THREE.EffectComposer = function ( renderer, renderTarget ) {
//这里初始化renderer和renderTarget没啥说的
this.renderer = renderer;
if ( renderTarget === undefined ) {
var parameters = {
minFilter: THREE.LinearFilter,
magFilter: THREE.LinearFilter,
format: THREE.RGBAFormat,
stencilBuffer: false
};
var size = renderer.getDrawingBufferSize();
renderTarget = new THREE.WebGLRenderTarget( size.width, size.height, parameters );
renderTarget.texture.name = 'EffectComposer.rt1';
}
this.renderTarget1 = renderTarget;
this.renderTarget2 = renderTarget.clone();
this.renderTarget2.texture.name = 'EffectComposer.rt2';
this.writeBuffer = this.renderTarget1;//到这里write read都是来自传入的renderTarget或者创建的新的那个
this.readBuffer = this.renderTarget2;
this.passes = [];//装所有PASS的
// dependencies
if ( THREE.CopyShader === undefined ) {
console.error( 'THREE.EffectComposer relies on THREE.CopyShader' );
}
if ( THREE.ShaderPass === undefined ) {
console.error( 'THREE.EffectComposer relies on THREE.ShaderPass' );
}
this.copyPass = new THREE.ShaderPass( THREE.CopyShader );
};
Object.assign( THREE.EffectComposer.prototype, {
swapBuffers: function () {//双缓冲用的
var tmp = this.readBuffer;
this.readBuffer = this.writeBuffer;
this.writeBuffer = tmp;
},
addPass: function ( pass ) {
this.passes.push( pass );//增加pass
var size = this.renderer.getDrawingBufferSize();
pass.setSize( size.width, size.height );
},
insertPass: function ( pass, index ) {//给pass换个顺序
this.passes.splice( index, 0, pass );
},
render: function ( delta ) {
var maskActive = false;
var pass, i, il = this.passes.length;
for ( i = 0; i < il; i ++ ) {//遍历所有pass
pass = this.passes[ i ];
if ( pass.enabled === false ) continue;//不用这个pass就过
pass.render( this.renderer, this.writeBuffer, this.readBuffer, delta, maskActive );
//这个render就要看看那个pass里面咋写的了 一般是renderer readBuffer这俩参数传入渲完再给writeBuffer
//有的是用readBuffer渲完了继续给readBuffer覆盖了原来的readBuffer
if ( pass.needsSwap ) {
if ( maskActive ) {
var context = this.renderer.context;
context.stencilFunc( context.NOTEQUAL, 1, 0xffffffff );//模板测试
this.copyPass.render( this.renderer, this.writeBuffer, this.readBuffer, delta );
context.stencilFunc( context.EQUAL, 1, 0xffffffff );
}
this.swapBuffers();
}
if ( THREE.MaskPass !== undefined ) {
if ( pass instanceof THREE.MaskPass ) {
maskActive = true;
} else if ( pass instanceof THREE.ClearMaskPass ) {
maskActive = false;
}
}
}
},
reset: function ( renderTarget ) {
if ( renderTarget === undefined ) {
var size = this.renderer.getDrawingBufferSize();
renderTarget = this.renderTarget1.clone();
renderTarget.setSize( size.width, size.height );
}
this.renderTarget1.dispose();
this.renderTarget2.dispose();
this.renderTarget1 = renderTarget;
this.renderTarget2 = renderTarget.clone();
this.writeBuffer = this.renderTarget1;
this.readBuffer = this.renderTarget2;
},
setSize: function ( width, height ) {
this.renderTarget1.setSize( width, height );
this.renderTarget2.setSize( width, height );
for ( var i = 0; i < this.passes.length; i ++ ) {
this.passes[ i ].setSize( width, height );
}
}
} );
THREE.Pass = function () {
// if set to true, the pass is processed by the composer
this.enabled = true;
// if set to true, the pass indicates to swap read and write buffer after rendering
this.needsSwap = true;
// if set to true, the pass clears its buffer before rendering
this.clear = false;
// if set to true, the result of the pass is rendered to screen
this.renderToScreen = false;
};
Object.assign( THREE.Pass.prototype, {
setSize: function ( width, height ) {},
render: function ( renderer, writeBuffer, readBuffer, delta, maskActive ) {
console.error( 'THREE.Pass: .render() must be implemented in derived pass.' );
}
} );
