svn-gvsig-desktop / trunk / libraries / libjni-proj4 / src / pj_datum_set.c @ 21615
History | View | Annotate | Download (5.79 KB)
1 |
/******************************************************************************
|
---|---|
2 |
* $Id: pj_datum_set.c,v 1.2 2001/04/04 21:13:21 warmerda Exp $
|
3 |
*
|
4 |
* Project: PROJ.4
|
5 |
* Purpose: Apply datum definition to PJ structure from initialization string.
|
6 |
* Author: Frank Warmerdam, warmerda@home.com
|
7 |
*
|
8 |
******************************************************************************
|
9 |
* Copyright (c) 2000, Frank Warmerdam
|
10 |
*
|
11 |
* Permission is hereby granted, free of charge, to any person obtaining a
|
12 |
* copy of this software and associated documentation files (the "Software"),
|
13 |
* to deal in the Software without restriction, including without limitation
|
14 |
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
15 |
* and/or sell copies of the Software, and to permit persons to whom the
|
16 |
* Software is furnished to do so, subject to the following conditions:
|
17 |
*
|
18 |
* The above copyright notice and this permission notice shall be included
|
19 |
* in all copies or substantial portions of the Software.
|
20 |
*
|
21 |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
22 |
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
23 |
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
24 |
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
25 |
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
26 |
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
27 |
* DEALINGS IN THE SOFTWARE.
|
28 |
******************************************************************************
|
29 |
*
|
30 |
* $Log: pj_datum_set.c,v $
|
31 |
* Revision 1.2 2001/04/04 21:13:21 warmerda
|
32 |
* do arcsecond/radian and ppm datum parm transformation in pj_set_datum()
|
33 |
*
|
34 |
* Revision 1.1 2000/07/06 23:32:27 warmerda
|
35 |
* New
|
36 |
*
|
37 |
*/
|
38 |
|
39 |
#include <projects.h> |
40 |
#include <string.h> |
41 |
|
42 |
/* SEC_TO_RAD = Pi/180/3600 */
|
43 |
#define SEC_TO_RAD 4.84813681109535993589914102357e-6 |
44 |
|
45 |
/************************************************************************/
|
46 |
/* pj_datum_set() */
|
47 |
/************************************************************************/
|
48 |
|
49 |
int pj_datum_set(paralist *pl, PJ *projdef)
|
50 |
|
51 |
{ |
52 |
const char *name, *towgs84, *nadgrids; |
53 |
|
54 |
projdef->datum_type = PJD_UNKNOWN; |
55 |
|
56 |
/* -------------------------------------------------------------------- */
|
57 |
/* Is there a datum definition in the parameters list? If so, */
|
58 |
/* add the defining values to the parameter list. Note that */
|
59 |
/* this will append the ellipse definition as well as the */
|
60 |
/* towgs84= and related parameters. It should also be pointed */
|
61 |
/* out that the addition is permanent rather than temporary */
|
62 |
/* like most other keyword expansion so that the ellipse */
|
63 |
/* definition will last into the pj_ell_set() function called */
|
64 |
/* after this one. */
|
65 |
/* -------------------------------------------------------------------- */
|
66 |
if( (name = pj_param(pl,"sdatum").s) != NULL ) |
67 |
{ |
68 |
paralist *curr; |
69 |
const char *s; |
70 |
int i;
|
71 |
|
72 |
/* find the end of the list, so we can add to it */
|
73 |
for (curr = pl; curr && curr->next ; curr = curr->next) {}
|
74 |
|
75 |
/* find the datum definition */
|
76 |
for (i = 0; (s = pj_datums[i].id) && strcmp(name, s) ; ++i) {} |
77 |
|
78 |
if (!s) { pj_errno = -9; return 1; } |
79 |
|
80 |
if( pj_datums[i].ellipse_id && strlen(pj_datums[i].ellipse_id) > 0 ) |
81 |
{ |
82 |
char entry[100]; |
83 |
|
84 |
strcpy( entry, "ellps=" );
|
85 |
strncat( entry, pj_datums[i].ellipse_id, 80 );
|
86 |
curr = curr->next = pj_mkparam(entry); |
87 |
} |
88 |
|
89 |
if( pj_datums[i].defn && strlen(pj_datums[i].defn) > 0 ) |
90 |
curr = curr->next = pj_mkparam(pj_datums[i].defn); |
91 |
} |
92 |
|
93 |
/* -------------------------------------------------------------------- */
|
94 |
/* Check for nadgrids parameter. */
|
95 |
/* -------------------------------------------------------------------- */
|
96 |
if( (nadgrids = pj_param(pl,"snadgrids").s) != NULL ) |
97 |
{ |
98 |
/* We don't actually save the value separately. It will continue
|
99 |
to exist int he param list for use in pj_apply_gridshift.c */
|
100 |
|
101 |
projdef->datum_type = PJD_GRIDSHIFT; |
102 |
} |
103 |
|
104 |
/* -------------------------------------------------------------------- */
|
105 |
/* Check for towgs84 parameter. */
|
106 |
/* -------------------------------------------------------------------- */
|
107 |
else if( (towgs84 = pj_param(pl,"stowgs84").s) != NULL ) |
108 |
{ |
109 |
int parm_count = 0; |
110 |
const char *s; |
111 |
|
112 |
memset( projdef->datum_params, 0, sizeof(double) * 7); |
113 |
|
114 |
/* parse out the parameters */
|
115 |
s = towgs84; |
116 |
for( s = towgs84; *s != '\0'; ) |
117 |
{ |
118 |
projdef->datum_params[parm_count++] = atof(s); |
119 |
while( *s != '\0' && *s != ',' ) |
120 |
s++; |
121 |
if( *s == ',' ) |
122 |
s++; |
123 |
} |
124 |
|
125 |
if( projdef->datum_params[3] != 0.0 |
126 |
|| projdef->datum_params[4] != 0.0 |
127 |
|| projdef->datum_params[5] != 0.0 |
128 |
|| projdef->datum_params[6] != 0.0 ) |
129 |
{ |
130 |
projdef->datum_type = PJD_7PARAM; |
131 |
|
132 |
/* transform from arc seconds to radians */
|
133 |
projdef->datum_params[3] *= SEC_TO_RAD;
|
134 |
projdef->datum_params[4] *= SEC_TO_RAD;
|
135 |
projdef->datum_params[5] *= SEC_TO_RAD;
|
136 |
/* transform from parts per million to scaling factor */
|
137 |
projdef->datum_params[6] =
|
138 |
(projdef->datum_params[6]/1000000.0) + 1; |
139 |
} |
140 |
else
|
141 |
projdef->datum_type = PJD_3PARAM; |
142 |
|
143 |
/* Note that pj_init() will later switch datum_type to
|
144 |
PJD_WGS84 if shifts are all zero, and ellipsoid is WGS84 or GRS80 */
|
145 |
} |
146 |
|
147 |
return 0; |
148 |
} |