diff --git a/src/ol/webgl/buffer.js b/src/ol/webgl/buffer.js
index eb4caae934..d7f7c43f08 100644
--- a/src/ol/webgl/buffer.js
+++ b/src/ol/webgl/buffer.js
@@ -4,52 +4,56 @@ goog.require('ol');
 goog.require('ol.webgl');
 
 
-/**
- * @constructor
- * @param {Array.<number>=} opt_arr Array.
- * @param {number=} opt_usage Usage.
- * @struct
- */
-ol.webgl.Buffer = function(opt_arr, opt_usage) {
+if (ol.ENABLE_WEBGL) {
 
   /**
-   * @private
-   * @type {Array.<number>}
+   * @constructor
+   * @param {Array.<number>=} opt_arr Array.
+   * @param {number=} opt_usage Usage.
+   * @struct
    */
-  this.arr_ = opt_arr !== undefined ? opt_arr : [];
+  ol.webgl.Buffer = function(opt_arr, opt_usage) {
+
+    /**
+     * @private
+     * @type {Array.<number>}
+     */
+    this.arr_ = opt_arr !== undefined ? opt_arr : [];
+
+    /**
+     * @private
+     * @type {number}
+     */
+    this.usage_ = opt_usage !== undefined ?
+        opt_usage : ol.webgl.Buffer.Usage_.STATIC_DRAW;
+
+  };
+
 
   /**
-   * @private
-   * @type {number}
+   * @return {Array.<number>} Array.
    */
-  this.usage_ = opt_usage !== undefined ?
-      opt_usage : ol.webgl.Buffer.Usage_.STATIC_DRAW;
-
-};
+  ol.webgl.Buffer.prototype.getArray = function() {
+    return this.arr_;
+  };
 
 
-/**
- * @return {Array.<number>} Array.
- */
-ol.webgl.Buffer.prototype.getArray = function() {
-  return this.arr_;
-};
+  /**
+   * @return {number} Usage.
+   */
+  ol.webgl.Buffer.prototype.getUsage = function() {
+    return this.usage_;
+  };
 
 
-/**
- * @return {number} Usage.
- */
-ol.webgl.Buffer.prototype.getUsage = function() {
-  return this.usage_;
-};
+  /**
+   * @enum {number}
+   * @private
+   */
+  ol.webgl.Buffer.Usage_ = {
+    STATIC_DRAW: ol.webgl.STATIC_DRAW,
+    STREAM_DRAW: ol.webgl.STREAM_DRAW,
+    DYNAMIC_DRAW: ol.webgl.DYNAMIC_DRAW
+  };
 
-
-/**
- * @enum {number}
- * @private
- */
-ol.webgl.Buffer.Usage_ = {
-  STATIC_DRAW: ol.webgl.STATIC_DRAW,
-  STREAM_DRAW: ol.webgl.STREAM_DRAW,
-  DYNAMIC_DRAW: ol.webgl.DYNAMIC_DRAW
-};
+}
diff --git a/src/ol/webgl/context.js b/src/ol/webgl/context.js
index 3707a3507c..2ae876cce6 100644
--- a/src/ol/webgl/context.js
+++ b/src/ol/webgl/context.js
@@ -9,363 +9,367 @@ goog.require('ol.webgl');
 goog.require('ol.webgl.ContextEventType');
 
 
-/**
- * @classdesc
- * A WebGL context for accessing low-level WebGL capabilities.
- *
- * @constructor
- * @extends {ol.Disposable}
- * @param {HTMLCanvasElement} canvas Canvas.
- * @param {WebGLRenderingContext} gl GL.
- */
-ol.webgl.Context = function(canvas, gl) {
+if (ol.ENABLE_WEBGL) {
 
