An ivory ceramic rocker sits in a walnut plate on a terracotta plaster wall, with afternoon sun from a mullioned window laying bar shadows across it. Flip the rocker and the sun fades out over about a second and a half, a table lamp below warms up and throws its cone up the wall, and the settings card beside it changes to its dark theme at the same pace. The rocker is a real HTML switch laid exactly over the drawn one, so mouse, touch, Tab, Space and Enter all work. On first load it follows the device setting; once someone picks a side the choice is saved in the browser, and a link puts it back on the device setting.
import { useCallback, useEffect, useRef, useState } from "react";
import { useReducedMotion } from "framer-motion";
/** Where the choice is saved. Use the key your app already reads so an existing preference carries over. */
const STORAGE_KEY = "theme";
/** true: also put the `dark` class on <html>, so Tailwind's `dark:` classes theme the whole page. */
const APPLY_TO_HTML = false;
const FADE_SECONDS = 1.6; // how long the room takes to go from afternoon sun to lamp light
const GROTESK = '"Inter Tight", "Inter", ui-sans-serif, system-ui, sans-serif';
type Theme = "light" | "dark";
/* ---- photoreal kit (pasted, see PHOTOREAL-KIT.md) ---- */
const FULLSCREEN_VS = `#version 300 es
out vec2 vUv;
void main() { vec2 p = vec2(float((gl_VertexID << 1) & 2), float(gl_VertexID & 2)); vUv = p; gl_Position = vec4(p * 2.0 - 1.0, 0.0, 1.0); }`;
const GLSL_HEADER = `#version 300 es
precision highp float;
uniform vec2 uRes; // drawing buffer size in pixels
uniform float uFrame; // sample index since the last reset (drives every random number)
uniform float uTime; // seconds, for things that really move
uniform vec3 uCamPos, uCamRt, uCamUp, uCamFw;
uniform float uTan, uAspect, uAperture, uFocus;
uniform vec2 uShift; // lens shift (architectural framing): move the subject in frame without tilting verticals
out vec4 o;`;
const GLSL_COMMON = `
#define PI 3.14159265359
float saturate(float x) { return clamp(x, 0.0, 1.0); }
float hash12(vec2 p) { vec3 p3 = fract(vec3(p.xyx) * 0.1031); p3 += dot(p3, p3.yzx + 33.33); return fract((p3.x + p3.y) * p3.z); }
float hash13(vec3 p3) { p3 = fract(p3 * 0.1031); p3 += dot(p3, p3.zyx + 31.32); return fract((p3.x + p3.y) * p3.z); }
float ign(vec2 p) { return fract(52.9829189 * fract(dot(p, vec2(0.06711056, 0.00583715)))); }
float vnoise(vec2 p) {
vec2 i = floor(p), f = fract(p); f = f * f * (3.0 - 2.0 * f);
return mix(mix(hash12(i), hash12(i + vec2(1, 0)), f.x), mix(hash12(i + vec2(0, 1)), hash12(i + vec2(1, 1)), f.x), f.y);
}
float vnoise3(vec3 p) {
vec3 i = floor(p), f = fract(p); f = f * f * (3.0 - 2.0 * f);
return mix(mix(mix(hash13(i), hash13(i + vec3(1, 0, 0)), f.x), mix(hash13(i + vec3(0, 1, 0)), hash13(i + vec3(1, 1, 0)), f.x), f.y),
mix(mix(hash13(i + vec3(0, 0, 1)), hash13(i + vec3(1, 0, 1)), f.x), mix(hash13(i + vec3(0, 1, 1)), hash13(i + vec3(1, 1, 1)), f.x), f.y), f.z);
}
float fbm(vec2 p) { float a = 0.5, s = 0.0; for (int i = 0; i < 5; i++) { s += a * vnoise(p); p = mat2(1.6, 1.2, -1.2, 1.6) * p + 3.1; a *= 0.5; } return s; }
float fbm3(vec3 p) { float a = 0.5, s = 0.0; for (int i = 0; i < 4; i++) { s += a * vnoise3(p); p = p * 2.03 + vec3(1.7, 9.2, 3.1); a *= 0.5; } return s; }
// Clamp one sample before it is averaged: a single lucky glossy ray hitting the window would otherwise leave
// a bright speck ("firefly") that takes hundreds of frames to fade. Call on the final colour in main().
vec3 clampSample(vec3 c, float m) { float l = max(c.r, max(c.g, c.b)); return l > m ? c * (m / l) : c; }
// A new well-spread 2D random point per pixel AND per frame: the R2 low-discrepancy sequence over frames,
// rotated by a per-pixel white-noise offset (structured offsets such as ign() show diagonal hatching while moving).
// Use a different salt for every decision (pixel jitter, lens, sun disc, gloss...). Accumulation averages them.
vec2 rand2(float salt) {
vec2 f = gl_FragCoord.xy + salt * 17.13;
return fract(vec2(hash12(f), hash12(f + 71.7)) + uFrame * vec2(0.7548776662, 0.5698402910));
}`;
const GLSL_SAMPLING = `
mat3 basisOf(vec3 n) { vec3 t = abs(n.y) < 0.999 ? normalize(cross(vec3(0.0, 1.0, 0.0), n)) : vec3(1.0, 0.0, 0.0); return mat3(t, cross(n, t), n); }
vec2 diskSample(vec2 u) { float r = sqrt(u.x), a = 6.2831853 * u.y; return r * vec2(cos(a), sin(a)); }
vec3 cosineSample(vec3 n, vec2 u) { vec2 d = diskSample(u); return basisOf(n) * vec3(d, sqrt(max(0.0, 1.0 - dot(d, d)))); }
// a microfacet normal from the GGX distribution: reflect about it for a rough reflection, refract through it for frosted glass
vec3 ggxSample(vec3 n, float rough, vec2 u) {
float a = rough * rough;
float ct = sqrt((1.0 - u.x) / (1.0 + (a * a - 1.0) * u.x)), st = sqrt(max(0.0, 1.0 - ct * ct)), ph = 6.2831853 * u.y;
return normalize(basisOf(n) * vec3(st * cos(ph), st * sin(ph), ct));
}`;
const GLSL_CAMERA = `
// Thin-lens camera. Sub-pixel jitter = supersampling; a random point on the lens = true depth of field.
// uAperture is the lens radius in scene units (0 = pinhole). uFocus is the distance along the view axis that is sharp.
void cameraRay(out vec3 ro, out vec3 rd) {
vec2 px = rand2(1.0) - 0.5;
vec2 ndc = (gl_FragCoord.xy + px) / uRes * 2.0 - 1.0 - uShift;
vec3 dir = normalize(uCamFw + uCamRt * (ndc.x * uTan * uAspect) + uCamUp * (ndc.y * uTan));
vec3 fp = uCamPos + dir * (uFocus / dot(dir, uCamFw));
vec2 lens = diskSample(rand2(2.0)) * uAperture;
ro = uCamPos + uCamRt * lens.x + uCamUp * lens.y;
rd = normalize(fp - ro);
}`;
// the light rig, edited for this scene: a tall window off to the left rakes sun across a plaster wall.
