SwiftUIShaders

SwiftUIShaders

41 SwiftUI Metal shaders. Holographic foil, kaleidoscope mandalas, magnetic fields, glitch, neon edges, and a pile more. Each one is a [[ stitchable ]] Metal function with a typed SwiftUI View modifier wrapped around it, so dropping one onto a view is a single line.

These started as a hidden shader lab inside Epilogue, my reading app. I built way more than I ever shipped, so I pulled the good ones out to share. Every shader here got rendered on a real book cover and kept only if it actually looked good. The duds, the washed-out ones, and the ones that only work on a blank gradient got cut. What’s left is the set I’d reach for myself.

Drop them into your own project and mess around. They’re also built to hand straight to a coding agent like Claude Code or Codex. If one sparks an idea, point your agent at AGENTS.md and let it riff.

Want to dial them in by eye? Hand the repo to your agent and ask it to build a slider-based tuning tool. Everything it needs is in Docs/parameters.json, and the recipe is in AGENTS.md. Tune against your own content, copy the line it spits out, paste it into your code.

The bcs_ prefix is just the shader namespace. Nothing here is wired to Epilogue’s actual app code.

Requirements

• iOS 17+ / macOS 14+ / tvOS 17+ / visionOS 1+
• Xcode 15+ (the Metal toolchain compiles the shaders into the package’s default.metallib)

One gotcha: build with Xcode or xcodebuild, not bare swift build. SwiftPM’s command-line driver on macOS doesn’t run the Metal toolchain, so Bundle.module and default.metallib never get produced. In Xcode it just works.

Install

Swift Package Manager. In Xcode, go to File ▸ Add Package Dependencies and point it at this repo’s URL. Or add it in Package.swift:

.package(url: "https://github.com/krispuckett/SwiftUIShaders.git", from: "1.0.0")

Then add SwiftUIShaders to your target’s dependencies.

Quick start

import SwiftUI
import SwiftUIShaders

struct ContentView: View {
    var body: some View {
        Image("book-cover")
            .resizable()
            .scaledToFit()
            .bcsHolographic(intensity: 0.6, scale: 12, speed: 1.2)  // animated, self-driving
    }
}

Every shader is a View modifier. The animated ones run themselves with TimelineView(.animation), so there’s no timer for you to babysit. Every parameter has a sensible default, so .bcsKaleidoscope() works on its own.

Text("Chapter One")
    .font(.largeTitle)
    .bcsChromaticSplit(spread: 8, angle: .pi / 4)

bookCover
    .bcsAurora()             // ambient animated glow

myView
    .bcsEmboss(strength: 3)  // static relief

One heads up: these want real content. Photos, book covers, illustrations, text. Drop one on a flat single-color fill and the displacement and edge effects have nothing to grab onto.

How it works (conventions)

Each wrapper applies one Metal layerEffect. The mapping is uniform:

Shader argument	Supplied by the wrapper
position, layer	SwiftUI (automatic)
size	The view’s pixel size, from GeometryProxy
time	Elapsed seconds, from TimelineView(.animation) (animated shaders only)
interaction point (e.g. touchPos)	A UnitPoint (0…1) you pass, converted to pixels
everything else	Typed Float parameters with defaults

Every method also takes maxSampleOffset: (default 64×64). Raise it if a heavy displacement effect looks clipped at the edges. Lower it for a small perf win on cheap effects.

The shaders

37 animate. 4 are static (bcsEmboss, bcsFrosted, and the two interaction-driven ripples). Ranges in parentheses are the sweet spots. The defaults are tuned values that look good out of the box, so you can call any of these with no arguments and get something real.

