goog.provide('ol.proj');
goog.provide('ol.proj.METERS_PER_UNIT');
goog.provide('ol.proj.Projection');
goog.provide('ol.proj.ProjectionLike');
goog.provide('ol.proj.Units');
goog.require('goog.array');
goog.require('goog.asserts');
goog.require('goog.object');
goog.require('ol');
goog.require('ol.Extent');
goog.require('ol.TransformFunction');
goog.require('ol.extent');
goog.require('ol.sphere.NORMAL');
/**
* A projection as {@link ol.proj.Projection}, SRS identifier string or
* undefined.
* @typedef {ol.proj.Projection|string|undefined} ol.proj.ProjectionLike
* @api stable
*/
ol.proj.ProjectionLike;
/**
* Projection units: `'degrees'`, `'ft'`, `'m'` or `'pixels'`.
* @enum {string}
* @api stable
*/
ol.proj.Units = {
DEGREES: 'degrees',
FEET: 'ft',
METERS: 'm',
PIXELS: 'pixels'
};
/**
* Meters per unit lookup table.
* @const
* @type {Object.<ol.proj.Units, number>}
* @api stable
*/
ol.proj.METERS_PER_UNIT = {};
ol.proj.METERS_PER_UNIT[ol.proj.Units.DEGREES] =
2 * Math.PI * ol.sphere.NORMAL.radius / 360;
ol.proj.METERS_PER_UNIT[ol.proj.Units.FEET] = 0.3048;
ol.proj.METERS_PER_UNIT[ol.proj.Units.METERS] = 1;
/**
* @classdesc
* Projection definition class. One of these is created for each projection
* supported in the application and stored in the {@link ol.proj} namespace.
* You can use these in applications, but this is not required, as API params
* and options use {@link ol.proj.ProjectionLike} which means the simple string
* code will suffice.
*
* You can use {@link ol.proj.get} to retrieve the object for a particular
* projection.
*
* The library includes definitions for `EPSG:4326` and `EPSG:3857`, together
* with the following aliases:
* * `EPSG:4326`: CRS:84, urn:ogc:def:crs:EPSG:6.6:4326,
* urn:ogc:def:crs:OGC:1.3:CRS84, urn:ogc:def:crs:OGC:2:84,
* http://www.opengis.net/gml/srs/epsg.xml#4326,
* urn:x-ogc:def:crs:EPSG:4326
* * `EPSG:3857`: EPSG:102100, EPSG:102113, EPSG:900913,
* urn:ogc:def:crs:EPSG:6.18:3:3857,
* http://www.opengis.net/gml/srs/epsg.xml#3857
*
* If you use proj4js, aliases can be added using `proj4.defs()`; see
* [documentation](https://github.com/proj4js/proj4js).
*
* @constructor
* @param {olx.ProjectionOptions} options Projection options.
* @struct
* @api stable
*/
ol.proj.Projection = function(options) {
/**
* @private
* @type {string}
*/
this.code_ = options.code;
/**
* @private
* @type {ol.proj.Units}
*/
this.units_ = /** @type {ol.proj.Units} */ (options.units);
/**
* @private
* @type {ol.Extent}
*/
this.extent_ = goog.isDef(options.extent) ? options.extent : null;
/**
* @private
* @type {ol.Extent}
*/
this.worldExtent_ = goog.isDef(options.worldExtent) ?
options.worldExtent : null;
/**
* @private
* @type {string}
*/
this.axisOrientation_ = goog.isDef(options.axisOrientation) ?
options.axisOrientation : 'enu';
/**
* @private
* @type {boolean}
*/
this.global_ = goog.isDef(options.global) ? options.global : false;
/**
* @private
* @type {ol.tilegrid.TileGrid}
*/
this.defaultTileGrid_ = null;
};
/**
* Get the code for this projection, e.g. 'EPSG:4326'.
* @return {string} Code.
* @api stable
*/
ol.proj.Projection.prototype.getCode = function() {
return this.code_;
};
/**
* Get the validity extent for this projection.
* @return {ol.Extent} Extent.
* @api stable
*/
ol.proj.Projection.prototype.getExtent = function() {
return this.extent_;
};
/**
* Get the units of this projection.
* @return {ol.proj.Units} Units.
