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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Slapstack Studio — spawn objects, move them, in Gabor space</title>
<style>
:root {
  --chassis:#1d222e; --panel:#262c3b; --panel-edge:#333b4f; --well:#10131b;
  --ink:#e3e7f0; --muted:#8d96ab; --phosphor:#ffb454; --outlier:#78808f;
  --entropy:#c86bff; --go:#7fd98a; --bad:#ff7a7a;
  --mono: ui-monospace,"SF Mono","Cascadia Mono",Menlo,Consolas,monospace;
  --cond:"Bahnschrift","Arial Narrow","Roboto Condensed",sans-serif;
}
*{box-sizing:border-box;margin:0}
html,body{height:100%}
body{background:var(--chassis);color:var(--ink);font-family:var(--mono);
  font-size:13px;display:flex;flex-direction:column;overflow:hidden}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}
header{display:flex;align-items:baseline;gap:14px;padding:10px 16px 9px;
  border-bottom:1px solid var(--panel-edge);flex-wrap:wrap}
header h1{font-family:var(--cond);font-size:20px;letter-spacing:2.5px;font-weight:700}
header h1 em{color:var(--phosphor);font-style:normal}
header .claim{color:var(--muted);font-size:11.5px}
#state-lamp{margin-left:auto;font-size:11px;letter-spacing:1.5px;padding:3px 10px;
  border-radius:3px;border:1px solid var(--panel-edge);color:var(--muted)}
#state-lamp.soup{color:var(--outlier);border-color:var(--outlier)}
#state-lamp.binding{color:var(--entropy);border-color:var(--entropy)}
#state-lamp.bound{color:var(--go);border-color:var(--go)}
main{flex:1;display:flex;gap:12px;padding:12px 16px;min-height:0}
#stage-wrap{flex:1;display:flex;align-items:center;justify-content:center;min-width:0}
#stage{position:relative;background:var(--well);border:1px solid var(--panel-edge);
  border-radius:6px;box-shadow:inset 0 0 60px rgba(0,0,0,.55)}
#stage canvas{position:absolute;inset:0;width:100%;height:100%;border-radius:6px}
#overlay-canvas{cursor:grab}
#overlay-canvas.dragging{cursor:grabbing}
#stage .hint{position:absolute;bottom:7px;left:0;right:0;text-align:center;
  color:var(--muted);font-size:10.5px;pointer-events:none;text-shadow:0 1px 3px #000}
aside{width:330px;flex-shrink:0;display:flex;flex-direction:column;gap:9px;
  overflow-y:auto;padding-right:2px}
.card{background:var(--panel);border:1px solid var(--panel-edge);border-radius:6px;
  padding:10px 11px}
.card h2{font-family:var(--cond);font-size:12px;letter-spacing:2px;font-weight:700;
  color:var(--muted);margin-bottom:8px}
button{font-family:var(--mono);font-size:12px;background:var(--well);color:var(--ink);
  border:1px solid var(--panel-edge);border-radius:4px;padding:6px 11px;cursor:pointer}
button:hover{border-color:var(--phosphor);color:var(--phosphor)}
button:focus-visible{outline:2px solid var(--phosphor);outline-offset:1px}
button:disabled{opacity:.35;cursor:default}
button:disabled:hover{border-color:var(--panel-edge);color:var(--ink)}
button.primary{border-color:var(--phosphor);color:var(--phosphor)}
.row{display:flex;gap:7px;align-items:center}
.row+.row{margin-top:7px}
.readout{color:var(--phosphor)} .dim{color:var(--muted)} .spacer{flex:1}
#bind-meter{height:4px;background:var(--well);border-radius:2px;overflow:hidden;margin-top:8px}
#bind-meter>div{height:100%;width:0%;background:var(--entropy)}
#metrics{display:grid;grid-template-columns:1fr 1fr;gap:3px 10px;margin-top:8px;font-size:11.5px}
.layer{border-top:1px solid var(--panel-edge);padding:7px 0;border-radius:3px}
.layer:first-of-type{border-top:0}
.layer.sel{outline:1px solid var(--phosphor);outline-offset:2px}
.layer .name{display:flex;align-items:center;gap:7px;cursor:pointer}
.swatch{width:10px;height:10px;border-radius:2px;flex-shrink:0}
.layer .pose{color:var(--muted);font-size:10.5px;margin:4px 0 5px;min-height:13px}
.belief-bar{flex:1;height:5px;background:var(--well);border-radius:3px;overflow:hidden;max-width:80px}
.belief-bar>div{height:100%;background:var(--go)}
.layer .ctl{display:flex;gap:4px;flex-wrap:wrap;margin-top:5px}
.layer .ctl button{padding:3px 7px;font-size:10.5px}
#library{display:flex;gap:6px;flex-wrap:wrap;margin-top:6px}
.chip{display:flex;align-items:center;gap:5px;background:var(--well);
  border:1px solid var(--panel-edge);border-radius:12px;padding:3px 9px;font-size:11px}
.chip button{border:0;padding:0 2px;font-size:12px;background:none}
label.tog{display:flex;gap:8px;align-items:center;cursor:pointer;padding:2px 0;font-size:12px}
label.tog input{accent-color:var(--phosphor)}
input[type=range]{flex:1;accent-color:var(--phosphor)}
.gain-row{display:grid;grid-template-columns:54px 1fr 40px;gap:6px;align-items:center;margin-top:3px}
.gain-row input[type=range]{width:100%;margin:0}
.gain-row .val{text-align:right}
input[type=color]{width:36px;height:22px;padding:1px;border:1px solid var(--panel-edge);background:var(--well);border-radius:4px;cursor:pointer}
#stage.erasing #overlay-canvas{cursor:crosshair}
input[type=text],textarea{font-family:var(--mono);font-size:12px;background:var(--well);
  color:var(--ink);border:1px solid var(--panel-edge);border-radius:4px;padding:6px 8px;width:100%}
input[type=text]:focus-visible,textarea:focus-visible{outline:2px solid var(--phosphor);border-color:transparent}
#spawn-status,#prompt-log{color:var(--muted);font-size:10.5px;margin-top:6px;
  min-height:13px;white-space:pre-wrap}
#ledger p{font-size:10.5px;line-height:1.5;color:var(--muted);margin-bottom:6px}
#ledger b{color:var(--go);font-weight:400}
#ledger .no{color:var(--entropy)}
details summary{cursor:pointer;font-family:var(--cond);font-size:12px;letter-spacing:2px;color:var(--muted)}
details[open] summary{margin-bottom:7px}
input[type=file]{font-size:10.5px;color:var(--muted);max-width:170px}
@media (max-width:900px){main{flex-direction:column;overflow-y:auto}body{overflow:auto}aside{width:100%}}
</style>
</head>
<body>