Shader	Type	Parameters
.bcsAurora: Aurora	animated	intensity (0–1), bands (1–8), speed (0.3–3), colorShift (0–1)
.bcsBlackHole: Black Hole	animated	mass (0.05–0.5), spin (0–5), distortion (10–200), ringBrightness (0–2)
.bcsChromaticSplit: Chromatic Split	animated	spread (0–30), angle (0–6.28), edgeOnly (0–1), animate (0–1)
.bcsDatamosh: Datamosh	animated	blockCorruption (0–1), smearAmount (0–60), colorBleed (0–1), glitchRate (0.5–5)
.bcsDisintegrate: Disintegrate	animated	threshold (0–1), edgeWidth (0.05–0.3), driftAmount (0–50), direction (0–6.28)
.bcsDuochrome: Duochrome	animated	intensity (0–1), hue1 (0–1), hue2 (0–1), contrast (0.5–2)
.bcsEcho: Echo / Ghost	animated	echoCount (2–8), spread (5–50), direction (0–6.28), fade (0.3–0.9)
.bcsEmboss: Emboss / Relief	static	strength (0–5), angle (0–6.28), mixAmount (0–1)
.bcsEtherealAura: Ethereal Aura (v2)	animated	auraWidth, auraIntensity, pulseSpeed, distortion, hueShift
.bcsFrosted: Frosted Glass	static	frostAmount (0–1), grainSize (1–20), clearRadius (0–1), clearSoftness (0–1)
.bcsGeometricWarp: Geometric Warp	animated	spiralTight (1–8), zoomRepeat (0.3–2), rotation (0–6.28), blend (0–1)
.bcsGlitch: Glitch	animated	intensity (0–1), blockSize (2–50), scanLines (0–1), colorShift (0–20)
.bcsGravityWells: Gravity Wells	animated	wellStrength (10–200), wellCount (1–5), orbitSpeed (0.1–3), warpFalloff (0.5–5)
.bcsHeatShimmer: Heat Shimmer	animated	amplitude (0–20), frequency (1–30), speed (0.5–5), verticalBias (0–1)
.bcsHolographic: Holographic / Prismatic	animated	intensity (0–1), scale (1–20), speed (0.1–3), angleOffset (0–6.28)
.bcsInkBleed: Ink Bleed / Domain Warp	animated	warpStrength (0–50), scale (1–10), speed (0.1–2), detail (2–8)
.bcsKaleidoscope: Kaleidoscope	animated	segments (2–16), rotation (0–6.28), zoom (0.5–3), animateSpeed (0–2)
.bcsLiquidChrome: Liquid Chrome	animated	distortion (0–30), chromeIntensity (0–1), flowSpeed (0.1–3), reflectionScale (1–10)
.bcsLiquidMirror: Liquid Mirror	animated	mirrorAxis (0.3–0.7), ripple (2–30), speed (0.5–3), depth (0–1)
.bcsLiveRipple: Live Ripple	animated	amplitude (0–30), frequency (5–60), speed (1–10), damping (0.5–5), ringCount (1–5)
.bcsMagneticField: Magnetic Field	animated	fieldStrength (5–80), lineCount (3–20), fieldTurbulence (0–1), polarity (0–1)
.bcsMelt: Melt	animated	meltAmount (0–100), dripScale (1–15), speed (0.1–3), heat (0–1)
.bcsMorphBreathe: Morph Breathe	animated	breatheDepth (5–50), breatheRate (0.3–3), warpComplexity (1–8), organic (0–1)
.bcsNeonEdge: Neon Edge	animated	edgeStrength (1–10), glowAmount (0–2), colorCycle (0–3), mixOriginal (0–1)
.bcsPixelateMosaic: Pixelate Mosaic	animated	pixelSize (4–60), bevel (0–1), animateAssemble (0–1), gap (0–0.3)
.bcsPixelateStorm: Pixelate Storm	animated	pixelSize (2–40), stormAmount (0–1), swirl (0–3), pulse (0–3)
.bcsPlasma: Plasma	animated	intensity (0–1), scale (1–10), speed (0.5–5), colorMode (0–1)
.bcsPulse: Pulse / Heartbeat	animated	amplitude (0–30), bpm (30–180), sharpness (1–10), glowIntensity (0–1)
.bcsRefractLens: Refract Lens (Interactive)	static	touchPos (UnitPoint), lensRadius (0.1–0.5), refraction (1–3), aberration (0–15), wobble (0–1)
.bcsShatter: Shatter	animated	shardCount (3–30), explode (0–1), rotationAmt (0–3), edgeGlow (0–2)
.bcsShatterGlass: Shatter Glass	animated	crackDensity (3–15), glassRefraction (0–20), prismStrength (0–1), shatterSpread (0–1)
.bcsShockwave: Shockwave	animated	waveSpeed (50–500), ringWidth (5–60), strength (5–80), repeatRate (0.5–5)
.bcsSmokeReveal: Smoke Reveal	animated	smokeAmount (0–1), smokeScale (2–10), windSpeed (0.5–3), smokeTurb (0.5–3)
.bcsSolarize: Solarize	animated	threshold (0.2–0.8), curveIntensity (0–3), colorSeparation (0–1), animate (0–1)
.bcsThermal: Thermal	animated	intensity (0–1), shimmer (0–15), noiseSpeed (0.5–3), paletteShift (0–1)
.bcsTopographic: Topographic	animated	lineCount (5–40), lineWidth (0.01–0.15), colorize (0–1), animate (0–1)
.bcsTouchRipple: Touch Ripple	static	touchPos (UnitPoint), touchAge, amplitude (0–30), frequency (5–40), speed (50–500), decay (0.5–4)
.bcsUnderwaterCaustics: Underwater Caustics	animated	causticScale (2–15), causticIntensity (0–2), waterDistortion (0–30), waterDepth (0–1)
.bcsVortex: Vortex Spiral	animated	twistAmount (0–10), radius (0.1–1), speed (0.1–3), falloff (0.5–5)
.bcsWavePool: Wave Pool	animated	amplitude (0–25), wavelength (5–40), speed (0.5–5), complexity (1–6)
.bcsWormhole: Wormhole	animated	depth (1–8), speed (0.3–3), twist (0–5), radius (0.1–0.5)

Interaction-driven shaders

bcsTouchRipple and bcsRefractLens take a touchPos: UnitPoint. Feed them a drag location for a touch-reactive effect, and use a GeometryReader to normalize the point:

@State private var touch: UnitPoint = .center

GeometryReader { geo in
    myView
        .bcsRefractLens(touchPos: touch, lensRadius: 0.3)
        .gesture(DragGesture(minimumDistance: 0).onChanged { v in
            touch = UnitPoint(x: v.location.x / geo.size.width,
                              y: v.location.y / geo.size.height)
        })
}

Performance notes

• These are GPU fragment effects. Most are cheap, but the blur and displacement-heavy ones (bcsFrosted, bcsShatterGlass, bcsMagneticField) sample a lot of neighbors, so profile before you stack them on big, fast-scrolling views.
• Animated shaders re-render every frame while they’re on screen. Don’t leave dozens running off-screen.
• half-precision is used throughout for speed. Expect a little banding at extreme parameter values.

License

MIT. See LICENSE. Use them, ship them, remix them. Attribution’s appreciated, never required.