/src/com/google/maps/extras/arcgislink/ArcGISTileConfig.as

  1/*
  2 * ArcGIS for Google Maps Flash API
  3 *
  4 * License http://www.apache.org/licenses/LICENSE-2.0
  5 */
  6 /**
  7 * @author nianwei at gmail dot com
  8 */ 
  9
 10package com.google.maps.extras.arcgislink {
 11  import com.google.maps.*;
 12  import com.google.maps.interfaces.*;
 13  
 14  import flash.geom.Point;
 15
 16  /**
 17   * This class is a bridge between Google's projection and ArcGIS's spatial reference system.
 18   */
 19  public class ArcGISTileConfig extends ProjectionBase {
 20    private var tileInfo_:*;
 21    private var spatialReference_:SpatialReference;
 22    internal var zoomOffset_:int; //used in TileLayer
 23    private var fullExtent_:*;
 24
 25
 26    public function ArcGISTileConfig( /*TileInfo*/ tileInfo:*, /*Envelope*/  opt_fullExtent:*=null) {
 27      super();
 28      if (!tileInfo) {
 29        throw new Error('map service is not tiled');
 30      }
 31      this.tileInfo_=tileInfo;
 32      this.spatialReference_=SpatialReferences.getSpatialReference(tileInfo.spatialReference.wkid);
 33      if (!this.spatialReference_) {
 34        throw new Error('unsupported Spatial Reference: ' + tileInfo.spatialReference.wkid);
 35      }
 36      this.zoomOffset_=Math.floor(Math.log(this.spatialReference_.getCircumference() / this.tileInfo_.lods[0].resolution / 256) / Math.LN2 + 0.5);
 37      this.fullExtent_=opt_fullExtent;
 38
 39
 40    }
 41
 42
 43
 44    /**
 45     * See <a href  = 'http://code.google.com/apis/maps/documentation/reference.html#GProjection'>GProjection</a>.
 46     * @param {GLatLng} gLatLng
 47     * @param {Number} zoom
 48     * @return {GPoint} pixel
 49     */
 50    override public function fromLatLngToPixel(gLatLng:LatLng, zoom:Number):flash.geom.Point {
 51      if (!gLatLng || isNaN(gLatLng.lat()) || isNaN(gLatLng.lng())) {
 52        return null;
 53      }
 54      var coords:Array=this.spatialReference_.forward([gLatLng.lng(), gLatLng.lat()]);
 55      var zoomIdx:int=zoom - this.zoomOffset_;
 56      var res:Number=this.getUnitsPerPixel(zoom);
 57      //!!!! must NOT round to integer, even it is fine in JS version, Flex version 
 58      // will cause HUGE shift!
 59      var px:Number=(coords[0] - (this.tileInfo_.origin.x as Number)) / res;
 60      var py:Number=((this.tileInfo_.origin.y as Number) - coords[1]) / res;
 61      
 62      return new Point(px, py);
 63    }
 64
 65    /**
 66     * Get resolution (Units per Pixel) at given zoom level.
 67     * @param {Number} zoom
 68     * @return Number
 69     */
 70    public function getUnitsPerPixel(zoom:int):Number {
 71      var zoomIdx:int=zoom - this.zoomOffset_;
 72      var res:Number=Number.MAX_VALUE;
 73      var factor:Number = 1;
 74      if (zoomIdx <0){
 75       // trace('invalid zoom: ' +zoom);
 76        factor = Math.pow(2, -zoomIdx);
 77        res=this.tileInfo_.lods[0].resolution * factor;
 78        
 79      } else if (zoomIdx > this.tileInfo_.lods.length-1){
 80       // trace('invalid zoom: ' +zoom);
 81        factor=Math.pow(2, zoom - this.maxResolution());
 82        res=this.tileInfo_.lods[this.tileInfo_.lods.length - 1].resolution / factor;
 83        
 84      } else {
 85        res=this.tileInfo_.lods[zoomIdx].resolution;
 86      }
 87      return res;
 88    }
 89
 90    /**
 91     * Get the scale at given level;
 92     * @param {Number} zoom
 93     * @return {Number}
 94    
 95    public function getScale(zoom:int):Number {
 96      var zoomIdx:int=zoom - this.zoomOffset_;
 97      var res:Number=0;
 98      if (this.tileInfo_.lods[zoomIdx]) {
 99        res=this.tileInfo_.lods[zoomIdx].scale;
100      } else {
101        //this is a special case when the maxZoom is set larger than what's actually defined in the tiling scheme.
