svn-gvsig-desktop / trunk / libraries / libjni-proj4 / src / PJ_mbtfpp.c @ 7098
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#ifndef lint
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static const char SCCSID[]="@(#)PJ_mbtfpp.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(mbtfpp, "McBride-Thomas Flat-Polar Parabolic") "\n\tCyl., Sph."; |
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#define CS .95257934441568037152 |
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#define FXC .92582009977255146156 |
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#define FYC 3.40168025708304504493 |
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#define C23 .66666666666666666666 |
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#define C13 .33333333333333333333 |
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#define ONEEPS 1.0000001 |
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FORWARD(s_forward); /* spheroid */
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lp.phi = asin(CS * sin(lp.phi)); |
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xy.x = FXC * lp.lam * (2. * cos(C23 * lp.phi) - 1.); |
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xy.y = FYC * sin(C13 * lp.phi); |
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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; |
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if (fabs(lp.phi) >= 1.) { |
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if (fabs(lp.phi) > ONEEPS) I_ERROR
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else lp.phi = (lp.phi < 0.) ? -HALFPI : HALFPI; |
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} else
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lp.phi = asin(lp.phi); |
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lp.lam = xy.x / ( FXC * (2. * cos(C23 * (lp.phi *= 3.)) - 1.) ); |
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if (fabs(lp.phi = sin(lp.phi) / CS) >= 1.) { |
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if (fabs(lp.phi) > ONEEPS) I_ERROR
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else lp.phi = (lp.phi < 0.) ? -HALFPI : HALFPI; |
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} else
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lp.phi = asin(lp.phi); |
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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(mbtfpp) P->es = 0.; P->inv = s_inverse; P->fwd = s_forward; ENDENTRY(P)
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