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/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
* full list of contributors). Published under the 2-clause BSD license.
* See license.txt in the OpenLayers distribution or repository for the
* full text of the license. */
/**
* @requires OpenLayers/Format.js
* @requires OpenLayers/Feature/Vector.js
*/
/**
* Class: OpenLayers.Format.EncodedPolyline
* Class for reading and writing encoded polylines. Create a new instance
* with the <OpenLayers.Format.EncodedPolyline> constructor.
*
* Inherits from:
* - <OpenLayers.Format>
*/
OpenLayers.Format.EncodedPolyline = OpenLayers.Class(OpenLayers.Format, {
/**
* APIProperty: geometryType
* {String} Geometry type to output. One of: linestring (default),
* linearring, point, multipoint or polygon. If the geometryType is
* point, only the first point of the string is returned.
*/
geometryType: "linestring",
/**
* Constructor: OpenLayers.Format.EncodedPolyline
* Create a new parser for encoded polylines
*
* Parameters:
* options - {Object} An optional object whose properties will be set on
* this instance
*
* Returns:
* {<OpenLayers.Format.EncodedPolyline>} A new encoded polylines parser.
*/
initialize: function(options) {
OpenLayers.Format.prototype.initialize.apply(this, [options]);
},
/**
* APIMethod: read
* Deserialize an encoded polyline string and return a vector feature.
*
* Parameters:
* encoded - {String} An encoded polyline string
*
* Returns:
* {<OpenLayers.Feature.Vector>} A vector feature with a linestring.
*/
read: function(encoded) {
var geomType;
if (this.geometryType == "linestring")
geomType = OpenLayers.Geometry.LineString;
else if (this.geometryType == "linearring")
geomType = OpenLayers.Geometry.LinearRing;
else if (this.geometryType == "multipoint")
geomType = OpenLayers.Geometry.MultiPoint;
else if (this.geometryType != "point" && this.geometryType != "polygon")
return null;
var flatPoints = this.decodeDeltas(encoded, 2);
var flatPointsLength = flatPoints.length;
var pointGeometries = [];
for (var i = 0; i + 1 < flatPointsLength;) {
var y = flatPoints[i++], x = flatPoints[i++];
pointGeometries.push(new OpenLayers.Geometry.Point(x, y));
}
if (this.geometryType == "point")
return new OpenLayers.Feature.Vector(
pointGeometries[0]
);
if (this.geometryType == "polygon")
return new OpenLayers.Feature.Vector(
new OpenLayers.Geometry.Polygon([
new OpenLayers.Geometry.LinearRing(pointGeometries)
])
);
return new OpenLayers.Feature.Vector(
new geomType(pointGeometries)
);
},
/**
* APIMethod: decode
* Deserialize an encoded string and return an array of n-dimensional
* points.
*
* Parameters:
* encoded - {String} An encoded string
* dims - {int} The dimension of the points that are returned
*
* Returns:
* {Array(Array(int))} An array containing n-dimensional arrays of
* coordinates.
*/
decode: function(encoded, dims, opt_factor) {
var factor = opt_factor || 1e5;
var flatPoints = this.decodeDeltas(encoded, dims, factor);
var flatPointsLength = flatPoints.length;
var points = [];
for (var i = 0; i + (dims - 1) < flatPointsLength;) {
var point = [];
for (var dim = 0; dim < dims; ++dim) {
point.push(flatPoints[i++])
}
points.push(point);
}
return points;
},
/**
* APIMethod: write
* Serialize a feature or array of features into a WKT string.
*
* Parameters:
* features - {<OpenLayers.Feature.Vector>|Array} A feature or array of
* features
*
* Returns:
* {String} The WKT string representation of the input geometries
*/
write: function(features) {
var feature;
if (features.constructor == Array)
feature = features[0];
else
feature = features;
var geometry = feature.geometry;
var type = geometry.CLASS_NAME.split('.')[2].toLowerCase();
var pointGeometries;
if (type == "point")
pointGeometries = new Array(geometry);
else if (type == "linestring" ||
type == "linearring" ||
type == "multipoint")
pointGeometries = geometry.components;
else if (type == "polygon")
pointGeometries = geometry.components[0].components;
else
return null;
var flatPoints = [];
var pointGeometriesLength = pointGeometries.length;
for (var i = 0; i < pointGeometriesLength; ++i) {
var pointGeometry = pointGeometries[i];
flatPoints.push(pointGeometry.y);
flatPoints.push(pointGeometry.x);
}
return this.encodeDeltas(flatPoints, 2);
},
/**
* APIMethod: encode
* Serialize an array of n-dimensional points and return an encoded string
*
* Parameters:
* points - {Array(Array(int))} An array containing n-dimensional
* arrays of coordinates
* dims - {int} The dimension of the points that should be read
*
* Returns:
* {String} An encoded string
*/
encode: function (points, dims, opt_factor) {
var factor = opt_factor || 1e5;
var flatPoints = [];
var pointsLength = points.length;
for (var i = 0; i < pointsLength; ++i) {
var point = points[i];
for (var dim = 0; dim < dims; ++dim) {
flatPoints.push(point[dim]);
}
}
return this.encodeDeltas(flatPoints, dims, factor);
},
/**
* APIMethod: encodeDeltas
* Encode a list of n-dimensional points and return an encoded string
*
* Attention: This function will modify the passed array!
