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

1 files changed, 101 insertions, 0 deletions

diff --git a/src/projections/merc.cpp b/src/projections/merc.cpp
new file mode 100644
index 00000000..1998234e
--- /dev/null
+++ b/src/projections/merc.cpp
@@ -0,0 +1,101 @@
+#define PJ_LIB__
+
+#include <float.h>
+#include <math.h>
+
+#include "proj_internal.h"
+#include "proj.h"
+#include "proj_math.h"
+#include "projects.h"
+
+PROJ_HEAD(merc, "Mercator") "\n\tCyl, Sph&Ell\n\tlat_ts=";
+PROJ_HEAD(webmerc, "Web Mercator / Pseudo Mercator") "\n\tCyl, Ell\n\t";
+
+#define EPS10 1.e-10
+static double logtanpfpim1(double x) {       /* log(tan(x/2 + M_FORTPI)) */
+    if (fabs(x) <= DBL_EPSILON) {
+        /* tan(M_FORTPI + .5 * x) can be approximated by  1.0 + x */
+        return log1p(x);
+    }
+    return log(tan(M_FORTPI + .5 * x));
+}
+
+static XY e_forward (LP lp, PJ *P) {          /* Ellipsoidal, forward */
+    XY xy = {0.0,0.0};
+    if (fabs(fabs(lp.phi) - M_HALFPI) <= EPS10) {
+        proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+        return xy;
+    }
+    xy.x = P->k0 * lp.lam;
+    xy.y = - P->k0 * log(pj_tsfn(lp.phi, sin(lp.phi), P->e));
+    return xy;
+}
+
+
+static XY s_forward (LP lp, PJ *P) {           /* Spheroidal, forward */
+    XY xy = {0.0,0.0};
+    if (fabs(fabs(lp.phi) - M_HALFPI) <= EPS10) {
+        proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+        return xy;
+}
+    xy.x = P->k0 * lp.lam;
+    xy.y = P->k0 * logtanpfpim1(lp.phi);
+    return xy;
+}
+
+
+static LP e_inverse (XY xy, PJ *P) {          /* Ellipsoidal, inverse */
+    LP lp = {0.0,0.0};
+    if ((lp.phi = pj_phi2(P->ctx, exp(- xy.y / P->k0), P->e)) == HUGE_VAL) {
+        proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+        return lp;
+}
+    lp.lam = xy.x / P->k0;
+    return lp;
+}
+
+
+static LP s_inverse (XY xy, PJ *P) {           /* Spheroidal, inverse */
+    LP lp = {0.0,0.0};
+    lp.phi = atan(sinh(xy.y / P->k0));
+    lp.lam = xy.x / P->k0;
+    return lp;
+}
+
+
+PJ *PROJECTION(merc) {
+    double phits=0.0;
+    int is_phits;
+
+    if( (is_phits = pj_param(P->ctx, P->params, "tlat_ts").i) ) {
+        phits = fabs(pj_param(P->ctx, P->params, "rlat_ts").f);
+        if (phits >= M_HALFPI)
+            return pj_default_destructor(P, PJD_ERR_LAT_TS_LARGER_THAN_90);
+    }
+
+    if (P->es != 0.0) { /* ellipsoid */
+        if (is_phits)
+            P->k0 = pj_msfn(sin(phits), cos(phits), P->es);
+        P->inv = e_inverse;
+        P->fwd = e_forward;
+    }
+
+    else { /* sphere */
+        if (is_phits)
+            P->k0 = cos(phits);
+        P->inv = s_inverse;
+        P->fwd = s_forward;
+    }
+
+    return P;
+}
+
+PJ *PROJECTION(webmerc) {
+
+    /* Overriding k_0 with fixed parameter */
+    P->k0 = 1.0;
+
+    P->inv = s_inverse;
+    P->fwd = s_forward;
+    return P;
+}