   /**
-   * @private
-   * @type {HTMLCanvasElement}
+   * @classdesc
+   * A WebGL context for accessing low-level WebGL capabilities.
+   *
+   * @constructor
+   * @extends {ol.Disposable}
+   * @param {HTMLCanvasElement} canvas Canvas.
+   * @param {WebGLRenderingContext} gl GL.
    */
-  this.canvas_ = canvas;
+  ol.webgl.Context = function(canvas, gl) {
+
+    /**
+     * @private
+     * @type {HTMLCanvasElement}
+     */
+    this.canvas_ = canvas;
+
+    /**
+     * @private
+     * @type {WebGLRenderingContext}
+     */
+    this.gl_ = gl;
+
+    /**
+     * @private
+     * @type {Object.<string, ol.WebglBufferCacheEntry>}
+     */
+    this.bufferCache_ = {};
+
+    /**
+     * @private
+     * @type {Object.<string, WebGLShader>}
+     */
+    this.shaderCache_ = {};
+
+    /**
+     * @private
+     * @type {Object.<string, WebGLProgram>}
+     */
+    this.programCache_ = {};
+
+    /**
+     * @private
+     * @type {WebGLProgram}
+     */
+    this.currentProgram_ = null;
+
+    /**
+     * @private
+     * @type {WebGLFramebuffer}
+     */
+    this.hitDetectionFramebuffer_ = null;
+
+    /**
+     * @private
+     * @type {WebGLTexture}
+     */
+    this.hitDetectionTexture_ = null;
+
+    /**
+     * @private
+     * @type {WebGLRenderbuffer}
+     */
+    this.hitDetectionRenderbuffer_ = null;
+
+    /**
+     * @type {boolean}
+     */
+    this.hasOESElementIndexUint = ol.array.includes(
+        ol.WEBGL_EXTENSIONS, 'OES_element_index_uint');
+
+    // use the OES_element_index_uint extension if available
+    if (this.hasOESElementIndexUint) {
+      gl.getExtension('OES_element_index_uint');
+    }
+
+    ol.events.listen(this.canvas_, ol.webgl.ContextEventType.LOST,
+        this.handleWebGLContextLost, this);
+    ol.events.listen(this.canvas_, ol.webgl.ContextEventType.RESTORED,
+        this.handleWebGLContextRestored, this);
+
+  };
+  ol.inherits(ol.webgl.Context, ol.Disposable);
+
 
   /**
-   * @private
-   * @type {WebGLRenderingContext}
+   * Just bind the buffer if it's in the cache. Otherwise create
+   * the WebGL buffer, bind it, populate it, and add an entry to
+   * the cache.
+   * @param {number} target Target.
+   * @param {ol.webgl.Buffer} buf Buffer.
    */
-  this.gl_ = gl;
+  ol.webgl.Context.prototype.bindBuffer = function(target, buf) {
+    var gl = this.getGL();
+    var arr = buf.getArray();
+    var bufferKey = String(ol.getUid(buf));
+    if (bufferKey in this.bufferCache_) {
+      var bufferCacheEntry = this.bufferCache_[bufferKey];
+      gl.bindBuffer(target, bufferCacheEntry.buffer);
+    } else {
+      var buffer = gl.createBuffer();
+      gl.bindBuffer(target, buffer);
+      var /** @type {ArrayBufferView} */ arrayBuffer;
+      if (target == ol.webgl.ARRAY_BUFFER) {
+        arrayBuffer = new Float32Array(arr);
+      } else if (target == ol.webgl.ELEMENT_ARRAY_BUFFER) {
+        arrayBuffer = this.hasOESElementIndexUint ?
+            new Uint32Array(arr) : new Uint16Array(arr);
+      }
+      gl.bufferData(target, arrayBuffer, buf.getUsage());
+      this.bufferCache_[bufferKey] = {
+        buf: buf,
+        buffer: buffer
+      };
+    }
+  };
+
 
