diff --git a/src/ol/renderer/canvas/canvasimagelayerrenderer.js b/src/ol/renderer/canvas/canvasimagelayerrenderer.js
index 2f80579ae7..c752dd4630 100644
--- a/src/ol/renderer/canvas/canvasimagelayerrenderer.js
+++ b/src/ol/renderer/canvas/canvasimagelayerrenderer.js
@@ -79,7 +79,7 @@ ol.renderer.canvas.ImageLayer.prototype.forEachFeatureAtCoordinate =
  */
 ol.renderer.canvas.ImageLayer.prototype.forEachLayerAtPixel =
     function(pixel, frameState, callback, thisArg) {
-  if (goog.isNull(this.getImage())) {
+  if (!this.getImage()) {
     return undefined;
   }
 
@@ -99,7 +99,7 @@ ol.renderer.canvas.ImageLayer.prototype.forEachLayerAtPixel =
     }
   } else {
     // for all other image sources directly check the image
-    if (goog.isNull(this.imageTransformInv_)) {
+    if (!this.imageTransformInv_) {
       this.imageTransformInv_ = goog.vec.Mat4.createNumber();
       goog.vec.Mat4.invert(this.imageTransform_, this.imageTransformInv_);
     }
@@ -107,7 +107,7 @@ ol.renderer.canvas.ImageLayer.prototype.forEachLayerAtPixel =
     var pixelOnCanvas =
         this.getPixelOnCanvas(pixel, this.imageTransformInv_);
 
-    if (goog.isNull(this.hitCanvasContext_)) {
+    if (!this.hitCanvasContext_) {
       this.hitCanvasContext_ = ol.dom.createCanvasContext2D(1, 1);
     }
 
@@ -129,8 +129,7 @@ ol.renderer.canvas.ImageLayer.prototype.forEachLayerAtPixel =
  * @inheritDoc
  */
 ol.renderer.canvas.ImageLayer.prototype.getImage = function() {
-  return goog.isNull(this.image_) ?
-      null : this.image_.getImage();
+  return !this.image_ ? null : this.image_.getImage();
 };
 
 
@@ -172,14 +171,14 @@ ol.renderer.canvas.ImageLayer.prototype.prepareFrame =
       !ol.extent.isEmpty(renderedExtent)) {
     var projection = viewState.projection;
     var sourceProjection = imageSource.getProjection();
-    if (!goog.isNull(sourceProjection)) {
+    if (sourceProjection) {
       goog.asserts.assert(ol.proj.equivalent(projection, sourceProjection),
           'projection and sourceProjection are equivalent');
       projection = sourceProjection;
     }
     image = imageSource.getImage(
         renderedExtent, viewResolution, pixelRatio, projection);
-    if (!goog.isNull(image)) {
+    if (image) {
       var loaded = this.loadImage(image);
       if (loaded) {
         this.image_ = image;
@@ -187,7 +186,7 @@ ol.renderer.canvas.ImageLayer.prototype.prepareFrame =
     }
   }
 
-  if (!goog.isNull(this.image_)) {
+  if (this.image_) {
     image = this.image_;
     var imageExtent = image.getExtent();
     var imageResolution = image.getResolution();
diff --git a/src/ol/renderer/canvas/canvaslayerrenderer.js b/src/ol/renderer/canvas/canvaslayerrenderer.js
index b011d30222..749297a6ca 100644
--- a/src/ol/renderer/canvas/canvaslayerrenderer.js
+++ b/src/ol/renderer/canvas/canvaslayerrenderer.js
@@ -44,7 +44,7 @@ ol.renderer.canvas.Layer.prototype.composeFrame =
   this.dispatchPreComposeEvent(context, frameState);
 
   var image = this.getImage();
-  if (!goog.isNull(image)) {
+  if (image) {
 
     // clipped rendering if layer extent is set
     var extent = layerState.extent;
@@ -252,7 +252,7 @@ ol.renderer.canvas.Layer.testCanvasSize = (function() {
   var imageData = null;
 
   return function(size) {
-    if (goog.isNull(context)) {
+    if (!context) {
       context = ol.dom.createCanvasContext2D(1, 1);
       imageData = context.createImageData(1, 1);
       var data = imageData.data;
diff --git a/src/ol/renderer/canvas/canvasmaprenderer.js b/src/ol/renderer/canvas/canvasmaprenderer.js
index edefe257ad..21c9f88285 100644
--- a/src/ol/renderer/canvas/canvasmaprenderer.js
+++ b/src/ol/renderer/canvas/canvasmaprenderer.js
@@ -146,7 +146,7 @@ ol.renderer.canvas.Map.prototype.getType = function() {
  */
 ol.renderer.canvas.Map.prototype.renderFrame = function(frameState) {
 