* @api stable
*/
ol.proj.Projection.prototype.getUnits = function() {
return this.units_;
};
/**
* Get the amount of meters per unit of this projection. If the projection is
* not configured with a units identifier, the return is `undefined`.
* @return {number|undefined} Meters.
* @api stable
*/
ol.proj.Projection.prototype.getMetersPerUnit = function() {
return ol.proj.METERS_PER_UNIT[this.units_];
};
/**
* Get the world extent for this projection.
* @return {ol.Extent} Extent.
* @api
*/
ol.proj.Projection.prototype.getWorldExtent = function() {
return this.worldExtent_;
};
/**
* Get the axis orientation of this projection.
* Example values are:
* enu - the default easting, northing, elevation.
* neu - northing, easting, up - useful for "lat/long" geographic coordinates,
* or south orientated transverse mercator.
* wnu - westing, northing, up - some planetary coordinate systems have
* "west positive" coordinate systems
* @return {string} Axis orientation.
*/
ol.proj.Projection.prototype.getAxisOrientation = function() {
return this.axisOrientation_;
};
/**
* Is this projection a global projection which spans the whole world?
* @return {boolean} Wether the projection is global.
* @api stable
*/
ol.proj.Projection.prototype.isGlobal = function() {
return this.global_;
};
/**
* @return {ol.tilegrid.TileGrid} The default tile grid.
*/
ol.proj.Projection.prototype.getDefaultTileGrid = function() {
return this.defaultTileGrid_;
};
/**
* @param {ol.tilegrid.TileGrid} tileGrid The default tile grid.
*/
ol.proj.Projection.prototype.setDefaultTileGrid = function(tileGrid) {
this.defaultTileGrid_ = tileGrid;
};
/**
* Set the validity extent for this projection.
* @param {ol.Extent} extent Extent.
* @api stable
*/
ol.proj.Projection.prototype.setExtent = function(extent) {
this.extent_ = extent;
};
/**
* Set the world extent for this projection.
* @param {ol.Extent} worldExtent World extent
* [minlon, minlat, maxlon, maxlat].
* @api
*/
ol.proj.Projection.prototype.setWorldExtent = function(worldExtent) {
this.worldExtent_ = worldExtent;
};
/**
* Get the resolution of the point in degrees. For projections with degrees as
* the unit this will simply return the provided resolution. For other
* projections the point resolution is estimated by transforming the center
* pixel to EPSG:4326, measuring its width and height on the normal sphere,
* and taking the average of the width and height.
* @param {number} resolution Resolution.
* @param {ol.Coordinate} point Point.
* @return {number} Point resolution.
*/
ol.proj.Projection.prototype.getPointResolution = function(resolution, point) {
if (this.getUnits() == ol.proj.Units.DEGREES) {
return resolution;
} else {
// Estimate point resolution by transforming the center pixel to EPSG:4326,
// measuring its width and height on the normal sphere, and taking the
// average of the width and height.
var toEPSG4326 = ol.proj.getTransformFromProjections(
this, ol.proj.get('EPSG:4326'));
var vertices = [
point[0] - resolution / 2, point[1],
point[0] + resolution / 2, point[1],
point[0], point[1] - resolution / 2,
point[0], point[1] + resolution / 2
];
vertices = toEPSG4326(vertices, vertices, 2);
var width = ol.sphere.NORMAL.haversineDistance(
vertices.slice(0, 2), vertices.slice(2, 4));
var height = ol.sphere.NORMAL.haversineDistance(
vertices.slice(4, 6), vertices.slice(6, 8));
var pointResolution = (width + height) / 2;
if (this.getUnits() == ol.proj.Units.FEET) {
// The radius of the normal sphere is defined in meters, so we must
// convert back to feet.
pointResolution /= 0.3048;
}
return pointResolution;
}
};
/**
* @private
* @type {Object.<string, ol.proj.Projection>}
*/
ol.proj.projections_ = {};
/**
* @private
* @type {Object.<string, Object.<string, ol.TransformFunction>>}
*/
ol.proj.transforms_ = {};
/**
* Registers transformation functions that don't alter coordinates. Those allow
* to transform between projections with equal meaning.
*
* @param {Array.<ol.proj.Projection>} projections Projections.
