1 files changed, 56 insertions, 0 deletions
diff --git a/src/projections/wink2.cpp b/src/projections/wink2.cpp
new file mode 100644
index 00000000..74a47283
--- /dev/null
+++ b/src/projections/wink2.cpp
@@ -0,0 +1,56 @@
+#define PJ_LIB__
+
+#include <errno.h>
+#include <math.h>
+
+#include "projects.h"
+
+PROJ_HEAD(wink2, "Winkel II") "\n\tPCyl, Sph, no inv\n\tlat_1=";
+
+namespace { // anonymous namespace
+struct pj_opaque {
+    double	cosphi1;
+};
+} // anonymous namespace
+
+#define MAX_ITER    10
+#define LOOP_TOL    1e-7
+
+
+static XY s_forward (LP lp, PJ *P) {           /* Spheroidal, forward */
+    XY xy = {0.0, 0.0};
+	double k, V;
+	int i;
+
+	xy.y = lp.phi * M_TWO_D_PI;
+	k = M_PI * sin (lp.phi);
+	lp.phi *= 1.8;
+	for (i = MAX_ITER; i ; --i) {
+		lp.phi -= V = (lp.phi + sin (lp.phi) - k) /
+			(1. + cos (lp.phi));
+		if (fabs (V) < LOOP_TOL)
+			break;
+	}
+	if (!i)
+		lp.phi = (lp.phi < 0.) ? -M_HALFPI : M_HALFPI;
+	else
+		lp.phi *= 0.5;
+	xy.x = 0.5 * lp.lam * (cos (lp.phi) + static_cast<struct pj_opaque*>(P->opaque)->cosphi1);
+	xy.y = M_FORTPI * (sin (lp.phi) + xy.y);
+	return xy;
+}
+
+
+PJ *PROJECTION(wink2) {
+    struct pj_opaque *Q = static_cast<struct pj_opaque*>(pj_calloc (1, sizeof (struct pj_opaque)));
+    if (nullptr==Q)
+        return pj_default_destructor(P, ENOMEM);
+    P->opaque = Q;
+
+	static_cast<struct pj_opaque*>(P->opaque)->cosphi1 = cos(pj_param(P->ctx, P->params, "rlat_1").f);
+	P->es  = 0.;
+    P->inv = nullptr;
+    P->fwd = s_forward;
+
+    return P;
+}