-  if (goog.isNull(frameState)) {
+  if (!frameState) {
     if (this.renderedVisible_) {
       goog.style.setElementShown(this.canvas_, false);
       this.renderedVisible_ = false;
diff --git a/src/ol/renderer/canvas/canvastilelayerrenderer.js b/src/ol/renderer/canvas/canvastilelayerrenderer.js
index 2ea1b9bd3b..7cca1ebb1b 100644
--- a/src/ol/renderer/canvas/canvastilelayerrenderer.js
+++ b/src/ol/renderer/canvas/canvastilelayerrenderer.js
@@ -231,12 +231,12 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame =
   var canvasHeight = tilePixelSize[1] * tileRange.getHeight();
 
   var canvas, context;
-  if (goog.isNull(this.canvas_)) {
-    goog.asserts.assert(goog.isNull(this.canvasSize_),
+  if (!this.canvas_) {
+    goog.asserts.assert(!this.canvasSize_,
         'canvasSize is null (because canvas is null)');
-    goog.asserts.assert(goog.isNull(this.context_),
+    goog.asserts.assert(!this.context_,
         'context is null (because canvas is null)');
-    goog.asserts.assert(goog.isNull(this.renderedCanvasTileRange_),
+    goog.asserts.assert(!this.renderedCanvasTileRange_,
         'renderedCanvasTileRange is null (because canvas is null)');
     context = ol.dom.createCanvasContext2D(canvasWidth, canvasHeight);
     this.canvas_ = context.canvas;
@@ -245,9 +245,9 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame =
     this.canvasTooBig_ =
         !ol.renderer.canvas.Layer.testCanvasSize(this.canvasSize_);
   } else {
-    goog.asserts.assert(!goog.isNull(this.canvasSize_),
+    goog.asserts.assert(this.canvasSize_,
         'non-null canvasSize (because canvas is not null)');
-    goog.asserts.assert(!goog.isNull(this.context_),
+    goog.asserts.assert(this.context_,
         'non-null context (because canvas is not null)');
     canvas = this.canvas_;
     context = this.context_;
@@ -277,7 +277,7 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame =
   }
 
   var canvasTileRange, canvasTileRangeWidth, minX, minY;
-  if (goog.isNull(this.renderedCanvasTileRange_)) {
+  if (!this.renderedCanvasTileRange_) {
     canvasTileRangeWidth = canvasWidth / tilePixelSize[0];
     var canvasTileRangeHeight = canvasHeight / tilePixelSize[1];
     minX = tileRange.minX -
@@ -336,7 +336,7 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame =
         tilesToClear.push(tile);
         childTileRange = tileGrid.getTileCoordChildTileRange(
             tile.tileCoord, tmpTileRange, tmpExtent);
-        if (!goog.isNull(childTileRange)) {
+        if (childTileRange) {
           findLoadedTiles(z + 1, childTileRange);
         }
       }
@@ -450,11 +450,11 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame =
  */
 ol.renderer.canvas.TileLayer.prototype.forEachLayerAtPixel =
     function(pixel, frameState, callback, thisArg) {
-  if (goog.isNull(this.context_)) {
+  if (!this.context_) {
     return undefined;
   }
 
