1 files changed, 158 insertions, 0 deletions
diff --git a/src/projections/rouss.cpp b/src/projections/rouss.cpp
new file mode 100644
index 00000000..3b4428bc
--- /dev/null
+++ b/src/projections/rouss.cpp
@@ -0,0 +1,158 @@
+/*
+** libproj -- library of cartographic projections
+**
+** Copyright (c) 2003, 2006   Gerald I. Evenden
+*/
+/*
+** Permission is hereby granted, free of charge, to any person obtaining
+** a copy of this software and associated documentation files (the
+** "Software"), to deal in the Software without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Software, and to
+** permit persons to whom the Software is furnished to do so, subject to
+** the following conditions:
+**
+** The above copyright notice and this permission notice shall be
+** included in all copies or substantial portions of the Software.
+**
+** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+** SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+#define PJ_LIB__
+
+#include <errno.h>
+#include <math.h>
+
+#include "proj.h"
+#include "projects.h"
+
+namespace { // anonymous namespace
+struct pj_opaque {
+    double s0;
+    double A1, A2, A3, A4, A5, A6;
+    double B1, B2, B3, B4, B5, B6, B7, B8;
+    double C1, C2, C3, C4, C5, C6, C7, C8;
+    double D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11;
+    void *en;
+};
+} // anonymous namespace
+PROJ_HEAD(rouss, "Roussilhe Stereographic") "\n\tAzi, Ell";
+
+
+static XY e_forward (LP lp, PJ *P) {          /* Ellipsoidal, forward */
+    XY xy = {0.0,0.0};
+    struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
+    double s, al, cp, sp, al2, s2;
+
+    cp = cos(lp.phi);
+    sp = sin(lp.phi);
+    s = proj_mdist(lp.phi, sp, cp,  Q->en) - Q->s0;
+    s2 = s * s;
+    al = lp.lam * cp / sqrt(1. - P->es * sp * sp);
+    al2 = al * al;
+    xy.x = P->k0 * al*(1.+s2*(Q->A1+s2*Q->A4)-al2*(Q->A2+s*Q->A3+s2*Q->A5
+                +al2*Q->A6));
+    xy.y = P->k0 * (al2*(Q->B1+al2*Q->B4)+
+        s*(1.+al2*(Q->B3-al2*Q->B6)+s2*(Q->B2+s2*Q->B8)+
+        s*al2*(Q->B5+s*Q->B7)));
+
+    return xy;
+}
+
+
+static LP e_inverse (XY xy, PJ *P) {          /* Ellipsoidal, inverse */
+    LP lp = {0.0,0.0};
+    struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
+    double s, al, x = xy.x / P->k0, y = xy.y / P->k0, x2, y2;;
+
+    x2 = x * x;
+    y2 = y * y;
+    al = x*(1.-Q->C1*y2+x2*(Q->C2+Q->C3*y-Q->C4*x2+Q->C5*y2-Q->C7*x2*y)
+        +y2*(Q->C6*y2-Q->C8*x2*y));
+    s = Q->s0 + y*(1.+y2*(-Q->D2+Q->D8*y2))+
+        x2*(-Q->D1+y*(-Q->D3+y*(-Q->D5+y*(-Q->D7+y*Q->D11)))+
+        x2*(Q->D4+y*(Q->D6+y*Q->D10)-x2*Q->D9));
+    lp.phi=proj_inv_mdist(P->ctx, s, Q->en);
+    s = sin(lp.phi);
+    lp.lam=al * sqrt(1. - P->es * s * s)/cos(lp.phi);
+
+    return lp;
+}
+
+
+static PJ *destructor (PJ *P, int errlev) {
+    if (nullptr==P)
+        return nullptr;
+
+    if (nullptr==P->opaque)
+        return pj_default_destructor (P, errlev);
+
+    if (static_cast<struct pj_opaque*>(P->opaque)->en)
+        pj_dealloc (static_cast<struct pj_opaque*>(P->opaque)->en);
+
+    return pj_default_destructor (P, ENOMEM);
+}
+
+
+PJ *PROJECTION(rouss) {
+    double N0, es2, t, t2, R_R0_2, R_R0_4;
+
+    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;
+
+    if (!((Q->en = proj_mdist_ini(P->es))))
+        return pj_default_destructor (P, ENOMEM);
+
+    es2 = sin(P->phi0);
+    Q->s0 = proj_mdist(P->phi0, es2, cos(P->phi0), Q->en);
+    t = 1. - (es2 = P->es * es2 * es2);
+    N0 = 1./sqrt(t);
+    R_R0_2 = t * t / P->one_es;
+    R_R0_4 = R_R0_2 * R_R0_2;
+    t = tan(P->phi0);
+    t2 = t * t;
+    Q->C1 = Q->A1 = R_R0_2 / 4.;
+    Q->C2 = Q->A2 = R_R0_2 * (2 * t2 - 1. - 2. * es2) / 12.;
+    Q->A3 = R_R0_2 * t * (1. + 4. * t2)/ ( 12. * N0);
+    Q->A4 = R_R0_4 / 24.;
+    Q->A5 = R_R0_4 * ( -1. + t2 * (11. + 12. * t2))/24.;
+    Q->A6 = R_R0_4 * ( -2. + t2 * (11. - 2. * t2))/240.;
+    Q->B1 = t / (2. * N0);
+    Q->B2 = R_R0_2 / 12.;
+    Q->B3 = R_R0_2 * (1. + 2. * t2 - 2. * es2)/4.;
+    Q->B4 = R_R0_2 * t * (2. - t2)/(24. * N0);
+    Q->B5 = R_R0_2 * t * (5. + 4.* t2)/(8. * N0);
+    Q->B6 = R_R0_4 * (-2. + t2 * (-5. + 6. * t2))/48.;
+    Q->B7 = R_R0_4 * (5. + t2 * (19. + 12. * t2))/24.;
+    Q->B8 = R_R0_4 / 120.;
+    Q->C3 = R_R0_2 * t * (1. + t2)/(3. * N0);
+    Q->C4 = R_R0_4 * (-3. + t2 * (34. + 22. * t2))/240.;
+    Q->C5 = R_R0_4 * (4. + t2 * (13. + 12. * t2))/24.;
+    Q->C6 = R_R0_4 / 16.;
+    Q->C7 = R_R0_4 * t * (11. + t2 * (33. + t2 * 16.))/(48. * N0);
+    Q->C8 = R_R0_4 * t * (1. + t2 * 4.)/(36. * N0);
+    Q->D1 = t / (2. * N0);
+    Q->D2 = R_R0_2 / 12.;
+    Q->D3 = R_R0_2 * (2 * t2 + 1. - 2. * es2) / 4.;
+    Q->D4 = R_R0_2 * t * (1. + t2)/(8. * N0);
+    Q->D5 = R_R0_2 * t * (1. + t2 * 2.)/(4. * N0);
+    Q->D6 = R_R0_4 * (1. + t2 * (6. + t2 * 6.))/16.;
+    Q->D7 = R_R0_4 * t2 * (3. + t2 * 4.)/8.;
+    Q->D8 = R_R0_4 / 80.;
+    Q->D9 = R_R0_4 * t * (-21. + t2 * (178. - t2 * 26.))/720.;
+    Q->D10 = R_R0_4 * t * (29. + t2 * (86. + t2 * 48.))/(96. * N0);
+    Q->D11 = R_R0_4 * t * (37. + t2 * 44.)/(96. * N0);
+
+    P->fwd = e_forward;
+    P->inv = e_inverse;
+    P->destructor = destructor;
+
+    return P;
+}