View detection

blog/2024-11-15-playing-with-fire/3-log-density/FlameColor.tsx

@@ -103,7 +103,7 @@ const ColorEditor: React.FC<ColorEditorProps> = ({title, palette, transformColor
                            onInput={e => setTransformColor({...transformColor, color: Number(e.currentTarget.value)})}/>
                 </div>
                 <div className={styles.inputElement}>
-                    <p>Color speed: {transformColor.colorSpeed}</p>
+                    <p>Speed: {transformColor.colorSpeed}</p>
                     <input type={'range'} min={0} max={1} step={.001} value={transformColor.colorSpeed}
                            onInput={e => setTransformColor({...transformColor, colorSpeed: Number(e.currentTarget.value)})}/>
                 </div>

blog/2024-11-15-playing-with-fire/3-log-density/FlameHistogram.tsx

@@ -1,24 +1,24 @@
 import React, {useContext, useEffect} from "react";
-import * as params from "../src/params";
+import {xforms as transforms, xformFinal as final} from "../src/params";
 import {PainterContext} from "../src/Canvas";
 import {chaosGameHistogram} from "./chaosGameHistogram";
 
 type Props = {
     quality?: number;
-    paintFn: (width: number, histogram: Uint32Array) => ImageData;
+    paint: (width: number, histogram: Uint32Array) => ImageData;
     children?: React.ReactElement;
 }
-export default function FlameHistogram({quality, paintFn, children}: Props) {
+export default function FlameHistogram({quality, paint, children}: Props) {
     const {width, height, setPainter} = useContext(PainterContext);
 
     useEffect(() => {
         const gameParams = {
             width,
             height,
-            transforms: params.xforms,
+            transforms,
-            final: params.xformFinal,
+            final,
             quality,
-            painter: paintFn
+            paint
         }
         setPainter(chaosGameHistogram(gameParams));
     }, []);

blog/2024-11-15-playing-with-fire/3-log-density/chaosGameColor.ts

@@ -20,7 +20,7 @@ export type ChaosGameColorProps = ChaosGameFinalProps & {
 }
 export function* chaosGameColor({width, height, transforms, final, palette, colors, finalColor, quality, step}: ChaosGameColorProps) {
     let iterations = (quality ?? 1) * width * height;
-    step = step ?? 100_000;
+    step = step ?? 10_000;
 
     let currentColor = Math.random();
     const red = Array(width * height).fill(0);

blog/2024-11-15-playing-with-fire/3-log-density/chaosGameHistogram.ts

@@ -9,7 +9,7 @@ export type ChaosGameHistogramProps = ChaosGameFinalProps & {
 }
 export function* chaosGameHistogram({width, height, transforms, final, quality, step, paint}: ChaosGameHistogramProps) {
     let iterations = (quality ?? 1) * width * height;
-    step = step ?? 100_000;
+    step = step ?? 10_000;
 
     const histogram = new Uint32Array(width * height);
 

blog/2024-11-15-playing-with-fire/3-log-density/index.mdx

@@ -32,7 +32,7 @@ import Canvas from "../src/Canvas";
 import FlameHistogram from "./FlameHistogram";
 import {paintLinear} from "./paintLinear";
 
-<Canvas><FlameHistogram quality={5} paintFn={paintLinear}/></Canvas>
+<Canvas><FlameHistogram quality={5} paint={paintLinear}/></Canvas>
 
 ## Log display
 
@@ -42,7 +42,7 @@ import paintLogarithmicSource from "!!raw-loader!./paintLogarithmic"
 
 import {paintLogarithmic} from './paintLogarithmic'
 
-<Canvas><FlameHistogram quality={5} paintFn={paintLogarithmic}/></Canvas>
+<Canvas><FlameHistogram quality={5} paint={paintLogarithmic}/></Canvas>
 
 ## Color
 

blog/2024-11-15-playing-with-fire/src/Canvas.tsx

@@ -1,4 +1,4 @@
-import React, {useCallback, useEffect, useState, createContext} from "react";
+import React, {useCallback, useEffect, useState, createContext, useRef} from "react";
 import {useColorMode} from "@docusaurus/theme-common";
 import BrowserOnly from "@docusaurus/BrowserOnly";
 
@@ -100,10 +100,32 @@ interface CanvasProps {
  * a good way to make those generic.
  */
 export default function Canvas({width, height, children}: CanvasProps) {
+    const viewportDetectionRef = useRef<HTMLDivElement>(null);
+    const [isVisible, setIsVisible] = useState(false);
+    useEffect(() => {
+        if (!viewportDetectionRef) {
+            return;
+        }
+
+        const observer = new IntersectionObserver(([entry]) => {
+            if (entry.isIntersecting) {
+                setIsVisible(true);
+            }
+        }, {root: null, threshold: .1});
+        observer.observe(viewportDetectionRef.current);
+
+        return () => {
+            if (viewportDetectionRef.current) {
+                observer.unobserve(viewportDetectionRef.current);
+            }
+        }
+    }, [viewportDetectionRef]);
+
     const [image, setImage] = useState<[ImageData]>(null);
     const [painterHolder, setPainterHolder] = useState<[Iterator<ImageData>]>(null);
     useEffect(() => {
-        if (!painterHolder) {
+        if (!isVisible || !painterHolder) {
+            console.log("Skipping, not visible");
             return;
         }
 
@@ -115,7 +137,7 @@ export default function Canvas({width, height, children}: CanvasProps) {
         } else {
             setPainterHolder(null);
         }
-    }, [painterHolder]);
+    }, [isVisible, painterHolder]);
 
     const [painter, setPainter] = useState<Iterator<ImageData>>(null);
     useEffect(() => {
@@ -129,7 +151,9 @@ export default function Canvas({width, height, children}: CanvasProps) {
     return (
         <>
             <center>
-                <InvertibleCanvas width={width} height={height} image={image}/>
+                <div ref={viewportDetectionRef}>
+                    <InvertibleCanvas width={width} height={height} image={image}/>
+                </div>
             </center>
             <PainterContext.Provider value={{width, height, setPainter}}>
                 <BrowserOnly>{() => children}</BrowserOnly>

package.json

@@ -4,7 +4,7 @@
   "private": true,
   "scripts": {
     "docusaurus": "docusaurus",
-    "start": "docusaurus start",
+    "start": "docusaurus start --host 0.0.0.0",
     "build": "docusaurus build",
     "swizzle": "docusaurus swizzle",
     "deploy": "docusaurus deploy",