-  if (goog.isNull(this.imageTransformInv_)) {
+  if (!this.imageTransformInv_) {
     this.imageTransformInv_ = goog.vec.Mat4.createNumber();
     goog.vec.Mat4.invert(this.imageTransform_, this.imageTransformInv_);
   }
diff --git a/src/ol/renderer/canvas/canvasvectorlayerrenderer.js b/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
index 14f27ef406..d0c96994cc 100644
--- a/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
+++ b/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
@@ -92,7 +92,7 @@ ol.renderer.canvas.VectorLayer.prototype.composeFrame =
   this.dispatchPreComposeEvent(context, frameState, transform);
 
   var replayGroup = this.replayGroup_;
-  if (!goog.isNull(replayGroup) && !replayGroup.isEmpty()) {
+  if (replayGroup && !replayGroup.isEmpty()) {
     var layer = this.getLayer();
     var replayContext;
     if (layer.hasListener(ol.render.EventType.RENDER)) {
@@ -156,7 +156,7 @@ ol.renderer.canvas.VectorLayer.prototype.composeFrame =
  */
 ol.renderer.canvas.VectorLayer.prototype.forEachFeatureAtCoordinate =
     function(coordinate, frameState, callback, thisArg) {
-  if (goog.isNull(this.replayGroup_)) {
+  if (!this.replayGroup_) {
     return undefined;
   } else {
     var resolution = frameState.viewState.resolution;
@@ -290,7 +290,7 @@ ol.renderer.canvas.VectorLayer.prototype.prepareFrame =
       this.dirty_ = this.dirty_ || dirty;
     }
   };
-  if (!goog.isNull(vectorLayerRenderOrder)) {
+  if (vectorLayerRenderOrder) {
     /** @type {Array.<ol.Feature>} */
     var features = [];
     vectorSource.forEachFeatureInExtentAtResolution(extent, resolution,
diff --git a/src/ol/renderer/dom/domimagelayerrenderer.js b/src/ol/renderer/dom/domimagelayerrenderer.js
index f4245e8217..77760bef1a 100644
--- a/src/ol/renderer/dom/domimagelayerrenderer.js
+++ b/src/ol/renderer/dom/domimagelayerrenderer.js
@@ -103,14 +103,14 @@ ol.renderer.dom.ImageLayer.prototype.prepareFrame =
       !ol.extent.isEmpty(renderedExtent)) {
     var projection = viewState.projection;
     var sourceProjection = imageSource.getProjection();
-    if (!goog.isNull(sourceProjection)) {
+    if (sourceProjection) {
       goog.asserts.assert(ol.proj.equivalent(projection, sourceProjection),
           'projection and sourceProjection are equivalent');
       projection = sourceProjection;
     }
     var image_ = imageSource.getImage(renderedExtent, viewResolution,
         frameState.pixelRatio, projection);
-    if (!goog.isNull(image_)) {
+    if (image_) {
       var loaded = this.loadImage(image_);
       if (loaded) {
         image = image_;
@@ -118,7 +118,7 @@ ol.renderer.dom.ImageLayer.prototype.prepareFrame =
     }
   }
 
-  if (!goog.isNull(image)) {
+  if (image) {
     var imageExtent = image.getExtent();
     var imageResolution = image.getResolution();
     var transform = goog.vec.Mat4.createNumber();
diff --git a/src/ol/renderer/dom/dommaprenderer.js b/src/ol/renderer/dom/dommaprenderer.js
index 67f86cefcd..4937cea77b 100644
--- a/src/ol/renderer/dom/dommaprenderer.js
+++ b/src/ol/renderer/dom/dommaprenderer.js
@@ -159,7 +159,7 @@ ol.renderer.dom.Map.prototype.getType = function() {
  */
 ol.renderer.dom.Map.prototype.renderFrame = function(frameState) {
 
