Files
openlayers/src/ol/projection.js
Tim Schaub 48e69f7559 Unused var
2013-02-25 10:36:21 -07:00

580 lines
15 KiB
JavaScript

goog.provide('ol.Projection');
goog.provide('ol.ProjectionUnits');
goog.require('goog.array');
goog.require('goog.asserts');
goog.require('goog.object');
goog.require('ol.Coordinate');
goog.require('ol.Extent');
goog.require('ol.TransformFunction');
/**
* @define {boolean} Enable Proj4js.
*/
ol.ENABLE_PROJ4JS = true;
/**
* @const {boolean} Have Proj4js.
*/
ol.HAVE_PROJ4JS = ol.ENABLE_PROJ4JS && typeof Proj4js == 'object';
/**
* @enum {string}
*/
ol.ProjectionUnits = {
DEGREES: 'degrees',
METERS: 'm'
};
/**
* @constructor
* @param {string} code Code.
* @param {ol.ProjectionUnits} units Units.
* @param {ol.Extent} extent Extent.
* @param {string=} opt_axis Axis order.
*/
ol.Projection = function(code, units, extent, opt_axis) {
/**
* @private
* @type {string}
*/
this.code_ = code;
/**
* @private
* @type {ol.ProjectionUnits}
*/
this.units_ = units;
/**
* @private
* @type {ol.Extent}
*/
this.extent_ = extent;
/**
* @private
* @type {string}
*/
this.axis_ = opt_axis || 'enu';
};
/**
* @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_;
};
/**
* @return {string} Axis.
*/
ol.Projection.prototype.getAxis = function() {
return this.axis_;
};
/**
* @constructor
* @extends {ol.Projection}
* @param {string} code Code.
* @param {Proj4js.Proj} proj4jsProj Proj4js projection.
*/
ol.Proj4jsProjection = function(code, proj4jsProj) {
var units = /** @type {ol.ProjectionUnits} */ (proj4jsProj.units);
goog.base(this, code, units, null);
/**
* @private
* @type {Proj4js.Proj}
*/
this.proj4jsProj_ = proj4jsProj;
};
goog.inherits(ol.Proj4jsProjection, ol.Projection);
/**
* @return {Proj4js.Proj} Proj4js projection.
*/
ol.Proj4jsProjection.prototype.getProj4jsProj = function() {
return this.proj4jsProj_;
};
/**
* @private
* @type {Object.<string, ol.Proj4jsProjection>}
*/
ol.Projection.proj4jsProjections_ = {};
/**
* @private
* @type {Object.<string, ol.Projection>}
*/
ol.Projection.projections_ = {};
/**
* @private
* @type {Object.<string, Object.<string, ol.TransformFunction>>}
*/
ol.Projection.transforms_ = {};
/**
* Registers transformation functions that don't alter coordinates. Those allow
* to transform between projections with equal meaning.
*
* @param {Array.<ol.Projection>} projections Projections.
* @private
*/
ol.Projection.addEquivalentProjections_ = function(projections) {
ol.Projection.addProjections(projections);
goog.array.forEach(projections, function(source) {
goog.array.forEach(projections, function(destination) {
if (source !== destination) {
ol.Projection.addTransform(
source, destination, ol.Projection.cloneTransform);
}
});
});
};
/**
* Registers transformation functions to convert coordinates in any projection
* in projection1 to any projection in projection2.
*
* @param {Array.<ol.Projection>} projections1 Projections with equal meaning.
* @param {Array.<ol.Projection>} projections2 Projections with equal meaning.
* @param {ol.TransformFunction} forwardTransform Transformation from any
* projection in projection1 to any projection in projection2.
* @param {ol.TransformFunction} inverseTransform Transform from any projection
* in projection2 to any projection in projection1..
* @private
*/
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.Proj4jsProjection} proj4jsProjection Proj4js projection.
*/
ol.Projection.addProj4jsProjection = function(proj4jsProjection) {
var proj4jsProjections = ol.Projection.proj4jsProjections_;
var code = proj4jsProjection.getCode();
goog.asserts.assert(!goog.object.containsKey(proj4jsProjections, code));
proj4jsProjections[code] = proj4jsProjection;
};
/**
* @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;
ol.Projection.addTransform(
projection, projection, ol.Projection.cloneTransform);
};
/**
* @param {Array.<ol.Projection>} projections Projections.