   /**
-   * @private
-   * @type {Object.<string, ol.WebglBufferCacheEntry>}
+   * @param {ol.webgl.Buffer} buf Buffer.
    */
-  this.bufferCache_ = {};
-
-  /**
-   * @private
-   * @type {Object.<string, WebGLShader>}
-   */
-  this.shaderCache_ = {};
-
-  /**
-   * @private
-   * @type {Object.<string, WebGLProgram>}
-   */
-  this.programCache_ = {};
-
-  /**
-   * @private
-   * @type {WebGLProgram}
-   */
-  this.currentProgram_ = null;
-
-  /**
-   * @private
-   * @type {WebGLFramebuffer}
-   */
-  this.hitDetectionFramebuffer_ = null;
-
-  /**
-   * @private
-   * @type {WebGLTexture}
-   */
-  this.hitDetectionTexture_ = null;
-
-  /**
-   * @private
-   * @type {WebGLRenderbuffer}
-   */
-  this.hitDetectionRenderbuffer_ = null;
-
-  /**
-   * @type {boolean}
-   */
-  this.hasOESElementIndexUint = ol.array.includes(
-      ol.WEBGL_EXTENSIONS, 'OES_element_index_uint');
-
-  // use the OES_element_index_uint extension if available
-  if (this.hasOESElementIndexUint) {
-    gl.getExtension('OES_element_index_uint');
-  }
-
-  ol.events.listen(this.canvas_, ol.webgl.ContextEventType.LOST,
-      this.handleWebGLContextLost, this);
-  ol.events.listen(this.canvas_, ol.webgl.ContextEventType.RESTORED,
-      this.handleWebGLContextRestored, this);
-
-};
-ol.inherits(ol.webgl.Context, ol.Disposable);
-
-
-/**
- * Just bind the buffer if it's in the cache. Otherwise create
- * the WebGL buffer, bind it, populate it, and add an entry to
- * the cache.
- * @param {number} target Target.
- * @param {ol.webgl.Buffer} buf Buffer.
- */
-ol.webgl.Context.prototype.bindBuffer = function(target, buf) {
-  var gl = this.getGL();
-  var arr = buf.getArray();
-  var bufferKey = String(ol.getUid(buf));
-  if (bufferKey in this.bufferCache_) {
+  ol.webgl.Context.prototype.deleteBuffer = function(buf) {
+    var gl = this.getGL();
+    var bufferKey = String(ol.getUid(buf));
     var bufferCacheEntry = this.bufferCache_[bufferKey];
-    gl.bindBuffer(target, bufferCacheEntry.buffer);
-  } else {
-    var buffer = gl.createBuffer();
-    gl.bindBuffer(target, buffer);
-    var /** @type {ArrayBufferView} */ arrayBuffer;
-    if (target == ol.webgl.ARRAY_BUFFER) {
-      arrayBuffer = new Float32Array(arr);
-    } else if (target == ol.webgl.ELEMENT_ARRAY_BUFFER) {
-      arrayBuffer = this.hasOESElementIndexUint ?
-          new Uint32Array(arr) : new Uint16Array(arr);
+    if (!gl.isContextLost()) {
+      gl.deleteBuffer(bufferCacheEntry.buffer);
     }
-    gl.bufferData(target, arrayBuffer, buf.getUsage());
-    this.bufferCache_[bufferKey] = {
-      buf: buf,
-      buffer: buffer
-    };
-  }
-};
+    delete this.bufferCache_[bufferKey];
+  };
 
