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-rw-r--r--src/pj_list.h1
-rw-r--r--src/proj_etmerc.c252
2 files changed, 253 insertions, 0 deletions
diff --git a/src/pj_list.h b/src/pj_list.h
index b965cc71..1e8df686 100644
--- a/src/pj_list.h
+++ b/src/pj_list.h
@@ -32,6 +32,7 @@ PROJ_HEAD(eck6, "Eckert VI")
PROJ_HEAD(eqc, "Equidistant Cylindrical (Plate Caree)")
PROJ_HEAD(eqdc, "Equidistant Conic")
PROJ_HEAD(euler, "Euler")
+PROJ_HEAD(etmerc, "Extended Transverse Mercator" )
PROJ_HEAD(fahey, "Fahey")
PROJ_HEAD(fouc, "Foucaut")
PROJ_HEAD(fouc_s, "Foucaut Sinusoidal")
diff --git a/src/proj_etmerc.c b/src/proj_etmerc.c
new file mode 100644
index 00000000..4b42f23a
--- /dev/null
+++ b/src/proj_etmerc.c
@@ -0,0 +1,252 @@
+/*
+** libproj -- library of cartographic projections
+**
+** Copyright (c) 2008 Gerald I. Evenden
+*/
+
+/*
+** Permission is hereby granted, free of charge, to any person obtaining
+** a copy of this software and associated documentation files (the
+** "Software"), to deal in the Software without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Software, and to
+** permit persons to whom the Software is furnished to do so, subject to
+** the following conditions:
+**
+** The above copyright notice and this permission notice shall be
+** included in all copies or substantial portions of the Software.
+**
+** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+/* The code in this file is largly based upon procedures:
+ *
+ * Written by: Knud Poder and Karsten Engsager
+ *
+ * Based on math from: R.Koenig and K.H. Weise, "Mathematische
+ * Grundlagen der hoeheren Geodaesie und Kartographie,
+ * Springer-Verlag, Berlin/Goettingen" Heidelberg, 1951.
+ *
+ * Modified and used here by permission of Reference Networks
+ * Division, Kort og Matrikelstyrelsen (KMS), Copenhagen, Denmark
+*/
+
+
+#define PROJ_PARMS__ \
+ double Qn; /* Merid. quad., scaled to the projection */ \
+ double Zb; /* Radius vector in polar coord. systems */ \
+ double cgb[5]; /* Constants for Gauss -> Geo lat */ \
+ double cbg[5]; /* Constants for Geo lat -> Gauss */ \
+ double utg[5]; /* Constants for transv. merc. -> geo */ \
+ double gtu[5]; /* Constants for geo -> transv. merc. */
+
+#define PROJ_LIB__
+#define PJ_LIB__
+
+#include <projects.h>
+
+PROJ_HEAD(etmerc, "Extended Transverse Mercator")
+ "\n\tCyl, Sph\n\tlat_ts=(0)\nlat_0=(0)";
+
+#define FABS(x) ((x)<0?-(x):(x))
+
+#ifdef _GNU_SOURCE
+ inline
+#endif
+ static double
+gatg(double *p1, int len_p1, double B) {
+ double *p;
+ double h = 0., h1, h2 = 0., cos_2B;
+
+ cos_2B = 2.*cos(2.0*B);
+ for (p = p1 + len_p1, h1 = *--p; p - p1; h2 = h1, h1 = h)
+ h = -h2 + cos_2B*h1 + *--p;
+ return (B + h*sin(2.0*B));
+}
+
