import { Uniform, WebGLRenderTarget } from "three";

import { Resolution } from "../core/index.js";

import { BlendFunction, KernelSize, SRGBColorSpace } from "../enums/index.js";

import { KawaseBlurPass, LuminancePass, MipmapBlurPass } from "../passes/index.js";

import { getOutputColorSpace, setTextureColorSpace } from "../utils/index.js";

import { Effect } from "./Effect.js";

import fragmentShader from "./glsl/bloom.frag";

/**

* A bloom effect.

*

* Based on an article by Fabrice Piquet:

* https://www.froyok.fr/blog/2021-12-ue4-custom-bloom/

*/

export class BloomEffect extends Effect {

/**

* Constructs a new bloom effect.

*

* @param {Object} [options] - The options.

* @param {BlendFunction} [options.blendFunction=BlendFunction.SCREEN] - The blend function of this effect.

* @param {Number} [options.luminanceThreshold=0.9] - The luminance threshold. Raise this value to mask out darker elements in the scene.

* @param {Number} [options.luminanceSmoothing=0.025] - Controls the smoothness of the luminance threshold.

* @param {Boolean} [options.mipmapBlur=false] - Enables or disables mipmap blur.

* @param {Number} [options.intensity=1.0] - The bloom intensity.

* @param {Number} [options.radius=0.85] - The blur radius. Only applies to mipmap blur.

* @param {Number} [options.levels=8] - The amount of MIP levels. Only applies to mipmap blur.

* @param {KernelSize} [options.kernelSize=KernelSize.LARGE] - Deprecated. Use mipmapBlur instead.

* @param {Number} [options.resolutionScale=0.5] - Deprecated. Use mipmapBlur instead.

* @param {Number} [options.resolutionX=Resolution.AUTO_SIZE] - Deprecated. Use mipmapBlur instead.

* @param {Number} [options.resolutionY=Resolution.AUTO_SIZE] - Deprecated. Use mipmapBlur instead.

* @param {Number} [options.width=Resolution.AUTO_SIZE] - Deprecated. Use mipmapBlur instead.

* @param {Number} [options.height=Resolution.AUTO_SIZE] - Deprecated. Use mipmapBlur instead.

*/

constructor({

blendFunction = BlendFunction.SCREEN,

luminanceThreshold = 0.9,

luminanceSmoothing = 0.025,

mipmapBlur = false,

intensity = 1.0,

radius = 0.85,

levels = 8,

kernelSize = KernelSize.LARGE,

resolutionScale = 0.5,

width = Resolution.AUTO_SIZE,

height = Resolution.AUTO_SIZE,

resolutionX = width,

resolutionY = height

} = {}) {

super("BloomEffect", fragmentShader, {

blendFunction,

uniforms: new Map([

["map", new Uniform(null)],

["intensity", new Uniform(intensity)]

])

});

/**

* A render target.

*

* @type {WebGLRenderTarget}

* @private

*/

this.renderTarget = new WebGLRenderTarget(1, 1, { depthBuffer: false });

this.renderTarget.texture.name = "Bloom.Target";

/**

* A blur pass.

*

* @type {KawaseBlurPass}

* @readonly

*/

this.blurPass = new KawaseBlurPass({ kernelSize });

/**

* A luminance pass.

*

* Disable to skip luminance filtering.

*

* @type {LuminancePass}

* @readonly

*/

this.luminancePass = new LuminancePass({ colorOutput: true });

this.luminanceMaterial.threshold = luminanceThreshold;

this.luminanceMaterial.smoothing = luminanceSmoothing;

/**

* A mipmap blur pass.

*

* @type {MipmapBlurPass}

* @private

*/

this.mipmapBlurPass = new MipmapBlurPass();

this.mipmapBlurPass.enabled = mipmapBlur;

this.mipmapBlurPass.radius = radius;

this.mipmapBlurPass.levels = levels;

this.uniforms.get("map").value = mipmapBlur ? this.mipmapBlurPass.texture : this.renderTarget.texture;

/**

* The render resolution.

*

* @type {Resolution}

* @readonly

* @deprecated

*/

const resolution = this.resolution = new Resolution(this, resolutionX, resolutionY, resolutionScale);

resolution.addEventListener("change", (e) => this.setSize(resolution.baseWidth, resolution.baseHeight));

}

/**

* A texture that contains the intermediate result of this effect.

*

* @type {Texture}

*/

get texture() {

return this.mipmapBlurPass.enabled ? this.mipmapBlurPass.texture : this.renderTarget.texture;

}

/**

* Returns the generated bloom texture.

*

* @deprecated Use texture instead.

* @return {Texture} The texture.

*/

getTexture() {

return this.texture;

}

/**

* Returns the resolution settings.

*

* @deprecated Use resolution instead.

* @return {Resolution} The resolution.

*/

getResolution() {

return this.resolution;

}

/**

* Returns the blur pass.

