import RnObject from '../core/RnObject' ; import RenderPass from './RenderPass' ; /**
 * Expression specifies the order of render passes on rendering process.
 */ export default class Expression extends RnObject { private __renderPasses : RenderPass [ ] = [ ] ; constructor ( ) { super ( ) ; } /**
     * Add render passes to the end of this expression.
     */ addRenderPasses ( renderPasses ) { for ( const renderPass of renderPasses ) { this . __renderPasses . push ( renderPass ) ; } } /**
     * Clear render passes of this expression.
     */ clearRenderPasses ( ) { this . __renderPasses . length = 0 ; } /**
     * Gets the list of render passes of this expression.
     */ get renderPasses ( ) : RenderPass [ ] { return this . __renderPasses ; } }