From bc2821adb11a30244fc4663f4fafb756877d9508 Mon Sep 17 00:00:00 2001
From: Yasutake Yohei <61961825+yasutakeyohei@users.noreply.github.com>
Date: Wed, 7 Oct 2026 23:09:40 +0900
Subject: bluebey-studio: public/ の外へ移動し非公開化
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 bluebey-studio/src/gacha.js | 481 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 481 insertions(+)
 create mode 100644 bluebey-studio/src/gacha.js

(limited to 'bluebey-studio/src/gacha.js')

diff --git a/bluebey-studio/src/gacha.js b/bluebey-studio/src/gacha.js
new file mode 100644
index 0000000..c44f80f
--- /dev/null
+++ b/bluebey-studio/src/gacha.js
@@ -0,0 +1,481 @@
+/**
+ * Seeded "おまかせ" rolls for the face and the pose.
+ *
+ * The studio is a hundred sliders, and that is exactly the problem: when you sit
+ * down to make an expression you reach for the same three settings every time.
+ * This module is the antidote - one press and a stranger picks the numbers for
+ * you, from ranges a person would actually dial in, so the result is plausible
+ * rather than a mash of the full slider span.
+ *
+ * Two ideas hold it together:
+ *
+ *  - A roll picks an *emotion* first (ふつう, うれしい, びっくり, ...), then samples
+ *    every part inside that emotion's window. Correlated parts read as one face;
+ *    an independent draw per slider reads as noise.
+ *
+ *  - The randomness is seeded, and the seed is a short base36 string that fits in
+ *    a URL. `rollAll(seed)` is a pure function of that string, so a look the user
+ *    liked can be reproduced and shared (`?seed=...`) instead of lost. A "seed"
+ *    is either a number or text; text that is already a base36 number is read as
+ *    one, so `decodeSeed(seed)` is always accepted back by `makeRandom`.
+ *
+ * The face and pose vocabulary, and every bound quoted below, follows
+ * `src/presets.js` and the slider ranges in `src/panel.js`. Nothing here touches
+ * the DOM or the app state: the functions return patches for `applyPatch`.
+ */
+
+/**
+ * FNV-1a over UTF-16 code units, for text that is not already a seed.
+ */
+function fnv1a(text) {
+  let hash = 0x811c9dc5;
+  for (let i = 0; i < text.length; i += 1) {
+    hash ^= text.charCodeAt(i);
+    hash = Math.imul(hash, 0x01000193);
+  }
+  return hash >>> 0;
+}
+
+/**
+ * Normalise any seed to a 32-bit integer. Text that is already a base36 number
+ * is read as one - that is what `decodeSeed` emits, so it has to come back in
+ * unchanged - and anything else is hashed. `hashSeed`, `makeRandom` and
+ * `decodeSeed` all go through this, so the four entry points never disagree.
+ */
+function toSeedInt(seed) {
+  if (typeof seed === 'number' && Number.isFinite(seed)) return Math.trunc(seed) >>> 0;
+  const text = String(seed ?? '').trim();
+  if (/^[0-9a-z]+$/.test(text)) {
+    const parsed = parseInt(text, 36);
+    if (Number.isFinite(parsed)) return parsed >>> 0;
+  }
+  return fnv1a(text);
+}
+
+/**
+ * Turn text into a stable 32-bit seed (for `?seed=` in a URL).
+ *
+ * A word becomes an FNV-1a hash; text that already looks like a base36 seed is
+ * passed through, so `decodeSeed`'s output round-trips.
+ */
+export function hashSeed(text) {
+  return toSeedInt(text);
+}
+
+/**
+ * A seeded PRNG (mulberry32). Returns `() => number` in `[0, 1)`.
+ * Accepts a number or a string; strings go through the same rule as `decodeSeed`.
+ */
+export function makeRandom(seed) {
+  let state = toSeedInt(seed);
+  return function random() {
+    state = (state + 0x6d2b79f5) >>> 0;
+    let t = state;
+    t = Math.imul(t ^ (t >>> 15), t | 1);
+    t ^= t + Math.imul(t ^ (t >>> 7), t | 61);
+    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
+  };
+}
+
+/**
+ * The short, readable form of a seed (base36), for the "現在のシード" field.
+ * Idempotent: `decodeSeed(decodeSeed(x)) === decodeSeed(x)`, and the result is
+ * accepted straight back by `makeRandom`.