* @api
*/
ol.proj.addEquivalentProjections = function(projections) {
ol.proj.addProjections(projections);
goog.array.forEach(projections, function(source) {
goog.array.forEach(projections, function(destination) {
if (source !== destination) {
ol.proj.addTransform(source, destination, ol.proj.cloneTransform);
}
});
});
};
/**
* Registers transformation functions to convert coordinates in any projection
* in projection1 to any projection in projection2.
*
* @param {Array.<ol.proj.Projection>} projections1 Projections with equal
* meaning.
* @param {Array.<ol.proj.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..
*/
ol.proj.addEquivalentTransforms =
function(projections1, projections2, forwardTransform, inverseTransform) {
goog.array.forEach(projections1, function(projection1) {
goog.array.forEach(projections2, function(projection2) {
ol.proj.addTransform(projection1, projection2, forwardTransform);
ol.proj.addTransform(projection2, projection1, inverseTransform);
});
});
};
/**
* Add a Projection object to the list of supported projections.
*
* @param {ol.proj.Projection} projection Projection instance.
* @api stable
*/
ol.proj.addProjection = function(projection) {
ol.proj.projections_[projection.getCode()] = projection;
ol.proj.addTransform(projection, projection, ol.proj.cloneTransform);
};
/**
* @param {Array.<ol.proj.Projection>} projections Projections.
*/
ol.proj.addProjections = function(projections) {
var addedProjections = [];
goog.array.forEach(projections, function(projection) {
addedProjections.push(ol.proj.addProjection(projection));
});
};
/**
* FIXME empty description for jsdoc
*/
ol.proj.clearAllProjections = function() {
ol.proj.projections_ = {};
ol.proj.transforms_ = {};
};
/**
* @param {ol.proj.Projection|string|undefined} projection Projection.
* @param {string} defaultCode Default code.
* @return {ol.proj.Projection} Projection.
*/
ol.proj.createProjection = function(projection, defaultCode) {
if (!goog.isDefAndNotNull(projection)) {
return ol.proj.get(defaultCode);
} else if (goog.isString(projection)) {
return ol.proj.get(projection);
} else {
goog.asserts.assertInstanceof(projection, ol.proj.Projection);
return projection;
}
};
/**
* Registers a conversion function to convert coordinates from the source
* projection to the destination projection.
*
* @param {ol.proj.Projection} source Source.
* @param {ol.proj.Projection} destination Destination.
* @param {ol.TransformFunction} transformFn Transform.
*/
ol.proj.addTransform = function(source, destination, transformFn) {
var sourceCode = source.getCode();
var destinationCode = destination.getCode();
var transforms = ol.proj.transforms_;
if (!goog.object.containsKey(transforms, sourceCode)) {
transforms[sourceCode] = {};
}
transforms[sourceCode][destinationCode] = transformFn;
};
/**
* Registers coordinate transform functions to convert coordinates between the
* source projection and the destination projection.
* The forward and inverse functions convert coordinate pairs; this function
* converts these into the functions used internally which also handle
* extents and coordinate arrays.
*
* @param {ol.proj.ProjectionLike} source Source projection.
* @param {ol.proj.ProjectionLike} destination Destination projection.
* @param {function(ol.Coordinate): ol.Coordinate} forward The forward transform
* function (that is, from the source projection to the destination
* projection) that takes a {@link ol.Coordinate} as argument and returns
* the transformed {@link ol.Coordinate}.
* @param {function(ol.Coordinate): ol.Coordinate} inverse The inverse transform
* function (that is, from the destination projection to the source
* projection) that takes a {@link ol.Coordinate} as argument and returns
* the transformed {@link ol.Coordinate}.
* @api stable
*/
ol.proj.addCoordinateTransforms =
function(source, destination, forward, inverse) {
var sourceProj = ol.proj.get(source);
var destProj = ol.proj.get(destination);
ol.proj.addTransform(sourceProj, destProj,
ol.proj.createTransformFromCoordinateTransform(forward));
ol.proj.addTransform(destProj, sourceProj,
ol.proj.createTransformFromCoordinateTransform(inverse));
};
/**
* Creates a {@link ol.TransformFunction} from a simple 2D coordinate transform
* function.
