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-rw-r--r--src/Makefile.am1
-rw-r--r--src/lib_proj.cmake1
-rw-r--r--src/pj_list.h5
-rw-r--r--src/projections/adams.cpp215
4 files changed, 222 insertions, 0 deletions
diff --git a/src/Makefile.am b/src/Makefile.am
index fe816af0..52e5584b 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -72,6 +72,7 @@ libproj_la_SOURCES = \
iso19111/c_api.cpp \
\
projections/aeqd.cpp \
+ projections/adams.cpp \
projections/gnom.cpp \
projections/laea.cpp \
projections/mod_ster.cpp \
diff --git a/src/lib_proj.cmake b/src/lib_proj.cmake
index 7c93b205..5dec3231 100644
--- a/src/lib_proj.cmake
+++ b/src/lib_proj.cmake
@@ -56,6 +56,7 @@ print_variable(ENABLE_IPO)
set(SRC_LIBPROJ_PROJECTIONS
projections/aeqd.cpp
+ projections/adams.cpp
projections/gnom.cpp
projections/laea.cpp
projections/mod_ster.cpp
diff --git a/src/pj_list.h b/src/pj_list.h
index 2e1bf759..b8790b45 100644
--- a/src/pj_list.h
+++ b/src/pj_list.h
@@ -5,6 +5,9 @@ static const char PJ_LIST_H_ID[] = "@(#)pj_list.h 4.5 95/08/09 GIE REL";
**
** Copy this file and retain only appropriate lines for subset list
*/
+PROJ_HEAD(adams_hemi, "Adams Hemisphere in a Square")
+PROJ_HEAD(adams_ws1, "Adams World in a Square I")
+PROJ_HEAD(adams_ws2, "Adams World in a Square II")
PROJ_HEAD(aea, "Albers Equal Area")
PROJ_HEAD(aeqd, "Azimuthal Equidistant")
PROJ_HEAD(affine, "Affine transformation")
@@ -56,6 +59,7 @@ PROJ_HEAD(gnom, "Gnomonic")
PROJ_HEAD(goode, "Goode Homolosine")
PROJ_HEAD(gs48, "Mod. Stererographics of 48 U.S.")
PROJ_HEAD(gs50, "Mod. Stererographics of 50 U.S.")
+PROJ_HEAD(guyou, "Guyou")
PROJ_HEAD(hammer, "Hammer & Eckert-Greifendorff")
PROJ_HEAD(hatano, "Hatano Asymmetrical Equal Area")
PROJ_HEAD(healpix, "HEALPix")
@@ -115,6 +119,7 @@ PROJ_HEAD(ortel, "Ortelius Oval")
PROJ_HEAD(ortho, "Orthographic")
PROJ_HEAD(pconic, "Perspective Conic")
PROJ_HEAD(patterson, "Patterson Cylindrical")
+PROJ_HEAD(peirce_q, "Peirce Quincuncial")
PROJ_HEAD(pipeline, "Transformation pipeline manager")
PROJ_HEAD(poly, "Polyconic (American)")
PROJ_HEAD(pop, "Retrieve coordinate value from pipeline stack")
diff --git a/src/projections/adams.cpp b/src/projections/adams.cpp
new file mode 100644
index 00000000..397584c7
--- /dev/null
+++ b/src/projections/adams.cpp
@@ -0,0 +1,215 @@
+/*
+* Implementation of the Guyou, Pierce Quincuncial, Adams Hemisphere in a Square,
+* Adams World in a Square I & II projections.
+*
+* Based on original code from libproj4 written by Gerald Evenden. Adapted to modern
+* PROJ by Kristian Evers. Original code found in file src/proj_guyou.c, see
+* https://github.com/rouault/libproj4/blob/master/libproject-1.01/src/proj_guyou.c
+* for reference.
+*
+* Copyright (c) 2005, 2006, 2009 Gerald I. Evenden
+* Copyright (c) 2020 Kristian Evers
+*
+* Related material
+* ----------------
+*
+* CONFORMAL PROJECTION OF THE SPHERE WITHIN A SQUARE, 1929, OSCAR S. ADAMS,
+* U.S. COAST AND GEODETIC SURVEY, Special Publication No.153,
+* ftp://ftp.library.noaa.gov/docs.lib/htdocs/rescue/cgs_specpubs/QB275U35no1531929.pdf
+*
+* https://en.wikipedia.org/wiki/Guyou_hemisphere-in-a-square_projection
+* https://en.wikipedia.org/wiki/Adams_hemisphere-in-a-square_projection
+* https://en.wikipedia.org/wiki/Peirce_quincuncial_projection
+*/
+
+#define PJ_LIB__
+
+#include <math.h>
+#include <errno.h>
+
+#include "proj.h"
+#include "proj_internal.h"
+
+PROJ_HEAD(guyou, "Guyou") "\n\tMisc Sph No inv";
+PROJ_HEAD(peirce_q, "Peirce Quincuncial") "\n\tMisc Sph No inv";
+PROJ_HEAD(adams_hemi, "Adams Hemisphere in a Square") "\n\tMisc Sph No inv";
+PROJ_HEAD(adams_ws1, "Adams World in a Square I") "\n\tMisc Sph No inv";
+PROJ_HEAD(adams_ws2, "Adams World in a Square II") "\n\tMisc Sph No inv";
+