+ */
+export function decodeSeed(seed) {
+  return (toSeedInt(seed) >>> 0).toString(36);
+}
+
+function rand(random, min, max) {
+  return min + random() * (max - min);
+}
+
+/** An angle in whole degrees, so the pose matches the step-1 sliders. */
+function deg(random, min, max) {
+  return Math.round(rand(random, min, max));
+}
+
+function round2(value) {
+  return Math.round(value * 100) / 100;
+}
+
+function pick(random, list) {
+  return list[Math.floor(random() * list.length)];
+}
+
+function chance(random, probability) {
+  return random() < probability;
+}
+
+function clamp(value, min, max) {
+  return Math.min(max, Math.max(min, value));
+}
+
+/**
+ * The mood table. Each entry samples only inside a range that reads as that
+ * emotion, which is what keeps the parts agreeing with each other.
+ *
+ * Fields: `eyes` (open/irisScale/lookMax/lookX/lookY, all in slider units),
+ * `mouth` (smile/open/round/corners/cornerAngle/tilt/offsetY/tongue/width/
+ * thickness), plus optional `tear`, `lowerLid`, `heart`, `wink` and `shutBoth`.
+ */
+const MOODS = [
+  {
+    id: 'normal',
+    eyes: {
+      open: [0.92, 1], irisScale: [0.95, 1.06], lookMax: [0.55, 1],
+      lookX: [-0.28, 0.28], lookY: [-0.16, 0.16],
+    },
+    mouth: {
+      smile: [0.62, 0.95], open: [0, 0.05], width: [0.9, 1.1], thickness: [0.9, 1.15],
+      corners: [0.8, 1.2], cornerAngle: [-6, 6], tilt: [-4, 4], offsetY: [-5, 6],
+      tongue: [0, 1.1],
+    },
+  },
+  {
+    id: 'happy',
+    eyes: {
+      open: [0.88, 1], irisScale: [0.96, 1.08], lookMax: [0.5, 0.95],
+      lookX: [-0.3, 0.3], lookY: [-0.2, 0.05],
+    },
+    mouth: {
+      smile: [1.05, 1.3], open: [0.02, 0.22], width: [0.95, 1.2], thickness: [0.9, 1.15],
+      corners: [1.05, 1.4], cornerAngle: [0, 12], tilt: [-4, 6], offsetY: [-8, 2],
+      tongue: [0.9, 1.35],
+    },
+  },
+  {
+    id: 'surprised',
+    eyes: {
+      open: [0.95, 1], irisScale: [0.8, 0.9], lookMax: [0.3, 0.5],
+      lookX: [-0.15, 0.15], lookY: [-0.1, 0.1],
+    },
+    mouth: {
+      smile: [0, 0.2], open: [0.1, 0.32], round: [0.55, 0.8], width: [0.82, 0.98],
+      thickness: [1, 1.2], corners: [0, 0.15], cornerAngle: [-3, 3], tilt: [-3, 3],
+      offsetY: [-6, 6], tongue: [0, 0.4],
+    },
+  },
+  {
+    id: 'sad',
+    eyes: {
+      open: [0.55, 0.75], irisScale: [0.95, 1.05], lookMax: [0.45, 0.85],
+      lookX: [-0.2, 0.2], lookY: [-0.35, -0.12],
+    },
+    mouth: {
+      smile: [-0.7, -0.4], open: [0, 0.05], width: [0.68, 0.88], thickness: [1.05, 1.3],
+      corners: [0, 0.1], cornerAngle: [-4, 4], tilt: [-5, 5], offsetY: [6, 16],
+      tongue: [0, 0.1],
+    },
+    lowerLid: [0.16, 0.28],
+    tear: [0.6, 1.2],
+    tearChance: 1,
+  },
+  {
+    id: 'angry',
+    eyes: {
+      open: [0.55, 0.7], irisScale: [0.82, 0.92], lookMax: [0.5, 0.9],
+      lookX: [-0.15, 0.15], lookY: [-0.16, 0.02],
+    },
+    mouth: {
+      smile: [-0.85, -0.5], open: [0, 0.04], width: [0.78, 0.94], thickness: [1.05, 1.3],
+      corners: [0, 0.05], cornerAngle: [-6, 6], tilt: [-6, 6], offsetY: [8, 18],
+      tongue: [0, 0.05],
+    },
+    lowerLid: [0.08, 0.2],
+  },
+  {
+    id: 'love',
+    eyes: {
+      open: [1, 1], irisScale: [0.9, 1.02], lookMax: [0.4, 0.8],
+      lookX: [-0.16, 0.16], lookY: [-0.36, -0.2],
+    },
+    mouth: {
+      smile: [1.15, 1.3], open: [0.08, 0.3], width: [0.98, 1.18], thickness: [0.98, 1.2],
+      corners: [1.2, 1.4], cornerAngle: [4, 14], tilt: [2, 8], offsetY: [-2, 6],
+      tongue: [1.1, 1.4],
+    },
+    heart: true,
+  },
+  {
+    id: 'sleepy',
+    eyes: {
+      open: [0.32, 0.5], irisScale: [0.95, 1.05], lookMax: [0.4, 0.7],
+      lookX: [-0.18, 0.18], lookY: [-0.26, -0.08],
+    },
+    mouth: {
+      smile: [0.5, 0.82], open: [0, 0.08], width: [0.82, 1], thickness: [0.92, 1.1],