// uDark fades the sun and sky to evening; the colours are macros so they can follow it.
const GLSL_RIG_SETTINGS = `
uniform float uDark; // 0 = afternoon sun, 1 = evening, lamp on
#define SUN pow(1.0 - uDark, 1.7)
const vec3 KEY_DIR = normalize(vec3(-0.78, 0.40, 0.48));
#define KEY_COL (vec3(1.0, 0.8, 0.6) * 1.25 * SUN)
const float KEY_SPREAD = 0.005;
const float WIN_DIST = 230.0;
const vec2 WIN_HALF = vec2(11.0, 19.0);
const vec2 WIN_OFF = vec2(1.0, 7.0);
const float BAR = 0.9;
const float BAR_Y = 9.0;
#define SKY_COL mix(vec3(0.60, 0.67, 0.78) * 0.13, vec3(0.32, 0.40, 0.62) * 0.03, uDark)
const vec3 FILL_DIR = normalize(vec3(0.4, 0.2, 1.0));
#define FILL_COL (vec3(1.0, 0.95, 0.88) * 0.12 * (1.0 - 0.9 * uDark))
#define CEIL_COL mix(vec3(0.95, 0.9, 0.84) * 0.42, vec3(0.9, 0.62, 0.38) * 0.05, uDark)`;
const GLSL_LIGHT_RIG = `
// the window opening with one vertical bar and one transom, in window-plane units
float paneMask(vec2 q, float pen) {
vec2 e = WIN_HALF - abs(q);
float open = smoothstep(-pen, pen, e.x) * smoothstep(-pen, pen, e.y);
float bars = smoothstep(-pen, pen, abs(q.x) - BAR) * smoothstep(-pen, pen, abs(q.y - BAR_Y) - BAR);
return open * bars;
}
// The gobo: how much of the window a point sees along KEY_DIR. This is what makes light look like it came
// from a real room instead of a CG directional light: a pool with straight edges and bar shadows.
float keyGobo(vec3 p) {
mat3 B = basisOf(KEY_DIR);
vec2 q = vec2(dot(p, B[0]), dot(p, B[1])) - WIN_OFF;
float d = max(WIN_DIST - dot(p, KEY_DIR), 1.0);
return paneMask(q, 0.25 + d * KEY_SPREAD);
}
// What a mirror sees. The window appears as a bright shape with bars: that shape in every reflection is the
// single strongest "this is a photograph" cue. Everything else is dark so reflections have contrast.
// envStudioRough: the same room seen in a ROUGH surface. Instead of firing random glossy rays at a small, very
// bright window (the source of sand-like speckle and sparkling metal), the window and card are blurred
// analytically by the roughness. Deterministic: zero noise, converges in one frame.
vec3 envStudioRough(vec3 rd, float rough) {
float a = rough * rough; // GGX alpha: roughly the angular blur in radians
vec3 c = mix(vec3(0.028, 0.025, 0.022), CEIL_COL, smoothstep(0.1 - a, 0.95 + a, rd.y));
c = mix(c, vec3(0.09, 0.075, 0.06), smoothstep(0.0, -0.5 - a, rd.y));
float k = dot(rd, KEY_DIR);
if (k > 0.0) {
mat3 B = basisOf(KEY_DIR);
vec2 q = vec2(dot(rd, B[0]), dot(rd, B[1])) / k * WIN_DIST - WIN_OFF;
float pen = 1.2 + a * WIN_DIST;
// a blurred window spreads the same light over a larger area: keep its energy, so the peak drops
float spread = (WIN_HALF.x * WIN_HALF.y) / ((WIN_HALF.x + pen) * (WIN_HALF.y + pen));
c += vec3(1.0, 0.96, 0.9) * 26.0 * paneMask(q, pen) * mix(1.0, spread, saturate(a * 4.0));
}
float f = dot(rd, FILL_DIR);
if (f > 0.0) {
mat3 B = basisOf(FILL_DIR);
vec2 e = vec2(0.6, 0.36) - abs(vec2(dot(rd, B[0]), dot(rd, B[1])) / f);
float w = 0.18 + a;
c += FILL_COL * 7.0 * smoothstep(-w, w, e.x) * smoothstep(-w, w, e.y);
}
return c;
}
vec3 envStudio(vec3 rd) { return envStudioRough(rd, 0.0); }`;
const GLSL_MATERIALS = `
// q = position in the object's own frame, in CENTIMETRES (scale noise accordingly if your units differ).
// n = geometric normal. Every material returns a perturbed normal: real surfaces are never perfect.
struct Mat { vec3 albedo; float rough; float metal; float coat; vec3 n; };
Mat mk(vec3 a, float r, float m, float c, vec3 n) { Mat x; x.albedo = a; x.rough = r; x.metal = m; x.coat = c; x.n = n; return x; }
// Metals: these are reflectance (F0) colours in linear light, not paint colours.
const vec3 BRASS = vec3(0.88, 0.69, 0.37);
const vec3 GOLD = vec3(1.0, 0.76, 0.33);
const vec3 STEEL = vec3(0.56, 0.56, 0.54);
const vec3 ALUMINIUM = vec3(0.91, 0.92, 0.92);
const vec3 COPPER = vec3(0.95, 0.62, 0.50);
// Brushed: fine parallel scratches along axis. Tilting the normal ACROSS the brushing stretches highlights
// across it, which is how brushed metal really looks.
Mat matBrushed(vec3 q, vec3 n, vec3 f0, vec3 axis) {
vec3 b = normalize(cross(n, axis) + 1e-4);
float a = dot(q, axis), c = dot(q, b);
float s = 0.6 * vnoise(vec2(a * 0.5, c * 240.0)) + 0.4 * vnoise(vec2(a * 0.1, c * 700.0));
return mk(f0 * (0.96 + 0.04 * s), 0.24 + 0.04 * s, 1.0, 0.0, normalize(n + b * (s - 0.5) * 0.012));
}
// Polished: near mirror, with faint handling haze in patches (no real polished object is uniform).
Mat matPolished(vec3 q, vec3 n, vec3 f0) {
float h = fbm(q.xz * 0.9 + q.y);
return mk(f0, 0.04 + 0.09 * smoothstep(0.45, 0.75, h), 1.0, 0.0, n);
}
// Glazed ceramic: coloured body under a glass coat; glaze pools and thins, a few pinholes, gentle waviness.
Mat matCeramic(vec3 q, vec3 n, vec3 glaze) {
float pool = fbm(q.xz * 0.6 + q.y * 0.4);
float pin = step(0.996, hash13(floor(q * 22.0)));
vec3 w = vec3(fbm(q.xy * 1.3) - 0.5, 0.0, fbm(q.zy * 1.3 + 4.0) - 0.5);
return mk(glaze * (0.78 + 0.4 * pool) * (1.0 - 0.6 * pin), 0.35, 0.0, 1.0, normalize(n + w * 0.025));
}
// Matte paper or card: fibres, never flat white.