 
-/**
- * @param {ol.webgl.Buffer} buf Buffer.
- */
-ol.webgl.Context.prototype.deleteBuffer = function(buf) {
-  var gl = this.getGL();
-  var bufferKey = String(ol.getUid(buf));
-  var bufferCacheEntry = this.bufferCache_[bufferKey];
-  if (!gl.isContextLost()) {
-    gl.deleteBuffer(bufferCacheEntry.buffer);
-  }
-  delete this.bufferCache_[bufferKey];
-};
-
-
-/**
- * @inheritDoc
- */
-ol.webgl.Context.prototype.disposeInternal = function() {
-  ol.events.unlistenAll(this.canvas_);
-  var gl = this.getGL();
-  if (!gl.isContextLost()) {
-    var key;
-    for (key in this.bufferCache_) {
-      gl.deleteBuffer(this.bufferCache_[key].buffer);
-    }
-    for (key in this.programCache_) {
-      gl.deleteProgram(this.programCache_[key]);
-    }
-    for (key in this.shaderCache_) {
-      gl.deleteShader(this.shaderCache_[key]);
-    }
-    // delete objects for hit-detection
-    gl.deleteFramebuffer(this.hitDetectionFramebuffer_);
-    gl.deleteRenderbuffer(this.hitDetectionRenderbuffer_);
-    gl.deleteTexture(this.hitDetectionTexture_);
-  }
-};
-
-
-/**
- * @return {HTMLCanvasElement} Canvas.
- */
-ol.webgl.Context.prototype.getCanvas = function() {
-  return this.canvas_;
-};
-
-
-/**
- * Get the WebGL rendering context
- * @return {WebGLRenderingContext} The rendering context.
- * @api
- */
-ol.webgl.Context.prototype.getGL = function() {
-  return this.gl_;
-};
-
-
-/**
- * Get the frame buffer for hit detection.
- * @return {WebGLFramebuffer} The hit detection frame buffer.
- */
-ol.webgl.Context.prototype.getHitDetectionFramebuffer = function() {
-  if (!this.hitDetectionFramebuffer_) {
-    this.initHitDetectionFramebuffer_();
-  }
-  return this.hitDetectionFramebuffer_;
-};
-
-
-/**
- * Get shader from the cache if it's in the cache. Otherwise, create
- * the WebGL shader, compile it, and add entry to cache.
- * @param {ol.webgl.Shader} shaderObject Shader object.
- * @return {WebGLShader} Shader.
- */
-ol.webgl.Context.prototype.getShader = function(shaderObject) {
-  var shaderKey = String(ol.getUid(shaderObject));
-  if (shaderKey in this.shaderCache_) {
-    return this.shaderCache_[shaderKey];
-  } else {
+  /**
+   * @inheritDoc
+   */
+  ol.webgl.Context.prototype.disposeInternal = function() {
+    ol.events.unlistenAll(this.canvas_);
     var gl = this.getGL();
-    var shader = gl.createShader(shaderObject.getType());
-    gl.shaderSource(shader, shaderObject.getSource());
-    gl.compileShader(shader);
-    this.shaderCache_[shaderKey] = shader;
-    return shader;
-  }
-};
+    if (!gl.isContextLost()) {
+      var key;
+      for (key in this.bufferCache_) {
+        gl.deleteBuffer(this.bufferCache_[key].buffer);
+      }
+      for (key in this.programCache_) {
+        gl.deleteProgram(this.programCache_[key]);
+      }
+      for (key in this.shaderCache_) {
+        gl.deleteShader(this.shaderCache_[key]);
+      }
+      // delete objects for hit-detection
+      gl.deleteFramebuffer(this.hitDetectionFramebuffer_);
+      gl.deleteRenderbuffer(this.hitDetectionRenderbuffer_);
+      gl.deleteTexture(this.hitDetectionTexture_);
+    }
+  };
 
 
-/**
- * Get the program from the cache if it's in the cache. Otherwise create
- * the WebGL program, attach the shaders to it, and add an entry to the
- * cache.
- * @param {ol.webgl.Fragment} fragmentShaderObject Fragment shader.
- * @param {ol.webgl.Vertex} vertexShaderObject Vertex shader.
- * @return {WebGLProgram} Program.
- */
-ol.webgl.Context.prototype.getProgram = function(
-    fragmentShaderObject, vertexShaderObject) {
-  var programKey =
-      ol.getUid(fragmentShaderObject) + '/' + ol.getUid(vertexShaderObject);
-  if (programKey in this.programCache_) {
-    return this.programCache_[programKey];
-  } else {
-    var gl = this.getGL();
-    var program = gl.createProgram();
-    gl.attachShader(program, this.getShader(fragmentShaderObject));
-    gl.attachShader(program, this.getShader(vertexShaderObject));
-    gl.linkProgram(program);
-    this.programCache_[programKey] = program;
-    return program;
-  }
-};
+  /**
+   * @return {HTMLCanvasElement} Canvas.
+   */
+  ol.webgl.Context.prototype.getCanvas = function() {
+    return this.canvas_;
+  };
 
