Add getBounds to geometry

src/ol/geom/geometry.js

@@ -1,3 +1,4 @@
+goog.require('ol.Extent');
 goog.provide('ol.geom.Coordinate');
 goog.provide('ol.geom.CoordinateArray');
 goog.provide('ol.geom.Geometry');
@@ -10,6 +11,20 @@ goog.provide('ol.geom.Geometry');
 ol.geom.Geometry = function() {};
 
 
+/**
+ * The dimension of this geometry (2 or 3).
+ * @type {number}
+ */
+ol.geom.Geometry.prototype.dimension;
+
+
+/**
+ * Get the rectangular 2D evelope for this geoemtry.
+ * @return {ol.Extent} The bounding rectangular envelope.
+ */
+ol.geom.Geometry.prototype.getBounds = goog.abstractMethod;
+
+
 /**
  * @typedef {Array.<number>}
  */

src/ol/geom/geometrycollection.js

@@ -0,0 +1,70 @@
+goog.provide('ol.geom.GeometryCollection');
+
+goog.require('goog.asserts');
+goog.require('ol.Extent');
+goog.require('ol.geom.Geometry');
+
+
+
+/**
+ * A mixed collection of geometries.  This constructor is typically not called
+ * directly.  Instead call @see ol.geom.GeometryCollection#fromGeometries.
+ * @constructor
+ * @implements {ol.geom.Geometry}
+ */
+ol.geom.GeometryCollection = function() {
+
+  /**
+   * @type {Array.<ol.geom.Geometry>}
+   */
+  this.components = null;
+
+  /**
+   * @type {number}
+   */
+  this.dimension;
+
+  /**
+   * @type {ol.Extent}
+   * @protected
+   */
+  this.bounds = null;
+
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.geom.GeometryCollection.prototype.getBounds = function() {
+  if (goog.isNull(this.bounds)) {
+    var minX,
+        minY = minX = Number.POSITIVE_INFINITY,
+        maxX,
+        maxY = maxX = Number.NEGATIVE_INFINITY,
+        components = this.components,
+        len = components.length,
+        bounds, i;
+
+    for (i = 0; i < len; ++i) {
+      bounds = components[i].getBounds();
+      minX = Math.min(bounds.minX, minX);
+      minY = Math.min(bounds.minY, minY);
+      maxX = Math.max(bounds.maxX, maxX);
+      maxY = Math.max(bounds.maxY, maxY);
+    }
+    this.bounds = new ol.Extent(minX, minY, maxX, maxY);
+  }
+  return this.bounds;
+};
+
+
+/**
+ * @param {Array.<ol.geom.Geometry>} components Array of geometries.
+ * @return {ol.geom.GeometryCollection} A mixed geometry collection.
+ */
+ol.geom.GeometryCollection.fromGeometries = function(components) {
+  var collection = new ol.geom.GeometryCollection();
+  collection.components = components;
+  return collection;
+};

src/ol/geom/linestring.js

@@ -2,6 +2,7 @@ goog.provide('ol.geom.LineString');
 
 goog.require('goog.asserts');
 goog.require('goog.vec.Float64Array');
+goog.require('ol.Extent');
 goog.require('ol.geom.CoordinateArray');
 goog.require('ol.geom.Geometry');
 
@@ -35,4 +36,38 @@ ol.geom.LineString = function(coordinates) {
   this.dimension = dimension;
   goog.asserts.assert(this.dimension >= 2);
 
+  /**
+   * @type {ol.Extent}
+   * @private
+   */
+  this.bounds_ = null;
+
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.geom.LineString.prototype.getBounds = function() {
+  if (goog.isNull(this.bounds_)) {
+    var minX,
+        minY = minX = Number.POSITIVE_INFINITY,
+        maxX,
+        maxY = maxX = Number.NEGATIVE_INFINITY,
+        coordinates = this.coordinates,
+        len = coordinates.length,
+        dim = this.dimension,
+        x, y, i;
+
+    for (i = 0; i < len; i += dim) {
+      x = coordinates[i];
+      y = coordinates[i + 1];
+      minX = Math.min(minX, x);
+      minY = Math.min(minY, y);
+      maxX = Math.max(maxX, x);
+      maxY = Math.max(maxY, y);
+    }
+    this.bounds_ = new ol.Extent(minX, minY, maxX, maxY);
+  }
+  return this.bounds_;
 };

src/ol/geom/multilinestring.js

@@ -2,17 +2,18 @@ goog.provide('ol.geom.MultiLineString');
 
 goog.require('goog.asserts');
 goog.require('ol.geom.CoordinateArray');
-goog.require('ol.geom.Geometry');
+goog.require('ol.geom.GeometryCollection');
 goog.require('ol.geom.LineString');
 
