Files
openlayers/src/ol/projection.js
2012-07-11 17:20:06 +02:00

364 lines
8.7 KiB
JavaScript

goog.provide('ol.Projection');
goog.require('goog.array');
goog.require('goog.asserts');
goog.require('goog.math.Coordinate');
goog.require('goog.object');
goog.require('ol.Extent');
goog.require('ol.TransformFunction');
/**
* @enum {string}
*/
ol.ProjectionUnits = {
DEGREES: 'degrees',
METERS: 'm'
};
/**
* @constructor
* @param {string} code Code.
* @param {ol.ProjectionUnits} units Units.
* @param {ol.Extent} extent Extent.
*/
ol.Projection = function(code, units, extent) {
/**
* @private
* @type {string}
*/
this.code_ = code;
/**
* @private
* @type {ol.ProjectionUnits}
*/
this.units_ = units;
/**
* @private
* @type {ol.Extent}
*/
this.extent_ = extent;
};
/**
* @return {string} Code.
*/
ol.Projection.prototype.getCode = function() {
return this.code_;
};
/**
* @return {ol.Extent} Extent.
*/
ol.Projection.prototype.getExtent = function() {
return this.extent_;
};
/**
* @return {ol.ProjectionUnits} Units.
*/
ol.Projection.prototype.getUnits = function() {
return this.units_;
};
/**
* @private
* @type {Object.<string, ol.Projection>}
*/
ol.Projection.projections_ = {};
/**
* @private
* @type {Object.<string, Object.<string, ol.TransformFunction>>}
*/
ol.Projection.transforms_ = {};
/**
* @param {Array.<ol.Projection>} projections Projections.
*/
ol.Projection.addEquivalentProjections = function(projections) {
ol.Projection.addProjections(projections);
goog.array.forEach(projections, function(source) {
goog.array.forEach(projections, function(destination) {
ol.Projection.addTransform(
source, destination, ol.Projection.identityTransform);
});
});
};
/**
* @param {Array.<ol.Projection>} projections1 Projections.
* @param {Array.<ol.Projection>} projections2 Projections.
* @param {ol.TransformFunction} forwardTransform Forward transform.
* @param {ol.TransformFunction} inverseTransform Inverse transform.
*/
ol.Projection.addEquivalentTransforms =
function(projections1, projections2, forwardTransform, inverseTransform) {
goog.array.forEach(projections1, function(projection1) {
goog.array.forEach(projections2, function(projection2) {
ol.Projection.addTransform(projection1, projection2, forwardTransform);
ol.Projection.addTransform(projection2, projection1, inverseTransform);
});
});
};
/**
* @param {ol.Projection} projection Projection.
*/
ol.Projection.addProjection = function(projection) {
var projections = ol.Projection.projections_;
var code = projection.getCode();
goog.asserts.assert(!goog.object.containsKey(projections, code));
projections[code] = projection;
};
/**
* @param {Array.<ol.Projection>} projections Projections.
*/
ol.Projection.addProjections = function(projections) {
goog.array.forEach(projections, function(projection) {
ol.Projection.addProjection(projection);
});
};
/**
* @param {ol.Projection} source Source.
* @param {ol.Projection} destination Destination.
* @param {ol.TransformFunction} transform Transform.
*/
ol.Projection.addTransform = function(source, destination, transform) {
var projections = ol.Projection.projections_;
var sourceCode = source.getCode();
goog.asserts.assert(goog.object.containsKey(projections, sourceCode));
var destinationCode = destination.getCode();
goog.asserts.assert(goog.object.containsKey(projections, destinationCode));
var transforms = ol.Projection.transforms_;
if (!goog.object.containsKey(transforms, sourceCode)) {
transforms[sourceCode] = {};
}
goog.asserts.assert(
!goog.object.containsKey(transforms[sourceCode], destinationCode));
transforms[sourceCode][destinationCode] = transform;
};
/**
* @param {string} code Code.
* @return {ol.Projection} Projection.
*/
ol.Projection.createFromCode = function(code) {
var projections = ol.Projection.projections_;
goog.asserts.assert(goog.object.containsKey(projections, code));
return projections[code];
};
/**
* @param {ol.Projection} projection1 Projection 1.
* @param {ol.Projection} projection2 Projection 2.
* @return {boolean} Equivalent.
*/
ol.Projection.equivalent = function(projection1, projection2) {
if (projection1.getUnits() != projection2.getUnits()) {
return false;
} else {
var transform = ol.Projection.getTransform(projection1, projection2);
return transform === ol.Projection.identityTransform;
}
};
/**
* @param {ol.Projection} source Source.
* @param {ol.Projection} destination Destination.
* @return {ol.TransformFunction} Transform.
*/
ol.Projection.getTransform = function(source, destination) {
var transforms = ol.Projection.transforms_;
var sourceCode = source.getCode();
var destinationCode = destination.getCode();
goog.asserts.assert(goog.object.containsKey(transforms, sourceCode));
goog.asserts.assert(
goog.object.containsKey(transforms[sourceCode], destinationCode));
return transforms[sourceCode][destinationCode];
};
/**
* @param {string} sourceCode Source code.
