Component now reuses its canvas. regl implementation reuses its regl instance, and caches resources that already loaded.

js/Matrix.js

@@ -1,5 +1,5 @@
-import React, { useEffect, useRef, memo } from "react";
-import { createRain, destroyRain } from "./regl/main";
+import React, { useEffect, useState, useRef, memo } from "react";
+import { init as initRain, formulate as refreshRain, destroy as destroyRain } from "./regl/main";
 import makeConfig from "./utils/config";
 
 /**
@@ -110,29 +110,33 @@ export const Matrix = memo((props) => {
 	const { style, className, ...rest } = props;
 	const elProps = { style, className };
 	const matrix = useRef(null);
-	const rainRef = useRef(null);
-	const canvasRef = useRef(null);
+	const [rain, setRain] = useState(null);
 
 	useEffect(() => {
 		const canvas = document.createElement("canvas");
+		matrix.current.appendChild(canvas);
 		canvas.style.width = "100%";
 		canvas.style.height = "100%";
-		canvasRef.current = canvas;
+		const init = async () => {
+			setRain(await initRain(canvas));
+		}
+		init();
+
+		return () => {
+			destroyRain(rain);
+			setRain(null);
+		};
 	}, []);
 
 	useEffect(() => {
-		matrix.current.appendChild(canvasRef.current);
-		const gl = canvasRef.current.getContext("webgl");
-		createRain(canvasRef.current, makeConfig({ ...rest }), gl).then((handles) => {
-			rainRef.current = handles;
-		});
-
-		return () => {
-			if (rainRef.current) {
-				destroyRain(rainRef.current);
-			}
+		if (rain == null) {
+			return;
+		}
+		const refresh = async () => {
+			await refreshRain(rain, makeConfig({ ...rest }));
 		};
-	}, [props]);
+		refresh();
+	}, [props, rain]);
 
 	return <div ref={matrix} {...elProps}></div>;
 });

js/index.js

@@ -23,7 +23,7 @@ const versions = [
 ];
 const App = () => {
 	const [version, setVersion] = React.useState(versions[0]);
-	// const [number, setNumber] = React.useState(0);
+	const [numColumns, setNumColumns] = React.useState(10);
 	const onButtonClick = () => {
 		setVersion((s) => {
 			const newVersion = versions[idx];
@@ -31,17 +31,19 @@ const App = () => {
 			console.log(newVersion);
 			return newVersion;
 		});
+		setNumColumns(() => {
+			const newColumns = 10 + Math.floor(Math.random() * 50);
+			console.log(newColumns);
+			return newColumns;
+		});
 	};
-	// const newNum = () => setNumber((n) => n + 1);
-	console.log("version", version);
-	// console.log("num", number);
 
 	return (
 		<div>
 			<h1>Rain</h1>
-			<button onClick={onButtonClick}>change version</button>
+			<button onClick={onButtonClick}>Change</button>
 			{/* <button onClick={newNum}>change number</button> */}
-			<Matrix version={version} density={7.0} />
+			<Matrix style={{width: "80vw", height: "45vh"}} version={version} numColumns={numColumns} density={2.0} />
 		</div>
 	);
 };

js/regl/imagePass.js

@@ -6,10 +6,10 @@ import imagePassFrag from "../../shaders/glsl/imagePass.frag.glsl";
 const defaultBGURL =
 	"https://upload.wikimedia.org/wikipedia/commons/thumb/0/0a/Flammarion_Colored.jpg/917px-Flammarion_Colored.jpg";
 
-export default ({ regl, config }, inputs) => {
+export default ({ regl, cache, config }, inputs) => {
 	const output = makePassFBO(regl, config.useHalfFloat);
 	const bgURL = "bgURL" in config ? config.bgURL : defaultBGURL;
-	const background = loadImage(regl, bgURL);
+	const background = loadImage(cache, regl, bgURL);
 	const render = regl({
 		frag: regl.prop("frag"),
 		uniforms: {

js/regl/main.js

@@ -23,45 +23,27 @@ const effects = {
 	mirror: makeMirrorPass,
 };
 