*

* @deprecated

* @return {KawaseBlurPass} The blur pass.

*/

getBlurPass() {

return this.blurPass;

}

/**

* Returns the luminance pass.

*

* @deprecated Use luminancePass instead.

* @return {LuminancePass} The luminance pass.

*/

getLuminancePass() {

return this.luminancePass;

}

/**

* The luminance material.

*

* @type {LuminanceMaterial}

*/

get luminanceMaterial() {

return this.luminancePass.fullscreenMaterial;

}

/**

* Returns the luminance material.

*

* @deprecated Use luminanceMaterial instead.

* @return {LuminanceMaterial} The material.

*/

getLuminanceMaterial() {

return this.luminancePass.fullscreenMaterial;

}

/**

* The current width of the internal render targets.

*

* @type {Number}

* @deprecated

*/

get width() {

return this.resolution.width;

}

set width(value) {

this.resolution.preferredWidth = value;

}

/**

* The current height of the internal render targets.

*

* @type {Number}

* @deprecated

*/

get height() {

return this.resolution.height;

}

set height(value) {

this.resolution.preferredHeight = value;

}

/**

* Indicates whether dithering is enabled.

*

* @type {Boolean}

* @deprecated Use EffectPass.dithering instead.

*/

get dithering() {

return this.blurPass.dithering;

}

set dithering(value) {

this.blurPass.dithering = value;

}

/**

* The blur kernel size.

*

* @type {KernelSize}

* @deprecated

*/

get kernelSize() {

return this.blurPass.kernelSize;

}

set kernelSize(value) {

this.blurPass.kernelSize = value;

}

/**

* @type {Number}

* @deprecated

*/

get distinction() {

console.warn(this.name, "distinction was removed");

return 1.0;

}

set distinction(value) {

console.warn(this.name, "distinction was removed");

}

/**

* The bloom intensity.

*

* @type {Number}

*/

get intensity() {

return this.uniforms.get("intensity").value;

}

set intensity(value) {

this.uniforms.get("intensity").value = value;

}

/**

* The bloom intensity.

*

* @deprecated Use intensity instead.

* @return {Number} The intensity.

*/

getIntensity() {

return this.intensity;

}

/**

* Sets the bloom intensity.

*

* @deprecated Use intensity instead.

* @param {Number} value - The intensity.

*/

setIntensity(value) {

this.intensity = value;

}

/**

* Returns the current resolution scale.

*

* @return {Number} The resolution scale.

* @deprecated

*/

getResolutionScale() {

return this.resolution.scale;

}

/**

* Sets the resolution scale.

*

* @param {Number} scale - The new resolution scale.

* @deprecated

*/

setResolutionScale(scale) {

this.resolution.scale = scale;

}

/**

* Updates this effect.

*

* @param {WebGLRenderer} renderer - The renderer.

* @param {WebGLRenderTarget} inputBuffer - A frame buffer that contains the result of the previous pass.

* @param {Number} [deltaTime] - The time between the last frame and the current one in seconds.

*/

update(renderer, inputBuffer, deltaTime) {

const renderTarget = this.renderTarget;

const luminancePass = this.luminancePass;

if(luminancePass.enabled) {

luminancePass.render(renderer, inputBuffer);

if(this.mipmapBlurPass.enabled) {

this.mipmapBlurPass.render(renderer, luminancePass.renderTarget);

} else {

this.blurPass.render(renderer, luminancePass.renderTarget, renderTarget);

}

} else {

if(this.mipmapBlurPass.enabled) {

this.mipmapBlurPass.render(renderer, inputBuffer);

} else {

this.blurPass.render(renderer, inputBuffer, renderTarget);

}

}

}

/**

* Updates the size of internal render targets.

*

* @param {Number} width - The width.

* @param {Number} height - The height.

*/

setSize(width, height) {

const resolution = this.resolution;

resolution.setBaseSize(width, height);

this.renderTarget.setSize(resolution.width, resolution.height);

this.blurPass.resolution.copy(resolution);

this.luminancePass.setSize(width, height);

this.mipmapBlurPass.setSize(width, height);

}

/**

* Performs initialization tasks.

*

* @param {WebGLRenderer} renderer - The renderer.

* @param {Boolean} alpha - Whether the renderer uses the alpha channel or not.

* @param {Number} frameBufferType - The type of the main frame buffers.

*/

initialize(renderer, alpha, frameBufferType) {

this.blurPass.initialize(renderer, alpha, frameBufferType);

this.luminancePass.initialize(renderer, alpha, frameBufferType);

this.mipmapBlurPass.initialize(renderer, alpha, frameBufferType);

if(frameBufferType !== undefined) {

this.renderTarget.texture.type = frameBufferType;

if(getOutputColorSpace(renderer) === SRGBColorSpace) {

setTextureColorSpace(this.renderTarget.texture, SRGBColorSpace);

}

}

}

}