Shaders Cursor Ripples

Core Contract

1. Preserve the existing page, content, and semantic image.
2. Install shaders and import from the active framework subpath.
3. Render the source image through one Shader canvas.
4. Place CursorRipples after ImageTexture so it post-processes that image.
5. Keep toneMapping="aces" on the root.
6. Let Shaders track the cursor. Remove custom spotlight coordinates, radial masks, duplicated reveal images, and pointer animation loops.
7. Keep one real image beneath the canvas as the accessible loading and WebGPU fallback.
8. Disable the shader for reduced motion and unsupported WebGPU.
9. Lazy-load the shader code so the library does not inflate the initial page bundle.

When the user asks for only the shader effect, do not copy a reference's ribbon, blob, glow, typography, layout, copy, colors, or identity. Do not substitute the Shaders Water component: CursorRipples is the interactive image-displacement effect.

Inspect Before Editing

• Find the real media wrapper, image URL, crop, overlays, z-index, and existing motion.
• Confirm the wrapper has a non-zero rendered width and height.
• Search for old reveal code such as data-reveal-hover, mask-image: radial-gradient, duplicated images, requestAnimationFrame, and manual pointer listeners.
• Preserve unrelated parallax or entrance motion unless it conflicts with the shader canvas.
• Check the installed shaders version and current framework API when the package may have changed.

Install

npm install shaders

Import from shaders/react, shaders/vue, shaders/svelte, or shaders/solid. For Vite projects, never add shaders to optimizeDeps.exclude; its CommonJS dependencies need Vite pre-bundling. No optimizeDeps entry is normally required.

This is a paid, non-OSS dependency. The shaders package ships a proprietary "Shader Effects License Agreement" and npm reports license: None — rights are granted only subject to payment. It is not MIT/Apache and cannot be treated as a free transitive dependency. Clear licensing before any commercial release, and prefer webgl-laser or a hand-rolled shader when the project cannot take a paid dependency.

Required Composition

Keep the component order and values below:

<Shader toneMapping="aces">
  <ImageTexture url={imageUrl} objectFit="cover" />
  <CursorRipples decay={7.3} radius={0.6} />
</Shader>

Use this as the baseline before tuning intensity, chromaticSplit, or edges. Do not add SolidColor, Blob, Form3D, GaborNoise, Glow, or another generator unless the user explicitly requests the reference's generated artwork.

For React, copy and adapt assets/react/cursor-ripple-shader.tsx and assets/react/cursor-ripple-media.css.

Client and Fallback Pattern

Mount the shader only after the browser confirms WebGPU and motion is allowed:

const CursorRippleShader = lazy(() => import("./cursor-ripple-shader"));

const [shaderEnabled, setShaderEnabled] = useState(false);
const [shaderReady, setShaderReady] = useState(false);

useEffect(() => {
  const reduceMotion = window.matchMedia("(prefers-reduced-motion: reduce)");

  const sync = () => {
    const enabled = "gpu" in navigator && !reduceMotion.matches;
    setShaderEnabled(enabled);
    if (!enabled) setShaderReady(false);
  };

  sync();
  reduceMotion.addEventListener("change", sync);
  return () => reduceMotion.removeEventListener("change", sync);
}, []);

Keep the semantic image in the wrapper, then overlay the lazy shader:

<figure className="cursor-ripple-media">
  <img
    className="cursor-ripple-media__fallback"
    src={imageUrl}
    alt={meaningfulAlt}
    width={width}
    height={height}
  />

  {shaderEnabled ? (
    <Suspense fallback={null}>
      <CursorRippleShader
        imageUrl={imageUrl}
        ready={shaderReady}
        onReady={() => setShaderReady(true)}
      />
    </Suspense>
  ) : null}
</figure>

For Next.js, an ssr: false dynamic import is also valid. Do not hide the fallback until the shader calls onReady; a failed WebGPU initialization must leave the page legible and complete.

Layering Rules

• Give the media wrapper position: relative, a definite size, overflow: hidden, and isolation: isolate.
• Keep the fallback at z-index 0 and the canvas at z-index 1.
• Fill the wrapper with position: absolute; inset: 0; width: 100%; height: 100%.
• Set the shader layer to pointer-events: none; Shaders listens globally and converts pointer coordinates using the canvas bounds.
• Mark the shader wrapper aria-hidden="true"; the fallback image owns the accessible name.
• Place copy, links, and controls above the canvas so the effect never intercepts interaction.
• Preserve the same crop between the fallback and ImageTexture. Use objectFit="cover" for full-bleed media.

Remove the Failed Spotlight Pattern

Delete the old implementation rather than leaving it hidden:

• second reveal image;
• radial mask-image and custom reveal variables;
• smoke or blur overlays tied to pointer position;
• component-local requestAnimationFrame pointer easing;
• pointerenter, pointermove, pointerleave, and resize bookkeeping created only for the flashlight;
• coarse-pointer rules that reference the retired reveal layers.

Keeping both systems causes coordinate drift, extra GPU work, and confusing fallbacks.

Performance and Motion

• Lazy-load the shader module behind the WebGPU check.
• Keep exactly one shader canvas for the media panel.
• Use the library's onReady callback for a short opacity handoff.
• Use disableTelemetry when telemetry is not required.
• Do not animate the canvas size; animate a stable parent if parallax is needed.
• Disable or unmount the shader under prefers-reduced-motion: reduce.
• Keep touch layouts usable with the static image; never put essential information inside the effect.

Verification

Run the project's lint, production build, rendered tests, and git diff --check. Then verify in a real browser:

1. Confirm exactly one canvas[data-renderer="shaders"] exists.
2. Confirm the shader reaches its ready class and the fallback image remains present.
3. Sweep the pointer across several points in the media. The distortion must follow that path without a detached circle.
4. Confirm links and controls remain clickable.
5. Confirm no console errors or warnings occur.
6. Confirm the static image remains when WebGPU is unavailable or reduced motion is enabled.
7. Confirm the old data-reveal-hover or radial-mask layer is absent.
8. Check mobile and desktop crops after the canvas initializes.

Failure Diagnosis

• Canvas exists but is blank: verify the wrapper has non-zero dimensions and the image URL is same-origin or CORS-readable.
• Image renders but does not ripple: keep CursorRipples after ImageTexture; it requires a child/input surface.
• Ripple is offset: remove manual pointer transforms and check whether a transformed ancestor changes the canvas bounds.
• Page crashes during SSR: move the shader into a client-only, lazy-loaded component.
• Image flashes on load: retain the fallback and fade the shader in only from onReady.
• Initial bundle becomes large: confirm the Shaders import lives only inside the lazy module.
• Effect blocks buttons: keep the canvas pointer-transparent and controls in a higher stacking layer.

Handoff

Report the affected media, Shaders package version, fallback behavior, reduced-motion behavior, build/test results, and live interaction verification. Distinguish a locally ready effect from a published deployment.