-const dimensions = { width: 1, height: 1 };
-
-// const loadJS = (src) =>
-//   new Promise((resolve, reject) => {
-//     const tag = document.createElement("script");
-//     tag.onload = resolve;
-//     tag.onerror = reject;
-//     tag.src = src;
-//     document.body.appendChild(tag);
-//   });
-
-// Promise.all([loadJS("lib/regl.min.js"), loadJS("lib/gl-matrix.js")]);
-
-export const createRain = async (canvas, config, gl) => {
+export const init = async (canvas) => {
 	const resize = () => {
-		const dpr = window.devicePixelRatio || 1;
-		canvas.width = Math.ceil(window.innerWidth * dpr * config.resolution);
-		canvas.height = Math.ceil(window.innerHeight * dpr * config.resolution);
+		const devicePixelRatio = window.devicePixelRatio ?? 1;
+		canvas.width = Math.ceil(canvas.clientWidth * devicePixelRatio * rain.resolution);
+		canvas.height = Math.ceil(canvas.clientHeight * devicePixelRatio * rain.resolution);
 	};
 
-	window.onresize = resize;
-	if (document.fullscreenEnabled || document.webkitFullscreenEnabled) {
-		window.ondblclick = () => {
-			if (document.fullscreenElement == null) {
-				if (canvas.webkitRequestFullscreen != null) {
-					canvas.webkitRequestFullscreen();
-				} else {
-					canvas.requestFullscreen();
-				}
-			} else {
-				document.exitFullscreen();
-			}
-		};
-	}
-	resize();
-
-	if (config.useCamera) {
-		await setupCamera();
-	}
+	const doubleClick = () => {
+		if (!document.fullscreenEnabled && !document.webkitFullscreenEnabled) {
+			return;
+		}
+		if (document.fullscreenElement != null) {
+			document.exitFullscreen();
+			return;
+		}
+		if (canvas.webkitRequestFullscreen != null) {
+			canvas.webkitRequestFullscreen();
+		} else {
+			canvas.requestFullscreen();
+		}
+	};
 
 	const extensions = ["OES_texture_half_float", "OES_texture_half_float_linear"];
 	// These extensions are also needed, but Safari misreports that they are missing
@@ -71,22 +53,35 @@ export const createRain = async (canvas, config, gl) => {
 		"OES_standard_derivatives",
 	];
 
-	switch (config.testFix) {
-		case "fwidth_10_1_2022_A":
-			extensions.push("OES_standard_derivatives");
-			break;
-		case "fwidth_10_1_2022_B":
-			optionalExtensions.forEach((ext) => extensions.push(ext));
-			extensions.length = 0;
-			break;
-	}
+	const regl = createREGL({ canvas, pixelRatio: 1, extensions, optionalExtensions });
+	const cache = new Map();
+	const rain = { canvas, resize, doubleClick, cache, regl, resolution: 1 };
 
-	const regl = createREGL({
-		gl,
-		pixelRatio: 1,
-		extensions,
-		optionalExtensions,
-	});
+	window.addEventListener("dblclick", doubleClick);
+	window.addEventListener("resize", resize);
+	resize();
+
+	return rain;
+};
+
+export const destroy = (rain) => {
+	rain.resizeObserver.disconnect();
+	window.removeEventListener("resize", resize);
+	window.removeEventListener("dblclick", doubleClick);
+	cache.clear();
+};
+
+export const formulate = async (rain, config) => {
+
+	const { resize, canvas, cache, regl } = rain;
+	rain.resolution = config.resolution;
+	resize();
+
+	const dimensions = { width: 1, height: 1 };
+
+	if (config.useCamera) {
+		await setupCamera();
+	}
 
 	const cameraTex = regl.texture(cameraCanvas);
 	const lkg = await getLKG(config.useHoloplay, true);
@@ -94,7 +89,7 @@ export const createRain = async (canvas, config, gl) => {
 	// All this takes place in a full screen quad.
 	const fullScreenQuad = makeFullScreenQuad(regl);
 	const effectName = config.effect in effects ? config.effect : "palette";
-	const context = { regl, config, lkg, cameraTex, cameraAspectRatio };
+	const context = { regl, cache, config, lkg, cameraTex, cameraAspectRatio };
 	const pipeline = makePipeline(context, [
 		makeRain,
 		makeBloomPass,
@@ -112,6 +107,14 @@ export const createRain = async (canvas, config, gl) => {
 	const targetFrameTimeMilliseconds = 1000 / config.fps;
 	let last = NaN;
 
