offline-editor-js/lib/tiles/tilingScheme.js

"use strict"

define([
	"esri/geometry"
	], function(geometry)
	{

	var TilingScheme = function(layer)
	{
		this.tileInfo = layer.tileInfo;
	}

	TilingScheme.prototype = 
	{
		getCellIdFromXy: function(x,y,level)
		{
			var col = Math.floor((x-this.tileInfo.origin.x) / (this.tileInfo.cols*this.tileInfo.lods[level].resolution));
			var row = Math.floor((this.tileInfo.origin.y-y) / (this.tileInfo.rows*this.tileInfo.lods[level].resolution));
			return [col,row];
		},

		getCellPolygonFromCellId: function(cellId,level)
		{
		    var col1 = cellId[0];
		    var row1 = cellId[1];
		    var col2 = col1+1;
		    var row2 = row1+1;

		    var x1 = this.tileInfo.origin.x + (col1 * this.tileInfo.cols * this.tileInfo.lods[level].resolution);
		    var y1 = this.tileInfo.origin.y - (row1 * this.tileInfo.rows * this.tileInfo.lods[level].resolution);
		    var x2 = this.tileInfo.origin.x + (col2 * this.tileInfo.cols * this.tileInfo.lods[level].resolution);
		    var y2 = this.tileInfo.origin.y - (row2 * this.tileInfo.rows * this.tileInfo.lods[level].resolution);

		    var polygon = new geometry.Polygon(this.tileInfo.spatialReference);
		    polygon.addRing([
				[x1,y1],  // clockwise
				[x2,y1],
				[x2,y2],
				[x1,y2],
				[x1,y1],
			]);
		    return polygon;
		},

		getAllCellIdsInExtent : function(extent, gridLevel)
		{
			var cellId0 = this.getCellIdFromXy(extent.xmin, extent.ymin, gridLevel);
			var cellId1 = this.getCellIdFromXy(extent.xmax, extent.ymax, gridLevel);

			var i,j;
			var i0 = Math.max(Math.min(cellId0[0], cellId1[0]), this.tileInfo.lods[gridLevel].startTileCol);
			var i1 = Math.min(Math.max(cellId0[0], cellId1[0]), this.tileInfo.lods[gridLevel].endTileCol);
			var j0 = Math.max(Math.min(cellId0[1], cellId1[1]), this.tileInfo.lods[gridLevel].startTileRow);
			var j1 = Math.min(Math.max(cellId0[1], cellId1[1]), this.tileInfo.lods[gridLevel].endTileRow);

			var cellIds = [];

			for(i=i0; i<=i1; i++)
				for(j=j0; j<=j1; j++)
				{
					cellIds.push([i,j]);
				}

			return cellIds;
		}
	}

	return TilingScheme;
});