+namespace { // anonymous namespace
+
+enum projection_type {
+ GUYOU,
+ PEIRCE_Q,
+ ADAMS_HEMI,
+ ADAMS_WS1,
+ ADAMS_WS2,
+};
+
+struct pj_opaque {
+ projection_type mode;
+};
+
+} // anonymous namespace
+
+
+#define TOL 1e-9
+#define RSQRT2 0.7071067811865475244008443620
+
+static double ell_int_5(double phi) {
+/* Procedure to compute elliptic integral of the first kind
+ * where k^2=0.5. Precision good to better than 1e-7
+ * The approximation is performed with an even Chebyshev
+ * series, thus the coefficients below are the even values
+ * and where series evaluation must be multiplied by the argument. */
+ double d1 = 0.0;
+ double d2 = 0.0;
+ static double C0 = 2.19174570831038;
+ static const double C[] = {
+ -8.58691003636495e-07,
+ 2.02692115653689e-07,
+ 3.12960480765314e-05,
+ 5.30394739921063e-05,
+ -0.0012804644680613,
+ -0.00575574836830288,
+ 0.0914203033408211,
+ };
+
+ double y = phi * M_2_PI;
+ y = 2. * y * y - 1.;
+ double y2 = 2. * y;
+ for ( double c: C ) {
+ double temp = d1;
+ d1 = y2 * d1 - d2 + c;
+ d2 = temp;
+ }
+
+ return phi * (y * d1 - d2 + 0.5 * C0);
+
+}
+
+static PJ_XY forward(PJ_LP lp, PJ *P) {
+ double a=0., b=0.;
+ bool sm=false, sn=false;
+ PJ_XY xy;
+ struct pj_opaque *Q = static_cast<struct pj_opaque*>(P->opaque);
+
+ switch (Q->mode) {
+ case GUYOU:
+ if ((fabs(lp.lam) - TOL) > M_PI_2) {
+ proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+ return proj_coord_error().xy;
+ }
+
+ if (fabs(fabs(lp.phi) - M_PI_2) < TOL) {
+ xy.x = 0;
+ xy.y = lp.phi < 0 ? -1.85407 : 1.85407;
+ return xy;
+ } else {
+ double sl = sin(lp.lam);
+ double sp = sin(lp.phi);
+ double cp = cos(lp.phi);
+ a = aacos(P->ctx, (cp * sl - sp) * RSQRT2);
+ b = aacos(P->ctx, (cp * sl + sp) * RSQRT2);
+ sm = lp.lam < 0.;
+ sn = lp.phi < 0.;
+ }
+ break;
+ case PEIRCE_Q: {
+ double sl = sin(lp.lam);
+ double cl = cos(lp.lam);
+ double cp = cos(lp.phi);
+ a = aacos(P->ctx, cp * (sl + cl) * RSQRT2);
+ b = aacos(P->ctx, cp * (sl - cl) * RSQRT2);
+ sm = sl < 0.;
+ sn = cl > 0.;
+ }
+ break;
+ case ADAMS_HEMI: {
+ double sp = sin(lp.phi);
+ if ((fabs(lp.lam) - TOL) > M_PI_2) {
+ proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
+ return proj_coord_error().xy;
+ }
+ a = cos(lp.phi) * sin(lp.lam);
+ sm = (sp + a) < 0.;
+ sn = (sp - a) < 0.;
+ a = aacos(P->ctx, a);
+ b = M_PI_2 - lp.phi;
+ }
+ break;
+ case ADAMS_WS1: {
+ double sp = tan(0.5 * lp.phi);
+ b = cos(aasin(P->ctx, sp)) * sin(0.5 * lp.lam);
+ a = aacos(P->ctx, (b - sp) * RSQRT2);
+ b = aacos(P->ctx, (b + sp) * RSQRT2);
+ sm = lp.lam < 0.;
+ sn = lp.phi < 0.;
+ }
+ break;
+ case ADAMS_WS2: {
+ double spp = tan(0.5 * lp.phi);
+ a = cos(aasin(P->ctx, spp)) * sin(0.5 * lp.lam);
+ sm = (spp + a) < 0.;
+ sn = (spp - a) < 0.;
+ b = aacos(P->ctx, spp);
+ a = aacos(P->ctx, a);
+ }
+ break;
+ }
+
+ double m = aasin(P->ctx, sqrt((1. + cos(a + b))));
+ if (sm) m = -m;
+
+ double n = aasin(P->ctx, sqrt(fabs(1. - cos(a - b))));
+ if (sn) n = -n;
+
+ xy.x = ell_int_5(m);
+ xy.y = ell_int_5(n);
+
+ if (Q->mode == ADAMS_HEMI || Q->mode == ADAMS_WS2) { /* rotate by 45deg. */
+ double temp = xy.x;
+ xy.x = RSQRT2 * (xy.x - xy.y);
+ xy.y = RSQRT2 * (temp + xy.y);
+ }
+
+ return xy;
+}
+
+
+static PJ *setup(PJ *P, projection_type mode) {
+ 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;
+
+ P->es = 0;
+ P->fwd = forward;
+
+ Q->mode = mode;
+
+ return P;
+}
+
+
+PJ *PROJECTION(guyou) {
+ return setup(P, GUYOU);
+}
+
+PJ *PROJECTION(peirce_q) {
+ return setup(P, PEIRCE_Q);
+}
+
+PJ *PROJECTION(adams_hemi) {
+ return setup(P, ADAMS_HEMI);
+}
+
+PJ *PROJECTION(adams_ws1) {
+ return setup(P, ADAMS_WS1);
+}
+
+PJ *PROJECTION(adams_ws2) {
+ return setup(P, ADAMS_WS2);
+}
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