/src/PROJ/src/projections/eck3.cpp

Source


#include <errno.h>
#include <math.h>

#include "proj.h"
#include "proj_internal.h"

PROJ_HEAD(eck3, "Eckert III") "\n\tPCyl, Sph";
PROJ_HEAD(putp1, "Putnins P1") "\n\tPCyl, Sph";
PROJ_HEAD(wag6, "Wagner VI") "\n\tPCyl, Sph";
PROJ_HEAD(kav7, "Kavrayskiy VII") "\n\tPCyl, Sph";

namespace { // anonymous namespace
struct pj_opaque {
    double C_x, C_y, A, B;
};
} // anonymous namespace

static PJ_XY eck3_s_forward(PJ_LP lp, PJ *P) { /* Spheroidal, forward */
    PJ_XY xy = {0.0, 0.0};
    struct pj_opaque *Q = static_cast<struct pj_opaque *>(P->opaque);

    xy.y = Q->C_y * lp.phi;
    xy.x = Q->C_x * lp.lam * (Q->A + asqrt(1. - Q->B * lp.phi * lp.phi));
    return xy;
}

static PJ_LP eck3_s_inverse(PJ_XY xy, PJ *P) { /* Spheroidal, inverse */
    PJ_LP lp = {0.0, 0.0};
    struct pj_opaque *Q = static_cast<struct pj_opaque *>(P->opaque);
    double denominator;

    lp.phi = xy.y / Q->C_y;
    denominator = (Q->C_x * (Q->A + asqrt(1. - Q->B * lp.phi * lp.phi)));
    if (denominator == 0.0)
        lp.lam = HUGE_VAL;
    else
        lp.lam = xy.x / denominator;
    return lp;
}

static PJ *setup(PJ *P) {
    P->es = 0.;
    P->inv = eck3_s_inverse;
    P->fwd = eck3_s_forward;
    return P;
}

PJ *PJ_PROJECTION(eck3) {
    struct pj_opaque *Q =
        static_cast<struct pj_opaque *>(calloc(1, sizeof(struct pj_opaque)));
    if (nullptr == Q)
        return pj_default_destructor(P, PROJ_ERR_OTHER /*ENOMEM*/);
    P->opaque = Q;

    Q->C_x = 0.42223820031577120149;
    Q->C_y = 0.84447640063154240298;
    Q->A = 1.0;
    Q->B = 0.4052847345693510857755;

    return setup(P);
}

PJ *PJ_PROJECTION(kav7) {
    struct pj_opaque *Q =
        static_cast<struct pj_opaque *>(calloc(1, sizeof(struct pj_opaque)));
    if (nullptr == Q)
        return pj_default_destructor(P, PROJ_ERR_OTHER /*ENOMEM*/);
    P->opaque = Q;

    /* Defined twice in original code - Using 0.866...,
     * but leaving the other one here as a safety measure.
     * Q->C_x = 0.2632401569273184856851; */
    Q->C_x = 0.8660254037844;
    Q->C_y = 1.;
    Q->A = 0.;
    Q->B = 0.30396355092701331433;

    return setup(P);
}

PJ *PJ_PROJECTION(wag6) {
    struct pj_opaque *Q =
        static_cast<struct pj_opaque *>(calloc(1, sizeof(struct pj_opaque)));
    if (nullptr == Q)
        return pj_default_destructor(P, PROJ_ERR_OTHER /*ENOMEM*/);
    P->opaque = Q;

    Q->C_x = 1.0;
    Q->C_y = 1.0;
    Q->A = 0.0;
    Q->B = 0.30396355092701331433;

    return setup(P);
}

PJ *PJ_PROJECTION(putp1) {
    struct pj_opaque *Q =
        static_cast<struct pj_opaque *>(calloc(1, sizeof(struct pj_opaque)));
    if (nullptr == Q)
        return pj_default_destructor(P, PROJ_ERR_OTHER /*ENOMEM*/);
    P->opaque = Q;