 
 
 /**
  * @constructor
- * @implements {ol.geom.Geometry}
+ * @extends {ol.geom.GeometryCollection}
  * @param {Array.<ol.geom.CoordinateArray>} coordinates Coordinates array.
  */
 ol.geom.MultiLineString = function(coordinates) {
+  goog.base(this);
 
   var numParts = coordinates.length,
       dimension;
@@ -24,7 +25,7 @@ ol.geom.MultiLineString = function(coordinates) {
   for (var i = 0; i < numParts; ++i) {
     this.components[i] = new ol.geom.LineString(coordinates[i]);
     if (!goog.isDef(dimension)) {
-      dimension = this.components[i];
+      dimension = this.components[i].dimension;
     } else {
       goog.asserts.assert(this.components[i].dimension === dimension);
     }
@@ -37,3 +38,4 @@ ol.geom.MultiLineString = function(coordinates) {
   goog.asserts.assert(this.dimension >= 2);
 
 };
+goog.inherits(ol.geom.MultiLineString, ol.geom.GeometryCollection);

src/ol/geom/multipoint.js

@@ -2,17 +2,18 @@ goog.provide('ol.geom.MultiPoint');
 
 goog.require('goog.asserts');
 goog.require('ol.geom.CoordinateArray');
-goog.require('ol.geom.Geometry');
+goog.require('ol.geom.GeometryCollection');
 goog.require('ol.geom.Point');
 
 
 
 /**
  * @constructor
- * @implements {ol.geom.Geometry}
+ * @extends {ol.geom.GeometryCollection}
  * @param {ol.geom.CoordinateArray} coordinates Coordinates array.
  */
 ol.geom.MultiPoint = function(coordinates) {
+  goog.base(this);
 
   var numParts = coordinates.length,
       dimension;
@@ -37,3 +38,4 @@ ol.geom.MultiPoint = function(coordinates) {
   goog.asserts.assert(this.dimension >= 2);
 
 };
+goog.inherits(ol.geom.MultiPoint, ol.geom.GeometryCollection);

src/ol/geom/multipolygon.js

@@ -2,18 +2,19 @@ goog.provide('ol.geom.MultiPolygon');
 
 goog.require('goog.asserts');
 goog.require('ol.geom.CoordinateArray');
-goog.require('ol.geom.Geometry');
+goog.require('ol.geom.GeometryCollection');
 goog.require('ol.geom.Polygon');
 
 
 
 /**
  * @constructor
- * @implements {ol.geom.Geometry}
+ * @extends {ol.geom.GeometryCollection}
  * @param {Array.<Array.<ol.geom.CoordinateArray>>} coordinates Coordinates
  *    array.
  */
 ol.geom.MultiPolygon = function(coordinates) {
+  goog.base(this);
 
   var numParts = coordinates.length,
       dimension;
@@ -25,7 +26,7 @@ ol.geom.MultiPolygon = function(coordinates) {
   for (var i = 0; i < numParts; ++i) {
     this.components[i] = new ol.geom.Polygon(coordinates[i]);
     if (!goog.isDef(dimension)) {
-      dimension = this.components[i];
+      dimension = this.components[i].dimension;
     } else {
       goog.asserts.assert(this.components[i].dimension === dimension);
     }
@@ -38,3 +39,4 @@ ol.geom.MultiPolygon = function(coordinates) {
   goog.asserts.assert(this.dimension >= 2);
 
 };
+goog.inherits(ol.geom.MultiPolygon, ol.geom.GeometryCollection);

src/ol/geom/point.js

@@ -2,6 +2,7 @@ goog.provide('ol.geom.Point');
 
 goog.require('goog.asserts');
 goog.require('goog.vec.Float64Array');
+goog.require('ol.Extent');
 goog.require('ol.geom.Coordinate');
 goog.require('ol.geom.Geometry');
 
