/usr/lib/nodejs/srs/srs.js is in node-srs 0.3.2+ds1-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 | var path = require('path');
var fs = require('fs');
var srs = require('./_srs');
var exists = require('fs').existsSync || require('path').existsSync;
if (exists('./settings.js')) {
var _settings = require('./settings');
}
exports.version = require('./package').version;
/*
This is a custom srs definition for
spherical mercator that we make
canonical because no single variant
of the projection stored by various
applications is optimal.
This is basically a modification of gdal's
understanding of epsg 3857
Changes:
* add +over and +wktext to proj4 string
* remove any double spaces in proj4 string
* epsg is 3857, the new official epsg for 900913
* name is pulled from gdal/data/cubwerx_extra.wkt for 900913
instead of using 'WGS 84 / Pseudo-Mercator' or 'Popular...'
TODO:
* +x_0=0.0 vs +x_0=0 (same with +y_0)
* handle two scaling aliases +k and +k_0
* meaning of +k=1. vs +k=1.0 ?
*/
var merc_pretty_wkt = 'PROJCS["WGS 84 / Pseudo-Mercator",\n GEOGCS["WGS 84",\n DATUM["WGS_1984",\n SPHEROID["WGS 84",6378137,298.257223563,\n AUTHORITY["EPSG","7030"]],\n AUTHORITY["EPSG","6326"]],\n PRIMEM["Greenwich",0,\n AUTHORITY["EPSG","8901"]],\n UNIT["degree",0.0174532925199433,\n AUTHORITY["EPSG","9122"]],\n AUTHORITY["EPSG","4326"]],\n UNIT["metre",1,\n AUTHORITY["EPSG","9001"]],\n PROJECTION["Mercator_1SP"],\n PARAMETER["central_meridian",0],\n PARAMETER["scale_factor",1],\n PARAMETER["false_easting",0],\n PARAMETER["false_northing",0],\n EXTENSION["PROJ4","+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over"],\n AUTHORITY["EPSG","3857"],\n AXIS["X",EAST],\n AXIS["Y",NORTH]]';
var lon_lat_pretty_wkt = 'GEOGCS["WGS 84",\n DATUM["WGS_1984",\n SPHEROID["WGS 84",6378137,298.257223563,\n AUTHORITY["EPSG","7030"]],\n TOWGS84[0,0,0,0,0,0,0],\n AUTHORITY["EPSG","6326"]],\n PRIMEM["Greenwich",0,\n AUTHORITY["EPSG","8901"]],\n UNIT["degree",0.0174532925199433,\n AUTHORITY["EPSG","9108"]],\n AUTHORITY["EPSG","4326"]]';
var canonical = {
spherical_mercator: {
proj4: '+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over',
srid: 3857, // or 900913
auth: 'EPSG',
pretty_wkt: merc_pretty_wkt,
esri: false,
name: 'Google Maps Global Mercator', // so many variants here
valid: true,
is_geographic: false
},
wgs_84: {
proj4: '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs',
srid: 4326,
auth: 'EPSG',
pretty_wkt: lon_lat_pretty_wkt,
esri: false,
name: 'WGS 84',
valid: true,
is_geographic: true
}
};
function oc(a) {
var o = {};
for (var i = 0; i < a.length; i++) {
o[a[i]] = '';
}
return o;
}
var merc_names = [
'Google_Maps_Global_Mercator',
'Google Maps Global Mercator',
'WGS 84 / Pseudo-Mercator', // 3857
'WGS_84_Pseudo_Mercator', // 3857 with new gdal/ogr name as per https://github.com/springmeyer/node-srs/issues/27
'Popular Visualisation CRS / Mercator', // 3785
'WGS_1984_Web_Mercator', // ESRI
'WGS_1984_Web_Mercator_Auxiliary_Sphere', // ESRI
'Popular_Visualisation_CRS_Mercator_deprecated', // wtf
'Mercator_1SP',
'Mercator_2SP'
];
var merc_srids = [
900913, // http://crschmidt.net/blog/archives/243/google-projection-900913/
3857, // epsg official, second try
3785, // epsg deprecated, failed first try
102100, // esri official, second try
102113, // esri deprecated, failed first try
41001 //osgeo
];
// commonly confused as spherical mercator, but not, right?
// here only for reference currently, nothing done programmatically
var other_merc_srids = [
3395, // "WGS 84 / World Mercator" or normal, no googlized mercator: lacked +a=6378137 +b=6378137
3587, // common typo but actually NAD83(NSRS2007) / Michigan Central
// for these see also notes in shapefile.3857.test.js
9804, // older, esri style-named traditional merc: http://www.remotesensing.org/geotiff/proj_list/mercator_1sp.html
9805, // older, esri style-named traditional merc: http://www.remotesensing.org/geotiff/proj_list/mercator_2sp.html
]
var known_esri_variant_special_cases = [
['DATUM["D_OSGB_1936"','DATUM["OSGB_1936"']
];
/*
if we have statically linked libosr then we need
to set the GDAL_DATA directory so that the bundled
.csv and .wkt files are found.
