code: function reset() {
           this.sbIndex = 0;
           this.length = 0;
           var samplers = []; // WebGL context
  
           this.gl = this.renderer.gl;
  
           for (var i = 0; i < this.maxTextures; i++) {
             this.units[i] = false;
             samplers[i] = i;
           } // set the quad shader as the default program
  
  
           this.useShader(this.quadShader);
           this.quadShader.uniforms.uSampler = samplers;
         }
docs: Reset compositor internal state
  @ignore