*/
ol.Projection.addProjections = function(projections) {
goog.array.forEach(projections, function(projection) {
ol.Projection.addProjection(projection);
});
};
/**
* @param {ol.Projection|string|undefined} projection Projection.
* @param {string} defaultCode Default code.
* @return {ol.Projection} Projection.
*/
ol.Projection.createProjection = function(projection, defaultCode) {
if (!goog.isDefAndNotNull(projection)) {
return ol.Projection.getFromCode(defaultCode);
} else if (goog.isString(projection)) {
return ol.Projection.getFromCode(projection);
} else {
goog.asserts.assert(projection instanceof ol.Projection);
return projection;
}
};
/**
* Registers a conversion function to convert coordinates from the source
* projection to the destination projection.
*
* @param {ol.Projection} source Source.
* @param {ol.Projection} destination Destination.
* @param {ol.TransformFunction} transformFn Transform.
*/
ol.Projection.addTransform = function(source, destination, transformFn) {
var sourceCode = source.getCode();
var destinationCode = destination.getCode();
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] = transformFn;
};
/**
* @param {string} code Code which is a combination of authority and identifier
* such as “EPSG:4326”.
* @return {ol.Projection} Projection.
*/
ol.Projection.getFromCode = function(code) {
var projection = ol.Projection.projections_[code];
if (ol.HAVE_PROJ4JS && !goog.isDef(projection)) {
projection = ol.Projection.getProj4jsProjectionFromCode_(code);
}
if (!goog.isDef(projection)) {
goog.asserts.assert(goog.isDef(projection));
projection = null;
}
return projection;
};
/**
* @param {string} code Code.
* @private
* @return {ol.Proj4jsProjection} Proj4js projection.
*/
ol.Projection.getProj4jsProjectionFromCode_ = function(code) {
var proj4jsProjections = ol.Projection.proj4jsProjections_;
var proj4jsProjection = proj4jsProjections[code];
if (!goog.isDef(proj4jsProjection)) {
var proj4jsProj = new Proj4js.Proj(code);
proj4jsProjection = new ol.Proj4jsProjection(code, proj4jsProj);
proj4jsProjections[code] = proj4jsProjection;
}
return proj4jsProjection;
};
/**
* Checks if two projections are the same, that is every coordinate in one
* projection does represent the same geographic point as the same coordinate in
* the other projection.
*
* @param {ol.Projection} projection1 Projection 1.
* @param {ol.Projection} projection2 Projection 2.
* @return {boolean} Equivalent.
*/
ol.Projection.equivalent = function(projection1, projection2) {
if (projection1 === projection2) {
return true;
} else if (projection1.getUnits() != projection2.getUnits()) {
return false;
} else {
var transformFn = ol.Projection.getTransform(projection1, projection2);
return transformFn === ol.Projection.cloneTransform;
}
};
/**
* Searches a function that can be used to convert coordinates from the source
* projection to the destination projection.
*
* @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();
var transform;
if (goog.object.containsKey(transforms, sourceCode) &&
goog.object.containsKey(transforms[sourceCode], destinationCode)) {
transform = transforms[sourceCode][destinationCode];
}
if (ol.HAVE_PROJ4JS && !goog.isDef(transform)) {
var proj4jsSource;
if (source instanceof ol.Proj4jsProjection) {
proj4jsSource = source;
} else {
proj4jsSource =
ol.Projection.getProj4jsProjectionFromCode_(source.getCode());
}
var sourceProj4jsProj = proj4jsSource.getProj4jsProj();
var proj4jsDestination;
if (destination instanceof ol.Proj4jsProjection) {
proj4jsDestination = destination;
} else {
proj4jsDestination =
ol.Projection.getProj4jsProjectionFromCode_(destination.getCode());
}
var destinationProj4jsProj = proj4jsDestination.getProj4jsProj();
transform =
/**
* @param {ol.Coordinate} coordinate Coordinate.
* @return {ol.Coordinate} Coordinate.
