playcanvas/build/playcanvas/src/scene/area-light-luts.js

Open-source WebGL/WebGPU 3D engine for the web

import { FloatPacking } from "../core/math/float-packing.js";
import { Texture } from "../platform/graphics/texture.js";
import { DeviceCache } from "../platform/graphics/device-cache.js";
import {
	ADDRESS_CLAMP_TO_EDGE,
	FILTER_LINEAR,
	FILTER_NEAREST,
	PIXELFORMAT_RGBA16F,
	TEXTURETYPE_DEFAULT
} from "../platform/graphics/constants.js";
class AreaLightCacheEntry {
	constructor(texture0, texture1) {
		this.texture0 = texture0;
		this.texture1 = texture1;
	}
	destroy() {
		this.texture0?.destroy();
		this.texture1?.destroy();
	}
}
const deviceCache = new DeviceCache();
class AreaLightLuts {
	static createTexture(device, format, size, postfix = "") {
		const tex = new Texture(device, {
			name: `AreaLightLUT${postfix}`,
			width: size,
			height: size,
			format,
			addressU: ADDRESS_CLAMP_TO_EDGE,
			addressV: ADDRESS_CLAMP_TO_EDGE,
			type: TEXTURETYPE_DEFAULT,
			magFilter: FILTER_LINEAR,
			minFilter: FILTER_NEAREST,
			anisotropy: 1,
			mipmaps: false
		});
		return tex;
	}
	static applyTextures(device, texture1, texture2) {
		deviceCache.remove(device);
		deviceCache.get(device, () => {
			return new AreaLightCacheEntry(texture1, texture1 === texture2 ? null : texture2);
		});
		device.scope.resolve("areaLightsLutTex1").setValue(texture1);
		device.scope.resolve("areaLightsLutTex2").setValue(texture2);
	}
	// placeholder LUT textures for area light
	static createPlaceholder(device) {
		const texture = AreaLightLuts.createTexture(device, PIXELFORMAT_RGBA16F, 2, "placeholder");
		const pixels = texture.lock();
		pixels.fill(0);
		texture.unlock();
		AreaLightLuts.applyTextures(device, texture, texture);
	}
	// creates LUT texture used by area lights
	static set(device, ltcMat1, ltcMat2) {
		function buildTexture(device2, data, format) {
			const texture = AreaLightLuts.createTexture(device2, format, 64);
			texture.lock().set(data);
			texture.unlock();
			return texture;
		}
		function convertToHalfFloat(data) {
			const count = data.length;
			const ret = new Uint16Array(count);
			const float2Half = FloatPacking.float2Half;
			for (let i = 0; i < count; i++) {
				ret[i] = float2Half(data[i]);
			}
			return ret;
		}
		const srcData1 = ltcMat1;
		const srcData2 = ltcMat2;
		const data1 = convertToHalfFloat(srcData1);
		const data2 = convertToHalfFloat(srcData2);
		const tex1 = buildTexture(device, data1, PIXELFORMAT_RGBA16F);
		const tex2 = buildTexture(device, data2, PIXELFORMAT_RGBA16F);
		AreaLightLuts.applyTextures(device, tex1, tex2);
	}
}
export {
	AreaLightLuts
};