-  if (goog.isNull(frameState)) {
+  if (!frameState) {
     if (this.renderedVisible_) {
       goog.style.setElementShown(this.layersPane_, false);
       this.renderedVisible_ = false;
diff --git a/src/ol/renderer/dom/domtilelayerrenderer.js b/src/ol/renderer/dom/domtilelayerrenderer.js
index 49197cd7cf..b8f2cca1a9 100644
--- a/src/ol/renderer/dom/domtilelayerrenderer.js
+++ b/src/ol/renderer/dom/domtilelayerrenderer.js
@@ -148,7 +148,7 @@ ol.renderer.dom.TileLayer.prototype.prepareFrame =
       if (!fullyLoaded) {
         childTileRange = tileGrid.getTileCoordChildTileRange(
             tile.tileCoord, tmpTileRange, tmpExtent);
-        if (!goog.isNull(childTileRange)) {
+        if (childTileRange) {
           findLoadedTiles(z + 1, childTileRange);
         }
       }
@@ -376,7 +376,7 @@ ol.renderer.dom.TileLayerZ_.prototype.addTile = function(tile, tileGutter) {
       ((tileCoordX - this.tileCoordOrigin_[1]) * tileSize[0]) + 'px';
   tileElementStyle.top =
       ((this.tileCoordOrigin_[2] - tileCoordY) * tileSize[1]) + 'px';
-  if (goog.isNull(this.documentFragment_)) {
+  if (!this.documentFragment_) {
     this.documentFragment_ = document.createDocumentFragment();
   }
   goog.dom.appendChild(this.documentFragment_, tileElement);
@@ -388,7 +388,7 @@ ol.renderer.dom.TileLayerZ_.prototype.addTile = function(tile, tileGutter) {
  * FIXME empty description for jsdoc
  */
 ol.renderer.dom.TileLayerZ_.prototype.finalizeAddTiles = function() {
-  if (!goog.isNull(this.documentFragment_)) {
+  if (this.documentFragment_) {
     goog.dom.appendChild(this.target, this.documentFragment_);
     this.documentFragment_ = null;
   }
diff --git a/src/ol/renderer/dom/domvectorlayerrenderer.js b/src/ol/renderer/dom/domvectorlayerrenderer.js
index 28844f426e..3239f82c72 100644
--- a/src/ol/renderer/dom/domvectorlayerrenderer.js
+++ b/src/ol/renderer/dom/domvectorlayerrenderer.js
@@ -138,7 +138,7 @@ ol.renderer.dom.VectorLayer.prototype.composeFrame =
 
   var replayGroup = this.replayGroup_;
 
-  if (!goog.isNull(replayGroup) && !replayGroup.isEmpty()) {
+  if (replayGroup && !replayGroup.isEmpty()) {
 