@@ -25,4 +26,23 @@ ol.geom.Point = function(coordinates) {
   this.dimension = coordinates.length;
   goog.asserts.assert(this.dimension >= 2);
 
+  /**
+   * @type {ol.Extent}
+   * @private
+   */
+  this.bounds_ = null;
+
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.geom.Point.prototype.getBounds = function() {
+  if (goog.isNull(this.bounds_)) {
+    var x = this.coordinates[0],
+        y = this.coordinates[1];
+    this.bounds_ = new ol.Extent(x, y, x, y);
+  }
+  return this.bounds_;
 };

src/ol/geom/polygon.js

@@ -2,6 +2,7 @@ goog.provide('ol.geom.Polygon');
 
 goog.require('goog.asserts');
 goog.require('goog.vec.Float64Array');
+goog.require('ol.Extent');
 goog.require('ol.geom.CoordinateArray');
 goog.require('ol.geom.Geometry');
 goog.require('ol.geom.LinearRing');
@@ -38,4 +39,18 @@ ol.geom.Polygon = function(coordinates) {
   this.dimension = dimension;
   goog.asserts.assert(this.dimension >= 2);
 
+  /**
+   * @type {ol.Extent}
+   * @private
+   */
+  this.bounds_ = null;
+
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.geom.Polygon.prototype.getBounds = function() {
+  return this.rings[0].getBounds();
 };

test/ol.html

@@ -81,6 +81,9 @@
   <script type="text/javascript" src="spec/ol/resolutionconstraint.test.js"></script>
   <script type="text/javascript" src="spec/ol/view2d.test.js"></script>
   <script type="text/javascript" src="spec/ol/io/geojson.test.js"></script>
+  <script type="text/javascript" src="spec/ol/geom/multipoint.test.js"></script>
+  <script type="text/javascript" src="spec/ol/geom/multilinestring.test.js"></script>
+  <script type="text/javascript" src="spec/ol/geom/multipolygon.test.js"></script>
   <script type="text/javascript" src="spec/ol/geom/linearring.test.js"></script>
   <script type="text/javascript" src="spec/ol/geom/linestring.test.js"></script>
   <script type="text/javascript" src="spec/ol/geom/point.test.js"></script>

test/spec/ol/geom/linearring.test.js

@@ -15,7 +15,7 @@ describe('ol.geom.LinearRing', function() {
 
   });
 
-  describe('coordinates', function() {
+  describe('#coordinates', function() {
 
     it('is a Float64Array', function() {
       var ring = new ol.geom.LinearRing([[10, 20], [30, 40]]);
@@ -30,7 +30,7 @@ describe('ol.geom.LinearRing', function() {
 
   });
 
-  describe('dimension', function() {
+  describe('#dimension', function() {
 
     it('can be 2', function() {
       var ring = new ol.geom.LinearRing([[10, 20], [30, 40]]);

test/spec/ol/geom/linestring.test.js

@@ -15,7 +15,7 @@ describe('ol.geom.LineString', function() {
 
   });
 
-  describe('coordinates', function() {
+  describe('#coordinates', function() {
 
     it('is a Float64Array', function() {
       var line = new ol.geom.LineString([[10, 20], [30, 40]]);
@@ -30,7 +30,7 @@ describe('ol.geom.LineString', function() {
 
   });
 
-  describe('dimension', function() {
+  describe('#dimension', function() {
 
     it('can be 2', function() {
       var line = new ol.geom.LineString([[10, 20], [30, 40]]);
@@ -44,6 +44,19 @@ describe('ol.geom.LineString', function() {
 
   });
 
+  describe('#getBounds()', function() {
+
+    it('returns the bounding extent', function() {
+      var line = new ol.geom.LineString([[10, 20], [20, 30], [30, 40]]);
+      var bounds = line.getBounds();
+      expect(bounds.minX).toBe(10);
+      expect(bounds.minY).toBe(20);
+      expect(bounds.maxX).toBe(30);
+      expect(bounds.maxY).toBe(40);
+    });
+
+  });
+
 
 });