cpp conversion: remove useless pj_, PJ_ and proj_ filename prefixes

1 files changed, 98 insertions, 0 deletions

diff --git a/src/projections/lagrng.cpp b/src/projections/lagrng.cpp
new file mode 100644
index 00000000..8c0150aa
--- /dev/null
+++ b/src/projections/lagrng.cpp
@@ -0,0 +1,98 @@
+#define PJ_LIB__
+#include <errno.h>
+#include <math.h>
+
+#include "proj.h"
+#include "projects.h"
+
+PROJ_HEAD(lagrng, "Lagrange") "\n\tMisc Sph\n\tW=";
+
+#define TOL 1e-10
+
+namespace { // anonymous namespace
+struct pj_opaque {
+    double  a1;
+    double  a2;
+    double  hrw;
+    double  hw;
+    double  rw;
+    double  w;
+};
+} // 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 v, c;
+
+    if (fabs(fabs(lp.phi) - M_HALFPI) < TOL) {
+        xy.x = 0;
+        xy.y = lp.phi < 0 ? -2. : 2.;
+    } else {
+        lp.phi = sin(lp.phi);
+        v = Q->a1 * pow((1. + lp.phi)/(1. - lp.phi), Q->hrw);
+        lp.lam *= Q->rw;
+        c = 0.5 * (v + 1./v) + cos(lp.lam);
+        if (c < TOL) {
+            proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+            return xy;
+        }
+        xy.x = 2. * sin(lp.lam) / c;
+        xy.y = (v - 1./v) / c;
+    }
+    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, x2, y2p, y2m;
+
+    if (fabs(fabs(xy.y) - 2.) < TOL) {
+        lp.phi = xy.y < 0 ? -M_HALFPI : M_HALFPI;
+        lp.lam = 0;
+    } else {
+        x2 = xy.x * xy.x;
+        y2p = 2. + xy.y;
+        y2m = 2. - xy.y;
+        c = y2p * y2m - x2;
+        if (fabs(c) < TOL) {
+            proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+            return lp;
+        }
+        lp.phi = 2. * atan(pow((y2p * y2p + x2) / (Q->a2 * (y2m * y2m + x2)), Q->hw)) - M_HALFPI;
+        lp.lam = Q->w * atan2(4. * xy.x, c);
+    }
+    return lp;
+}
+
+
+PJ *PROJECTION(lagrng) {
+    double phi1;
+    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;
+
+    Q->w = pj_param(P->ctx, P->params, "dW").f;
+    if (Q->w <= 0)
+        return pj_default_destructor(P, PJD_ERR_W_OR_M_ZERO_OR_LESS);
+    Q->hw = 0.5 * Q->w;
+    Q->rw = 1. / Q->w;
+    Q->hrw = 0.5 * Q->rw;
+    phi1 = sin(pj_param(P->ctx, P->params, "rlat_1").f);
+    if (fabs(fabs(phi1) - 1.) < TOL)
+        return pj_default_destructor(P, PJD_ERR_LAT_LARGER_THAN_90);
+
+    Q->a1 = pow((1. - phi1)/(1. + phi1), Q->hrw);
+    Q->a2 = Q->a1 * Q->a1;
+
+    P->es = 0.;
+    P->inv = s_inverse;
+    P->fwd = s_forward;
+
+    return P;
+}
+