+      corners: [0.5, 0.9], cornerAngle: [-4, 4], tilt: [-7, -1], offsetY: [4, 13],
+      tongue: [0.3, 0.8],
+    },
+    lowerLid: [0.1, 0.24],
+    tear: [0.2, 0.5],
+    tearChance: 0.5,
+    shutBoth: { chance: 0.4, closed: 'line', closedLines: 1 },
+  },
+  {
+    id: 'wink',
+    eyes: {
+      open: [0.95, 1], irisScale: [0.95, 1.05], lookMax: [0.5, 0.9],
+      lookX: [-0.2, 0.2], lookY: [-0.15, 0.1],
+    },
+    mouth: {
+      smile: [1, 1.3], open: [0.02, 0.18], width: [0.95, 1.15], thickness: [0.92, 1.12],
+      corners: [0.9, 1.2], cornerAngle: [4, 12], tilt: [-5, 5], offsetY: [-6, 4],
+      tongue: [0.8, 1.25],
+    },
+    wink: true,
+  },
+];
+
+/**
+ * Sample the eyes. Both eyes normally agree (a tiny jitter keeps the face from
+ * looking printed); a wink shuts exactly one, and ねむい sometimes shuts both.
+ * A shut-eye style below 1 line is only ever picked when that eye is closed.
+ */
+function rollEyes(random, spec) {
+  const [openMin, openMax] = spec.open;
+  let leftOpen = round2(rand(random, openMin, openMax));
+  let rightOpen = round2(clamp(leftOpen + rand(random, -0.06, 0.06), 0, 1));
+  let leftShape = 'open';
+  let rightShape = 'open';
+  let leftClosed = 'line';
+  let rightClosed = 'line';
+  let leftLines = 1;
+  let rightLines = 1;
+
+  if (spec.wink) {
+    const side = chance(random, 0.5) ? 'left' : 'right';
+    const lines = pick(random, [2, 3]);
+    // A shut eye is the artwork with the lids open now; the lid height is its own
+    // slider, so `open` is 1 and the shape says which line it is.
+    if (side === 'left') {
+      leftOpen = 1;
+      leftLines = lines;
+      leftShape = `line${lines}`;
+    } else {
+      rightOpen = 1;
+      rightLines = lines;
+      rightShape = `line${lines}`;
+    }
+  } else if (spec.shutBoth && chance(random, spec.shutBoth.chance)) {
+    leftOpen = 1;
+    rightOpen = 1;
+    leftClosed = spec.shutBoth.closed;
+    rightClosed = spec.shutBoth.closed;
+    leftLines = spec.shutBoth.closedLines;
+    rightLines = spec.shutBoth.closedLines;
+    const shape = spec.shutBoth.closed === 'line'
+      ? `line${spec.shutBoth.closedLines}`
+      : spec.shutBoth.closed;
+    leftShape = shape;
+    rightShape = shape;
+  }
+
+  const lookX = round2(rand(random, spec.lookX[0], spec.lookX[1]));
+  const lookY = round2(rand(random, spec.lookY[0], spec.lookY[1]));
+
+  return {
+    left: { shape: leftShape, open: leftOpen, lookX, lookY, closed: leftClosed, closedLines: leftLines, irisShape: 'circle' },
+    right: { shape: rightShape, open: rightOpen, lookX, lookY, closed: rightClosed, closedLines: rightLines, irisShape: 'circle' },
+    irisScale: round2(rand(random, spec.irisScale[0], spec.irisScale[1])),
+    lookMax: round2(rand(random, spec.lookMax[0], spec.lookMax[1])),
+    highlight: true,
+  };
+}
+
+/** Sample the mouth. A round "O" and a smile are mutually exclusive by design. */
+function rollMouth(random, spec) {
+  return {
+    visible: true,
+    smile: round2(rand(random, spec.smile[0], spec.smile[1])),
+    open: round2(rand(random, spec.open[0], spec.open[1])),
+    round: spec.round ? round2(rand(random, spec.round[0], spec.round[1])) : 0,
+    width: round2(rand(random, spec.width[0], spec.width[1])),
+    thickness: round2(rand(random, spec.thickness[0], spec.thickness[1])),
+    tilt: Math.round(rand(random, spec.tilt[0], spec.tilt[1])),
+    offsetY: Math.round(rand(random, spec.offsetY[0], spec.offsetY[1])),
+    corners: round2(rand(random, spec.corners[0], spec.corners[1])),
+    cornerAngle: Math.round(rand(random, spec.cornerAngle[0], spec.cornerAngle[1])),
+    tongue: round2(rand(random, spec.tongue[0], spec.tongue[1])),
+  };
+}
+
+/**
+ * A patch for the `face` section: `{ eyes, mouth }`, ready for
+ * `applyPatch(state.face, patch)`.