+#ifdef _GNU_SOURCE
+ inline
+#endif
+ static double
+clenS(double *a, int size, double arg_r, double arg_i, double *R, double *I) {
+ double *p, r, i, hr, hr1, hr2, hi, hi1, hi2;
+ double sin_arg_r, cos_arg_r, sinh_arg_i, cosh_arg_i;
+ double exp_arg_i, pxe_arg_i;
+
+ /* arguments */
+ p = a + size;
+#ifdef _GNU_SOURCE
+ sincos(arg_r, &sin_arg_r, &cos_arg_r);
+#else
+ sin_arg_r = sin(arg_r);
+ cos_arg_r = cos(arg_r);
+#endif
+ exp_arg_i = exp( arg_i);
+ pxe_arg_i = exp(-arg_i);
+ sinh_arg_i = (exp_arg_i-pxe_arg_i)/2;
+ cosh_arg_i = (exp_arg_i+pxe_arg_i)/2;
+ r = 2.0*cos_arg_r*cosh_arg_i;
+ i = -2.0*sin_arg_r*sinh_arg_i;
+ /* summation loop */
+ for (hi1 = hr1 = hi = 0.0, hr = *--p; a - p;) {
+ hr2 = hr1;
+ hi2 = hi1;
+ hr1 = hr;
+ hi1 = hi;
+ hr = -hr2 + r*hr1 - i*hi1 + *--p;
+ hi = -hi2 + i*hr1 + r*hi1;
+ }
+ r = sin_arg_r*cosh_arg_i;
+ i = cos_arg_r*sinh_arg_i;
+ *R = r*hr - i*hi;
+ *I = r*hi + i*hr;
+ return(*R);
+}
+ static double
+clens(double *a, int size, double arg_r) {
+ double *p, r, hr, hr1, hr2, cos_arg_r;
+
+ p = a + size;
+ cos_arg_r = cos(arg_r);
+ r = 2.0*cos_arg_r;
+ /* summation loop */
+ for (hr1 = 0.0, hr = *--p; a - p;) {
+ hr2 = hr1;
+ hr1 = hr;
+ hr = -hr2 + r*hr1 + *--p;
+ }
+ return(sin(arg_r)*hr);
+}
+
+
+FORWARD(e_forward); /* ellipsoid */
+ double sin_Cn, cos_Cn, cos_Ce, sin_Ce, dCn, dCe;
+ double Cn = lp.phi, Ce = lp.lam;
+
+ /* ell. LAT, LNG -> Gaussian LAT, LNG */
+ Cn = gatg(P->cbg, 5, Cn);
+ /* Gaussian LAT, LNG -> compl. sph. LAT */
+#ifdef _GNU_SOURCE
+ sincos(Cn, &sin_Cn, &cos_Cn);
+ sincos(Ce, &sin_Ce, &cos_Ce);
+#else
+ sin_Cn = sin(Cn);
+ cos_Cn = cos(Cn);
+ sin_Ce = sin(Ce);
+ cos_Ce = cos(Ce);
+#endif
+
+ Cn = atan2(sin_Cn, cos_Ce*cos_Cn);
+ Ce = atan2(sin_Ce*cos_Cn, hypot(sin_Cn, cos_Cn*cos_Ce));
+ /* compl. sph. N, E -> ell. norm. N, E */
+ Ce = log(tan(M_PI_4 + Ce*0.5));
+ Cn += clenS(P->gtu, 5, 2.*Cn, 2.*Ce, &dCn, &dCe);
+ Ce += dCe;
+ if (FABS(Ce) <= 2.623395162778) {
+ xy.y = P->Qn * Cn + P->Zb; /* Northing */
+ xy.x = P->Qn * Ce; /* Easting */
+ } else
+ xy.x = xy.y = HUGE_VAL;
+ return (xy);
+}
+
+
+INVERSE(e_inverse); /* ellipsoid */
+ double sin_Cn, cos_Cn, cos_Ce, sin_Ce, dCn, dCe;
+ double Cn = xy.y, Ce = xy.x;
+
+ /* normalize N, E */
+ Cn = (Cn - P->Zb)/P->Qn;
+ Ce = Ce/P->Qn;
+ if (FABS(Ce) <= 2.623395162778) { /* 150 degrees */
+ /* norm. N, E -> compl. sph. LAT, LNG */
+ Cn += clenS(P->utg, 5, 2.*Cn, 2.*Ce, &dCn, &dCe);
+ Ce += dCe;
+ Ce = 2.0*(atan(exp(Ce)) - M_PI_4);
+ /* compl. sph. LAT -> Gaussian LAT, LNG */
+#ifdef _GNU_SOURCE
+ sincos(Cn, &sin_Cn, &cos_Cn);
+ sincos(Ce, &sin_Ce, &cos_Ce);
+#else
+ sin_Cn = sin(Cn);
+ cos_Cn = cos(Cn);
+ sin_Ce = sin(Ce);
+ cos_Ce = cos(Ce);
+#endif
+ Ce = atan2(sin_Ce, cos_Ce*cos_Cn);
