Merge pull request #813 from Turbo87/encoded-polyline

Format: Added EncodedPolyline class. Merging this as a first step towards
support for alternative geometry encodings. See #813 for TBDs.
This commit is contained in:
ahocevar
2012-12-28 11:55:12 -08:00
5 changed files with 436 additions and 0 deletions

File diff suppressed because one or more lines are too long

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@@ -306,6 +306,7 @@
"OpenLayers/Format/GML/v2.js",
"OpenLayers/Format/GML/v3.js",
"OpenLayers/Format/Atom.js",
"OpenLayers/Format/EncodedPolyline.js",
"OpenLayers/Format/KML.js",
"OpenLayers/Format/GeoRSS.js",
"OpenLayers/Format/WFS.js",

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@@ -0,0 +1,254 @@
/* Copyright (c) 2006-2012 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 points = this.decode(encoded, 2);
var pointGeometries = new Array();
for (i in points) {
var point = points[i];
pointGeometries.push(
new OpenLayers.Geometry.Point(point[1] * 1e-5, point[0] * 1e-5)
);
}
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) {
var points = new Array();
var point = new Array(dims);
// Reset the point array
for (var i = 0; i < point.length; ++i)
point[i] = 0;
for (var i = 0; i < encoded.length;) {
for (var dim = 0; dim < dims; ++dim) {
var result = 0;
var shift = 0;
var b;
do {
b = encoded.charCodeAt(i++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
point[dim] += ((result & 1) ? ~(result >> 1) : (result >> 1));
}
points.push(point.slice(0));
}
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 points = new Array();
for (var i in pointGeometries) {
var pointGeometry = pointGeometries[i];
var point = [Math.round(pointGeometry.y * 1e5),
Math.round(pointGeometry.x * 1e5)];
points.push(point);
}
var result = this.encode(points, 2);
return result;
},
/**
* 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) {
var encoded_points = "";
var lastPoint = new Array(dims);
for (var i = 0; i < lastPoint.length; ++i)
lastPoint[i] = 0;
for (var i = 0; i < points.length; i++) {
var point = points[i];
for (var dim = 0; dim < lastPoint.length; ++dim) {
var delta = point[dim] - lastPoint[dim];
encoded_points += this.encodeSignedNumber(delta);
}
lastPoint = point;
}
return encoded_points;
},
/**
* Method: encodeSignedNumber
* Encode one single signed integer and return an encoded string
*
* Parameters:
* num - {int} A signed integer that should be encoded
*
* Returns:
* {String} An encoded string
*/
encodeSignedNumber: function (num) {
var sgn_num = num << 1;
if (num < 0)
sgn_num = ~(sgn_num);
return this.encodeNumber(sgn_num);
},
/**
* Method: encodeNumber
* Encode one single unsigned integer and return an encoded string
*
* encodeSignedNumber should be used instead of using this method directly!
*
* Parameters:
* num - {int} An unsigned integer that should be encoded
*
* Returns:
* {String} An encoded string
*/
encodeNumber: function (num) {
var encodeString = "";
var value;
while (num >= 0x20) {
value = (0x20 | (num & 0x1f)) + 63;
encodeString += (String.fromCharCode(value));
num >>= 5;
}
value = num + 63;
encodeString += (String.fromCharCode(value));
return encodeString;
},
CLASS_NAME: "OpenLayers.Format.EncodedPolyline"
});