<header>
  <h1>SLAPSTACK <em>STUDIO</em></h1>
  <span class="claim">spawn layers with AI &middot; scramble &middot; bind &middot; grab &middot; stack &middot; every entity is a posterior</span>
  <span id="state-lamp" class="soup">ATOM SOUP</span>
</header>

<main>
  <div id="stage-wrap">
    <div id="stage">
      <canvas id="scene-canvas"></canvas>
      <canvas id="overlay-canvas"></canvas>
      <div class="hint">drag = pose clamp &middot; wheel rotate &middot; shift+wheel scale &middot; shift+click = hint &middot; erase tool: brush deletes atoms</div>
    </div>
  </div>

  <aside>
    <div class="card">
      <h2>SCENE</h2>
      <div class="row">
        <button id="btn-scramble">Scramble</button>
        <button id="btn-bind" class="primary">Bind</button>
        <span class="spacer"></span>
        <span class="dim">noise</span>
        <input type="range" id="noise" min="0" max="10" value="1" style="width:60px" aria-label="observation noise">
      </div>
      <div class="row">
        <span class="dim">composite</span>
        <label class="tog"><input type="radio" name="comp" value="field" checked> field</label>
        <label class="tog"><input type="radio" name="comp" value="painter"> painter (depth)</label>
        <span class="spacer"></span>
        <label class="tog"><input type="checkbox" id="auto-occ" checked> depth occlusion</label>
      </div>
      <div id="bind-meter"><div></div></div>
      <div id="metrics">
        <span class="dim">binding vs truth</span><span class="readout" id="m-acc"></span>
        <span class="dim">mean entropy</span><span class="readout" id="m-ent"></span>
        <span class="dim">BP iterations</span><span class="readout" id="m-it"></span>
        <span class="dim">atoms in scene</span><span class="readout" id="m-n"></span>
      </div>
    </div>

