import { Color } from "../../components" ; import { Variation } from "../../systems/variation" ; import { Particle } from "../particle" ; /**
 * Represents a delegate used by the renderer to apply a certain property to the
 * particle's HTMLElement. Note that this property is generic and does not
 * have to contain the particle itself.
 */ export type ApplyFunction < T > = ( property : T , element : HTMLElement ) => void ; /**
 * Holds the options used to configure the renderer for a particle system.
 */ export interface RenderOptions { remarks defaultValue shapeFactory : Variation < HTMLElement | string > ; defaultValue applyColor ? : ApplyFunction < Color > ; defaultValue applyOpacity ? : ApplyFunction < number > ; defaultValue applyLighting ? : ApplyFunction < number > ; defaultValue applyTransform ? : ApplyFunction < Particle > ; } /**
 * Returns the default set of renderer options.
 */ export function getDefaultRendererOptions ( ) { return { shapeFactory : "square" , applyColor : defaultApplyColor , applyOpacity : defaultApplyOpacity , applyLighting : defaultApplyLighting , applyTransform : defaultApplyTransform , } ; } remarks function defaultApplyColor ( color , element ) { const hex = color . toHex ( ) ; switch ( element . nodeName . toLowerCase ( ) ) { case "div" : element . style . background = hex ; break ; case "svg" : element . style . fill = element . style . color = hex ; break ; default : element . style . color = hex ; break ; } } /**
 * Applies the specified opacity to the element.
 */ function defaultApplyOpacity ( opacity , element ) { element . style . opacity = opacity . toString ( ) ; } remarks function defaultApplyLighting ( lighting , element ) { element . style . filter = `brightness(${ 0.5 + Math . abs ( lighting ) })` ; } /**
 * Applies the specified transform to the element as a 3D CSS transform.
 * Also takes into account the current window scroll, to make sure that particles are
 * rendered inside of the fixed container.
 */ function defaultApplyTransform ( particle , element ) { element . style . transform = `translateX(${ ( particle . location . x - window . scrollX ) . toFixed ( 3 ) }px) ` + `translateY(${ ( particle . location . y - window . scrollY ) . toFixed ( 3 ) }px) ` + `translateZ(${ particle . location . z . toFixed ( 3 ) }px) ` + `rotateX(${ particle . rotation . x . toFixed ( 3 ) }deg) ` + `rotateY(${ particle . rotation . y . toFixed ( 3 ) }deg) ` + `rotateZ(${ particle . rotation . z . toFixed ( 3 ) }deg) ` + `scale(${ particle . size . toFixed ( 3 ) })` ; }