1 files changed, 130 insertions, 0 deletions
diff --git a/src/projections/PJ_lcc.cpp b/src/projections/PJ_lcc.cpp
new file mode 100644
index 00000000..7d6e3f57
--- /dev/null
+++ b/src/projections/PJ_lcc.cpp
@@ -0,0 +1,130 @@
+#define PJ_LIB__
+#include <errno.h>
+#include "proj.h"
+#include "projects.h"
+#include "proj_math.h"
+
+PROJ_HEAD(lcc, "Lambert Conformal Conic")
+    "\n\tConic, Sph&Ell\n\tlat_1= and lat_2= or lat_0, k_0=";
+
+#define EPS10 1.e-10
+
+namespace { // anonymous namespace
+struct pj_opaque {
+    double phi1;
+    double phi2;
+    double n;
+    double rho0;
+    double c;
+};
+} // anonymous namespace
+
+
+static XY e_forward (LP lp, PJ *P) {          /* Ellipsoidal, forward */
+    XY xy = {0., 0.};
+    struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
+    double rho;
+
+    if (fabs(fabs(lp.phi) - M_HALFPI) < EPS10) {
+        if ((lp.phi * Q->n) <= 0.) {
+            proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+            return xy;
+        }
+        rho = 0.;
+    } else {
+        rho = Q->c * (P->es != 0. ?
+                      pow(pj_tsfn(lp.phi, sin(lp.phi), P->e), Q->n) :
+                      pow(tan(M_FORTPI + .5 * lp.phi), -Q->n));
+    }
+    lp.lam *= Q->n;
+    xy.x = P->k0 * (rho * sin(lp.lam));
+    xy.y = P->k0 * (Q->rho0 - rho * cos(lp.lam));
+    return xy;
+}
+
+
+static LP e_inverse (XY xy, PJ *P) {          /* Ellipsoidal, inverse */
+    LP lp = {0., 0.};
+    struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
+    double rho;
+
+    xy.x /= P->k0;
+    xy.y /= P->k0;
+
+    xy.y = Q->rho0 - xy.y;
+    rho = hypot(xy.x, xy.y);
+    if (rho != 0.) {
+        if (Q->n < 0.) {
+            rho = -rho;
+            xy.x = -xy.x;
+            xy.y = -xy.y;
+        }
+        if (P->es != 0.) {
+            lp.phi = pj_phi2(P->ctx, pow(rho / Q->c, 1./Q->n), P->e);
+            if (lp.phi == HUGE_VAL) {
+                proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+                return lp;
+            }
+
+        } else
+            lp.phi = 2. * atan(pow(Q->c / rho, 1./Q->n)) - M_HALFPI;
+        lp.lam = atan2(xy.x, xy.y) / Q->n;
+    } else {
+        lp.lam = 0.;
+        lp.phi = Q->n > 0. ? M_HALFPI : -M_HALFPI;
+    }
+    return lp;
+}
+
+
+PJ *PROJECTION(lcc) {
+    double cosphi, sinphi;
+    int secant;
+    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->phi1 = pj_param(P->ctx, P->params, "rlat_1").f;
+    if (pj_param(P->ctx, P->params, "tlat_2").i)
+        Q->phi2 = pj_param(P->ctx, P->params, "rlat_2").f;
+    else {
+        Q->phi2 = Q->phi1;
+        if (!pj_param(P->ctx, P->params, "tlat_0").i)
+            P->phi0 = Q->phi1;
+    }
+    if (fabs(Q->phi1 + Q->phi2) < EPS10)
+        return pj_default_destructor(P, PJD_ERR_CONIC_LAT_EQUAL);
+
+    Q->n = sinphi = sin(Q->phi1);
+    cosphi = cos(Q->phi1);
+    secant = fabs(Q->phi1 - Q->phi2) >= EPS10;
+    if (P->es != 0.) {
+        double ml1, m1;
+
+        m1 = pj_msfn(sinphi, cosphi, P->es);
+        ml1 = pj_tsfn(Q->phi1, sinphi, P->e);
+        if (secant) { /* secant cone */
+            sinphi = sin(Q->phi2);
+            Q->n = log(m1 / pj_msfn(sinphi, cos(Q->phi2), P->es));
+            Q->n /= log(ml1 / pj_tsfn(Q->phi2, sinphi, P->e));
+        }
+        Q->c = (Q->rho0 = m1 * pow(ml1, -Q->n) / Q->n);
+        Q->rho0 *= (fabs(fabs(P->phi0) - M_HALFPI) < EPS10) ? 0. :
+            pow(pj_tsfn(P->phi0, sin(P->phi0), P->e), Q->n);
+    } else {
+        if (secant)
+            Q->n = log(cosphi / cos(Q->phi2)) /
+               log(tan(M_FORTPI + .5 * Q->phi2) /
+               tan(M_FORTPI + .5 * Q->phi1));
+        Q->c = cosphi * pow(tan(M_FORTPI + .5 * Q->phi1), Q->n) / Q->n;
+        Q->rho0 = (fabs(fabs(P->phi0) - M_HALFPI) < EPS10) ? 0. :
+            Q->c * pow(tan(M_FORTPI + .5 * P->phi0), -Q->n);
+    }
+
+    P->inv = e_inverse;
+    P->fwd = e_forward;
+
+    return P;
+}