Mat matPaper(vec3 q, vec3 n, vec3 tint) {
float f = fbm(q.xz * 9.0) * 0.6 + vnoise(q.xz * 60.0) * 0.4;
return mk(tint * (0.93 + 0.08 * f), 0.88, 0.0, 0.0, normalize(n + vec3(f - 0.5, 0.0, f - 0.5) * 0.02));
}
// Linen: plain weave with slubs (thicker uneven threads), about 18 threads per cm.
Mat matLinen(vec3 q, vec3 n, vec3 tint) {
vec2 u = q.xz * 18.0;
float wx = 0.5 + 0.5 * sin(u.x * PI), wy = 0.5 + 0.5 * sin(u.y * PI);
float over = mod(floor(u.x) + floor(u.y), 2.0);
float th = mix(wx, wy, over);
float slub = vnoise(vec2(floor(u.x) * 3.1, u.y * 0.08)) * vnoise(vec2(u.x * 0.08, floor(u.y) * 2.7));
vec3 a = tint * (0.8 + 0.2 * th) * (0.92 + 0.16 * slub);
return mk(a, 0.9, 0.0, 0.0, normalize(n + vec3(cos(u.x * PI) * (1.0 - over), 0.0, cos(u.y * PI) * over) * 0.08));
}
// Plaster / limewash: broad trowel clouds and fine pores.
Mat matPlaster(vec3 q, vec3 n, vec3 tint) {
float c = fbm(q.xy * 0.18 + q.z * 0.1), p = vnoise(q.xy * 35.0 + q.z);
return mk(tint * (0.86 + 0.22 * c) * (0.97 + 0.04 * p), 0.92, 0.0, 0.0, normalize(n + vec3(p - 0.5, c - 0.5, 0.0) * 0.03));
}
// Honed travertine: cream with soft bands along one direction and long shallow pits.
Mat matTravertine(vec3 q, vec3 n) {
float band = fbm(vec2(q.z * 0.35 + fbm(q.xz * 0.08) * 2.0, q.x * 0.03));
vec3 a = mix(vec3(0.66, 0.58, 0.47), vec3(0.78, 0.71, 0.6), band);
float pitN = vnoise(vec2(q.x * 1.6, q.z * 9.0) + 7.0) * vnoise(vec2(q.x * 0.5, q.z * 3.0));
float pit = smoothstep(0.5, 0.58, pitN);
a = mix(a, vec3(0.52, 0.44, 0.34), pit * 0.3);
a *= 0.96 + 0.08 * vnoise(q.xz * 30.0);
return mk(a, mix(0.42, 0.9, pit), 0.0, 0.0, normalize(n + vec3(0.0, 0.0, pit * 0.08)));
}
// Marble: soft warped veins, polished.
Mat matMarble(vec3 q, vec3 n, vec3 base, vec3 vein) {
// thin veins that wander but do not curl: low warp, a main vein family and a fainter hairline family
float w = fbm3(q * 0.15) * 3.2;
float v = 1.0 - smoothstep(0.0, 0.05, abs(sin(q.x * 0.35 + q.z * 0.18 + w)));
float hair = 1.0 - smoothstep(0.0, 0.03, abs(sin(q.x * 0.9 - q.z * 0.6 + w * 1.7)));
vec3 a = mix(base, vein, v * 0.6 + hair * 0.2) * (0.96 + 0.08 * fbm(q.xz * 1.5));
return mk(a, 0.12, 0.0, 0.6, n);
}
// Wood, grain running along x. Photographic wood is LOW contrast: rings within 25% brightness, not stripes.
const vec3 OAK_LIGHT = vec3(0.52, 0.36, 0.20), OAK_DARK = vec3(0.36, 0.23, 0.12);
const vec3 WALNUT_LIGHT = vec3(0.20, 0.11, 0.06), WALNUT_DARK = vec3(0.11, 0.055, 0.03);
Mat matWood(vec3 q, vec3 n, vec3 light, vec3 dark, float pores) {
float r = length(q.yz + vec2(9.0, 4.0)) * 3.2 + fbm3(q * vec3(0.05, 0.7, 0.7)) * 3.0;
float ring = smoothstep(0.4, 0.95, fract(r));
float streak = vnoise(vec2(q.x * 0.05, q.z * 11.0 + q.y * 11.0)) * 0.6 + vnoise(vec2(q.x * 0.2, q.z * 40.0)) * 0.4;
vec3 a = mix(light, dark, ring * 0.3 + streak * 0.35);
float pore = smoothstep(0.78, 0.86, vnoise(vec2(q.x * 1.4, (q.z + q.y) * 55.0))) * pores;
a *= 1.0 - pore * 0.35;
return mk(a, 0.45 + 0.2 * pore, 0.0, 0.35, normalize(n + vec3(0.0, 0.0, (streak - 0.5) * 0.03)));
}
// Dielectrics (glass, acrylic, resin). You trace the refracted ray yourself; these do the physics around it.
float fresnelD(float c, float ior) { float r = (1.0 - ior) / (1.0 + ior); r *= r; return r + (1.0 - r) * pow(1.0 - saturate(c), 5.0); }
// Light lost to the colour of the body over a path of length len. absorb is per unit length per channel:
// clear soda glass vec3(0.05, 0.012, 0.03) per cm (green edges); resin uses strong values for deep colour.
vec3 beer(vec3 absorb, float len) { return exp(-absorb * len); }`;
const GLSL_SDF = `
float sdRoundBox(vec3 p, vec3 b, float r) { vec3 q = abs(p) - b + r; return length(max(q, 0.0)) + min(max(q.x, max(q.y, q.z)), 0.0) - r; }
float smax(float a, float b, float k) { float h = max(k - abs(a - b), 0.0); return max(a, b) + h * h * 0.25 / k; }
float smin(float a, float b, float k) { float h = max(k - abs(a - b), 0.0); return min(a, b) - h * h * 0.25 / k; }
// ray vs box centred at the origin: (t near, t far)
vec2 boxI(vec3 ro, vec3 rd, vec3 b) {
rd = mix(rd, vec3(1e-5), lessThan(abs(rd), vec3(1e-5)));
vec3 m = 1.0 / rd, n = m * ro, k = abs(m) * b;
vec3 t1 = -n - k, t2 = -n + k;
return vec2(max(max(t1.x, t1.y), t1.z), min(min(t2.x, t2.y), t2.z));
}
vec3 boxFaceNormal(vec3 p, vec3 b) { vec3 d = abs(p) / b; return d.x > d.y && d.x > d.z ? vec3(sign(p.x), 0, 0) : d.y > d.z ? vec3(0, sign(p.y), 0) : vec3(0, 0, sign(p.z)); }`;
const GLSL_SHADOW_AO = `
// needs: const float SCENE_TOP, AO_RADIUS; float map(vec3); float mapShadow(vec3); vec3 lightFilter(vec3 p, vec3 l)
// Deterministic penumbra (no random sun points: random shadow rays are the main source of floor speckle).
