Use a sizing ref to avoid resizing the canvas

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

@@ -2,14 +2,32 @@ import React, {useContext, useEffect, useMemo, useRef, useState} from "react";
 import * as params from "../src/params";
 import {PainterContext} from "../src/Canvas";
 import {colorFromPalette} from "./paintColor";
-import {chaosGameColor, ChaosGameColorProps, TransformColor} from "./chaosGameColor";
+import {chaosGameColor, Props as ChaosGameColorProps, TransformColor} from "./chaosGameColor";
 
 import styles from "../src/css/styles.module.css";
 import {histIndex} from "../src/camera";
 import {useColorMode} from "@docusaurus/theme-common";
 
-const paletteBarPainter = (palette: number[]) =>
-    (width: number, height: number) => {
+type PaletteBarProps = {
+    height: number;
+    palette: number[];
+    children?: React.ReactNode;
+}
+const PaletteBar: React.FC<PaletteBarProps> = ({height, palette, children}) => {
+    const sizingRef = useRef<HTMLDivElement>(null);
+    const [width, setWidth] = useState(0);
+    useEffect(() => {
+        if (sizingRef) {
+            setWidth(sizingRef.current.offsetWidth);
+        }
+    }, [sizingRef]);
+
+    const canvasRef = useRef<HTMLCanvasElement>(null);
+    const paletteImage = useMemo(() => {
+        if (width === 0) {
+            return;
+        }
+
         const image = new ImageData(width, height);
         for (let x = 0; x < width; x++) {
             const colorIndex = x / width;
@@ -23,21 +41,20 @@ const paletteBarPainter = (palette: number[]) =>
                 image.data[pixelIndex + 3] = 0xff;
             }
         }
-        return image;
-    }
 
-type PaletteBarProps = {
-    height: number;
-    palette: number[];
-    children?: React.ReactNode;
+        return image;
+    }, [width, height, palette]);
+
+    useEffect(() => {
+        if (canvasRef && paletteImage) {
+            canvasRef.current.getContext("2d").putImageData(paletteImage, 0, 0);
         }
-const PaletteBar: React.FC<PaletteBarProps> = ({height, palette, children}) => {
-    const painter = useMemo(() => paletteBarPainter(palette), [palette]);
+    }, [canvasRef, paletteImage]);
 
     return (
         <>
-            <div style={{width: '100%', height, marginTop: '1em', marginBottom: '1em'}}>
-                {/*<AutoSizingCanvas painter={painter}/>*/}
+            <div ref={sizingRef} style={{width: '100%', height}}>
+                {width > 0 ? <canvas ref={canvasRef} width={width} height={height}/> : null}
             </div>
             {children}
         </>
@@ -115,7 +132,6 @@ export default function FlameColor({quality, children}: Props) {
             height,
             transforms: params.xforms,
             final: params.xformFinal,
-            quality,
             palette: params.palette,
             colors: [xform1Color, xform2Color, xform3Color],
             finalColor: xformFinalColor

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

@@ -4,11 +4,10 @@ import {PainterContext} from "../src/Canvas";
 import {chaosGameHistogram} from "./chaosGameHistogram";
 
 type Props = {
-    quality?: number;
-    paint: (width: number, histogram: Uint32Array) => ImageData;
+    paint: (width: number, height: number, histogram: number[]) => ImageData;
     children?: React.ReactElement;
 }
-export default function FlameHistogram({quality, paint, children}: Props) {
+export default function FlameHistogram({paint, children}: Props) {
     const {width, height, setPainter} = useContext(PainterContext);
 
     useEffect(() => {
@@ -17,11 +16,10 @@ export default function FlameHistogram({quality, paint, children}: Props) {
             height,
             transforms,
             final,
-            quality,
             paint
         }
         setPainter(chaosGameHistogram(gameParams));
-    }, []);
+    }, [width, height]);
 
     return children;
 }

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

@@ -17,7 +17,7 @@ function mixColor(color1: number, color2: number, colorSpeed: number) {
     return color1 * (1 - colorSpeed) + color2 * colorSpeed;
 }
 
-type Props = ChaosGameFinalProps & {
+export type Props = ChaosGameFinalProps & {
     palette: number[];
     colors: TransformColor[];
     finalColor: TransformColor;

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

@@ -14,8 +14,17 @@ type CanvasProps = {
     children?: React.ReactElement
 }
 export const Canvas: React.FC<CanvasProps> = ({style, children}) => {
-    const canvasRef = useRef<HTMLCanvasElement>(null);
+    const sizingRef = useRef<HTMLDivElement>(null);
+    const [width, setWidth] = useState(0);
+    const [height, setHeight] = useState(0);
+    useEffect(() => {
+        if (sizingRef.current) {
+            setWidth(sizingRef.current.offsetWidth);
+            setHeight(sizingRef.current.offsetHeight);
+        }
+    }, [sizingRef]);
 
+    const canvasRef = useRef<HTMLCanvasElement>(null);
     const [isVisible, setIsVisible] = useState(false);
     useEffect(() => {
         if (!canvasRef.current) {
@@ -35,16 +44,7 @@ export const Canvas: React.FC<CanvasProps> = ({style, children}) => {
                 observer.unobserve(canvasRef.current);
             }
         }
-    }, [canvasRef]);
-
-    const [width, setWidth] = useState(0);
-    const [height, setHeight] = useState(0);
-    useEffect(() => {
-        if (canvasRef.current) {
-            setWidth(canvasRef.current.offsetWidth);
-            setHeight(canvasRef.current.offsetHeight);
-        }
-    }, [canvasRef]);
+    }, [canvasRef.current]);
 
     const [imageHolder, setImageHolder] = useState<[ImageData]>(null);
     useEffect(() => {
@@ -76,25 +76,22 @@ export const Canvas: React.FC<CanvasProps> = ({style, children}) => {
         }
     }, [painter]);
 
-    const {colorMode} = useColorMode();
+    const filter = useColorMode().colorMode === 'dark' ? 'invert(1)' : '';
+
     return (
         <>
-            <canvas
-                ref={canvasRef}
-                width={width}
-                height={height}
-                style={{
-                    filter: colorMode === 'dark' ? 'invert(1)' : '',
-                    ...style
-                }}
-            />
+            <center>
+                <div ref={sizingRef} style={style}>
+                    {width > 0 ? <canvas ref={canvasRef} width={width} height={height} style={{filter}}/> : null}
+                </div>
+            </center>
             <PainterContext.Provider value={{width, height, setPainter}}>
-                <BrowserOnly>{() => children}</BrowserOnly>
+                {width > 0 ? children : null}
             </PainterContext.Provider>
         </>
     )
 }
 
 export const SquareCanvas: React.FC<CanvasProps> = ({style, children}) => {
-    return <Canvas style={{width: '100%', aspectRatio: '1/1', ...style}} children={children}/>
+    return <center><Canvas style={{width: '75%', aspectRatio: '1/1', ...style}} children={children}/></center>
 }