1 files changed, 45 insertions, 0 deletions
diff --git a/src/3rdparty/proj/PJ_fouc_s.c b/src/3rdparty/proj/PJ_fouc_s.c
new file mode 100644
index 00000000..dee05a96
--- /dev/null
+++ b/src/3rdparty/proj/PJ_fouc_s.c
@@ -0,0 +1,45 @@
+#define PROJ_PARMS__ \
+	double n, n1;
+#define PJ_LIB__
+#include	<projects.h>
+PROJ_HEAD(fouc_s, "Foucaut Sinusoidal") "\n\tPCyl., Sph.";
+#define MAX_ITER    10
+#define LOOP_TOL    1e-7
+FORWARD(s_forward); /* spheroid */
+	double t;
+
+	t = cos(lp.phi);
+	xy.x = lp.lam * t / (P->n + P->n1 * t);
+	xy.y = P->n * lp.phi + P->n1 * sin(lp.phi);
+	return (xy);
+}
+INVERSE(s_inverse); /* spheroid */
+	double V;
+	int i;
+
+	if (P->n) {
+		lp.phi = xy.y;
+		for (i = MAX_ITER; i ; --i) {
+			lp.phi -= V = (P->n * lp.phi + P->n1 * sin(lp.phi) - xy.y ) /
+				(P->n + P->n1 * cos(lp.phi));
+			if (fabs(V) < LOOP_TOL)
+				break;
+		}
+		if (!i)
+			lp.phi = xy.y < 0. ? -HALFPI : HALFPI;
+	} else
+		lp.phi = aasin(xy.y);
+	V = cos(lp.phi);
+	lp.lam = xy.x * (P->n + P->n1 * V) / V;
+	return (lp);
+}
+FREEUP; if (P) pj_dalloc(P); }
+ENTRY0(fouc_s)
+	P->n = pj_param(P->params, "dn").f;
+	if (P->n < 0. || P->n > 1.)
+		E_ERROR(-99)
+	P->n1 = 1. - P->n;
+	P->es = 0;
+	P->inv = s_inverse;
+	P->fwd = s_forward;
+ENDENTRY(P)