     context.globalAlpha = layerState.opacity;
     replayGroup.replay(context, pixelRatio, transform, viewRotation,
@@ -178,7 +178,7 @@ ol.renderer.dom.VectorLayer.prototype.dispatchEvent_ =
  */
 ol.renderer.dom.VectorLayer.prototype.forEachFeatureAtCoordinate =
     function(coordinate, frameState, callback, thisArg) {
-  if (goog.isNull(this.replayGroup_)) {
+  if (!this.replayGroup_) {
     return undefined;
   } else {
     var resolution = frameState.viewState.resolution;
@@ -298,7 +298,7 @@ ol.renderer.dom.VectorLayer.prototype.prepareFrame =
       this.dirty_ = this.dirty_ || dirty;
     }
   };
-  if (!goog.isNull(vectorLayerRenderOrder)) {
+  if (vectorLayerRenderOrder) {
     /** @type {Array.<ol.Feature>} */
     var features = [];
     vectorSource.forEachFeatureInExtentAtResolution(extent, resolution,
diff --git a/src/ol/renderer/maprenderer.js b/src/ol/renderer/maprenderer.js
index bd2a57adb5..7cd56f3c00 100644
--- a/src/ol/renderer/maprenderer.js
+++ b/src/ol/renderer/maprenderer.js
@@ -71,8 +71,8 @@ goog.inherits(ol.renderer.Map, goog.Disposable);
 ol.renderer.Map.prototype.calculateMatrices2D = function(frameState) {
   var viewState = frameState.viewState;
   var coordinateToPixelMatrix = frameState.coordinateToPixelMatrix;
-  goog.asserts.assert(!goog.isNull(coordinateToPixelMatrix),
-      'frameState has non-null coordinateToPixelMatrix');
+  goog.asserts.assert(coordinateToPixelMatrix,
+      'frameState has a coordinateToPixelMatrix');
   ol.vec.Mat4.makeTransform2D(coordinateToPixelMatrix,
       frameState.size[0] / 2, frameState.size[1] / 2,
       1 / viewState.resolution, -1 / viewState.resolution,
@@ -171,7 +171,7 @@ ol.renderer.Map.prototype.forEachFeatureAtCoordinate =
         (ol.layer.Layer.visibleAtResolution(layerState, viewResolution) &&
         layerFilter.call(thisArg2, layer))) {
       var layerRenderer = this.getLayerRenderer(layer);
-      if (!goog.isNull(layer.getSource())) {
+      if (layer.getSource()) {
         result = layerRenderer.forEachFeatureAtCoordinate(
             layer.getSource().getWrapX() ? translatedCoordinate : coordinate,
             frameState, callback, thisArg);
@@ -347,7 +347,7 @@ ol.renderer.Map.prototype.removeUnusedLayerRenderers_ =
     function(map, frameState) {
   var layerKey;
   for (layerKey in this.layerRenderers_) {
-    if (goog.isNull(frameState) || !(layerKey in frameState.layerStates)) {
+    if (!frameState || !(layerKey in frameState.layerStates)) {
       goog.dispose(this.removeLayerRendererByKey_(layerKey));
     }
   }
diff --git a/src/ol/renderer/webgl/webglimagelayerrenderer.js b/src/ol/renderer/webgl/webglimagelayerrenderer.js
index 8f8964d65e..317544fc66 100644
--- a/src/ol/renderer/webgl/webglimagelayerrenderer.js
+++ b/src/ol/renderer/webgl/webglimagelayerrenderer.js
@@ -126,19 +126,19 @@ ol.renderer.webgl.ImageLayer.prototype.prepareFrame =
       !ol.extent.isEmpty(renderedExtent)) {
     var projection = viewState.projection;
     var sourceProjection = imageSource.getProjection();
-    if (!goog.isNull(sourceProjection)) {
+    if (sourceProjection) {
       goog.asserts.assert(ol.proj.equivalent(projection, sourceProjection),
           'projection and sourceProjection are equivalent');
       projection = sourceProjection;
     }
     var image_ = imageSource.getImage(renderedExtent, viewResolution,
         pixelRatio, projection);
-    if (!goog.isNull(image_)) {
+    if (image_) {
       var loaded = this.loadImage(image_);
       if (loaded) {
         image = image_;
         texture = this.createTexture_(image_);
-        if (!goog.isNull(this.texture)) {
+        if (this.texture) {
           frameState.postRenderFunctions.push(
               goog.partial(
                   /**
@@ -155,8 +155,8 @@ ol.renderer.webgl.ImageLayer.prototype.prepareFrame =
     }
   }
 
-  if (!goog.isNull(image)) {
-    goog.asserts.assert(!goog.isNull(texture), 'texture is not null');
+  if (image) {
+    goog.asserts.assert(texture, 'texture is truthy');
 
     var canvas = this.mapRenderer.getContext().getCanvas();
 
@@ -234,7 +234,7 @@ ol.renderer.webgl.ImageLayer.prototype.hasFeatureAtCoordinate =
  */
 ol.renderer.webgl.ImageLayer.prototype.forEachLayerAtPixel =
     function(pixel, frameState, callback, thisArg) {
-  if (goog.isNull(this.image_) || goog.isNull(this.image_.getImage())) {
+  if (!this.image_ || !this.image_.getImage()) {
     return undefined;
   }
 
@@ -256,7 +256,7 @@ ol.renderer.webgl.ImageLayer.prototype.forEachLayerAtPixel =
     var imageSize =
         [this.image_.getImage().width, this.image_.getImage().height];
 
-    if (goog.isNull(this.hitTransformationMatrix_)) {
+    if (!this.hitTransformationMatrix_) {
       this.hitTransformationMatrix_ = this.getHitTransformationMatrix_(
           frameState.size, imageSize);
     }
@@ -271,7 +271,7 @@ ol.renderer.webgl.ImageLayer.prototype.forEachLayerAtPixel =
       return undefined;
     }
 
