code: function Sampler( gl ){
    this._uid = _UID++;
    this.gl = gl;
    this.id = gl.createSampler();
    this.setFilter( true );
  }
docs: @class
  @classdesc Sampler class wrapper for GLES3 Samplers
  
  @param {WebGLRenderingContext} gl webgl context the sampler belongs to