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
|
/*
** 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_LIB__
#include <lib_proj.h>
#define MAX_ITER 20
struct GAUSS {
double C;
double K;
double e;
double ratexp;
};
#define EN ((struct GAUSS *)en)
#define DEL_TOL 1e-14
static double
srat(double esinp, double expval) {
return(pow((1.-esinp)/(1.+esinp), expval));
}
void *
proj_gauss_ini(double e, double phi0, double *chi, double *rc) {
double sphi, cphi, es;
struct GAUSS *en;
if ((en = (struct GAUSS *)malloc(sizeof(struct GAUSS))) == NULL)
return (NULL);
es = e * e;
EN->e = e;
sphi = sin(phi0);
cphi = cos(phi0); cphi *= cphi;
*rc = sqrt(1. - es) / (1. - es * sphi * sphi);
EN->C = sqrt(1. + es * cphi * cphi / (1. - es));
*chi = asin(sphi / EN->C);
EN->ratexp = 0.5 * EN->C * e;
EN->K = tan(.5 * *chi + FORTPI) / (
pow(tan(.5 * phi0 + FORTPI), EN->C) *
srat(EN->e * sphi, EN->ratexp) );
return ((void *)en);
}
PROJ_LP
proj_gauss(PROJ_LP elp, const void *en) {
PROJ_LP slp;
slp.phi = 2. * atan( EN->K *
pow(tan(.5 * elp.phi + FORTPI), EN->C) *
srat(EN->e * sin(elp.phi), EN->ratexp) ) - HALFPI;
slp.lam = EN->C * (elp.lam);
return(slp);
}
PROJ_LP
proj_inv_gauss(PROJ_LP slp, const void *en) {
PROJ_LP elp;
double num;
int i;
elp.lam = slp.lam / EN->C;
num = pow(tan(.5 * slp.phi + FORTPI)/EN->K, 1./EN->C);
for (i = MAX_ITER; i; --i) {
elp.phi = 2. * atan(num * srat(EN->e * sin(slp.phi), -.5 * EN->e))
- HALFPI;
if (fabs(elp.phi - slp.phi) < DEL_TOL) break;
slp.phi = elp.phi;
}
/* convergence failed */
if (!i)
proj_errno = -17;
return (elp);
}
/* Revision Log:
** Log: proj_gauss.c
** Revision 1.1 2008-11-07 16:41:14 jeff
** ENH: Adding a 2D geoview. Adding the geographic projection library libproj4
** to Utilities. Updating the architecture of the geospatial views. All
** multi-resolution sources are now subclasses of vtkGeoSource. Each source
** has its own worker thread for fetching refined images or geometry.
** On the 3D side, vtkGeoGlobeSource is an appropriate source for vtkGeoTerrain,
** and vtkGeoAlignedImageSource is an appropriate source for
** vtkGeoAlignedImageRepresentation. On the 2D side, vtkGeoProjectionSource is an
** appropriate source for vtkGeoTerrain2D, and the image source is the same.
**
** Revision 3.1 2006/01/11 01:38:18 gie
** Initial
**
*/
|