-    if (goog.isNull(this.hitCanvasContext_)) {
+    if (!this.hitCanvasContext_) {
       this.hitCanvasContext_ = ol.dom.createCanvasContext2D(1, 1);
     }
 
diff --git a/src/ol/renderer/webgl/webgllayerrenderer.js b/src/ol/renderer/webgl/webgllayerrenderer.js
index 3e5a56c3b6..d03e23edfe 100644
--- a/src/ol/renderer/webgl/webgllayerrenderer.js
+++ b/src/ol/renderer/webgl/webgllayerrenderer.js
@@ -151,7 +151,7 @@ ol.renderer.webgl.Layer.prototype.composeFrame =
   var program = context.getProgram(fragmentShader, vertexShader);
 
   var locations;
-  if (goog.isNull(this.defaultLocations_)) {
+  if (!this.defaultLocations_) {
     locations =
         new ol.renderer.webgl.map.shader.Default.Locations(gl, program);
     this.defaultLocations_ = locations;
diff --git a/src/ol/renderer/webgl/webglmaprenderer.js b/src/ol/renderer/webgl/webglmaprenderer.js
index c368f6965c..ac51b46854 100644
--- a/src/ol/renderer/webgl/webglmaprenderer.js
+++ b/src/ol/renderer/webgl/webglmaprenderer.js
@@ -100,7 +100,7 @@ ol.renderer.webgl.Map = function(container, map) {
     preserveDrawingBuffer: false,
     stencil: true
   });
-  goog.asserts.assert(!goog.isNull(this.gl_), 'got a WebGLRenderingContext');
+  goog.asserts.assert(this.gl_, 'got a WebGLRenderingContext');
 
   /**
    * @private
@@ -194,7 +194,7 @@ ol.renderer.webgl.Map.prototype.bindTileTexture =
   var tileKey = tile.getKey();
   if (this.textureCache_.containsKey(tileKey)) {
     var textureCacheEntry = this.textureCache_.get(tileKey);
-    goog.asserts.assert(!goog.isNull(textureCacheEntry),
+    goog.asserts.assert(textureCacheEntry,
         'a texture cache entry exists for key %s', tileKey);
     gl.bindTexture(goog.webgl.TEXTURE_2D, textureCacheEntry.texture);
     if (textureCacheEntry.magFilter != magFilter) {
@@ -309,7 +309,7 @@ ol.renderer.webgl.Map.prototype.disposeInternal = function() {
          *     Texture cache entry.
          */
         function(textureCacheEntry) {
-          if (!goog.isNull(textureCacheEntry)) {
+          if (textureCacheEntry) {
             gl.deleteTexture(textureCacheEntry.texture);
           }
         });
@@ -330,7 +330,7 @@ ol.renderer.webgl.Map.prototype.expireCache_ = function(map, frameState) {
   while (this.textureCache_.getCount() - this.textureCacheFrameMarkerCount_ >
       ol.WEBGL_TEXTURE_CACHE_HIGH_WATER_MARK) {
     textureCacheEntry = this.textureCache_.peekLast();
-    if (goog.isNull(textureCacheEntry)) {
+    if (!textureCacheEntry) {
       if (+this.textureCache_.peekLastKey() == frameState.index) {
         break;
       } else {
@@ -452,7 +452,7 @@ ol.renderer.webgl.Map.prototype.renderFrame = function(frameState) {
     return false;
   }
 
-  if (goog.isNull(frameState)) {
+  if (!frameState) {
     if (this.renderedVisible_) {
       goog.style.setElementShown(this.canvas_, false);
       this.renderedVisible_ = false;
diff --git a/src/ol/renderer/webgl/webgltilelayerrenderer.js b/src/ol/renderer/webgl/webgltilelayerrenderer.js
index dc644383c4..6752062548 100644
--- a/src/ol/renderer/webgl/webgltilelayerrenderer.js
+++ b/src/ol/renderer/webgl/webgltilelayerrenderer.js
@@ -186,7 +186,7 @@ ol.renderer.webgl.TileLayer.prototype.prepareFrame =
       extent, tileResolution);
 
   var framebufferExtent;
-  if (!goog.isNull(this.renderedTileRange_) &&
+  if (this.renderedTileRange_ &&
       this.renderedTileRange_.equals(tileRange) &&
       this.renderedRevision_ == tileSource.getRevision()) {
     framebufferExtent = this.renderedFramebufferExtent_;
@@ -218,7 +218,7 @@ ol.renderer.webgl.TileLayer.prototype.prepareFrame =
 
