anchor.diff:        throw "Error";
       }
   
  +    ext_OES_texture_float = gl.getExtension("OES_texture_float");
  +    if (ext_OES_texture_float == null) {
  +      throw "Error";
  +    }
  +
  +    ext_OES_texture_float_linear = gl.getExtension("OES_texture_float_linear");
  +    if (ext_OES_texture_float_linear == null) {
  +      throw "Error";
  +    }
  +
       gl.clearColor(0.0, 0.0, 0.0, 1.0);
       gl.enable(WEBGL.DEPTH_TEST);
       if (faceCulling) {
  
positive.code:   dynamic ext_OES_element_index_uint;
    dynamic ext_WEBGL_depth_texture;
    dynamic ext_ANGLE_instanced_arrays;
  
    ChronosGL(this._canvas,
        {bool preserveDrawingBuffer: false, bool faceCulling: false, bool antialiasing: true}) {
      Map attributes = {
        "alpha": false,
        "depth": true,
  
negative.code:     gl.bindBuffer(kind, buffer);
    }
  
    void ChangeArrayBuffer(WEBGL.Buffer buffer, Float32List data) {
      gl.bindBuffer(WEBGL.ARRAY_BUFFER, buffer);
      gl.bufferData(WEBGL.ARRAY_BUFFER, data, WEBGL.DYNAMIC_DRAW);
  