    Q->C_x = 1.89490;
    Q->C_y = 0.94745;
    Q->A = -0.5;
    Q->B = 0.30396355092701331433;

    return setup(P);
}

Coverage Report

Created: 2026-08-13 07:07

Line	Count	Source
1
2
3		#include <errno.h>
4		#include <math.h>
5
6		#include "proj.h"
7		#include "proj_internal.h"
8
9		PROJ_HEAD(eck3, "Eckert III") "\n\tPCyl, Sph";
10		PROJ_HEAD(putp1, "Putnins P1") "\n\tPCyl, Sph";
11		PROJ_HEAD(wag6, "Wagner VI") "\n\tPCyl, Sph";
12		PROJ_HEAD(kav7, "Kavrayskiy VII") "\n\tPCyl, Sph";
13
14		namespace { // anonymous namespace
15		struct pj_opaque {
16		double C_x, C_y, A, B;
17		};
18		} // anonymous namespace
19
20	20.0k	static PJ_XY eck3_s_forward(PJ_LP lp, PJ P) { / Spheroidal, forward */
21	20.0k	PJ_XY xy = {0.0, 0.0};
22	20.0k	struct pj_opaque Q = static_cast<struct pj_opaque >(P->opaque);
23
24	20.0k	xy.y = Q->C_y * lp.phi;
25	20.0k	xy.x = Q->C_x * lp.lam * (Q->A + asqrt(1. - Q->B * lp.phi * lp.phi));
26	20.0k	return xy;
27	20.0k	}
28
29	0	static PJ_LP eck3_s_inverse(PJ_XY xy, PJ P) { / Spheroidal, inverse */
30	0	PJ_LP lp = {0.0, 0.0};
31	0	struct pj_opaque Q = static_cast<struct pj_opaque >(P->opaque);
32	0	double denominator;
33
34	0	lp.phi = xy.y / Q->C_y;
35	0	denominator = (Q->C_x * (Q->A + asqrt(1. - Q->B * lp.phi * lp.phi)));
36	0	if (denominator == 0.0)
37	0	lp.lam = HUGE_VAL;
38	0	else
39	0	lp.lam = xy.x / denominator;
40	0	return lp;
41	0	}
42
43	445	static PJ setup(PJ P) {
44	445	P->es = 0.;
45	445	P->inv = eck3_s_inverse;
46	445	P->fwd = eck3_s_forward;
47	445	return P;
48	445	}
49
50	12	PJ *PJ_PROJECTION(eck3) {
51	12	struct pj_opaque *Q =
52	12	static_cast<struct pj_opaque *>(calloc(1, sizeof(struct pj_opaque)));
53	12	if (nullptr == Q)
54	0	return pj_default_destructor(P, PROJ_ERR_OTHER /ENOMEM/);
55	12	P->opaque = Q;
56
57	12	Q->C_x = 0.42223820031577120149;
58	12	Q->C_y = 0.84447640063154240298;
59	12	Q->A = 1.0;
60	12	Q->B = 0.4052847345693510857755;
61
62	12	return setup(P);
63	12	}
64
65	71	PJ *PJ_PROJECTION(kav7) {
66	71	struct pj_opaque *Q =
67	71	static_cast<struct pj_opaque *>(calloc(1, sizeof(struct pj_opaque)));
68	71	if (nullptr == Q)
69	0	return pj_default_destructor(P, PROJ_ERR_OTHER /ENOMEM/);
70	71	P->opaque = Q;
71
72		/* Defined twice in original code - Using 0.866...,
73		* but leaving the other one here as a safety measure.
74		* Q->C_x = 0.2632401569273184856851; */
75	71	Q->C_x = 0.8660254037844;
76	71	Q->C_y = 1.;
77	71	Q->A = 0.;
78	71	Q->B = 0.30396355092701331433;
79
80	71	return setup(P);
81	71	}
82
83	348	PJ *PJ_PROJECTION(wag6) {
84	348	struct pj_opaque *Q =
85	348	static_cast<struct pj_opaque *>(calloc(1, sizeof(struct pj_opaque)));
86	348	if (nullptr == Q)
87	0	return pj_default_destructor(P, PROJ_ERR_OTHER /ENOMEM/);
88	348	P->opaque = Q;
89
90	348	Q->C_x = 1.0;
91	348	Q->C_y = 1.0;
92	348	Q->A = 0.0;
93	348	Q->B = 0.30396355092701331433;
94
95	348	return setup(P);
96	348	}
97
98	14	PJ *PJ_PROJECTION(putp1) {
99	14	struct pj_opaque *Q =
100	14	static_cast<struct pj_opaque *>(calloc(1, sizeof(struct pj_opaque)));
101	14	if (nullptr == Q)
102	0	return pj_default_destructor(P, PROJ_ERR_OTHER /ENOMEM/);
103	14	P->opaque = Q;
104
105	14	Q->C_x = 1.89490;
106	14	Q->C_y = 0.94745;
107	14	Q->A = -0.5;
108	14	Q->B = 0.30396355092701331433;
109
110	14	return setup(P);
111	14	}