Files
openlayers/src/ol/geom/linestring.js
2013-03-04 20:25:18 +01:00

150 lines
3.3 KiB
JavaScript

goog.provide('ol.geom.LineString');
goog.require('goog.asserts');
goog.require('ol.Extent');
goog.require('ol.geom.Geometry');
goog.require('ol.geom.GeometryType');
goog.require('ol.geom.SharedVertices');
goog.require('ol.geom.VertexArray');
/**
* @constructor
* @extends {ol.geom.Geometry}
* @param {ol.geom.VertexArray} coordinates Vertex array (e.g.
* [[x0, y0], [x1, y1]]).
* @param {ol.geom.SharedVertices=} opt_shared Shared vertices.
*/
ol.geom.LineString = function(coordinates, opt_shared) {
goog.base(this);
goog.asserts.assert(goog.isArray(coordinates[0]));
var vertices = opt_shared,
dimension;
if (!goog.isDef(vertices)) {
dimension = coordinates[0].length;
vertices = new ol.geom.SharedVertices({dimension: dimension});
}
/**
* @type {ol.geom.SharedVertices}
*/
this.vertices = vertices;
/**
* @type {string}
* @private
*/
this.sharedId_ = vertices.add(coordinates);
/**
* @type {number}
*/
this.dimension = vertices.getDimension();
goog.asserts.assert(this.dimension >= 2);
/**
* @type {ol.Extent}
* @private
*/
this.bounds_ = null;
};
goog.inherits(ol.geom.LineString, ol.geom.Geometry);
/**
* Get a vertex coordinate value for the given dimension.
* @param {number} index Vertex index.
* @param {number} dim Coordinate dimension.
* @return {number} The vertex coordinate value.
*/
ol.geom.LineString.prototype.get = function(index, dim) {
return this.vertices.get(this.sharedId_, index, dim);
};
/**
* @inheritDoc
* @return {ol.geom.VertexArray} Coordinates array.
*/
ol.geom.LineString.prototype.getCoordinates = function() {
var count = this.getCount();
var coordinates = new Array(count);
var vertex;
for (var i = 0; i < count; ++i) {
vertex = new Array(this.dimension);
for (var j = 0; j < this.dimension; ++j) {
vertex[j] = this.get(i, j);
}
coordinates[i] = vertex;
}
return coordinates;
};
/**
* Get the count of vertices in this linestring.
* @return {number} The vertex count.
*/
ol.geom.LineString.prototype.getCount = function() {
return this.vertices.getCount(this.sharedId_);
};
/**
* @inheritDoc
*/
ol.geom.LineString.prototype.getBounds = function() {
if (goog.isNull(this.bounds_)) {
var dimension = this.dimension,
vertices = this.vertices,
id = this.sharedId_,
count = vertices.getCount(id),
start = vertices.getStart(id),
end = start + (count * dimension),
coordinates = vertices.coordinates,
minX, maxX,
minY, maxY,
x, y, i;
minX = maxX = coordinates[start];
minY = maxY = coordinates[start + 1];
for (i = start + dimension; i < end; i += dimension) {
x = coordinates[i];
y = coordinates[i + 1];
if (x < minX) {
minX = x;
} else if (x > maxX) {
maxX = x;
}
if (y < minY) {
minY = y;
} else if (y > maxY) {
maxY = y;
}
}
this.bounds_ = new ol.Extent(minX, minY, maxX, maxY);
}
return this.bounds_;
};
/**
* @inheritDoc
*/
ol.geom.LineString.prototype.getType = function() {
return ol.geom.GeometryType.LINESTRING;
};
/**
* Get the identifier used to mark this line in the shared vertices structure.
* @return {string} The identifier.
*/
ol.geom.LineString.prototype.getSharedId = function() {
return this.sharedId_;
};