*
* Parameters:
* numbers - {Array.<number>} A list of n-dimensional points.
* dimension - {number} The dimension of the points in the list.
* opt_factor - {number=} The factor by which the numbers will be
* multiplied. The remaining decimal places will get rounded away.
*
* Returns:
* {string} The encoded string.
*/
encodeDeltas: function(numbers, dimension, opt_factor) {
var factor = opt_factor || 1e5;
var d;
var lastNumbers = new Array(dimension);
for (d = 0; d < dimension; ++d) {
lastNumbers[d] = 0;
}
var numbersLength = numbers.length;
for (var i = 0; i < numbersLength;) {
for (d = 0; d < dimension; ++d, ++i) {
var num = numbers[i];
var delta = num - lastNumbers[d];
lastNumbers[d] = num;
numbers[i] = delta;
}
}
return this.encodeFloats(numbers, factor);
},
/**
* APIMethod: decodeDeltas
* Decode a list of n-dimensional points from an encoded string
*
* Parameters:
* encoded - {string} An encoded string.
* dimension - {number} The dimension of the points in the encoded string.
* opt_factor - {number=} The factor by which the resulting numbers will
* be divided.
*
* Returns:
* {Array.<number>} A list of n-dimensional points.
*/
decodeDeltas: function(encoded, dimension, opt_factor) {
var factor = opt_factor || 1e5;
var d;
var lastNumbers = new Array(dimension);
for (d = 0; d < dimension; ++d) {
lastNumbers[d] = 0;
}
var numbers = this.decodeFloats(encoded, factor);
var numbersLength = numbers.length;
for (var i = 0; i < numbersLength;) {
for (d = 0; d < dimension; ++d, ++i) {
lastNumbers[d] += numbers[i];
numbers[i] = lastNumbers[d];
}
}
return numbers;
},
/**
* APIMethod: encodeFloats
* Encode a list of floating point numbers and return an encoded string
*
* Attention: This function will modify the passed array!
*
* Parameters:
* numbers - {Array.<number>} A list of floating point numbers.
* opt_factor - {number=} The factor by which the numbers will be
* multiplied. The remaining decimal places will get rounded away.
*
* Returns:
* {string} The encoded string.
*/
encodeFloats: function(numbers, opt_factor) {
var factor = opt_factor || 1e5;
var numbersLength = numbers.length;
for (var i = 0; i < numbersLength; ++i) {
numbers[i] = Math.round(numbers[i] * factor);
}
return this.encodeSignedIntegers(numbers);
},
/**
* APIMethod: decodeFloats
* Decode a list of floating point numbers from an encoded string
*
* Parameters:
* encoded - {string} An encoded string.
* opt_factor - {number=} The factor by which the result will be divided.
*
* Returns:
* {Array.<number>} A list of floating point numbers.
*/
decodeFloats: function(encoded, opt_factor) {
var factor = opt_factor || 1e5;
var numbers = this.decodeSignedIntegers(encoded);
var numbersLength = numbers.length;
for (var i = 0; i < numbersLength; ++i) {
numbers[i] /= factor;
}
return numbers;
},
/**
* APIMethod: encodeSignedIntegers
* Encode a list of signed integers and return an encoded string
*
* Attention: This function will modify the passed array!
*
* Parameters:
* numbers - {Array.<number>} A list of signed integers.
*
* Returns:
* {string} The encoded string.
*/
encodeSignedIntegers: function(numbers) {
var numbersLength = numbers.length;
for (var i = 0; i < numbersLength; ++i) {
var num = numbers[i];
var signedNum = num << 1;
if (num < 0) {
signedNum = ~(signedNum);
}
numbers[i] = signedNum;
}
return this.encodeUnsignedIntegers(numbers);
},
/**
* APIMethod: decodeSignedIntegers
* Decode a list of signed integers from an encoded string
*
* Parameters:
* encoded - {string} An encoded string.
