text: import {
  	WebGLRenderTarget
  } from "../../../build/three.module.js";
  import { SSAARenderPass } from "../postprocessing/SSAARenderPass.js";
  
  /**
   *
   * Temporal Anti-Aliasing Render Pass
   *
   * When there is no motion in the scene, the TAA render pass accumulates jittered camera samples across frames to create a high quality anti-aliased result.
   *
   * References:
   *
   * TODO: Add support for motion vector pas so that accumulation of samples across frames can occur on dynamics scenes.
   *
   */
  
  var TAARenderPass = function ( scene, camera, clearColor, clearAlpha ) {
  
  	if ( SSAARenderPass === undefined ) {
  
  		console.error( 'THREE.TAARenderPass relies on SSAARenderPass' );
  
  	}
  
  	SSAARenderPass.call( this, scene, camera, clearColor, clearAlpha );
  
  	this.sampleLevel = 0;
  	this.accumulate = false;
  
  };
  
  TAARenderPass.JitterVectors = SSAARenderPass.JitterVectors;
  
  TAARenderPass.prototype = Object.assign( Object.create( SSAARenderPass.prototype ), {
  
  	constructor: TAARenderPass,
  
  	render: function ( renderer, writeBuffer, readBuffer, deltaTime ) {
  
  		if ( ! this.accumulate ) {
  
  			SSAARenderPass.prototype.render.call( this, renderer, writeBuffer, readBuffer, deltaTime );
  
  			this.accumulateIndex = - 1;
  			return;
  
  		}
  
  		var jitterOffsets = TAARenderPass.JitterVectors[ 5 ];
  
  		if ( ! this.sampleRenderTarget ) {
  
  			this.sampleRenderTarget = new WebGLRenderTarget( readBuffer.width, readBuffer.height, this.params );
  			this.sampleRenderTarget.texture.name = 'TAARenderPass.sample';
  
  		}
  
  		if ( ! this.holdRenderTarget ) {
  
  			this.holdRenderTarget = new WebGLRenderTarget( readBuffer.width, readBuffer.height, this.params );
  			this.holdRenderTarget.texture.name = 'TAARenderPass.hold';
  
  		}
  
  		if ( this.accumulate && this.accumulateIndex === - 1 ) {
  
  			SSAARenderPass.prototype.render.call( this, renderer, this.holdRenderTarget, readBuffer, deltaTime );
  
  			this.accumulateIndex = 0;
  
  		}
  
  		var autoClear = renderer.autoClear;
  		renderer.autoClear = false;
  
  		var sampleWeight = 1.0 / ( jitterOffsets.length );
  
  		if ( this.accumulateIndex >= 0 && this.accumulateIndex < jitterOffsets.length ) {
  
  			this.copyUniforms[ 'opacity' ].value = sampleWeight;
  			this.copyUniforms[ 'tDiffuse' ].value = writeBuffer.texture;
  
  			// render the scene multiple times, each slightly jitter offset from the last and accumulate the results.
  			var numSamplesPerFrame = Math.pow( 2, this.sampleLevel );
  			for ( var i = 0; i < numSamplesPerFrame; i ++ ) {
  
  				var j = this.accumulateIndex;
  				var jitterOffset = jitterOffsets[ j ];
  
  				if ( this.camera.setViewOffset ) {
  
  					this.camera.setViewOffset( readBuffer.width, readBuffer.height,
  						jitterOffset[ 0 ] * 0.0625, jitterOffset[ 1 ] * 0.0625, // 0.0625 = 1 / 16
  						readBuffer.width, readBuffer.height );
  
  				}
  
  				renderer.setRenderTarget( writeBuffer );
  				renderer.clear();
  				renderer.render( this.scene, this.camera );
  
  				renderer.setRenderTarget( this.sampleRenderTarget );
  				if ( this.accumulateIndex === 0 ) renderer.clear();
  				this.fsQuad.render( renderer );
  
  				this.accumulateIndex ++;
  
  				if ( this.accumulateIndex >= jitterOffsets.length ) break;
  
  			}
  
  			if ( this.camera.clearViewOffset ) this.camera.clearViewOffset();
  
  		}
  
  		var accumulationWeight = this.accumulateIndex * sampleWeight;
  
  		if ( accumulationWeight > 0 ) {
  
  			this.copyUniforms[ 'opacity' ].value = 1.0;
  			this.copyUniforms[ 'tDiffuse' ].value = this.sampleRenderTarget.texture;
  			renderer.setRenderTarget( writeBuffer );
  			renderer.clear();
  			this.fsQuad.render( renderer );
  
  		}
  
  		if ( accumulationWeight < 1.0 ) {
  
  			this.copyUniforms[ 'opacity' ].value = 1.0 - accumulationWeight;
  			this.copyUniforms[ 'tDiffuse' ].value = this.holdRenderTarget.texture;
  			renderer.setRenderTarget( writeBuffer );
  			if ( accumulationWeight === 0 ) renderer.clear();
  			this.fsQuad.render( renderer );
  
  		}
  
  		renderer.autoClear = autoClear;
  
  	}
  
  } );
  
  export { TAARenderPass };
  