 
-/**
- * FIXME empy description for jsdoc
- */
-ol.webgl.Context.prototype.handleWebGLContextLost = function() {
-  ol.obj.clear(this.bufferCache_);
-  ol.obj.clear(this.shaderCache_);
-  ol.obj.clear(this.programCache_);
-  this.currentProgram_ = null;
-  this.hitDetectionFramebuffer_ = null;
-  this.hitDetectionTexture_ = null;
-  this.hitDetectionRenderbuffer_ = null;
-};
+  /**
+   * Get the WebGL rendering context
+   * @return {WebGLRenderingContext} The rendering context.
+   * @api
+   */
+  ol.webgl.Context.prototype.getGL = function() {
+    return this.gl_;
+  };
 
 
-/**
- * FIXME empy description for jsdoc
- */
-ol.webgl.Context.prototype.handleWebGLContextRestored = function() {
-};
+  /**
+   * Get the frame buffer for hit detection.
+   * @return {WebGLFramebuffer} The hit detection frame buffer.
+   */
+  ol.webgl.Context.prototype.getHitDetectionFramebuffer = function() {
+    if (!this.hitDetectionFramebuffer_) {
+      this.initHitDetectionFramebuffer_();
+    }
+    return this.hitDetectionFramebuffer_;
+  };
 
 
-/**
- * Creates a 1x1 pixel framebuffer for the hit-detection.
- * @private
- */
-ol.webgl.Context.prototype.initHitDetectionFramebuffer_ = function() {
-  var gl = this.gl_;
-  var framebuffer = gl.createFramebuffer();
-  gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
-
-  var texture = ol.webgl.Context.createEmptyTexture(gl, 1, 1);
-  var renderbuffer = gl.createRenderbuffer();
-  gl.bindRenderbuffer(gl.RENDERBUFFER, renderbuffer);
-  gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, 1, 1);
-  gl.framebufferTexture2D(
-      gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
-  gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT,
-      gl.RENDERBUFFER, renderbuffer);
-
-  gl.bindTexture(gl.TEXTURE_2D, null);
-  gl.bindRenderbuffer(gl.RENDERBUFFER, null);
-  gl.bindFramebuffer(gl.FRAMEBUFFER, null);
-
-  this.hitDetectionFramebuffer_ = framebuffer;
-  this.hitDetectionTexture_ = texture;
-  this.hitDetectionRenderbuffer_ = renderbuffer;
-};
+  /**
+   * Get shader from the cache if it's in the cache. Otherwise, create
+   * the WebGL shader, compile it, and add entry to cache.
+   * @param {ol.webgl.Shader} shaderObject Shader object.
+   * @return {WebGLShader} Shader.
+   */
+  ol.webgl.Context.prototype.getShader = function(shaderObject) {
+    var shaderKey = String(ol.getUid(shaderObject));
+    if (shaderKey in this.shaderCache_) {
+      return this.shaderCache_[shaderKey];
+    } else {
+      var gl = this.getGL();
+      var shader = gl.createShader(shaderObject.getType());
+      gl.shaderSource(shader, shaderObject.getSource());
+      gl.compileShader(shader);
+      this.shaderCache_[shaderKey] = shader;
+      return shader;
+    }
+  };
 
 
-/**
- * Use a program.  If the program is already in use, this will return `false`.
- * @param {WebGLProgram} program Program.
- * @return {boolean} Changed.
- * @api
- */
-ol.webgl.Context.prototype.useProgram = function(program) {
-  if (program == this.currentProgram_) {
-    return false;
-  } else {
-    var gl = this.getGL();
-    gl.useProgram(program);
-    this.currentProgram_ = program;
-    return true;
-  }
-};
+  /**
+   * Get the program from the cache if it's in the cache. Otherwise create
+   * the WebGL program, attach the shaders to it, and add an entry to the
+   * cache.
+   * @param {ol.webgl.Fragment} fragmentShaderObject Fragment shader.
+   * @param {ol.webgl.Vertex} vertexShaderObject Vertex shader.
+   * @return {WebGLProgram} Program.
+   */
+  ol.webgl.Context.prototype.getProgram = function(
+      fragmentShaderObject, vertexShaderObject) {
+    var programKey =
+        ol.getUid(fragmentShaderObject) + '/' + ol.getUid(vertexShaderObject);
+    if (programKey in this.programCache_) {
+      return this.programCache_[programKey];
+    } else {
+      var gl = this.getGL();
+      var program = gl.createProgram();
+      gl.attachShader(program, this.getShader(fragmentShaderObject));
+      gl.attachShader(program, this.getShader(vertexShaderObject));
+      gl.linkProgram(program);
+      this.programCache_[programKey] = program;
+      return program;
+    }
+  };
 
