1 files changed, 74 insertions, 0 deletions
diff --git a/src/PJ_putp4p.cpp b/src/PJ_putp4p.cpp
new file mode 100644
index 00000000..77a18651
--- /dev/null
+++ b/src/PJ_putp4p.cpp
@@ -0,0 +1,74 @@
+#define PJ_LIB__
+
+#include <errno.h>
+#include <math.h>
+
+#include "projects.h"
+
+struct pj_opaque {
+    double C_x, C_y;
+};
+
+PROJ_HEAD(putp4p, "Putnins P4'") "\n\tPCyl, Sph";
+PROJ_HEAD(weren, "Werenskiold I") "\n\tPCyl, Sph";
+
+
+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);
+
+    lp.phi = aasin(P->ctx,0.883883476 * sin(lp.phi));
+    xy.x = Q->C_x * lp.lam * cos(lp.phi);
+    xy.x /= cos(lp.phi *= 0.333333333333333);
+    xy.y = Q->C_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);
+
+    lp.phi = aasin(P->ctx,xy.y / Q->C_y);
+    lp.lam = xy.x * cos(lp.phi) / Q->C_x;
+    lp.phi *= 3.;
+    lp.lam /= cos(lp.phi);
+    lp.phi = aasin(P->ctx,1.13137085 * sin(lp.phi));
+
+    return lp;
+}
+
+
+PJ *PROJECTION(putp4p) {
+    struct pj_opaque *Q = static_cast<struct pj_opaque*>(pj_calloc (1, sizeof (struct pj_opaque)));
+    if (0==Q)
+        return pj_default_destructor (P, ENOMEM);
+    P->opaque = Q;
+
+    Q->C_x = 0.874038744;
+    Q->C_y = 3.883251825;
+
+    P->es = 0.;
+    P->inv = s_inverse;
+    P->fwd = s_forward;
+
+    return P;
+}
+
+
+PJ *PROJECTION(weren) {
+    struct pj_opaque *Q = static_cast<struct pj_opaque*>(pj_calloc (1, sizeof (struct pj_opaque)));
+    if (0==Q)
+        return pj_default_destructor (P, ENOMEM);
+    P->opaque = Q;
+
+    Q->C_x = 1.;
+    Q->C_y = 4.442882938;
+
+    P->es = 0.;
+    P->inv = s_inverse;
+    P->fwd = s_forward;
+
+    return P;
+}