |
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lp.phi = asin(lp.phi); |
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else if (fabs(lp.phi) > ONEEPS) I_ERROR |
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else lp.phi = lp.phi < 0. ? -HALFPI : HALFPI; |
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if ((lp.lam = 1. - sin(lp.phi)) <= 0.) |
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lp.lam = 0.;
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else
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lp.lam = xy.x / (FXC * sqrt(lp.lam)); |
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return (lp);
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} |
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FREEUP; if (P) pj_dalloc(P); }
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ENTRY0(collg) P->es = 0.; P->inv = s_inverse; P->fwd = s_forward; ENDENTRY(P)
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