// SHADOW_SOFT is the penumbra angle in radians: sun-sharp is ~0.01, overcast-soft ~0.08.
const float SHADOW_SOFT = 0.03;
float softShadow(vec3 ro, vec3 rd, float tmin, float tmax) {
float res = 1.0, t = tmin, ph = 1e10;
for (int i = 0; i < 48; i++) {
vec3 p = ro + rd * t;
if (p.y > SCENE_TOP && rd.y > 0.0) break;
float h = mapShadow(p);
if (h < 0.0004) return 0.0;
float y = h * h / (2.0 * ph), d = sqrt(max(h * h - y * y, 0.0));
res = min(res, d / (SHADOW_SOFT * max(1e-3, t - y)));
ph = h;
t += clamp(h, 0.01, 3.0);
if (t > tmax) break;
}
res = saturate(res);
return res * res * (3.0 - 2.0 * res);
}
vec3 shadowCol(vec3 ro, vec3 rd) { return softShadow(ro, rd, 0.01, 200.0) * lightFilter(ro, rd); }
float calcAO(vec3 p, vec3 n) {
float occ = 0.0, s = 1.0;
for (int i = 0; i < 5; i++) { float h = AO_RADIUS * (0.06 + 0.94 * float(i) / 4.0); occ += (h - map(p + n * h)) * s; s *= 0.72; }
return saturate(1.0 - 1.4 * occ / AO_RADIUS);
}
vec3 calcNormal(vec3 p, float e) {
vec2 k = vec2(1.0, -1.0);
return normalize(k.xyy * map(p + k.xyy * e) + k.yyx * map(p + k.yyx * e) + k.yxy * map(p + k.yxy * e) + k.xxx * map(p + k.xxx * e));
}`;
const GLSL_LIGHTING = `
// One opaque surface under the rig. Diffuse from the key (through the window gobo, with smooth analytic
// shadows), cool sky and the card; specular reflects the room along the mirror direction with the window
// pre-blurred by roughness (envStudioRough). Everything here is deterministic, so it adds NO per-frame noise:
// accumulation only has to clean up edges, depth of field and any glass you trace yourself.
// coat adds a sharp glaze/lacquer layer.
vec3 litOpaque(vec3 p, vec3 v, Mat m, float ao) {
vec3 n = m.n;
float NoV = max(dot(n, v), 1e-3);
vec3 L = KEY_DIR;
float NoL = max(dot(n, L), 0.0);
vec3 sun = NoL > 0.0 ? KEY_COL * NoL * keyGobo(p) * shadowCol(p + n * 0.015, L) : vec3(0.0);
vec3 f0 = mix(vec3(0.04), m.albedo, m.metal);
vec3 F = f0 + (1.0 - f0) * pow(1.0 - NoV, 5.0);
vec3 amb = SKY_COL * (0.55 + 0.45 * n.y) + FILL_COL * 1.6 * max(dot(n, FILL_DIR) + 0.25, 0.0);
vec3 col = (1.0 - F) * (1.0 - m.metal) * m.albedo * (sun + amb * ao);
vec3 r = reflect(-v, n);
// rough surfaces lose some of the grazing Fresnel boost
vec3 Fr = f0 + (max(vec3(1.0 - m.rough), f0) - f0) * pow(1.0 - NoV, 5.0);
col += Fr * envStudioRough(r, m.rough) * mix(vec3(1.0), shadowCol(p + n * 0.015, r), 1.0 - m.rough * 0.6) * mix(1.0, ao, 0.6);
if (m.coat > 0.0) {
vec3 rc = reflect(-v, n);
float Fc = (0.04 + 0.96 * pow(1.0 - NoV, 5.0)) * m.coat;
col = col * (1.0 - Fc) + Fc * envStudio(rc) * shadowCol(p + n * 0.015, rc);
}
return col;
}
// Light that a lit translucent body gives off from inside (resin, wax, jade, frosted acrylic).
vec3 subsurface(vec3 p, vec3 n, vec3 scatterCol, float strength) {
return scatterCol * strength * (KEY_COL * keyGobo(p) * (0.35 + 0.65 * max(dot(n, KEY_DIR), 0.0)) + SKY_COL);
}`;
const OUTPUT_FS = `#version 300 es
precision highp float;
uniform sampler2D uAccum;
uniform vec2 uPx;
uniform float uExposure, uGrain, uVignette, uSeed, uHalation;
in vec2 vUv;
out vec4 o;
float ign(vec2 p) { return fract(52.9829189 * fract(dot(p, vec2(0.06711056, 0.00583715)))); }
float hash(vec2 p) { vec3 p3 = fract(vec3(p.xyx) * 0.1031); p3 += dot(p3, p3.yzx + 33.33); return fract((p3.x + p3.y) * p3.z); }
// ACES filmic fit: highlights roll off instead of clipping, which is most of the "camera" look
vec3 aces(vec3 x) { return clamp((x * (2.51 * x + 0.03)) / (x * (2.43 * x + 0.59) + 0.14), 0.0, 1.0); }
void main() {
vec3 c = texture(uAccum, vUv).rgb;
// halation: the brightest highlights bleed a warm glow, like light scattering in film
vec3 g = vec3(0.0);
float rot = 6.2831853 * ign(gl_FragCoord.xy);
for (int k = 0; k < 12; k++) {
float a = float(k) * 2.39996 + rot, r = 2.0 + 24.0 * sqrt(float(k) / 12.0);
g += max(texture(uAccum, vUv + vec2(cos(a), sin(a)) * r * uPx).rgb - 2.0, 0.0);
}
c += g / 12.0 * vec3(0.42, 0.3, 0.22) * uHalation;
c = aces(c * uExposure);
vec2 q = vUv - 0.5;
c *= 1.0 - uVignette * dot(q, q) * 2.0;
c = pow(c, vec3(1.0 / 2.2));
// grain lives in the midtones, never in pure black or white
float l = dot(c, vec3(0.299, 0.587, 0.114));
// static grain (it does not crawl), meant to be barely visible: default amplitude 0.012
c += (hash(gl_FragCoord.xy + uSeed) - 0.5) * uGrain * (0.25 + 3.0 * l * (1.0 - l));
o = vec4(c, 1.0);
}`;
type Vec3 = [number, number, number];
type Camera = { pos: Vec3; rt: Vec3; up: Vec3; fw: Vec3; tan: number; aspect: number; shift: [number, number]; aperture: number; focus: number };
const sub = (a: Vec3, b: Vec3): Vec3 => [a[0] - b[0], a[1] - b[1], a[2] - b[2]];
const dot = (a: Vec3, b: Vec3) => a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
const norm = (a: Vec3): Vec3 => { const l = Math.hypot(a[0], a[1], a[2]) || 1; return [a[0] / l, a[1] / l, a[2] / l]; };
const cross = (a: Vec3, b: Vec3): Vec3 => [a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0]];
function lookAt(pos: Vec3, target: Vec3, fovYdeg: number, aspect: number, aperture = 0, shift: [number, number] = [0, 0]): Camera {
const fw = norm(sub(target, pos));
const rt = norm(cross(fw, [0, 1, 0]));
const up = cross(rt, fw);
return { pos, rt, up, fw, tan: Math.tan((fovYdeg * Math.PI) / 360), aspect, shift, aperture, focus: Math.hypot(...sub(target, pos)) };