* @param {function(ol.Coordinate): ol.Coordinate} transform Coordinate
* transform.
* @return {ol.TransformFunction} Transform function.
*/
ol.proj.createTransformFromCoordinateTransform = function(transform) {
return (
/**
* @param {Array.<number>} input Input.
* @param {Array.<number>=} opt_output Output.
* @param {number=} opt_dimension Dimension.
* @return {Array.<number>} Output.
*/
function(input, opt_output, opt_dimension) {
var length = input.length;
var dimension = goog.isDef(opt_dimension) ? opt_dimension : 2;
var output = goog.isDef(opt_output) ? opt_output : new Array(length);
var point, i, j;
for (i = 0; i < length; i += dimension) {
point = transform([input[i], input[i + 1]]);
output[i] = point[0];
output[i + 1] = point[1];
for (j = dimension - 1; j >= 2; --j) {
output[i + j] = input[i + j];
}
}
return output;
});
};
/**
* Unregisters the conversion function to convert coordinates from the source
* projection to the destination projection. This method is used to clean up
* cached transforms during testing.
*
* @param {ol.proj.Projection} source Source projection.
* @param {ol.proj.Projection} destination Destination projection.
* @return {ol.TransformFunction} transformFn The unregistered transform.
*/
ol.proj.removeTransform = function(source, destination) {
var sourceCode = source.getCode();
var destinationCode = destination.getCode();
var transforms = ol.proj.transforms_;
goog.asserts.assert(sourceCode in transforms);
goog.asserts.assert(destinationCode in transforms[sourceCode]);
var transform = transforms[sourceCode][destinationCode];
delete transforms[sourceCode][destinationCode];
var keys = goog.object.getKeys(transforms[sourceCode]);
if (keys.length === 0) {
delete transforms[sourceCode];
}
return transform;
};
/**
* Fetches a Projection object for the code specified.
*
* @param {ol.proj.ProjectionLike} projectionLike Either a code string which is
* a combination of authority and identifier such as "EPSG:4326", or an
* existing projection object, or undefined.
* @return {ol.proj.Projection} Projection object, or null if not in list.
* @api stable
*/
ol.proj.get = function(projectionLike) {
var projection;
if (projectionLike instanceof ol.proj.Projection) {
projection = projectionLike;
} else if (goog.isString(projectionLike)) {
var code = projectionLike;
var projections = ol.proj.projections_;
projection = projections[code];
if (ol.ENABLE_PROJ4JS && !goog.isDef(projection) &&
typeof proj4 == 'function') {
var def = proj4.defs(code);
if (goog.isDef(def)) {
var units = def.units;
if (!goog.isDef(units)) {
if (goog.isDef(def.to_meter)) {
units = def.to_meter.toString();
ol.proj.METERS_PER_UNIT[units] = def.to_meter;
}
}
projection = new ol.proj.Projection({
code: code,
units: units,
axisOrientation: def.axis
});
ol.proj.addProjection(projection);
var currentCode, currentDef, currentProj, proj4Transform;
for (currentCode in projections) {
currentDef = proj4.defs(currentCode);
if (goog.isDef(currentDef)) {
currentProj = ol.proj.get(currentCode);
if (currentDef === def) {
ol.proj.addEquivalentProjections([currentProj, projection]);
} else {
proj4Transform = proj4(currentCode, code);
ol.proj.addCoordinateTransforms(currentProj, projection,
proj4Transform.forward, proj4Transform.inverse);
}
}
}
} else {
goog.asserts.assert(goog.isDef(projection));
projection = null;
}
}
} else {
projection = null;
}
return projection;
};
/**
* 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.proj.Projection} projection1 Projection 1.
* @param {ol.proj.Projection} projection2 Projection 2.
* @return {boolean} Equivalent.
*/
ol.proj.equivalent = function(projection1, projection2) {
if (projection1 === projection2) {
return true;
} else if (projection1.getUnits() != projection2.getUnits()) {
return false;
} else {
var transformFn = ol.proj.getTransformFromProjections(
projection1, projection2);
return transformFn === ol.proj.cloneTransform;
}
};
/**
* Given the projection-like objects, searches for a transformation
* function to convert a coordinates array from the source projection to the
* destination projection.
*
* @param {ol.proj.ProjectionLike} source Source.