+ *
+ * Bounds, in case you are reading this from the tests:
+ *   eyes.open 0..1, irisScale 0.8..1.1, lookMax 0.3..1,
+ *   lookX -0.35..0.35, lookY -0.45..0.2,
+ *   mouth.smile -1..1.4 (negative = frown, only when the eyes agree),
+ *   mouth.open 0..0.35, mouth.round 0 or 0.4..0.8,
+ *   corners 0..1.4, cornerAngle -30..30, tilt -8..8, offsetY -20..30,
+ *   width 0.6..1.3, thickness 0.7..1.4, tongue 0..1.6,
+ *   eyes.left/right.tear 0..1.6.
+ */
+export function randomFace(random) {
+  const mood = pick(random, MOODS);
+  const eyes = rollEyes(random, mood.eyes);
+  const mouth = rollMouth(random, mood.mouth);
+
+  // Tears only read on a sad or sleepy face: a frown, or eyes that are half shut.
+  // A fully shut eye never cries.
+  const halfShut = eyes.left.open > 0 && eyes.left.open < 0.78;
+  if (mood.tear && eyes.left.open > 0 && (mouth.smile < 0 || halfShut)
+    && chance(random, mood.tearChance ?? 1)) {
+    // The tears are per eye, so both have to be set. (A crying face wants both;
+    // the shape still allows one eye to cry on its own.)
+    const amount = round2(rand(random, mood.tear[0], mood.tear[1]));
+    eyes.left.tear = amount;
+    eyes.right.tear = amount;
+    eyes.left.tearOn = true;
+    eyes.right.tearOn = true;
+  }
+
+  if (mood.lowerLid) {
+    eyes.lowerLid = round2(rand(random, mood.lowerLid[0], mood.lowerLid[1]));
+  }
+
+  // A heart pupil needs both eyes open, or it reads as a broken iris.
+  if (mood.heart && eyes.left.open >= 0.9 && eyes.right.open >= 0.9) {
+    eyes.left.irisShape = 'heart';
+    eyes.right.irisShape = 'heart';
+    eyes.left.shape = 'heart';
+    eyes.right.shape = 'heart';
+    eyes.heartScale = round2(rand(random, 0.9, 1.15));
+    eyes.heartColor = '#e0344f';
+    eyes.highlight = false;
+  }
+
+  return { eyes, mouth };
+}
+
+/**
+ * The pose moves. Each composes one to three bones (never the whole rig) inside
+ * safe limits: arms up to ~74°, master lean up to 24°, root offsets small.
+ *
+ * Bounds: master [-20..24, -28..28, -14..14], armsupport [-18..76, -12..12,
+ * -24..24], arm [-14..20, -8..8, -12..12], legsupport [-8..24, -8..8, -12..12],
+ * root x/z -0.15..0.15 and y 0..0.45.
+ */
+const POSE_MOVES = [
+  // A lean or a nod - one bone, the safest thing in the table.
+  (random) => ({
+    bones: { master: [deg(random, 6, 24), deg(random, -10, 10), deg(random, -6, 6)] },
+  }),
+  // A curious tilt to one side.
+  (random) => {
+    const sign = chance(random, 0.5) ? 1 : -1;
+    return { bones: { master: [deg(random, -6, 8), 0, sign * deg(random, 8, 14)] } };
+  },
+  // A wave from one arm.
