1 files changed, 109 insertions, 0 deletions
diff --git a/src/projections/sts.cpp b/src/projections/sts.cpp
new file mode 100644
index 00000000..9f889611
--- /dev/null
+++ b/src/projections/sts.cpp
@@ -0,0 +1,109 @@
+#define PJ_LIB__
+
+#include <errno.h>
+#include <math.h>
+
+#include "projects.h"
+
+PROJ_HEAD(kav5,    "Kavraisky V")         "\n\tPCyl, Sph";
+PROJ_HEAD(qua_aut, "Quartic Authalic")    "\n\tPCyl, Sph";
+PROJ_HEAD(fouc,    "Foucaut")             "\n\tPCyl, Sph";
+PROJ_HEAD(mbt_s,   "McBryde-Thomas Flat-Polar Sine (No. 1)") "\n\tPCyl, Sph";
+
+
+namespace { // anonymous namespace
+struct pj_opaque {
+	double C_x, C_y, C_p;
+	int tan_mode;
+};
+} // anonymous namespace
+
+
+static XY s_forward (LP lp, PJ *P) {           /* Spheroidal, forward */
+    XY xy = {0.0,0.0};
+    struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
+	double c;
+
+	xy.x = Q->C_x * lp.lam * cos(lp.phi);
+	xy.y = Q->C_y;
+	lp.phi *= Q->C_p;
+	c = cos(lp.phi);
+	if (Q->tan_mode) {
+		xy.x *= c * c;
+		xy.y *= tan (lp.phi);
+	} else {
+		xy.x /= c;
+		xy.y *= sin (lp.phi);
+	}
+	return xy;
+}
+
+
+static LP s_inverse (XY xy, PJ *P) {           /* Spheroidal, inverse */
+    LP lp = {0.0,0.0};
+    struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
+	double c;
+
+	xy.y /= Q->C_y;
+	c = cos (lp.phi = Q->tan_mode ? atan (xy.y) : aasin (P->ctx, xy.y));
+	lp.phi /= Q->C_p;
+	lp.lam = xy.x / (Q->C_x * cos(lp.phi));
+	if (Q->tan_mode)
+		lp.lam /= c * c;
+	else
+		lp.lam *= c;
+	return lp;
+}
+
+
+static PJ *setup(PJ *P, double p, double q, int mode) {
+	P->es  = 0.;
+	P->inv = s_inverse;
+	P->fwd = s_forward;
+	static_cast<struct pj_opaque*>(P->opaque)->C_x = q / p;
+	static_cast<struct pj_opaque*>(P->opaque)->C_y = p;
+	static_cast<struct pj_opaque*>(P->opaque)->C_p = 1/ q;
+	static_cast<struct pj_opaque*>(P->opaque)->tan_mode = mode;
+	return P;
+}
+
+
+
+PJ *PROJECTION(fouc) {
+    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;
+    return setup(P, 2., 2., 1);
+}
+
+
+
+PJ *PROJECTION(kav5) {
+    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;
+
+    return setup(P, 1.50488, 1.35439, 0);
+}
+
+
+
+PJ *PROJECTION(qua_aut) {
+    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;
+    return setup(P, 2., 2., 0);
+}
+
+
+
+PJ *PROJECTION(mbt_s) {
+    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;
+    return setup(P, 1.48875, 1.36509, 0);
+}