* @param {ol.proj.ProjectionLike} destination Destination.
* @return {ol.TransformFunction} Transform function.
* @api stable
*/
ol.proj.getTransform = function(source, destination) {
var sourceProjection = ol.proj.get(source);
var destinationProjection = ol.proj.get(destination);
return ol.proj.getTransformFromProjections(
sourceProjection, destinationProjection);
};
/**
* Searches in the list of transform functions for the function for converting
* coordinates from the source projection to the destination projection.
*
* @param {ol.proj.Projection} sourceProjection Source Projection object.
* @param {ol.proj.Projection} destinationProjection Destination Projection
* object.
* @return {ol.TransformFunction} Transform function.
*/
ol.proj.getTransformFromProjections =
function(sourceProjection, destinationProjection) {
var transforms = ol.proj.transforms_;
var sourceCode = sourceProjection.getCode();
var destinationCode = destinationProjection.getCode();
var transform;
if (goog.object.containsKey(transforms, sourceCode) &&
goog.object.containsKey(transforms[sourceCode], destinationCode)) {
transform = transforms[sourceCode][destinationCode];
}
if (!goog.isDef(transform)) {
goog.asserts.assert(goog.isDef(transform));
transform = ol.proj.identityTransform;
}
return transform;
};
/**
* @param {Array.<number>} input Input coordinate array.
* @param {Array.<number>=} opt_output Output array of coordinate values.
* @param {number=} opt_dimension Dimension.
* @return {Array.<number>} Input coordinate array (same array as input).
*/
ol.proj.identityTransform = function(input, opt_output, opt_dimension) {
if (goog.isDef(opt_output) && input !== opt_output) {
// TODO: consider making this a warning instead
goog.asserts.fail('This should not be used internally.');
for (var i = 0, ii = input.length; i < ii; ++i) {
opt_output[i] = input[i];
}
input = opt_output;
}
return input;
};
/**
* @param {Array.<number>} input Input coordinate array.
* @param {Array.<number>=} opt_output Output array of coordinate values.
* @param {number=} opt_dimension Dimension.
* @return {Array.<number>} Output coordinate array (new array, same coordinate
* values).
*/
ol.proj.cloneTransform = function(input, opt_output, opt_dimension) {
var output;
if (goog.isDef(opt_output)) {
for (var i = 0, ii = input.length; i < ii; ++i) {
opt_output[i] = input[i];
}
output = opt_output;
} else {
output = input.slice();
}
return output;
};
/**
* Transforms a coordinate from source projection to destination projection.
* This returns a new coordinate (and does not modify the original).
*
* See {@link ol.proj.transformExtent} for extent transformation.
* See the transform method of {@link ol.geom.Geometry} and its subclasses for
* geometry transforms.
*
* @param {ol.Coordinate} coordinate Coordinate.
* @param {ol.proj.ProjectionLike} source Source projection-like.
* @param {ol.proj.ProjectionLike} destination Destination projection-like.
* @return {ol.Coordinate} Coordinate.
* @api stable
*/
ol.proj.transform = function(coordinate, source, destination) {
var transformFn = ol.proj.getTransform(source, destination);
return transformFn(coordinate);
};
/**
* Transforms an extent from source projection to destination projection. This
* returns a new extent (and does not modify the original).
*
* @param {ol.Extent} extent The extent to transform.
* @param {ol.proj.ProjectionLike} source Source projection-like.
* @param {ol.proj.ProjectionLike} destination Destination projection-like.
* @return {ol.Extent} The transformed extent.
* @api stable
*/
ol.proj.transformExtent = function(extent, source, destination) {
var transformFn = ol.proj.getTransform(source, destination);
return ol.extent.applyTransform(extent, transformFn);
};
/**
* Transforms the given point to the destination projection.
*
* @param {ol.Coordinate} point Point.
* @param {ol.proj.Projection} sourceProjection Source projection.
* @param {ol.proj.Projection} destinationProjection Destination projection.
* @return {ol.Coordinate} Point.
*/
ol.proj.transformWithProjections =
function(point, sourceProjection, destinationProjection) {
var transformFn = ol.proj.getTransformFromProjections(
sourceProjection, destinationProjection);
return transformFn(point);
};
OpenLayers 3