+ Cn = atan2(sin_Cn*cos_Ce, hypot(sin_Ce, cos_Ce*cos_Cn));
+ /* Gaussian LAT, LNG -> ell. LAT, LNG */
+ lp.phi = gatg(P->cgb, 5, Cn);
+ lp.lam = Ce;
+ }
+ else
+ lp.phi = lp.lam = HUGE_VAL;
+ return (lp);
+}
+
+
+FREEUP; if (P) free(P); }
+
+
+ENTRY0(etmerc)
+ double f, n, np, Z;
+
+ if (P->es <= 0.) E_ERROR(-34);
+ f = 1. - sqrt(1. - P->es);
+ /* third flattening */
+ np = n = f/(2.0 - f);
+
+ /* COEF. OF TRIG SERIES GEO <-> GAUSS */
+ /* cgb := Gaussian -> Geodetic, KW p190 - 191 (61) - (62) */
+ /* cbg := Geodetic -> Gaussian, KW p186 - 187 (51) - (52) */
+ /* 5 degree : Engsager and Poder: ICC2007 */
+ P->cgb[0] = n*( 2.0 + n*(-2.0/3.0 + n*(-2.0 + n*(116.0/45.0 + n*(26.0/45.0)))));
+ P->cbg[0] = n*(-2.0 + n*( 2.0/3.0 + n*( 4.0/3.0 + n*(-82.0/45.0 + n*(32.0/45.0)))));
+ np *= n;
+ P->cgb[1] = np*(7.0/3.0 + n*( -8.0/5.0 + n*(-227.0/45.0 + n*(2704.0/315.0))));
+ P->cbg[1] = np*(5.0/3.0 + n*(-16.0/15.0 + n*( -13.0/ 9.0 + n*( 904.0/315.0))));
+ np *= n;
+ P->cgb[2] = np*( 56.0/15.0 + n*(-136.0/35.0 + n*(1262.0/105.0)));
+ P->cbg[2] = np*(-26.0/15.0 + n*( 34.0/21.0 + n*( 8.0/ 5.0)));
+ np *= n;
+ P->cgb[3] = np*(4279.0/630.0 + n*(-322.0/35.0));
+ P->cbg[3] = np*(1237.0/630.0 + n*( -12.0/ 5.0));
+ np *= n;
+ P->cgb[4] = np*(4174.0/315.0);
+ P->cbg[4] = np*(-734.0/315.0);
+
+ /* Constants of the projections */
+ /* Transverse Mercator (UTM, ITM, etc) */
+ np = n*n;
+ /* Norm. mer. quad, K&W p.50 (96), p.19 (38b), p.5 (2) */
+ P->Qn = P->k0/(1 + n) * (1. + np*(1./4.0 + np*(1./64.0 + np/256.0)));
+ /* coef of trig series */
+ /* utg := ell. N, E -> sph. N, E, KW p194 (65) */
+ /* gtu := sph. N, E -> ell. N, E, KW p196 (69) */
+ P->utg[0] = n*(-0.5 + n*( 2.0/3.0 + n*(-37.0/96.0 + n*( 1.0/360.0 + n*( 81.0/512.0)))));
+ P->gtu[0] = n*( 0.5 + n*(-2.0/3.0 + n*( 5.0/16.0 + n*(41.0/180.0 + n*(-127.0/288.0)))));
+ P->utg[1] = np*(-1.0/48.0 + n*(-1.0/15.0 + n*(437.0/1440.0 + n*(-46.0/105.0))));
+ P->gtu[1] = np*(13.0/48.0 + n*(-3.0/5.0 + n*(557.0/1440.0 + n*(281.0/630.0))));
+ np *= n;
+ P->utg[2] = np*(-17.0/480.0 + n*( 37.0/840.0 + n*( 209.0/ 4480.0)));
+ P->gtu[2] = np*( 61.0/240.0 + n*(-103.0/140.0 + n*(15061.0/26880.0)));
+ np *= n;
+ P->utg[3] = np*(-4397.0/161280.0 + n*( 11.0/504.0));
+ P->gtu[3] = np*(49561.0/161280.0 + n*(-179.0/168.0));
+ np *= n;
+ P->utg[4] = np*(-4583.0/161280.0);
+ P->gtu[4] = np*(34729.0/ 80640.0);
+ /* Gaussian latitude value of the origin latitude */
+ Z = gatg(P->cbg, 5, P->phi0);
+ /* Origin northing minus true northing at the origin latitude */
+ /* i.e. true northing = N - P->Zb */
+ P->Zb = - P->Qn*(Z + clens(P->gtu, 5, 2.0*Z));
+ P->inv = e_inverse;
+ P->fwd = e_forward;
+ENDENTRY(P)
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