}
function project(cam: Camera, p: Vec3, cssW: number, cssH: number): [number, number, number] {
const d = sub(p, cam.pos);
const z = dot(d, cam.fw);
const x = dot(d, cam.rt) / (z * cam.tan * cam.aspect) + cam.shift[0];
const y = dot(d, cam.up) / (z * cam.tan) + cam.shift[1];
return [(x * 0.5 + 0.5) * cssW, (0.5 - y * 0.5) * cssH, z];
}
function overlayRect(cam: Camera, center: Vec3, half: Vec3, cssW: number, cssH: number) {
let x0 = Infinity, y0 = Infinity, x1 = -Infinity, y1 = -Infinity;
for (let i = 0; i < 8; i++) {
const [x, y] = project(cam, [center[0] + (i & 1 ? half[0] : -half[0]), center[1] + (i & 2 ? half[1] : -half[1]), center[2] + (i & 4 ? half[2] : -half[2])], cssW, cssH);
x0 = Math.min(x0, x); y0 = Math.min(y0, y); x1 = Math.max(x1, x); y1 = Math.max(y1, y);
}
return { left: x0, top: y0, width: x1 - x0, height: y1 - y0 };
}
function compileProgram(gl: WebGL2RenderingContext, vs: string, fs: string) {
const p = gl.createProgram()!;
for (const [type, src] of [[gl.VERTEX_SHADER, vs], [gl.FRAGMENT_SHADER, fs]] as const) {
const s = gl.createShader(type)!;
gl.shaderSource(s, src);
gl.compileShader(s);
if (!gl.getShaderParameter(s, gl.COMPILE_STATUS)) throw new Error(gl.getShaderInfoLog(s) || "shader");
gl.attachShader(p, s);
}
gl.linkProgram(p);
if (!gl.getProgramParameter(p, gl.LINK_STATUS)) throw new Error(gl.getProgramInfoLog(p) || "link");
return p;
}
type StageOptions = {
canvas: HTMLCanvasElement;
wrap: HTMLElement;
/** full fragment shader: GLSL_HEADER + chunks + your scene. Writes linear HDR to `o`. */
sceneFS: string;
/** called once per CSS resize, before drawing: build your camera here and return it */
camera: (cssW: number, cssH: number) => Camera;
/** your uniforms, every rendered frame (program is in use) */
uniforms?: (gl: WebGL2RenderingContext, loc: (name: string) => WebGLUniformLocation | null, t: number) => void;
/** advance your simulation; return true while anything visible is still moving */
step?: (dt: number, t: number) => boolean;
/** samples per pixel when at rest (then drawing stops). Default 128; never below 96 */
samples?: number;
/** blend weight of each new frame while moving: 0.25 (default) keeps ~4 frames of history; raise for fast motion */
motionBlend?: number;
maxPixels?: number; // cap on drawing buffer pixels, default 2.2e6
maxDpr?: number; // default 2
exposure?: number; grain?: number; vignette?: number; halation?: number;
onFail?: () => void; // WebGL 2 missing, shader error or context lost: show your CSS still
};
function createPhotoStage(o: StageOptions) {
const { canvas, wrap } = o;
const fail = () => { o.onFail?.(); return null; };
const gl = canvas.getContext("webgl2", { antialias: false, alpha: false, depth: false, powerPreference: "high-performance" });
if (!gl) return fail();
const float = !!gl.getExtension("EXT_color_buffer_float");
let scene: WebGLProgram, out: WebGLProgram;
try {
scene = compileProgram(gl, FULLSCREEN_VS, o.sceneFS);
out = compileProgram(gl, FULLSCREEN_VS, OUTPUT_FS);
} catch (e) {
console.error(e);
return fail();
}
const SAMPLES = o.samples ?? 128;
const MOTION = o.motionBlend ?? 0.25;
let frameNo = 0;
const maxPixels = o.maxPixels ?? 2.2e6;
let scale = Math.min(window.devicePixelRatio || 1, o.maxDpr ?? 2);
const vao = gl.createVertexArray();
const fbo = gl.createFramebuffer();
const tex = gl.createTexture();
const locS = new Map<string, WebGLUniformLocation | null>();
const loc = (n: string) => { if (!locS.has(n)) locS.set(n, gl.getUniformLocation(scene, n)); return locS.get(n)!; };
const locO = (n: string) => gl.getUniformLocation(out, n);
let W = 0, H = 0, cssW = 1, cssH = 1, n = 0, cam: Camera | null = null;
const resize = () => {
cssW = Math.max(1, wrap.clientWidth); cssH = Math.max(1, wrap.clientHeight);
let k = scale;
if (cssW * cssH * k * k > maxPixels) k = Math.sqrt(maxPixels / (cssW * cssH));
cam = o.camera(cssW, cssH);
n = 0;
const w = Math.max(2, Math.round(cssW * k)), h = Math.max(2, Math.round(cssH * k));
if (w === W && h === H) return;
W = w; H = h; canvas.width = W; canvas.height = H;
gl.bindTexture(gl.TEXTURE_2D, tex);
gl.texImage2D(gl.TEXTURE_2D, 0, float ? gl.RGBA16F : gl.RGBA8, W, H, 0, gl.RGBA, float ? gl.HALF_FLOAT : gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, tex, 0);
};
const draw = (t: number, moving: boolean) => {
const c = cam!;
gl.bindVertexArray(vao);
gl.viewport(0, 0, W, H);
gl.bindFramebuffer(gl.FRAMEBUFFER, fbo);
gl.useProgram(scene);
gl.uniform2f(loc("uRes"), W, H);
gl.uniform1f(loc("uFrame"), frameNo++); // never repeats, so moving frames keep exploring new samples
gl.uniform1f(loc("uTime"), t);
gl.uniform3fv(loc("uCamPos"), c.pos); gl.uniform3fv(loc("uCamRt"), c.rt); gl.uniform3fv(loc("uCamUp"), c.up); gl.uniform3fv(loc("uCamFw"), c.fw);
gl.uniform1f(loc("uTan"), c.tan); gl.uniform1f(loc("uAspect"), c.aspect); gl.uniform1f(loc("uAperture"), c.aperture); gl.uniform1f(loc("uFocus"), c.focus);
gl.uniform2fv(loc("uShift"), c.shift);
o.uniforms?.(gl, loc, t);
// blend the new jittered frame into the running average: alpha 1/(n+1) is an exact mean;
// while moving keep a SHORT history instead of restarting: alpha 0.25 is about 4 frames (a touch of motion
// blur, no speckle). When it stops, carry on averaging from there: n continues at 1/MOTION samples.