 
-/**
- * @param {WebGLRenderingContext} gl WebGL rendering context.
- * @param {number=} opt_wrapS wrapS.
- * @param {number=} opt_wrapT wrapT.
- * @return {WebGLTexture} The texture.
- * @private
- */
-ol.webgl.Context.createTexture_ = function(gl, opt_wrapS, opt_wrapT) {
-  var texture = gl.createTexture();
-  gl.bindTexture(gl.TEXTURE_2D, texture);
-  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
-  gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
-
-  if (opt_wrapS !== undefined) {
-    gl.texParameteri(
-        ol.webgl.TEXTURE_2D, ol.webgl.TEXTURE_WRAP_S, opt_wrapS);
-  }
-  if (opt_wrapT !== undefined) {
-    gl.texParameteri(
-        ol.webgl.TEXTURE_2D, ol.webgl.TEXTURE_WRAP_T, opt_wrapT);
-  }
-
-  return texture;
-};
+  /**
+   * FIXME empy description for jsdoc
+   */
+  ol.webgl.Context.prototype.handleWebGLContextLost = function() {
+    ol.obj.clear(this.bufferCache_);
+    ol.obj.clear(this.shaderCache_);
+    ol.obj.clear(this.programCache_);
+    this.currentProgram_ = null;
+    this.hitDetectionFramebuffer_ = null;
+    this.hitDetectionTexture_ = null;
+    this.hitDetectionRenderbuffer_ = null;
+  };
 
 
-/**
- * @param {WebGLRenderingContext} gl WebGL rendering context.
- * @param {number} width Width.
- * @param {number} height Height.
- * @param {number=} opt_wrapS wrapS.
- * @param {number=} opt_wrapT wrapT.
- * @return {WebGLTexture} The texture.
- */
-ol.webgl.Context.createEmptyTexture = function(
-    gl, width, height, opt_wrapS, opt_wrapT) {
-  var texture = ol.webgl.Context.createTexture_(gl, opt_wrapS, opt_wrapT);
-  gl.texImage2D(
-      gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE,
-      null);
-
-  return texture;
-};
+  /**
+   * FIXME empy description for jsdoc
+   */
+  ol.webgl.Context.prototype.handleWebGLContextRestored = function() {
+  };
 
 
-/**
- * @param {WebGLRenderingContext} gl WebGL rendering context.
- * @param {HTMLCanvasElement|HTMLImageElement|HTMLVideoElement} image Image.
- * @param {number=} opt_wrapS wrapS.
- * @param {number=} opt_wrapT wrapT.
- * @return {WebGLTexture} The texture.
- */
-ol.webgl.Context.createTexture = function(gl, image, opt_wrapS, opt_wrapT) {
-  var texture = ol.webgl.Context.createTexture_(gl, opt_wrapS, opt_wrapT);
-  gl.texImage2D(
-      gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, image);
+  /**
+   * Creates a 1x1 pixel framebuffer for the hit-detection.
+   * @private
+   */
+  ol.webgl.Context.prototype.initHitDetectionFramebuffer_ = function() {
+    var gl = this.gl_;
+    var framebuffer = gl.createFramebuffer();
+    gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
 