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@@ -0,0 +1,133 @@
<html>
<head>
<script src="../OLLoader.js"></script>
<script type="text/javascript">
var basePoints = new Array(
new Array(3850000, -12020000),
new Array(4070000, -12095000),
new Array(4325200, -12645300)
);
var points = [
new OpenLayers.Geometry.Point(basePoints[0][1] * 1e-5,
basePoints[0][0] * 1e-5),
new OpenLayers.Geometry.Point(basePoints[1][1] * 1e-5,
basePoints[1][0] * 1e-5),
new OpenLayers.Geometry.Point(basePoints[2][1] * 1e-5,
basePoints[2][0] * 1e-5)
];
var singlePoint = new OpenLayers.Feature.Vector(points[0]);
var linestring = new OpenLayers.Feature.Vector(
new OpenLayers.Geometry.LineString(points)
);
var multipoint = new OpenLayers.Feature.Vector(
new OpenLayers.Geometry.MultiPoint(points)
);
var linearring = new OpenLayers.Feature.Vector(
new OpenLayers.Geometry.LinearRing(points)
);
var polygon = new OpenLayers.Feature.Vector(
new OpenLayers.Geometry.Polygon([
new OpenLayers.Geometry.LinearRing(points)
])
);
var encoded = "_p~iF~ps|U_ulLnnqC_mqNvxq`@";
function test_Format_EncodedPolyline_constructor(t) {
t.plan(4);
var options = {'foo': 'bar'};
var format = new OpenLayers.Format.EncodedPolyline(options);
t.ok(format instanceof OpenLayers.Format.EncodedPolyline,
"new OpenLayers.Format.EncodedPolyline returns object" );
t.eq(format.foo, "bar", "constructor sets options correctly");
t.eq(typeof format.read, "function", "format has a read function");
t.eq(typeof format.write, "function", "format has a write function");
}
function test_Format_EncodedPolyline_read(t) {
t.plan(5);
var format = new OpenLayers.Format.EncodedPolyline();
t.ok(linestring.geometry.equals(format.read(encoded).geometry),
"format correctly reads encoded polyline");
format = new OpenLayers.Format.EncodedPolyline({
geometryType: "multipoint"
});
t.ok(multipoint.geometry.equals(format.read(encoded).geometry),
"format correctly reads encoded multipoint");
format.geometryType = "linearring";
t.ok(linearring.geometry.equals(format.read(encoded).geometry),
"format correctly reads encoded linearring");
format.geometryType = "polygon";
t.ok(polygon.geometry.equals(format.read(encoded).geometry),
"format correctly reads encoded polygon");
format.geometryType = "point";
t.ok(points[0].equals(format.read(encoded).geometry),
"format correctly reads encoded point");
}
function test_Format_EncodedPolyline_decode(t) {
t.plan(6);
var format = new OpenLayers.Format.EncodedPolyline();
var decodedPoints = format.decode(encoded, 2);
for (i in decodedPoints) {
var point = basePoints[i];
var decodedPoint = decodedPoints[i];
t.eq(point[0], decodedPoint[0]);
t.eq(point[1], decodedPoint[1]);
}
}
function test_Format_EncodedPolyline_write(t) {
t.plan(5);
var format = new OpenLayers.Format.EncodedPolyline();
t.eq(format.write(linestring), encoded,
"format correctly writes encoded polyline");
t.eq(format.write(multipoint), encoded,
"format correctly writes encoded multipoint");
// Different output than encoded,
// because polygon closing point is included
t.eq(format.write(linearring),
"_p~iF~ps|U_ulLnnqC_mqNvxq`@~b_\\ghde@",
"format correctly writes encoded linearring");
t.eq(format.write(polygon),
"_p~iF~ps|U_ulLnnqC_mqNvxq`@~b_\\ghde@",
"format correctly writes encoded polygon");
t.eq(format.write(singlePoint), "_p~iF~ps|U",
"format correctly writes encoded point");
}
function test_Format_EncodedPolyline_encode(t) {
t.plan(1);
var format = new OpenLayers.Format.EncodedPolyline();
t.eq(format.encode(basePoints, 2), encoded);
}
</script>
</head>
<body>
</body>
</html>

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@@ -66,6 +66,7 @@
<li>Format/XML/VersionedOGC.html</li>
<li>Format/ArcXML/Features.html</li>
<li>Format/CQL.html</li>
<li>Format/EncodedPolyline.html</li>
<li>Format/GeoJSON.html</li>
<li>Format/GeoRSS.html</li>
<li>Format/GML.html</li>