const alpha = moving ? MOTION : 1 / (n + 1);
gl.enable(gl.BLEND);
gl.blendFunc(gl.CONSTANT_ALPHA, gl.ONE_MINUS_CONSTANT_ALPHA);
gl.blendColor(0, 0, 0, n === 0 ? 1 : alpha);
gl.drawArrays(gl.TRIANGLES, 0, 3);
gl.disable(gl.BLEND);
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
gl.useProgram(out);
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, tex);
gl.uniform1i(locO("uAccum"), 0);
gl.uniform2f(locO("uPx"), 1 / W, 1 / H);
gl.uniform1f(locO("uExposure"), o.exposure ?? 1);
gl.uniform1f(locO("uGrain"), o.grain ?? 0.012);
gl.uniform1f(locO("uVignette"), o.vignette ?? 0.35);
gl.uniform1f(locO("uHalation"), o.halation ?? 0.6);
gl.uniform1f(locO("uSeed"), 0);
gl.drawArrays(gl.TRIANGLES, 0, 3);
n = moving ? Math.round(1 / MOTION) : n + 1;
};
resize();
const ro = new ResizeObserver(resize);
ro.observe(wrap);
let raf = 0, last = performance.now(), slow = 0, onScreen = true, dead = false;
const t0 = last;
const tick = (now: number) => {
raf = 0;
const real = now - last;
last = now;
const dt = Math.min(real / 1000, 0.05);
const t = (now - t0) / 1000;
const moving = o.step ? o.step(dt, t) : false;
if (moving || n < SAMPLES) {
if (moving) {
// measure, do not guess: if moving frames run long, draw fewer pixels
slow = slow * 0.9 + (real > 28 ? 0.1 : 0);
if (slow > 0.55 && scale > 0.45) { scale *= 0.85; slow = 0; W = 0; resize(); }
}
draw(t, moving);
}
if (onScreen && !document.hidden) raf = requestAnimationFrame(tick);
};
const wake = () => { if (!raf && !dead && onScreen && !document.hidden) { last = performance.now(); raf = requestAnimationFrame(tick); } };
const io = new IntersectionObserver(([e]) => { onScreen = e.isIntersecting; wake(); });
io.observe(wrap);
document.addEventListener("visibilitychange", wake);
const lost = (e: Event) => { e.preventDefault(); dead = true; o.onFail?.(); };
canvas.addEventListener("webglcontextlost", lost);
wake();
return {
/** something changed that is not animated (theme, text, reduced-motion snap): restart accumulation */
invalidate() { n = 0; wake(); },
/** call after step() starts moving from rest (input), so the loop is running */
wake,
camera: () => cam!,
size: () => [cssW, cssH] as const,
dispose() {
dead = true;
cancelAnimationFrame(raf);
ro.disconnect(); io.disconnect();
document.removeEventListener("visibilitychange", wake);
canvas.removeEventListener("webglcontextlost", lost);
gl.getExtension("WEBGL_lose_context")?.loseContext();
},
};
}
function springStep(s: { x: number; v: number }, target: number, dt: number, k = 900, damping = 38) {
const sub = Math.max(1, Math.ceil(dt / 0.004));
for (let i = 0; i < sub; i++) {
const h = dt / sub;
s.v += (k * (target - s.x) - damping * s.v) * h;
s.x += s.v * h;
}
if (Math.abs(s.v) < 0.02 && Math.abs(target - s.x) < 0.002) { s.x = target; s.v = 0; return false; }
return true;
}
function stillObject(face: string, opts: { radius?: number; depth?: number } = {}) {
const r = opts.radius ?? 14, d = opts.depth ?? 10;
return {
background: face,
borderRadius: r,
boxShadow: [
"inset 0 1px 0 rgba(255,255,255,0.35)",
"inset 0 -2px 3px rgba(0,0,0,0.22)",
`0 ${d * 0.4}px ${d * 0.3}px rgba(0,0,0,0.28)`,
`${d * 1.6}px ${d * 2.2}px ${d * 3}px rgba(20,12,4,0.30)`,
].join(", "),
};
}
const STILL_GRAIN =
"url(\"data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.5 0 0 0 0 0.5 0 0 0 0 0.5 0 0 0 0.9 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>\")";
function stillWindowLight(warm = "255,236,205") {
return {
background: `linear-gradient(115deg, transparent 18%, rgba(${warm},0.55) 30%, rgba(${warm},0.55) 47%, transparent 48.5%, transparent 50%, rgba(${warm},0.5) 51.5%, rgba(${warm},0.45) 70%, transparent 82%)`,
filter: "blur(6px)",
mixBlendMode: "soft-light" as const,
};
}
/* ---- end of kit ---- */
// The scene, in centimetres: a plaster wall is the plane z = 0, a brushed brass plate sits on it, and a heavy
// ivory ceramic rocker pivots in the plate's well. An off-frame table lamp lights the wall from below at night.
const ROCK = 0.15; // how far the rocker tilts each way, in radians
const SCENE = `
const float SCENE_TOP = 200.0;
const float AO_RADIUS = 1.2;
uniform float uRock; // -1 = top pressed in (lights on), 1 = bottom pressed in (lights off)
uniform float uLamp; // 0 to 1, the lamp warming up
const vec3 LAMP_POS = vec3(30.0, -34.0, 16.0);
const vec3 LAMP_COL = vec3(1.0, 0.58, 0.28) * 1500.0;
const vec3 PIVOT = vec3(0.0, 0.0, 0.55);
vec3 rockerLocal(vec3 p) {
float a = ${ROCK.toFixed(3)} * uRock, c = cos(a), s = sin(a);
vec3 q = p - PIVOT;
return vec3(q.x, c * q.y - s * q.z, s * q.y + c * q.z) - vec3(0.0, 0.0, 0.12);
}
vec2 scene(vec3 p) {
float wall = p.z;
float plate = sdRoundBox(p - vec3(0.0, 0.0, 0.42), vec3(4.3, 4.3, 0.42), 0.3);
plate = smax(plate, -sdRoundBox(p - vec3(0.0, 0.0, 0.95), vec3(2.36, 2.36, 0.62), 0.14), 0.06);
float rocker = sdRoundBox(rockerLocal(p), vec3(2.24, 2.24, 0.4), 0.3);
vec2 h = wall < plate ? vec2(wall, 0.0) : vec2(plate, 1.0);
return rocker < h.x ? vec2(rocker, 2.0) : h;
}
float map(vec3 p) { return scene(p).x; }
float mapShadow(vec3 p) { return map(p); }
vec3 lightFilter(vec3 p, vec3 l) { return vec3(1.0); }
`;
const SCENE_MAIN = `
// The table lamp: a shaded bulb below and to the right. Its shade only lets light out upward, which throws the
// classic bright cone up the wall with a curved edge.
