/Proj4/pj_datum_set.c
C | 161 lines | 67 code | 22 blank | 72 comment | 35 complexity | 9c2b9a913d70034e3c20e30cd9fca7e0 MD5 | raw file
1/****************************************************************************** 2 * $Id: pj_datum_set.c,v 1.4 2007/11/29 21:06:50 fwarmerdam 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 1.4 2007/11/29 21:06:50 fwarmerdam 32 * make sure we only look for 7 parameters 33 * 34 * Revision 1.3 2007/01/31 06:41:01 fwarmerdam 35 * dont parse more datum parameters than we have room for in datum_params[] 36 * 37 * Revision 1.2 2001/04/04 21:13:21 warmerda 38 * do arcsecond/radian and ppm datum parm transformation in pj_set_datum() 39 * 40 * Revision 1.1 2000/07/06 23:32:27 warmerda 41 * New 42 * 43 */ 44 45#include "projects.h" 46#include <string.h> 47 48/* SEC_TO_RAD = Pi/180/3600 */ 49#define SEC_TO_RAD 4.84813681109535993589914102357e-6 50 51/************************************************************************/ 52/* pj_datum_set() */ 53/************************************************************************/ 54 55int pj_datum_set(paralist *pl, PJ *projdef) 56 57{ 58 const char *name, *towgs84; 59 60 projdef->datum_type = PJD_UNKNOWN; 61 62/* -------------------------------------------------------------------- */ 63/* Is there a datum definition in the parameters list? If so, */ 64/* add the defining values to the parameter list. Note that */ 65/* this will append the ellipse definition as well as the */ 66/* towgs84= and related parameters. It should also be pointed */ 67/* out that the addition is permanent rather than temporary */ 68/* like most other keyword expansion so that the ellipse */ 69/* definition will last into the pj_ell_set() function called */ 70/* after this one. */ 71/* -------------------------------------------------------------------- */ 72 name = pj_param(pl,"sdatum").s; 73 if( name != NULL ) 74 { 75 paralist *curr; 76 const char *s; 77 int i; 78 79 /* find the end of the list, so we can add to it */ 80 for (curr = pl; curr && curr->next ; curr = curr->next) {} 81 82 /* find the datum definition */ 83 for (i = 0; (s = pj_datums[i].id) && strcmp(name, s) ; ++i) {} 84 85 if (!s) { pj_errno = -9; return 1; } 86 87 if( pj_datums[i].ellipse_id && strlen(pj_datums[i].ellipse_id) > 0 ) 88 { 89 char entry[100]; 90 91 strcpy( entry, "ellps=" ); 92 strncat( entry, pj_datums[i].ellipse_id, 80 ); 93 if (curr) 94 { 95 curr->next = pj_mkparam(entry); 96 curr = curr->next; 97 } 98 } 99 100 if( pj_datums[i].defn && strlen(pj_datums[i].defn) > 0 ) 101 { 102 if (curr) 103 curr->next = pj_mkparam(pj_datums[i].defn); 104 } 105 } 106 107/* -------------------------------------------------------------------- */ 108/* Check for nadgrids parameter. */ 109/* -------------------------------------------------------------------- */ 110 if( pj_param(pl,"snadgrids").s != NULL ) 111 { 112 /* We don't actually save the value separately. It will continue 113 to exist int he param list for use in pj_apply_gridshift.c */ 114 115 projdef->datum_type = PJD_GRIDSHIFT; 116 } 117 118/* -------------------------------------------------------------------- */ 119/* Check for towgs84 parameter. */ 120/* -------------------------------------------------------------------- */ 121 else if( (towgs84 = pj_param(pl,"stowgs84").s) != NULL ) 122 { 123 int parm_count = 0; 124 const char *s; 125 126 memset( projdef->datum_params, 0, sizeof(double) * 7); 127 128 /* parse out the parameters */ 129 for( s = towgs84; *s != '\0' && parm_count < 7; ) 130 { 131 projdef->datum_params[parm_count++] = atof(s); 132 while( *s != '\0' && *s != ',' ) 133 s++; 134 if( *s == ',' ) 135 s++; 136 } 137 138 if( projdef->datum_params[3] != 0.0 139 || projdef->datum_params[4] != 0.0 140 || projdef->datum_params[5] != 0.0 141 || projdef->datum_params[6] != 0.0 ) 142 { 143 projdef->datum_type = PJD_7PARAM; 144 145 /* transform from arc seconds to radians */ 146 projdef->datum_params[3] *= SEC_TO_RAD; 147 projdef->datum_params[4] *= SEC_TO_RAD; 148 projdef->datum_params[5] *= SEC_TO_RAD; 149 /* transform from parts per million to scaling factor */ 150 projdef->datum_params[6] = 151 (projdef->datum_params[6]/1000000.0) + 1; 152 } 153 else 154 projdef->datum_type = PJD_3PARAM; 155 156 /* Note that pj_init() will later switch datum_type to 157 PJD_WGS84 if shifts are all zero, and ellipsoid is WGS84 or GRS80 */ 158 } 159 160 return 0; 161}