     var program = context.getProgram(this.fragmentShader_, this.vertexShader_);
     context.useProgram(program);
-    if (goog.isNull(this.locations_)) {
+    if (!this.locations_) {
       this.locations_ =
           new ol.renderer.webgl.tilelayer.shader.Locations(gl, program);
     }
@@ -275,7 +275,7 @@ ol.renderer.webgl.TileLayer.prototype.prepareFrame =
         if (!fullyLoaded) {
           childTileRange = tileGrid.getTileCoordChildTileRange(
               tile.tileCoord, tmpTileRange, tmpExtent);
-          if (!goog.isNull(childTileRange)) {
+          if (childTileRange) {
             findLoadedTiles(z + 1, childTileRange);
           }
         }
@@ -377,7 +377,7 @@ ol.renderer.webgl.TileLayer.prototype.prepareFrame =
  */
 ol.renderer.webgl.TileLayer.prototype.forEachLayerAtPixel =
     function(pixel, frameState, callback, thisArg) {
-  if (goog.isNull(this.framebuffer)) {
+  if (!this.framebuffer) {
     return undefined;
   }
 
diff --git a/src/ol/renderer/webgl/webglvectorlayerrenderer.js b/src/ol/renderer/webgl/webglvectorlayerrenderer.js
index ae53499fcd..211a9f37ed 100644
--- a/src/ol/renderer/webgl/webglvectorlayerrenderer.js
+++ b/src/ol/renderer/webgl/webglvectorlayerrenderer.js
@@ -78,7 +78,7 @@ ol.renderer.webgl.VectorLayer.prototype.composeFrame =
   this.layerState_ = layerState;
   var viewState = frameState.viewState;
   var replayGroup = this.replayGroup_;
-  if (!goog.isNull(replayGroup) && !replayGroup.isEmpty()) {
+  if (replayGroup && !replayGroup.isEmpty()) {
     replayGroup.replay(context,
         viewState.center, viewState.resolution, viewState.rotation,
         frameState.size, frameState.pixelRatio, layerState.opacity,
@@ -93,7 +93,7 @@ ol.renderer.webgl.VectorLayer.prototype.composeFrame =
  */
 ol.renderer.webgl.VectorLayer.prototype.disposeInternal = function() {
   var replayGroup = this.replayGroup_;
-  if (!goog.isNull(replayGroup)) {
+  if (replayGroup) {
     var context = this.mapRenderer.getContext();
     replayGroup.getDeleteResourcesFunction(context)();
     this.replayGroup_ = null;
@@ -107,7 +107,7 @@ ol.renderer.webgl.VectorLayer.prototype.disposeInternal = function() {
  */
 ol.renderer.webgl.VectorLayer.prototype.forEachFeatureAtCoordinate =
     function(coordinate, frameState, callback, thisArg) {
-  if (goog.isNull(this.replayGroup_) || goog.isNull(this.layerState_)) {
+  if (!this.replayGroup_ || !this.layerState_) {
     return undefined;
   } else {
     var context = this.mapRenderer.getContext();
@@ -141,7 +141,7 @@ ol.renderer.webgl.VectorLayer.prototype.forEachFeatureAtCoordinate =
  */
 ol.renderer.webgl.VectorLayer.prototype.hasFeatureAtCoordinate =
     function(coordinate, frameState) {
-  if (goog.isNull(this.replayGroup_) || goog.isNull(this.layerState_)) {
+  if (!this.replayGroup_ || !this.layerState_) {
     return false;
   } else {
     var context = this.mapRenderer.getContext();
@@ -233,7 +233,7 @@ ol.renderer.webgl.VectorLayer.prototype.prepareFrame =
     return true;
   }
 
-  if (!goog.isNull(this.replayGroup_)) {
+  if (this.replayGroup_) {
     frameState.postRenderFunctions.push(
         this.replayGroup_.getDeleteResourcesFunction(context));
   }
@@ -266,7 +266,7 @@ ol.renderer.webgl.VectorLayer.prototype.prepareFrame =
       this.dirty_ = this.dirty_ || dirty;
     }
   };
-  if (!goog.isNull(vectorLayerRenderOrder)) {
+  if (vectorLayerRenderOrder) {
     /** @type {Array.<ol.Feature>} */
     var features = [];
     vectorSource.forEachFeatureInExtentAtResolution(extent, resolution,