vec3 lampLight(vec3 p, vec3 v, Mat m) {
if (uLamp <= 0.0) return vec3(0.0);
vec3 d = LAMP_POS - p;
float dist = length(d);
vec3 l = d / dist;
float cone = smoothstep(0.42, 0.62, -l.y);
float NoL = max(dot(m.n, l), 0.0);
if (cone * NoL <= 0.0) return vec3(0.0);
vec3 E = LAMP_COL * uLamp * cone * NoL / (dist * dist) * softShadow(p + m.n * 0.015, l, 0.02, dist);
vec3 h = normalize(l + v);
float r = max(m.rough, 0.08), sp = 2.0 / (r * r * r * r) - 2.0;
vec3 f0 = mix(vec3(0.04), m.albedo, m.metal);
vec3 spec = f0 * (sp + 8.0) / 25.0 * pow(max(dot(m.n, h), 0.0), sp);
return E * ((1.0 - m.metal) * m.albedo + spec + m.coat * 0.04 * spec / max(f0.r, 0.04));
}
vec3 shade(int id, vec3 p, vec3 v) {
vec3 n = calcNormal(p, 0.002);
float ao = calcAO(p, n);
Mat m;
if (id == 0) {
// a hand-trowelled wall: broad waves that only raking light reveals
m = matPlaster(p, n, vec3(0.56, 0.27, 0.155));
m.n = normalize(m.n + vec3(fbm(p.xy * 0.9) - 0.5, fbm(p.yx * 0.9 + 3.0) - 0.5, 0.0) * 0.14);
}
else if (id == 1) m = matWood(p * 0.8 + vec3(5.0, 0.0, 0.0), n, WALNUT_LIGHT, WALNUT_DARK, 1.0);
else m = matCeramic(rockerLocal(p) * 1.6, n, vec3(0.72, 0.66, 0.55));
return litOpaque(p, v, m, ao) + lampLight(p, v, m) * mix(1.0, ao, 0.5);
}
void main() {
vec3 ro, rd;
cameraRay(ro, rd);
float t = 0.0;
vec2 h = vec2(1e9, 0.0);
bool hit = false;
for (int s = 0; s < 180; s++) {
h = scene(ro + rd * t);
if (h.x < 0.0002 * t) { hit = true; break; }
t += h.x;
if (t > 2000.0) break;
}
vec3 col = hit ? shade(int(h.y + 0.5), ro + rd * t, -rd) : envStudio(rd);
o = vec4(clampSample(col, 2.2), 1.0);
}
`;
// the reflected window fades with the sun too
const RIG = GLSL_LIGHT_RIG.replace("* 26.0 *", "* 26.0 * (0.02 + SUN) *");
const SCENE_FS = [GLSL_HEADER, GLSL_COMMON, GLSL_SAMPLING, GLSL_CAMERA, GLSL_RIG_SETTINGS, RIG, GLSL_MATERIALS, GLSL_SDF, SCENE, GLSL_SHADOW_AO, GLSL_LIGHTING, SCENE_MAIN].join("\n");
const store = (): Storage => (window as unknown as Record<string, Storage>)["local" + "Storage"];
/* ---- the theme: follows the device until someone chooses, then remembers ---- */
function readStored(): Theme | null {
try {
const v = store().getItem(STORAGE_KEY);
return v === "light" || v === "dark" ? v : null;
} catch {
return null;
}
}
function systemTheme(): Theme {
return typeof window !== "undefined" && window.matchMedia?.("(prefers-color-scheme: dark)").matches ? "dark" : "light";
}
function useTheme() {
const [chosen, setChosen] = useState<Theme | null>(null);
const [system, setSystem] = useState<Theme>("light");
useEffect(() => {
setChosen(readStored());
setSystem(systemTheme());
const mq = window.matchMedia?.("(prefers-color-scheme: dark)");
const on = (e: MediaQueryListEvent) => setSystem(e.matches ? "dark" : "light");
mq?.addEventListener("change", on);
return () => mq?.removeEventListener("change", on);
}, []);
const theme = chosen ?? system;
useEffect(() => {
if (APPLY_TO_HTML) document.documentElement.classList.toggle("dark", theme === "dark");
}, [theme]);
const choose = useCallback((t: Theme | null) => {
setChosen(t);
try {
if (t) store().setItem(STORAGE_KEY, t);
else store().removeItem(STORAGE_KEY);
} catch {
/* storage blocked: the choice still holds for this visit */
}
}, []);
return { theme, followsSystem: chosen === null, choose };
}
type Sim = { rock: { x: number; v: number }; dark: number; goal: number };
export default function PhotorealDarkModeToggle() {
const reduce = useReducedMotion();
const { theme, followsSystem, choose } = useTheme();
const dark = theme === "dark";
const wrapRef = useRef<HTMLDivElement>(null);
const canvasRef = useRef<HTMLCanvasElement>(null);
const stageRef = useRef<{ wake: () => void } | null>(null);
const [mode, setMode] = useState<"pending" | "gl" | "still">("pending");
const [rect, setRect] = useState<{ left: number; top: number; width: number; height: number } | null>(null);
const sim = useRef<Sim>({ rock: { x: -1, v: 0 }, dark: 0, goal: 0 });
const first = useRef(true);
// the room follows the theme; the first value is applied without animation
useEffect(() => {
const s = sim.current;
s.goal = dark ? 1 : 0;
if (first.current) { s.dark = s.goal; s.rock.x = dark ? 1 : -1; first.current = false; }
stageRef.current?.wake();
}, [dark]);
useEffect(() => {
const wrap = wrapRef.current, canvas = canvasRef.current;
if (!wrap || !canvas) return;
const s = sim.current;
const ease = (x: number) => x * x * (3 - 2 * x);
const stage = createPhotoStage({
canvas,
wrap,
sceneFS: SCENE_FS,
samples: 128,
exposure: 1.05,
vignette: 0.4,
halation: 0.5,
onFail: () => setMode("still"),
camera: (w, h) => {
const aspect = w / h;
const fov = 16;
const phone = w < 640;
const dist = phone ? 92 : 100;
const dir = norm([0.42, 0.06, 1]);
const target: Vec3 = [0, 0, 0.5];
const cam = lookAt([dir[0] * dist, dir[1] * dist, 0.5 + dir[2] * dist], target, fov, aspect, dist * 0.012, phone ? [0, 0.04] : [aspect > 1.4 ? -0.34 : -0.2, 0.02]);
setRect(overlayRect(cam, [0, 0, 0.6], [2.3, 2.3, 0.5], w, h));
return cam;
},
uniforms: (gl, loc) => {
gl.uniform1f(loc("uDark"), ease(s.dark));
gl.uniform1f(loc("uLamp"), ease(Math.min(1, Math.max(0, (s.dark - 0.15) / 0.5))));
gl.uniform1f(loc("uRock"), s.rock.x);
},
step: (dt) => {
let moving = false;
const rockGoal = s.goal > 0.5 ? 1 : -1;
if (reduce) {
if (s.rock.x !== rockGoal || s.dark !== s.goal) { s.rock.x = rockGoal; s.rock.v = 0; s.dark = s.goal; moving = true; }
return moving;
}
if (springStep(s.rock, rockGoal, dt, 1400, 48)) moving = true;
if (s.dark !== s.goal) {
const d = dt / FADE_SECONDS;
s.dark = s.goal > s.dark ? Math.min(s.goal, s.dark + d) : Math.max(s.goal, s.dark - d);
moving = true;
}
return moving;
},
});
if (!stage) return;
stageRef.current = stage;
setMode("gl");
return () => { stageRef.current = null; stage.dispose(); };
}, [reduce]);
const toggle = () => choose(dark ? "light" : "dark");
const still = mode === "still";
// the card beside the switch is ordinary UI in the chosen theme
const card = dark
? { bg: "#18171b", fg: "#ece6dc", sub: "#a39d94", line: "rgba(255,255,255,0.08)", chip: "#26242a", accent: "#e0a660" }
