message: Little improve: Don't query `currentState` again
diff: @@ -312,7 +312,7 @@ export default class FilterManager extends WebGLManager
  // see displacementFilter fragment shader for an example
  if (shader.uniforms.filterClamp)
  {
  - currentState = this.filterData.stack[this.filterData.index];
  + currentState = currentState || this.filterData.stack[this.filterData.index];
  const filterClamp = shader.uniforms.filterClamp;
  