text: import * as core from '../../core';
  import generateBlurVertSource from './generateBlurVertSource';
  import generateBlurFragSource from './generateBlurFragSource';
  import getMaxBlurKernelSize from './getMaxBlurKernelSize';
  
  /**
   * The BlurXFilter applies a horizontal Gaussian blur to an object.
   *
   * @class
   * @extends PIXI.Filter
   * @memberof PIXI.filters
   */
  export default class BlurXFilter extends core.Filter
  {
      /**
       * @param {number} strength - The strength of the blur filter.
       * @param {number} quality - The quality of the blur filter.
       * @param {number} resolution - The resolution of the blur filter.
       * @param {number} [kernelSize=5] - The kernelSize of the blur filter.Options: 5, 7, 9, 11, 13, 15.
       */
      constructor(strength, quality, resolution, kernelSize)
      {
          kernelSize = kernelSize || 5;
          const vertSrc = generateBlurVertSource(kernelSize, true);
          const fragSrc = generateBlurFragSource(kernelSize);
  
          super(
              // vertex shader
              vertSrc,
              // fragment shader
              fragSrc
          );
  
          this.resolution = resolution || 1;
  
          this._quality = 0;
  
          this.quality = quality || 4;
          this.strength = strength || 8;
  
          this.firstRun = true;
      }
  
      /**
       * Applies the filter.
       *
       * @param {PIXI.FilterManager} filterManager - The manager.
       * @param {PIXI.RenderTarget} input - The input target.
       * @param {PIXI.RenderTarget} output - The output target.
       * @param {boolean} clear - Should the output be cleared before rendering?
       */
      apply(filterManager, input, output, clear)
      {
          if (this.firstRun)
          {
              const gl = filterManager.renderer.gl;
              const kernelSize = getMaxBlurKernelSize(gl);
  
              this.vertexSrc = generateBlurVertSource(kernelSize, true);
              this.fragmentSrc = generateBlurFragSource(kernelSize);
  
              this.firstRun = false;
          }
  
          this.uniforms.strength = (1 / output.size.width) * (output.size.width / input.size.width);
  
          // screen space!
          this.uniforms.strength *= this.strength;
          this.uniforms.strength /= this.passes;// / this.passes//Math.pow(1, this.passes);
  
          if (this.passes === 1)
          {
              filterManager.applyFilter(this, input, output, clear);
          }
          else
          {
              const renderTarget = filterManager.getRenderTarget(true);
              let flip = input;
              let flop = renderTarget;
  
              for (let i = 0; i < this.passes - 1; i++)
              {
                  filterManager.applyFilter(this, flip, flop, true);
  
                  const temp = flop;
  
                  flop = flip;
                  flip = temp;
              }
  
              filterManager.applyFilter(this, flip, output, clear);
  
              filterManager.returnRenderTarget(renderTarget);
          }
      }
  
      /**
       * Sets the strength of both the blur.
       *
       * @member {number}
       * @memberof PIXI.filters.BlurXFilter#
       * @default 16
       */
      get blur()
      {
          return this.strength;
      }
  
      /**
       * Sets the strength of the blur.
       *
       * @param {number} value - The value to set.
       */
      set blur(value)
      {
          this.padding = Math.abs(value) * 2;
          this.strength = value;
      }
  
       /**
       * Sets the quality of the blur by modifying the number of passes. More passes means higher
       * quaility bluring but the lower the performance.
       *
       * @member {number}
       * @memberof PIXI.filters.BlurXFilter#
       * @default 4
       */
      get quality()
      {
          return this._quality;
      }
  
      /**
       * Sets the quality of the blur.
       *
       * @param {number} value - The value to set.
       */
      set quality(value)
      {
          this._quality = value;
          this.passes = value;
      }
  }
  