+	resetREGLTime: {
+		const reset = regl.frame(o => {
+			o.time = 0;
+			o.tick = 0;
+			reset.cancel();
+		})
+	}
+
 	const tick = regl.frame(({ viewportWidth, viewportHeight }) => {
 		if (config.once) {
 			tick.cancel();
@@ -150,10 +153,15 @@ export const createRain = async (canvas, config, gl) => {
 		});
 	});
 
-	return { regl, tick, canvas };
+	if (rain.tick != null) {
+		rain.tick.cancel();
+	}
+
+	rain.tick = tick;
 };
 
-export const destroyRain = ({ regl, tick, canvas }) => {
+export const destroyRain = ({ regl, cache, tick, canvas }) => {
+	cache.clear();
 	tick.cancel(); // stop RAF
 	regl.destroy(); // release all GPU resources & event listeners
 	//canvas.remove();   // drop from the DOM

js/regl/rainPass.js

@@ -37,7 +37,7 @@ const blVert = [1, 0];
 const brVert = [1, 1];
 const quadVertices = [tlVert, trVert, brVert, tlVert, brVert, blVert];
 
-export default ({ regl, config, lkg }) => {
+export default ({ regl, cache, config, lkg }) => {
 	// The volumetric mode multiplies the number of columns
 	// to reach the desired density, and then overlaps them
 	const volumetric = config.volumetric;
@@ -157,10 +157,10 @@ export default ({ regl, config, lkg }) => {
 		);
 
 	// We render the code into an FBO using MSDFs: https://github.com/Chlumsky/msdfgen
-	const glyphMSDF = loadImage(regl, config.glyphMSDFURL);
-	const glintMSDF = loadImage(regl, config.glintMSDFURL);
-	const baseTexture = loadImage(regl, config.baseTextureURL, true);
-	const glintTexture = loadImage(regl, config.glintTextureURL, true);
+	const glyphMSDF = loadImage(cache, regl, config.glyphMSDFURL);
+	const glintMSDF = loadImage(cache, regl, config.glintMSDFURL);
+	const baseTexture = loadImage(cache, regl, config.baseTextureURL, true);
+	const glintTexture = loadImage(cache, regl, config.glintTextureURL, true);
 	const output = makePassFBO(regl, config.useHalfFloat);
 	const renderUniforms = {
 		...commonUniforms,

js/regl/utils.js

@@ -28,10 +28,16 @@ const makeDoubleBuffer = (regl, props) => {
 
 const isPowerOfTwo = (x) => Math.log2(x) % 1 == 0;
 
-const loadImage = (regl, url, mipmap) => {
+const loadImage = (cache, regl, url, mipmap) => {
+
+	const key = `${url}_${mipmap}`;
+	if (cache.has(key)) {
+		return cache.get(key);
+	}
+
 	let texture = regl.texture([[0]]);
 	let loaded = false;
-	return {
+	const resource = {
 		texture: () => {
 			if (!loaded && url != null) {
 				console.warn(`texture still loading: ${url}`);
@@ -72,12 +78,18 @@ const loadImage = (regl, url, mipmap) => {
 			}
 		})(),
 	};
+	cache.set(key, resource);
+	return resource;
 };
 
-const loadText = (url) => {
+const loadText = (cache, url) => {
+	const key = url;
+	if (cache.has(key)) {
+		return cache.get(key);
+	}
 	let text = "";
 	let loaded = false;
-	return {
+	const resource = {
 		text: () => {
 			if (!loaded) {
 				console.warn(`text still loading: ${url}`);
@@ -91,6 +103,8 @@ const loadText = (url) => {
 			}
 		})(),
 	};
+	cache.set(key, resource);
+	return resource;
 };
 
 const makeFullScreenQuad = (regl, uniforms = {}, context = {}) =>