102        // the goal is to allow map continue to zoom to extremely detail level by using ArcGISMapOverlay.
103        var factor:Number=Math.pow(2, zoom - this.maxResolution());
104        res=this.tileInfo_.lods[this.tileInfo_.lods.length - 1].scale / factor;
105      }
106      return res;
107    }
108    */
109    /**
110     * See <a href  = 'http://code.google.com/apis/maps/documentation/reference.html#GProjection'>GProjection</a>.
111     * @param {GPoint} pixel
112     * @param {Number} zoom
113     * @param {Boolean} unbound
114     * @return {GLatLng} gLatLng
115     */
116    override public function fromPixelToLatLng(pixel:flash.geom.Point, zoom:Number, unbound:Boolean=false):LatLng {
117      if (pixel === null) {
118        return null;
119      }
120      var zoomIdx:int=zoom - this.zoomOffset_;
121      var res:Number=this.getUnitsPerPixel(zoom);
122      var x:Number=pixel.x * res + (this.tileInfo_.origin.x as Number);
123      var y:Number=(this.tileInfo_.origin.y as Number)- pixel.y * res;
124      var ll:Array=this.spatialReference_.reverse([x, y]);
125      return new LatLng(ll[1], ll[0]);
126    }
127
128    /**
129     * See <a href  = 'http://code.google.com/apis/maps/documentation/reference.html#GProjection'>GProjection</a>.
130     * @param {Object} tile
131     * @param {Number} zoom
132     * @param {Number} tilesize
133     */
134    override public function tileCheckRange(tile:flash.geom.Point, zoom:Number, tilesize:Number):Boolean {
135      var zoomIdx:Number=zoom - this.zoomOffset_;
136      if (this.tileInfo_.lods[zoomIdx]) {
137        var b:*=this.fullExtent_;
138        if (!b) {
139          return true;
140        }
141        var minX:Number=tile.x * tilesize * this.tileInfo_.lods[zoomIdx].resolution + this.tileInfo_.origin.x;
142        var minY:Number=this.tileInfo_.origin.y - (tile.y + 1) * tilesize * this.tileInfo_.lods[zoomIdx].resolution;
143        var maxX:Number=(tile.x + 1) * tilesize * this.tileInfo_.lods[zoomIdx].resolution + this.tileInfo_.origin.x;
144        var maxY:Number=this.tileInfo_.origin.y - tile.y * tilesize * this.tileInfo_.lods[zoomIdx].resolution;
145        var ret:Boolean=!(b.xmin > maxX || b.xmax < minX || b.ymax < minY || b.ymin > maxY);
146        return ret;
147      } else {
148        return false;
149      }
150    }
151
152    /**
153     * See <a href  = 'http://code.google.com/apis/maps/documentation/reference.html#GProjection'>GProjection</a>.