*/
if (_settings && _settings.static_osr) {
process.env.GDAL_DATA = path.join(__dirname, 'srs_data');
}
var force_merc = function(result) {
var new_merc = canonical.spherical_mercator;
new_merc.input = result.input;
return new_merc;
};
var split_proj = function(literal) {
var parts = literal.split(' ');
// remove blank parts due to double spaces (common in proj epsg table)
var len = parts.length;
for (i = 0; i < len; i++) {
if (parts[i] === '') {
parts.splice(i, 1);
}
}
// break into key=value pairs, discarding +modifiers without values
var pairs = {};
parts.sort();
var new_len = parts.length;
for (i = 0; i < new_len; i++) {
var p = parts[i];
if (p.indexOf('=') != -1) {
var pair = p.split('=');
if (pair[1] && pair[1] === '0') {
// https://github.com/mapbox/tilemill/issues/1866
pair[1] = '0.0'
}
pairs[pair[0]] = pair[1];
}
}
return pairs;
};
var canonical_parts = split_proj(canonical.spherical_mercator.proj4);
var canonical_stringify = JSON.stringify(canonical_parts);
var parse = function(arg) {
if (arg instanceof Buffer) {
arg = arg.toString();
}
if (exists(arg)) {
var extension = path.extname(arg).toLowerCase();
var is_json = false;
if (extension == '.json' || extension == '.geojson') {
is_json = true;
}
var file_data = fs.readFileSync(arg);
if (!is_json) {
if (file_data[0] == '{') {
is_json = true;
} else {
var fstring = file_data.toString();
if (
((fstring.search('"type"') > -1) && (fstring.search('"coordinates"') > -1))
|| (fstring.search('"FeatureCollection"') > -1)
|| ((fstring.search('"geometryType"') > -1) && (fstring.search('"esriGeometry"') > -1))
)
{
is_json = true;
}
}
}
if (is_json) {
var file = JSON.parse(file_data);
if (file.crs && file.crs.properties && file.crs.properties.urn) {
arg = file.crs.properties.urn;
} else if (file.crs && file.crs.properties && file.crs.properties.name) {
arg = file.crs.properties.name;
} else {
arg = '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs';
}
}
}
// early check for known +init=epsg: syntax, which we will
// translate to +proj literal to avoid requiring proj4 to do that in mapnik
var arg_lower = arg.toLowerCase();
if (arg_lower.indexOf('+init=') > -1) {
var parts = arg_lower.split(':');
if (parts[1]) {
var code = +parts[1];
if (merc_srids.indexOf(code) > -1) {
return force_merc({input:arg});
}
}
}
for (var hack in known_esri_variant_special_cases) {
var obj = known_esri_variant_special_cases[hack];
if (arg.indexOf(obj[0]) > -1) {
arg = arg.replace(obj[0],obj[1]);
}
}
var result;
try {
result = srs._parse(arg);
} catch (e) {
if (arg.indexOf('ESRI::') !== 0) {
result = srs._parse('ESRI::' + arg);
} else {
throw e;
}
}
// detect mercator variants and
// replace with canonical.spherical_mercator
if (result.name in oc(merc_names)) {
// this should be a fast track for many .prj files
return force_merc(result);
} else if (result.srid in oc(merc_srids)) {
return force_merc(result);
} else if (result.proj4 !== undefined && result.proj4.indexOf('+proj=merc') != -1) {
// catch case of gdal's translation to proj4 being used as input
if (result.proj4 === '+proj=merc +lon_0=0 +lat_ts=0 +x_0=0 +y_0=0 +ellps=WGS84 +units=m +no_defs') {
return force_merc(result);
} else if (result.proj4 === '+proj=merc +lon_0=0 +lat_ts=0 +x_0=0 +y_0=0 +a=6378137 +b=6378137 +units=m +no_defs') {
return force_merc(result);
}
// break into parts
// TODO - sort and remove less critical pairs
var parts = split_proj(result.proj4);
if (JSON.stringify(parts) === canonical_stringify) {
return force_merc(result);
}
}
// detect OSGB variant and fix the srid
// https://github.com/springmeyer/node-srs/issues/25
if (!result.srid && result.name == 'OSGB 1936 / British National Grid') {
result.srid = 27700;
result.auth = 27700;
}
return result;
};
// push all C++ symbols into js module
for (var k in srs) { exports[k] = srs[k]; }
// make available objects from js
exports.settings = _settings;
exports.canonical = canonical;
exports.split_proj = split_proj;
exports.parse = parse;
|