-  return texture;
-};
+    var texture = ol.webgl.Context.createEmptyTexture(gl, 1, 1);
+    var renderbuffer = gl.createRenderbuffer();
+    gl.bindRenderbuffer(gl.RENDERBUFFER, renderbuffer);
+    gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, 1, 1);
+    gl.framebufferTexture2D(
+        gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, texture, 0);
+    gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT,
+        gl.RENDERBUFFER, renderbuffer);
+
+    gl.bindTexture(gl.TEXTURE_2D, null);
+    gl.bindRenderbuffer(gl.RENDERBUFFER, null);
+    gl.bindFramebuffer(gl.FRAMEBUFFER, null);
+
+    this.hitDetectionFramebuffer_ = framebuffer;
+    this.hitDetectionTexture_ = texture;
+    this.hitDetectionRenderbuffer_ = renderbuffer;
+  };
+
+
+  /**
+   * Use a program.  If the program is already in use, this will return `false`.
+   * @param {WebGLProgram} program Program.
+   * @return {boolean} Changed.
+   * @api
+   */
+  ol.webgl.Context.prototype.useProgram = function(program) {
+    if (program == this.currentProgram_) {
+      return false;
+    } else {
+      var gl = this.getGL();
+      gl.useProgram(program);
+      this.currentProgram_ = program;
+      return true;
+    }
+  };
+
+
+  /**
+   * @param {WebGLRenderingContext} gl WebGL rendering context.
+   * @param {number=} opt_wrapS wrapS.
+   * @param {number=} opt_wrapT wrapT.
+   * @return {WebGLTexture} The texture.
+   * @private
+   */
+  ol.webgl.Context.createTexture_ = function(gl, opt_wrapS, opt_wrapT) {
+    var texture = gl.createTexture();
+    gl.bindTexture(gl.TEXTURE_2D, texture);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
+
+    if (opt_wrapS !== undefined) {
+      gl.texParameteri(
+          ol.webgl.TEXTURE_2D, ol.webgl.TEXTURE_WRAP_S, opt_wrapS);
+    }
+    if (opt_wrapT !== undefined) {
+      gl.texParameteri(
+          ol.webgl.TEXTURE_2D, ol.webgl.TEXTURE_WRAP_T, opt_wrapT);
+    }
+
+    return texture;
+  };
+
+
+  /**
+   * @param {WebGLRenderingContext} gl WebGL rendering context.
+   * @param {number} width Width.
+   * @param {number} height Height.
+   * @param {number=} opt_wrapS wrapS.
+   * @param {number=} opt_wrapT wrapT.
+   * @return {WebGLTexture} The texture.
+   */
+  ol.webgl.Context.createEmptyTexture = function(
+      gl, width, height, opt_wrapS, opt_wrapT) {
+    var texture = ol.webgl.Context.createTexture_(gl, opt_wrapS, opt_wrapT);
+    gl.texImage2D(
+        gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE,
+        null);
+
+    return texture;
+  };
+
+
+  /**
+   * @param {WebGLRenderingContext} gl WebGL rendering context.
+   * @param {HTMLCanvasElement|HTMLImageElement|HTMLVideoElement} image Image.
+   * @param {number=} opt_wrapS wrapS.
+   * @param {number=} opt_wrapT wrapT.
+   * @return {WebGLTexture} The texture.
+   */
+  ol.webgl.Context.createTexture = function(gl, image, opt_wrapS, opt_wrapT) {
+    var texture = ol.webgl.Context.createTexture_(gl, opt_wrapS, opt_wrapT);
+    gl.texImage2D(
+        gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, image);
+
+    return texture;
+  };
+
+}
diff --git a/src/ol/webgl/fragment.js b/src/ol/webgl/fragment.js
index 49bb0f0445..1d1bbc728f 100644
--- a/src/ol/webgl/fragment.js
+++ b/src/ol/webgl/fragment.js
@@ -5,21 +5,25 @@ goog.require('ol.webgl');
 goog.require('ol.webgl.Shader');
 
