1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
/*
** libproj -- library of cartographic projections
**
** Copyright (c) 2003, 2006 Gerald I. Evenden
*/
static const char
LIBPROJ_ID[] = "Id";
/*
** 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 PROJ_PARMS__ \
double sinph0; \
double cosph0; \
int mode;
#define PROJ_LIB__
#include <lib_proj.h>
PROJ_HEAD(ortho, "Orthographic") "\n\tAzi, Sph.";
#define EPS10 1.e-10
#define N_POLE 0
#define S_POLE 1
#define EQUIT 2
#define OBLIQ 3
FORWARD(s_forward); /* spheroid */
double coslam, cosphi, sinphi;
cosphi = cos(lp.phi);
coslam = cos(lp.lam);
switch (P->mode) {
case EQUIT:
if (cosphi * coslam < - EPS10 ||
fabs(lp.lam) - HALFPI > EPS10) F_ERROR;
xy.y = sin(lp.phi);
break;
case OBLIQ:
if (P->sinph0 * (sinphi = sin(lp.phi)) +
P->cosph0 * cosphi * coslam < - EPS10) F_ERROR;
xy.y = P->cosph0 * sinphi - P->sinph0 * cosphi * coslam;
break;
case N_POLE:
coslam = - coslam;
case S_POLE:
if (fabs(lp.phi - P->phi0) - EPS10 > HALFPI) F_ERROR;
xy.y = cosphi * coslam;
break;
}
xy.x = cosphi * sin(lp.lam);
return (xy);
}
INVERSE(s_inverse); /* spheroid */
double rh, cosc, sinc;
if ((sinc = (rh = hypot(xy.x, xy.y))) > 1.) {
if ((sinc - 1.) > EPS10) I_ERROR;
sinc = 1.;
}
cosc = sqrt(1. - sinc * sinc); /* in this range OK */
if (fabs(rh) <= EPS10) {
lp.phi = P->phi0;
lp.lam = 0.;
} else {
switch (P->mode) {
case N_POLE:
xy.y = -xy.y;
lp.phi = acos(sinc);
break;
case S_POLE:
lp.phi = - acos(sinc);
break;
case EQUIT:
lp.phi = xy.y * sinc / rh;
xy.x *= sinc;
xy.y = cosc * rh;
goto sinchk;
case OBLIQ:
lp.phi = cosc * P->sinph0 + xy.y * sinc * P->cosph0 / rh;
xy.y = (cosc - P->sinph0 * lp.phi) * rh;
xy.x *= sinc * P->cosph0;
sinchk:
if (fabs(lp.phi) >= 1.)
lp.phi = lp.phi < 0. ? -HALFPI : HALFPI;
else
lp.phi = asin(lp.phi);
break;
}
lp.lam = (xy.y == 0. && (P->mode == OBLIQ || P->mode == EQUIT)) ?
(xy.x == 0. ? 0. : xy.x < 0. ? -HALFPI : HALFPI) :
atan2(xy.x, xy.y);
}
return (lp);
}
FREEUP; if (P) free(P); }
ENTRY0(ortho)
if (fabs(fabs(P->phi0) - HALFPI) <= EPS10)
P->mode = P->phi0 < 0. ? S_POLE : N_POLE;
else if (fabs(P->phi0) > EPS10) {
P->mode = OBLIQ;
P->sinph0 = sin(P->phi0);
P->cosph0 = cos(P->phi0);
} else
P->mode = EQUIT;
P->inv = s_inverse;
P->fwd = s_forward;
P->es = 0.;
ENDENTRY(P)
/*
** Log: proj_ortho.c
** Revision 3.1 2006/01/11 01:38:18 gie
** Initial
**
*/
|