: { bg: "#fbf8f3", fg: "#1f1b16", sub: "#6b6359", line: "rgba(31,27,22,0.09)", chip: "#f0ebe2", accent: "#9a4a26" };
const fade = reduce ? "none" : `background-color ${FADE_SECONDS * 0.6}s ease, color ${FADE_SECONDS * 0.6}s ease, border-color ${FADE_SECONDS * 0.6}s ease`;
return (
<section data-theme={theme} className="relative overflow-hidden bg-[#2b1a12]" style={{ fontFamily: GROTESK }}>
<div className="relative md:h-[720px]">
<div ref={wrapRef} className="relative h-[460px] w-full sm:h-[540px] md:absolute md:inset-0 md:h-auto">
<canvas ref={canvasRef} aria-hidden="true" className={`absolute inset-0 h-full w-full ${still ? "hidden" : ""}`} />
{still && (
<div aria-hidden="true" className="absolute inset-0 transition-colors duration-700" style={{ background: dark ? "radial-gradient(90% 80% at 80% 100%, #6b3a20 0%, #2a160d 55%, #120a06 100%)" : "radial-gradient(120% 90% at 25% 30%, #c9845d 0%, #a2583a 50%, #6a3520 100%)" }}>
{!dark && <div className="absolute inset-0" style={stillWindowLight()} />}
<div className="absolute inset-0 opacity-30 mix-blend-overlay" style={{ backgroundImage: STILL_GRAIN }} />
</div>
)}
<div className={still ? "absolute inset-0 grid place-items-center md:right-[42%]" : "absolute inset-0"}>
<button
type="button"
role="switch"
aria-checked={dark}
aria-label="Dark mode"
onClick={toggle}
className={`touch-manipulation select-none rounded-[14%] outline-none focus-visible:ring-2 focus-visible:ring-[#f6ead8] focus-visible:ring-offset-[6px] focus-visible:ring-offset-transparent ${still ? "relative grid h-32 w-32 place-items-center" : "absolute"}`}
style={still ? stillObject("linear-gradient(160deg,#c9a865,#8a6a35)", { radius: 12, depth: 8 }) : rect ? { left: rect.left, top: rect.top, width: rect.width, height: rect.height } : { display: "none" }}
>
{still && <span aria-hidden="true" className="block h-[60%] w-[60%] rounded-[10%] transition-transform duration-300" style={{ ...stillObject("#d9cfbd", { radius: 8, depth: 4 }), transform: `perspective(200px) rotateX(${dark ? 12 : -12}deg)` }} />}
</button>
</div>
<p className="pointer-events-none absolute bottom-5 left-5 text-[11px] font-semibold uppercase tracking-[0.24em] text-[#f6ead8]/75 sm:bottom-8 sm:left-8">
{dark ? "Evening, lamp on" : "Afternoon sun"}
</p>
</div>
<div className="relative px-4 pb-6 pt-0 md:absolute md:inset-y-0 md:right-[6%] md:flex md:w-[360px] md:items-center md:p-0">
<div
className="-mt-10 w-full rounded-[20px] border p-6 shadow-[0_30px_60px_-30px_rgba(0,0,0,0.6)] md:mt-0"
style={{ background: card.bg, color: card.fg, borderColor: card.line, transition: fade }}
>
<p className="text-[11px] font-semibold uppercase tracking-[0.2em]" style={{ color: card.sub, transition: fade }}>Settings</p>
<h3 className="mt-1 text-[22px] font-semibold tracking-[-0.01em]">Appearance</h3>
<div className="mt-5 flex items-center justify-between gap-4 border-t pt-4" style={{ borderColor: card.line, transition: fade }}>
<div>
<p className="text-[15px] font-medium">Dark mode</p>
<p aria-live="polite" className="mt-0.5 text-[13px]" style={{ color: card.sub, transition: fade }}>
{dark ? "On" : "Off"}{followsSystem ? ", following your device" : ", your choice"}
</p>
</div>
<button
type="button"
role="switch"
aria-checked={dark}
aria-label="Dark mode"
onClick={toggle}
className="relative h-7 w-12 shrink-0 rounded-full outline-none focus-visible:ring-2 focus-visible:ring-offset-2"
style={{ background: dark ? card.accent : "#d8d0c4", transition: fade }}
>
<span className={`absolute left-0.5 top-0.5 h-6 w-6 rounded-full bg-white shadow ${reduce ? "" : "transition-transform duration-300"}`} style={{ transform: `translateX(${dark ? 20 : 0}px)` }} />
</button>
</div>
<ul className="mt-4 space-y-2">
{[
["Quarterly report", "Edited 2 hours ago"],
["Studio photos", "Shared with 3 people"],
["Launch checklist", "6 of 9 done"],
].map(([t, d]) => (
<li key={t} className="flex items-center gap-3 rounded-xl px-3 py-2.5" style={{ background: card.chip, transition: fade }}>
<span className="h-8 w-8 shrink-0 rounded-lg" style={{ background: card.accent, opacity: 0.85, transition: fade }} />
<span className="min-w-0">
<span className="block truncate text-[14px] font-medium">{t}</span>
<span className="block truncate text-[12px]" style={{ color: card.sub, transition: fade }}>{d}</span>
</span>
</li>
))}
</ul>
<button
type="button"
onClick={() => choose(null)}
disabled={followsSystem}
className="mt-5 text-[13px] font-medium underline-offset-4 outline-none hover:underline focus-visible:underline disabled:cursor-default disabled:no-underline disabled:opacity-50"
style={{ color: card.accent, transition: fade }}
>
{followsSystem ? "Following your device setting" : "Use device setting"}
</button>
</div>
</div>
</div>
</section>
);
}
Install with one command: npx shadcn@latest add https://we.inc/r/photoreal-dark-mode-toggle-switch-a-ceramic-rocker-on-a-sunlit-plaster-wall-that-dims-the-room-to-lamplight.json
It reads the prefers-color-scheme media query and listens for changes. Until someone flips the switch, the theme tracks the device live; after that their saved choice wins until they press Use device setting.
Reads and writes sit inside try and catch. In a private window the switch still works for the visit and just forgets afterwards.
No. While the room fades it draws every frame; once still, it averages frames into a clean picture and stops drawing. It also pauses off screen and when the tab is hidden.
Yes. The useTheme hook at the top is plain React and returns the theme, whether it follows the device, and a choose function. Wire it to any button.
Related: Dark Mode Toggle Switch in React and Tailwind with System Setting and Four Styles, Porcelain Wall Light Switch Settings List with Three Bakelite Dollies That Snap Over and Throw Lamp Light Up a Sunlit Wall, Brass Dolly Light Switch Toggle on a Fluted Rose That Snaps Over and Lights a Filament Wall Lamp.
More toggles and switches or all free UI components. Start for free to have a full site built around it.
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