three
Version:
JavaScript 3D library
168 lines (130 loc) • 4.01 kB
JavaScript
import {
HalfFloatType,
NearestFilter,
NoBlending,
ShaderMaterial,
UniformsUtils,
WebGLRenderTarget
} from 'three';
import { Pass, FullScreenQuad } from './Pass.js';
import { CopyShader } from '../shaders/CopyShader.js';
import { AfterimageShader } from '../shaders/AfterimageShader.js';
/**
* Pass for a basic after image effect.
*
* ```js
* const afterimagePass = new AfterimagePass( 0.9 );
* composer.addPass( afterimagePass );
* ```
*
* @augments Pass
*/
class AfterimagePass extends Pass {
/**
* Constructs a new after image pass.
*
* @param {number} [damp=0.96] - The damping intensity. A higher value means a stronger after image effect.
*/
constructor( damp = 0.96 ) {
super();
/**
* The pass uniforms. Use this object if you want to update the
* `damp` value at runtime.
* ```js
* pass.uniforms.damp.value = 0.9;
* ```
*
* @type {Object}
*/
this.uniforms = UniformsUtils.clone( AfterimageShader.uniforms );
this.uniforms[ 'damp' ].value = damp;
/**
* The composition material.
*
* @type {ShaderMaterial}
*/
this.compFsMaterial = new ShaderMaterial( {
uniforms: this.uniforms,
vertexShader: AfterimageShader.vertexShader,
fragmentShader: AfterimageShader.fragmentShader
} );
/**
* The copy material.
*
* @type {ShaderMaterial}
*/
this.copyFsMaterial = new ShaderMaterial( {
uniforms: UniformsUtils.clone( CopyShader.uniforms ),
vertexShader: CopyShader.vertexShader,
fragmentShader: CopyShader.fragmentShader,
blending: NoBlending,
depthTest: false,
depthWrite: false
} );
// internals
this._textureComp = new WebGLRenderTarget( window.innerWidth, window.innerHeight, {
magFilter: NearestFilter,
type: HalfFloatType
} );
this._textureOld = new WebGLRenderTarget( window.innerWidth, window.innerHeight, {
magFilter: NearestFilter,
type: HalfFloatType
} );
this._compFsQuad = new FullScreenQuad( this.compFsMaterial );
this._copyFsQuad = new FullScreenQuad( this.copyFsMaterial );
}
/**
* Performs the after image pass.
*
* @param {WebGLRenderer} renderer - The renderer.
* @param {WebGLRenderTarget} writeBuffer - The write buffer. This buffer is intended as the rendering
* destination for the pass.
* @param {WebGLRenderTarget} readBuffer - The read buffer. The pass can access the result from the
* previous pass from this buffer.
* @param {number} deltaTime - The delta time in seconds.
* @param {boolean} maskActive - Whether masking is active or not.
*/
render( renderer, writeBuffer, readBuffer/*, deltaTime, maskActive*/ ) {
this.uniforms[ 'tOld' ].value = this._textureOld.texture;
this.uniforms[ 'tNew' ].value = readBuffer.texture;
renderer.setRenderTarget( this._textureComp );
this._compFsQuad.render( renderer );
this._copyFsQuad.material.uniforms.tDiffuse.value = this._textureComp.texture;
if ( this.renderToScreen ) {
renderer.setRenderTarget( null );
this._copyFsQuad.render( renderer );
} else {
renderer.setRenderTarget( writeBuffer );
if ( this.clear ) renderer.clear();
this._copyFsQuad.render( renderer );
}
// Swap buffers.
const temp = this._textureOld;
this._textureOld = this._textureComp;
this._textureComp = temp;
// Now textureOld contains the latest image, ready for the next frame.
}
/**
* Sets the size of the pass.
*
* @param {number} width - The width to set.
* @param {number} height - The width to set.
*/
setSize( width, height ) {
this._textureComp.setSize( width, height );
this._textureOld.setSize( width, height );
}
/**
* Frees the GPU-related resources allocated by this instance. Call this
* method whenever the pass is no longer used in your app.
*/
dispose() {
this._textureComp.dispose();
this._textureOld.dispose();
this.compFsMaterial.dispose();
this.copyFsMaterial.dispose();
this._compFsQuad.dispose();
this._copyFsQuad.dispose();
}
}
export { AfterimagePass };