Revert "add TileLayerRenderer.getPreferredZ_ plus tests". As noted by @twpayne, TileGrid.getZForResolution already returns the "preferred" z for an arbitrary resolution.

This reverts commit 8f5d0ac642.

src/ol/dom/tilelayerrenderer.js

@@ -134,39 +134,3 @@ ol.dom.TileLayerRenderer.prototype.removeInvisibleTiles_ = function(
     }
   }
 };
-
-
-/**
- * Get the best/preferred z for an arbitrary resolution.
- * @private
- * @param {number} resolution Resolution.
- * @return {number} Z.
- * TODO: this should probably be shared with the WebGL TileLayerRenderer,
- * but our current class hierarchy does not allow this sharing.
-*/
-ol.dom.TileLayerRenderer.prototype.getPreferredZ_ = (function() {
-  var cache = {};
-  return function(resolution) {
-    if (resolution in cache) {
-      return cache[resolution];
-    }
-    var tileLayer = /** @type {ol.TileLayer} */ (this.getLayer());
-    var tileStore = tileLayer.getStore();
-    var tileGrid = tileStore.getTileGrid();
-    var gridResolutions = tileGrid.getResolutions();
-    var minDiff = Number.POSITIVE_INFINITY;
-    var candidate, diff, z, r;
-    for (var i = 0, ii = gridResolutions.length; i < ii; ++i) {
-      // assumes sorted resolutions
-      diff = Math.abs(resolution - gridResolutions[i]);
-      if (diff < minDiff) {
-        z = i;
-        minDiff = diff;
-      } else {
-        break;
-      }
-    }
-    cache[resolution] = z;
-    return z;
-  };
-})();

src/ol/dom/tilelayerrenderer_test.js

@@ -1,73 +0,0 @@
-goog.require('goog.dom');
-goog.require('goog.dom.TagName');
-goog.require('goog.testing.jsunit');
-goog.require('ol.Coordinate');
-goog.require('ol.Extent');
-goog.require('ol.Projection');
-goog.require('ol.TileGrid');
-goog.require('ol.TileLayer');
-goog.require('ol.TileStore');
-goog.require('ol.TileUrlFunction');
-goog.require('ol.dom.Map');
-goog.require('ol.dom.TileLayerRenderer');
-
-
-var tileLayerRenderer;
-
-
-function setUp() {
-  var map = new ol.dom.Map(
-      goog.dom.createElement(goog.dom.TagName.DIV));
-
-  var resolutions = [100, 80, 50, 10, 1, 0.1];
-  var extent = new ol.Extent(0, 0, 100000, 100000);
-  var origin = new ol.Coordinate(0, 0);
-  var tileGrid = new ol.TileGrid(resolutions, extent, origin);
-
-  var projection = ol.Projection.getFromCode('EPSG:3857');
-  var tileUrlFunction = ol.TileUrlFunction.createFromTemplate('{z}/{x}/{y}');
-  var tileStore = new ol.TileStore(projection, tileGrid, tileUrlFunction);
-
-  var tileLayer = new ol.TileLayer(tileStore);
-
-  tileLayerRenderer = new ol.dom.TileLayerRenderer(
-      map, tileLayer,
-      goog.dom.createElement(goog.dom.TagName.DIV));
-}
-
-
-function testGetPreferredZ() {
-
-  var z;
-
-  // gets the max resolution.
-  z = tileLayerRenderer.getPreferredZ_(100);
-  assertEquals(0, z);
-
-  // gets the min resolution.
-  z = tileLayerRenderer.getPreferredZ_(0.1);
-  assertEquals(5, z);
-
-  // gets the max when bigger.
-  z = tileLayerRenderer.getPreferredZ_(200);
-  assertEquals(0, z);
-
-  // gets the min when smaller.
-  z = tileLayerRenderer.getPreferredZ_(0.01);
-  assertEquals(5, z);
-
-  // gets the first when in the middle.
-  z = tileLayerRenderer.getPreferredZ_(90);
-  assertEquals(0, z);
-
-  // gets the closer when elsewhere.
-
-  z = tileLayerRenderer.getPreferredZ_(89);
-  assertEquals(1, z);
-
-  z = tileLayerRenderer.getPreferredZ_(49);
-  assertEquals(2, z);
-
-  z = tileLayerRenderer.getPreferredZ_(0.5);
-  assertEquals(5, z);
-}