* @param {string} destinationCode Destination code.
* @return {ol.TransformFunction} Transform.
*/
ol.Projection.getTransformFromCodes = function(sourceCode, destinationCode) {
var source = ol.Projection.createFromCode(sourceCode);
var destination = ol.Projection.createFromCode(destinationCode);
return ol.Projection.getTransform(source, destination);
};
/**
* @param {goog.math.Coordinate} point Point.
* @return {goog.math.Coordinate} Point.
*/
ol.Projection.identityTransform = function(point) {
return point.clone();
};
/**
* @param {goog.math.Coordinate} point Point.
* @param {ol.Projection} source Source.
* @param {ol.Projection} destination Destination.
* @return {goog.math.Coordinate} Point.
*/
ol.Projection.transform = function(point, source, destination) {
var transform = ol.Projection.getTransform(source, destination);
return transform(point);
};
/**
* @param {goog.math.Coordinate} point Point.
* @param {string} sourceCode Source code.
* @param {string} destinationCode Destination code.
* @return {goog.math.Coordinate} Point.
*/
ol.Projection.transformWithCodes =
function(point, sourceCode, destinationCode) {
var transform = ol.Projection.getTransformFromCodes(
sourceCode, destinationCode);
return transform(point);
};
/**
* @const
* @type {number}
*/
ol.Projection.EPSG_3857_RADIUS = 6378137;
/**
* @param {goog.math.Coordinate} point Point.
* @return {goog.math.Coordinate} Point.
*/
ol.Projection.forwardSphericalMercator = function(point) {
var x = ol.Projection.EPSG_3857_RADIUS * Math.PI * point.x / 180;
var y = ol.Projection.EPSG_3857_RADIUS *
Math.log(Math.tan(Math.PI * (point.y + 90) / 360));
return new goog.math.Coordinate(x, y);
};
/**
* @param {goog.math.Coordinate} point Point.
* @return {goog.math.Coordinate} Point.
*/
ol.Projection.inverseSphericalMercator = function(point) {
var x = 180 * point.x / (ol.Projection.EPSG_3857_RADIUS * Math.PI);
var y = 360 * Math.atan(
Math.exp(point.y / ol.Projection.EPSG_3857_RADIUS)) / Math.PI - 90;
return new goog.math.Coordinate(x, y);
};
/**
* @const
* @type {number}
*/
ol.Projection.EPSG_3857_HALF_SIZE = Math.PI * ol.Projection.EPSG_3857_RADIUS;
/**
* @const
* @type {ol.Extent}
*/
ol.Projection.EPSG_3857_EXTENT = new ol.Extent(
ol.Projection.EPSG_3857_HALF_SIZE,
ol.Projection.EPSG_3857_HALF_SIZE,
-ol.Projection.EPSG_3857_HALF_SIZE,
-ol.Projection.EPSG_3857_HALF_SIZE);
/**
* @type {Array.<string>}
*/
ol.Projection.EPSG_3857_LIKE_CODES = [
'EPSG:3857',
'EPSG:102113',
'EPSG:102100',
'EPSG:900913'
];
/**
* @const
* @type {Array.<ol.Projection>}
*/
ol.Projection.EPSG_3857_LIKE_PROJECTIONS = goog.array.map(
ol.Projection.EPSG_3857_LIKE_CODES,
function(code) {
return new ol.Projection(
code,
ol.ProjectionUnits.METERS,
ol.Projection.EPSG_3857_EXTENT);
});
/**
* @const
* @type {ol.Extent}
*/
ol.Projection.EPSG_4326_EXTENT = new ol.Extent(180, 90, -180, -90);
/**
* @type {Array.<string>}
*/
ol.Projection.EPSG_4326_LIKE_CODES = [
'EPSG:4326',
'CRS:84',
'urn:ogc:def:crs:EPSG:6.6:4326'
];
/**
* @const
* @type {Array.<ol.Projection>}
*/
ol.Projection.EPSG_4326_LIKE_PROJECTIONS = goog.array.map(
ol.Projection.EPSG_4326_LIKE_CODES,
function(code) {
return new ol.Projection(
code,
ol.ProjectionUnits.DEGREES,
ol.Projection.EPSG_4326_EXTENT);
});
ol.Projection.addEquivalentProjections(
ol.Projection.EPSG_3857_LIKE_PROJECTIONS);
ol.Projection.addEquivalentProjections(
ol.Projection.EPSG_4326_LIKE_PROJECTIONS);
ol.Projection.addEquivalentTransforms(
ol.Projection.EPSG_4326_LIKE_PROJECTIONS,
ol.Projection.EPSG_3857_LIKE_PROJECTIONS,
ol.Projection.forwardSphericalMercator,
ol.Projection.inverseSphericalMercator);