*
* Returns:
* {Array.<number>} A list of signed integers.
*/
decodeSignedIntegers: function(encoded) {
var numbers = this.decodeUnsignedIntegers(encoded);
var numbersLength = numbers.length;
for (var i = 0; i < numbersLength; ++i) {
var num = numbers[i];
numbers[i] = (num & 1) ? ~(num >> 1) : (num >> 1);
}
return numbers;
},
/**
* APIMethod: encodeUnsignedIntegers
* Encode a list of unsigned integers and return an encoded string
*
* Parameters:
* numbers - {Array.<number>} A list of unsigned integers.
*
* Returns:
* {string} The encoded string.
*/
encodeUnsignedIntegers: function(numbers) {
var encoded = '';
var numbersLength = numbers.length;
for (var i = 0; i < numbersLength; ++i) {
encoded += this.encodeUnsignedInteger(numbers[i]);
}
return encoded;
},
/**
* APIMethod: decodeUnsignedIntegers
* Decode a list of unsigned integers from an encoded string
*
* Parameters:
* encoded - {string} An encoded string.
*
* Returns:
* {Array.<number>} A list of unsigned integers.
*/
decodeUnsignedIntegers: function(encoded) {
var numbers = [];
var current = 0;
var shift = 0;
var encodedLength = encoded.length;
for (var i = 0; i < encodedLength; ++i) {
var b = encoded.charCodeAt(i) - 63;
current |= (b & 0x1f) << shift;
if (b < 0x20) {
numbers.push(current);
current = 0;
shift = 0;
} else {
shift += 5;
}
}
return numbers;
},
/**
* Method: encodeFloat
* Encode one single floating point number and return an encoded string
*
* Parameters:
* num - {number} Floating point number that should be encoded.
* opt_factor - {number=} The factor by which num will be multiplied.
* The remaining decimal places will get rounded away.
*
* Returns:
* {string} The encoded string.
*/
encodeFloat: function(num, opt_factor) {
num = Math.round(num * (opt_factor || 1e5));
return this.encodeSignedInteger(num);
},
/**
* Method: decodeFloat
* Decode one single floating point number from an encoded string
*
* Parameters:
* encoded - {string} An encoded string.
* opt_factor - {number=} The factor by which the result will be divided.
*
* Returns:
* {number} The decoded floating point number.
*/
decodeFloat: function(encoded, opt_factor) {
var result = this.decodeSignedInteger(encoded);
return result / (opt_factor || 1e5);
},
/**
* Method: encodeSignedInteger
* Encode one single signed integer and return an encoded string
*
* Parameters:
* num - {number} Signed integer that should be encoded.
*
* Returns:
* {string} The encoded string.
*/
encodeSignedInteger: function(num) {
var signedNum = num << 1;
if (num < 0) {
signedNum = ~(signedNum);
}
return this.encodeUnsignedInteger(signedNum);
},
/**
* Method: decodeSignedInteger
* Decode one single signed integer from an encoded string
*
* Parameters:
* encoded - {string} An encoded string.
*
* Returns:
* {number} The decoded signed integer.
*/
decodeSignedInteger: function(encoded) {
var result = this.decodeUnsignedInteger(encoded);
return ((result & 1) ? ~(result >> 1) : (result >> 1));
},
/**
* Method: encodeUnsignedInteger
* Encode one single unsigned integer and return an encoded string
*
* Parameters:
* num - {number} Unsigned integer that should be encoded.
*
* Returns:
* {string} The encoded string.
*/
encodeUnsignedInteger: function(num) {
var value, encoded = '';
while (num >= 0x20) {
value = (0x20 | (num & 0x1f)) + 63;
encoded += (String.fromCharCode(value));
num >>= 5;
}
value = num + 63;
encoded += (String.fromCharCode(value));
return encoded;
},
/**
* Method: decodeUnsignedInteger
* Decode one single unsigned integer from an encoded string
*
* Parameters:
* encoded - {string} An encoded string.
*
* Returns:
* {number} The decoded unsigned integer.
*/
decodeUnsignedInteger: function(encoded) {
var result = 0;
var shift = 0;
var encodedLength = encoded.length;
for (var i = 0; i < encodedLength; ++i) {
var b = encoded.charCodeAt(i) - 63;
result |= (b & 0x1f) << shift;
if (b < 0x20)
break;
shift += 5;
}
return result;
},
CLASS_NAME: "OpenLayers.Format.EncodedPolyline"
});
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