154     * @param {Number} zoom
155     * @return {Number} numOfpixel
156     */
157    override public function getWrapWidth(zoom:Number):Number {
158      var zoomIdx:Number=zoom - this.zoomOffset_;
159      if (this.tileInfo_.lods[zoomIdx]) {
160        return this.spatialReference_.getCircumference() / this.tileInfo_.lods[zoomIdx].resolution;
161      } else {
162        return Number.MAX_VALUE;
163      }
164    }
165
166    /**
167     * Get the tile size used by this Projection. Shortcut to tileInfo.rows;
168     * @return {Number}
169     */
170    public function getTileSize():Number {
171      return this.tileInfo_.rows;
172    }
173
174    /**
175     * Get min zoom level of actual tiles
176     * @return {Number}
177     */
178    public function minResolution():Number {
179      return this.zoomOffset_;
180    }
181
182    /**
183     * Get max zoom level of actual tiles
184     * @return {Number}
185     */
186    public function maxResolution():Number {
187      return this.zoomOffset_ + this.tileInfo_.lods.length - 1;
188    }
189
190    /**
191     * Get the underline {@link ArcGISSpatialReference}
192     * @return {ArcGISSpatialReference}
193     */
194    public function getSpatialReference():SpatialReference {
195      return this.spatialReference_;
196    }
197
198    /**
199     *tile configuration used by Google Maps 
200     */
201    public static const GOOGLE_MAPS:ArcGISTileConfig=new ArcGISTileConfig({"rows": 256, "cols": 256, "dpi": 96, "format": "PNG8", "compressionQuality": 0, "origin": {"x": -20037508.342787, "y": 20037508.342787}, "spatialReference": {"wkid": 102113}, "lods": [{"level": 0, "resolution": 156543.033928, "scale": 591657527.591555}, {"level": 1, "resolution": 78271.5169639999, "scale": 295828763.795777}, {"level": 2, "resolution": 39135.7584820001, "scale": 147914381.897889}, {"level": 3, "resolution": 19567.8792409999, "scale": 73957190.948944}, {"level": 4, "resolution": 9783.93962049996, "scale": 36978595.474472}, {"level": 5, "resolution": 4891.96981024998, "scale": 18489297.737236}, {"level": 6, "resolution": 2445.98490512499, "scale": 9244648.868618}, {"level": 7, "resolution": 1222.99245256249, "scale": 4622324.434309}, {"level": 8, "resolution": 611.49622628138, "scale": 2311162.217155}, {"level": 9, "resolution": 305.748113140558, "scale": 1155581.108577}, {"level": 10, "resolution": 152.874056570411, "scale": 577790.554289}, {"level": 11, "resolution": 76.4370282850732, "scale": 288895.277144}, {"level": 12, "resolution": 38.2185141425366, "scale": 144447.638572}, {"level": 13, "resolution": 19.1092570712683, "scale": 72223.819286}, {"level": 14, "resolution": 9.55462853563415, "scale": 36111.909643}, {"level": 15, "resolution": 4.77731426794937, "scale": 18055.954822}, {"level": 16, "resolution": 2.38865713397468, "scale": 9027.977411}, {"level": 17, "resolution": 1.19432856685505, "scale": 4513.988705}, {"level": 18, "resolution": 0.597164283559817, "scale": 2256.994353}, {"level": 19, "resolution": 0.298582141647617, "scale": 1128.497176}]}, null);
202    /**
203     *tile configuration used by ArcGIS online 
204     */
205    public static const ARCGIS_ONLINE:ArcGISTileConfig=new ArcGISTileConfig({"rows": 512, "cols": 512, "dpi": 96, "origin": {"x": -180, "y": 90}, "spatialReference": {"wkid": 4326}, "lods": [{"level": 0, "resolution": 0.351562499999999, "scale": 147748799.285417}, {"level": 1, "resolution": 0.17578125, "scale": 73874399.6427087}, {"level": 2, "resolution": 0.0878906250000001, "scale": 36937199.8213544}, {"level": 3, "resolution": 0.0439453125, "scale": 18468599.9106772}, {"level": 4, "resolution": 0.02197265625, "scale": 9234299.95533859}, {"level": 5, "resolution": 0.010986328125, "scale": 4617149.97766929}, {"level": 6, "resolution": 0.0054931640625, "scale": 2308574.98883465}, {"level": 7, "resolution": 0.00274658203124999, "scale": 1154287.49441732}, {"level": 8, "resolution": 0.001373291015625, "scale": 577143.747208662}, {"level": 9, "resolution": 0.0006866455078125, "scale": 288571.873604331}, {"level": 10, "resolution": 0.000343322753906249, "scale": 144285.936802165}, {"level": 11, "resolution": 0.000171661376953125, "scale": 72142.9684010827}, {"level": 12, "resolution": 8.58306884765626E-05, "scale": 36071.4842005414}, {"level": 13, "resolution": 4.29153442382813E-05, "scale": 18035.7421002707}, {"level": 14, "resolution": 2.14576721191406E-05, "scale": 9017.87105013534}, {"level": 15, "resolution": 1.07288360595703E-05, "scale": 4508.93552506767}]});
206
207
208  }
209}