+  (random) => {
+    const side = pick(random, ['l', 'r']);
+    return {
+      bones: {
+        [`armsupport.${side}`]: [deg(random, 42, 74), deg(random, -8, 8), deg(random, -14, 14)],
+        [`arm.${side}`]: [deg(random, 6, 18), 0, 0],
+      },
+    };
+  },
+  // A two-armed cheer, with a small hop.
+  (random) => ({
+    bones: {
+      master: [deg(random, -14, -2), 0, 0],
+      'armsupport.l': [deg(random, 52, 74), 0, deg(random, 4, 18)],
+      'armsupport.r': [deg(random, 52, 74), 0, -deg(random, 4, 18)],
+    },
+    root: [0, round2(rand(random, 0.05, 0.3)), 0],
+  }),
+  // Introducing something off to one side.
+  (random) => {
+    const side = pick(random, ['l', 'r']);
+    const sign = side === 'l' ? 1 : -1;
+    const other = side === 'l' ? 'r' : 'l';
+    return {
+      bones: {
+        master: [deg(random, 2, 8), sign * deg(random, 16, 26), 0],
+        [`armsupport.${side}`]: [deg(random, 24, 40), 0, sign * deg(random, 10, 20)],
+        [`armsupport.${other}`]: [deg(random, 2, 14), 0, 0],
+      },
+    };
+  },
+  // A little hop on the spot.
+  (random) => ({
+    bones: {
+      master: [deg(random, -12, -2), 0, 0],
+      'legsupport.l': [deg(random, 8, 22), 0, deg(random, -8, 8)],
+      'legsupport.r': [deg(random, 8, 22), 0, deg(random, -8, 8)],
+    },
+    root: [0, round2(rand(random, 0.18, 0.42)), 0],
+  }),
+  // Both arms up in a simple stretch.
+  (random) => ({
+    bones: {
+      'armsupport.l': [deg(random, 46, 74), 0, deg(random, 4, 16)],
+      'armsupport.r': [deg(random, 46, 74), 0, -deg(random, 4, 16)],
+    },
+  }),
+  // A dance sway: one arm leads, the other follows.
+  (random) => {
+    const sign = chance(random, 0.5) ? 1 : -1;
+    return {
+      bones: {
+        master: [deg(random, -4, 4), 0, sign * deg(random, 4, 12)],
+        'armsupport.l': [deg(random, 30, 46), 0, sign * deg(random, 8, 18)],
+        'armsupport.r': [deg(random, 12, 26), 0, -sign * deg(random, 8, 18)],
+      },
+      root: [round2(rand(random, -0.08, 0.08)), 0, 0],
+    };
+  },
+];
+
+/** A patch for the `pose` section: `{ bones, root }`. */
+export function randomPose(random) {
+  const move = pick(random, POSE_MOVES)(random);
+  return { bones: move.bones, root: move.root ?? [0, 0, 0] };
+}
+
+/**
+ * A patch for the `lookAt` section. About half the time it enables a target off
+ * to one side, so the character glances away instead of staring at the camera.
+ * Bounds: |x| 1.2..3.2 when enabled, y 1.6..3.4, z 2..4.2, amount 0.5..1.
+ */
+export function randomLook(random) {
+  if (chance(random, 0.45)) {
+    const sign = chance(random, 0.5) ? 1 : -1;
+    return {
+      lookAt: {
+        enabled: true,
+        x: round2(sign * rand(random, 1.2, 3.2)),
+        y: round2(rand(random, 1.6, 3.4)),
+        z: round2(rand(random, 2, 4.2)),
+        turnBody: chance(random, 0.35),
+        amount: round2(rand(random, 0.5, 1)),
+      },
+    };
+  }
+  return {
+    lookAt: { enabled: false, x: 0, y: 2.6, z: 3, turnBody: false, amount: round2(rand(random, 0.6, 1)) },
+  };
+}
+
+/**
+ * One press of おまかせ: face, pose and look, all from the same seed.
+ *
+ * @param {number | string} seed a number, or text that `decodeSeed` also accepts
+ * @returns {{ seed: string, patch: { face: object, pose: object, lookAt: object } }}
+ *   `seed` is the readable base36 form, for the URL and the seed field.
+ */
+export function rollAll(seed) {
+  const random = makeRandom(seed);
+  return {
+    seed: decodeSeed(seed),
+    patch: {
+      face: randomFace(random),
+      pose: randomPose(random),
+      lookAt: randomLook(random).lookAt,
+    },
+  };
+}
-- 
cgit v1.3.1