 
-/**
- * @constructor
- * @extends {ol.webgl.Shader}
- * @param {string} source Source.
- * @struct
- */
-ol.webgl.Fragment = function(source) {
-  ol.webgl.Shader.call(this, source);
-};
-ol.inherits(ol.webgl.Fragment, ol.webgl.Shader);
+if (ol.ENABLE_WEBGL) {
+
+  /**
+   * @constructor
+   * @extends {ol.webgl.Shader}
+   * @param {string} source Source.
+   * @struct
+   */
+  ol.webgl.Fragment = function(source) {
+    ol.webgl.Shader.call(this, source);
+  };
+  ol.inherits(ol.webgl.Fragment, ol.webgl.Shader);
 
 
-/**
- * @inheritDoc
- */
-ol.webgl.Fragment.prototype.getType = function() {
-  return ol.webgl.FRAGMENT_SHADER;
-};
+  /**
+   * @inheritDoc
+   */
+  ol.webgl.Fragment.prototype.getType = function() {
+    return ol.webgl.FRAGMENT_SHADER;
+  };
+
+}
diff --git a/src/ol/webgl/shader.js b/src/ol/webgl/shader.js
index 1a26cccf1c..da3ebcdc8a 100644
--- a/src/ol/webgl/shader.js
+++ b/src/ol/webgl/shader.js
@@ -4,38 +4,42 @@ goog.require('ol.functions');
 goog.require('ol.webgl');
 
 
-/**
- * @constructor
- * @param {string} source Source.
- * @struct
- */
-ol.webgl.Shader = function(source) {
+if (ol.ENABLE_WEBGL) {
 
   /**
-   * @private
-   * @type {string}
+   * @constructor
+   * @param {string} source Source.
+   * @struct
    */
-  this.source_ = source;
+  ol.webgl.Shader = function(source) {
 
-};
+    /**
+     * @private
+     * @type {string}
+     */
+    this.source_ = source;
+
+  };
 
 
-/**
- * @abstract
- * @return {number} Type.
- */
-ol.webgl.Shader.prototype.getType = function() {};
+  /**
+   * @abstract
+   * @return {number} Type.
+   */
+  ol.webgl.Shader.prototype.getType = function() {};
 
 
-/**
- * @return {string} Source.
- */
-ol.webgl.Shader.prototype.getSource = function() {
-  return this.source_;
-};
+  /**
+   * @return {string} Source.
+   */
+  ol.webgl.Shader.prototype.getSource = function() {
+    return this.source_;
+  };
 
 
-/**
- * @return {boolean} Is animated?
- */
-ol.webgl.Shader.prototype.isAnimated = ol.functions.FALSE;
+  /**
+   * @return {boolean} Is animated?
+   */
+  ol.webgl.Shader.prototype.isAnimated = ol.functions.FALSE;
+
+}
diff --git a/src/ol/webgl/vertex.js b/src/ol/webgl/vertex.js
index 024c7dc012..c68a9a2fe4 100644
--- a/src/ol/webgl/vertex.js
+++ b/src/ol/webgl/vertex.js
@@ -5,21 +5,25 @@ goog.require('ol.webgl');
 goog.require('ol.webgl.Shader');
 
 
-/**
- * @constructor
- * @extends {ol.webgl.Shader}
- * @param {string} source Source.
- * @struct
- */
-ol.webgl.Vertex = function(source) {
-  ol.webgl.Shader.call(this, source);
-};
-ol.inherits(ol.webgl.Vertex, ol.webgl.Shader);
+if (ol.ENABLE_WEBGL) {
+
+  /**
+   * @constructor
+   * @extends {ol.webgl.Shader}
+   * @param {string} source Source.
+   * @struct
+   */
+  ol.webgl.Vertex = function(source) {
+    ol.webgl.Shader.call(this, source);
+  };
+  ol.inherits(ol.webgl.Vertex, ol.webgl.Shader);
 
 
-/**
- * @inheritDoc
- */
-ol.webgl.Vertex.prototype.getType = function() {
-  return ol.webgl.VERTEX_SHADER;
-};
+  /**
+   * @inheritDoc
+   */
+  ol.webgl.Vertex.prototype.getType = function() {
+    return ol.webgl.VERTEX_SHADER;
+  };
+
+}