An image that starts as a 1-bit ordered dither. A diagonal scan line sweeps it a set number of times, and each pass sharpens the cells and brings back tone and color until the source is clean.
"use client"
import { useCallback, useState } from "react"
import { DitherScan } from "@/components/ui/dither-scan"
const settings = {
passes: 4,
duration: 1400,
pixelSize: 6,
blur: 6,
angle: 45,
alternate: true,
loop: true,
}
// Inline SVG landscapes, so the preview needs no network images.
function scene(
sky: [string, string],
sun: string,
hills: [string, string, string],
width = 1200,
height = 800
) {
const ridge = (base: number, amp: number, seed: number) => {
let d = `M0 ${height}L0 ${base}`
for (let x = 0; x <= width; x += width / 12) {
const y = base - amp * (0.5 + 0.5 * Math.sin(x / 140 + seed) * Math.cos(x / 310 + seed * 2))
d += `L${x.toFixed(0)} ${y.toFixed(0)}`
}
return `${d}L${width} ${height}Z`
}
const svg = `<svg xmlns="http://www.w3.org/2000/svg" width="${width}" height="${height}" viewBox="0 0 ${width} ${height}">
<defs><linearGradient id="s" x1="0" y1="0" x2="0" y2="1"><stop offset="0" stop-color="${sky[0]}"/><stop offset="1" stop-color="${sky[1]}"/></linearGradient>
<radialGradient id="g"><stop offset="0" stop-color="${sun}" stop-opacity=".9"/><stop offset="1" stop-color="${sun}" stop-opacity="0"/></radialGradient></defs>
<rect width="${width}" height="${height}" fill="url(#s)"/>
<circle cx="${width * 0.68}" cy="${height * 0.36}" r="${height * 0.34}" fill="url(#g)"/>
<circle cx="${width * 0.68}" cy="${height * 0.36}" r="${height * 0.08}" fill="${sun}"/>
<path d="${ridge(height * 0.58, height * 0.22, 1)}" fill="${hills[0]}"/>
<path d="${ridge(height * 0.72, height * 0.16, 4)}" fill="${hills[1]}"/>
<path d="${ridge(height * 0.86, height * 0.12, 7)}" fill="${hills[2]}"/>
</svg>`
return `data:image/svg+xml;charset=utf-8,${encodeURIComponent(svg)}`
}
const IMAGE = {
src: scene(["#F6C38B", "#FBE7C6"], "#FFF4D6", ["#7A8F6B", "#4E6650", "#2C4236"]),
alt: "Layered green hills under a warm sunrise",
}
export default function DitherScanDemo(props: Partial<typeof settings>) {
const s = { ...settings, ...props }
const [replayKey, setReplayKey] = useState(0)
const [cleared, setCleared] = useState(0)
const onStart = useCallback(() => setCleared(0), [])
const onPass = useCallback((pass: number) => setCleared(pass), [])
const total = Math.max(1, Math.round(s.passes))
const status = cleared >= total ? "Clean" : `${cleared} of ${total} passes`
return (
<div className="flex min-h-[520px] w-full flex-col items-center justify-center gap-3 bg-background p-4">
<div className="flex h-[440px] w-full max-w-4xl items-center justify-center [container-type:size]">
<DitherScan
src={IMAGE.src}
alt={IMAGE.alt}
// Fit the image's own ratio inside the stage, like object-contain.
className="w-[min(100cqw,calc(100cqh*var(--dither-scan-ratio)))] rounded-lg"
passes={s.passes}
duration={s.duration}
pixelSize={s.pixelSize}
blur={s.blur}
angle={s.angle}
alternate={s.alternate}
loop={s.loop}
replayKey={replayKey}
onStart={onStart}
onPass={onPass}
/>
</div>
<div className="flex items-center gap-3 text-xs text-muted-foreground">
<span className="tabular-nums" aria-live="polite">
{status}
</span>
<button
type="button"
className="rounded-md border border-border bg-background px-2 py-1 text-xs font-medium text-foreground transition-colors hover:bg-muted"
onClick={() => setReplayKey((key) => key + 1)}
>
Replay
</button>
</div>
</div>
)
}