1 files changed, 35 insertions, 0 deletions
diff --git a/src/3rdparty/proj/PJ_lagrng.c b/src/3rdparty/proj/PJ_lagrng.c
new file mode 100644
index 00000000..d0e123a9
--- /dev/null
+++ b/src/3rdparty/proj/PJ_lagrng.c
@@ -0,0 +1,35 @@
+#define PROJ_PARMS__ \
+	double	hrw; \
+	double	rw; \
+	double	a1;
+#define TOL	1e-10
+#define PJ_LIB__
+#include	<projects.h>
+PROJ_HEAD(lagrng, "Lagrange") "\n\tMisc Sph, no inv.\n\tW=";
+FORWARD(s_forward); /* spheroid */
+	double v, c;
+
+	if (fabs(fabs(lp.phi) - HALFPI) < TOL) {
+		xy.x = 0;
+		xy.y = lp.phi < 0 ? -2. : 2.;
+	} else {
+		lp.phi = sin(lp.phi);
+		v = P->a1 * pow((1. + lp.phi)/(1. - lp.phi), P->hrw);
+		if ((c = 0.5 * (v + 1./v) + cos(lp.lam *= P->rw)) < TOL)
+			F_ERROR;
+		xy.x = 2. * sin(lp.lam) / c;
+		xy.y = (v - 1./v) / c;
+	}
+	return (xy);
+}
+FREEUP; if (P) pj_dalloc(P); }
+ENTRY0(lagrng)
+	double phi1;
+
+	if ((P->rw = pj_param(P->params, "dW").f) <= 0) E_ERROR(-27);
+	P->hrw = 0.5 * (P->rw = 1. / P->rw);
+	phi1 = pj_param(P->params, "rlat_1").f;
+	if (fabs(fabs(phi1 = sin(phi1)) - 1.) < TOL) E_ERROR(-22);
+	P->a1 = pow((1. - phi1)/(1. + phi1), P->hrw);
+	P->es = 0.; P->fwd = s_forward;
+ENDENTRY(P)