*/
function(coordinate) {
var proj4jsPoint = new Proj4js.Point(coordinate.x, coordinate.y);
proj4jsPoint = Proj4js.transform(
sourceProj4jsProj, destinationProj4jsProj, proj4jsPoint);
return new ol.Coordinate(proj4jsPoint.x, proj4jsPoint.y);
};
ol.Projection.addTransform(source, destination, transform);
}
if (!goog.isDef(transform)) {
goog.asserts.assert(goog.isDef(transform));
transform = ol.Projection.identityTransform;
}
return transform;
};
/**
* Given the projection codes this method searches for a transformation function
* to convert coordinate from the source projection to the destination
* projection.
*
* @param {string} sourceCode Source code.
* @param {string} destinationCode Destination code.
* @return {ol.TransformFunction} Transform.
*/
ol.Projection.getTransformFromCodes = function(sourceCode, destinationCode) {
var source = ol.Projection.getFromCode(sourceCode);
var destination = ol.Projection.getFromCode(destinationCode);
return ol.Projection.getTransform(source, destination);
};
/**
* @param {ol.Coordinate} point Point.
* @return {ol.Coordinate} Unaltered point (same reference).
*/
ol.Projection.identityTransform = function(point) {
return point;
};
/**
* @param {ol.Coordinate} point Point.
* @return {ol.Coordinate} Equal point (different reference).
*/
ol.Projection.cloneTransform = function(point) {
return new ol.Coordinate(point.x, point.y);
};
/**
* Transforms the given point to the destination projection.
*
* @param {ol.Coordinate} point Point.
* @param {ol.Projection} source Source.
* @param {ol.Projection} destination Destination.
* @return {ol.Coordinate} Point.
*/
ol.Projection.transform = function(point, source, destination) {
var transformFn = ol.Projection.getTransform(source, destination);
return transformFn(point);
};
/**
* @param {ol.Coordinate} point Point.
* @param {string} sourceCode Source code.
* @param {string} destinationCode Destination code.
* @return {ol.Coordinate} Point.
*/
ol.Projection.transformWithCodes =
function(point, sourceCode, destinationCode) {
var transformFn = ol.Projection.getTransformFromCodes(
sourceCode, destinationCode);
return transformFn(point);
};
/**
* @const
* @type {number}
*/
ol.Projection.EPSG_3857_RADIUS = 6378137;
/**
* Transformation from EPSG:4326 to EPSG:3857.
*
* @param {ol.Coordinate} point Point.
* @return {ol.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 ol.Coordinate(x, y);
};
/**
* Transformation from EPSG:3857 to EPSG:4326.
*
* @param {ol.Coordinate} point Point.
* @return {ol.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 ol.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);
/**
* Lists several projection codes with the same meaning as EPSG:3857.
*
* @private
* @type {Array.<string>}
*/
ol.Projection.EPSG_3857_LIKE_CODES_ = [
'EPSG:3857',
'EPSG:102100',
'EPSG:102113',
'EPSG:900913'
];
/**
* Projections equal to EPSG:3857.
*
* @const
* @private
* @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);
});
/**
* Extent of the EPSG:4326 projection which is the whole world.
*
* @const
* @private
* @type {ol.Extent}
*/
ol.Projection.EPSG_4326_EXTENT_ = new ol.Extent(-180, -90, 180, 90);
/**
* Several projection code with the same meaning as EPSG:4326.
* @private
* @type {Array.<string>}
*/
ol.Projection.EPSG_4326_LIKE_CODES_ = [
'CRS:84',
'urn:ogc:def:crs:OGC:1.3:CRS84',
'EPSG:4326',
'urn:ogc:def:crs:EPSG:6.6:4326'
];
/**
* Projections equal to EPSG: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_,
code === 'CRS:84' || code === 'urn:ogc:def:crs:OGC:1.3:CRS84' ?
'enu' : 'neu');
});
// Add transformations that don't alter coordinates to convert within set of
// projections with equal meaning.
ol.Projection.addEquivalentProjections_(
ol.Projection.EPSG_3857_LIKE_PROJECTIONS_);
ol.Projection.addEquivalentProjections_(
ol.Projection.EPSG_4326_LIKE_PROJECTIONS);
// Add transformations to convert EPSG:4326 like coordinates to EPSG:3857 like
// coordinates and back.
ol.Projection.addEquivalentTransforms_(
ol.Projection.EPSG_4326_LIKE_PROJECTIONS,
ol.Projection.EPSG_3857_LIKE_PROJECTIONS_,
ol.Projection.forwardSphericalMercator,
ol.Projection.inverseSphericalMercator);