    <div class="card">
      <h2>EDIT &amp; LOOK</h2>
      <div class="row">
        <span class="dim">tool</span>
        <label class="tog"><input type="radio" name="tool" value="pose" checked> pose</label>
        <label class="tog"><input type="radio" name="tool" value="erase"> erase</label>
        <span class="spacer"></span>
        <span class="dim">brush</span>
        <label class="tog"><input type="radio" name="brush" value="0.05"> S</label>
        <label class="tog"><input type="radio" name="brush" value="0.12" checked> M</label>
        <label class="tog"><input type="radio" name="brush" value="0.25"> L</label>
      </div>
      <div class="row">
        <button id="btn-undo-erase" disabled>Undo erase</button>
        <button id="btn-restore-erase" disabled>Restore all</button>
        <label class="tog"><input type="checkbox" id="erase-burn"> burn into template</label>
      </div>
      <div class="row">
        <span class="dim">backdrop</span>
        <input type="color" id="bg-color" value="#808080" title="backdrop color">
        <input type="file" id="bg-file" accept="image/*" style="max-width:46%">
        <button id="btn-bg-clear">clear img</button>
      </div>
      <div class="gain-row"><span class="dim">coarse</span><input type="range" id="g-coarse" min="0" max="200" value="100"><span class="val readout" id="g-coarse-v">1.00</span></div>
      <div class="gain-row"><span class="dim">mid</span><input type="range" id="g-mid" min="0" max="200" value="100"><span class="val readout" id="g-mid-v">1.00</span></div>
      <div class="gain-row"><span class="dim">fine</span><input type="range" id="g-fine" min="0" max="200" value="100"><span class="val readout" id="g-fine-v">1.00</span></div>
      <div class="gain-row"><span class="dim">opacity</span><input type="range" id="g-op" min="0" max="200" value="100"><span class="val readout" id="g-op-v">1.00</span></div>
      <div class="dim" style="font-size:10.5px;margin-top:6px">Erase deletes atoms under the brush (render only, until <b>burn</b> writes it into the layer template; Scramble/Bind rebuild the scene from templates). Undo works until the next Bind. Backdrop is presentation and survives everything. Band gains (coarse&lt;4, mid 4&ndash;10, fine&gt;10&nbsp;c/img) scale atom colors in field mode; opacity blends the whole field over the backdrop.</div>
    </div>

    <div class="card">
      <h2>LAYERS <span class="dim" style="letter-spacing:0">(front is highest)</span></h2>
      <div id="layer-list"></div>
      <div class="dim" style="font-size:10.5px;margin-top:6px">library — place to add to the scene:</div>
      <div id="library"></div>
    </div>

    <div class="card">
      <h2>SPAWN A LAYER</h2>
      <div class="row">
        <input type="text" id="spawn-prompt" placeholder='prompt, e.g. "a red rocket, flat colors"'>
      </div>
      <div class="row">
        <input type="text" id="spawn-token" placeholder="matte token (e.g. rocket)" style="width:55%">
        <button id="btn-spawn-text">Distill (GPU)</button>
      </div>
      <div class="row">
        <input type="file" id="spawn-file" accept="image/*">
        <button id="btn-spawn-img">Fit (CPU)</button>
      </div>
      <div class="row">
        <input type="text" id="spawn-json" placeholder="or paste layer JSON">
        <button id="btn-spawn-json">Add</button>
      </div>
      <div id="spawn-status">Distill runs Stable Diffusion score distillation with a cross-attention matte (GPU Space only, untested — first run is a smoke test). Fit trains atoms to your image on CPU (~1 min; objects on plain mid-gray come out compact).</div>
    </div>

    <div class="card">
      <h2>PROMPT AS INTERVENTION</h2>
      <div class="row">
        <input type="text" id="prompt" placeholder='e.g. "move the boat left, put the star behind the tractor"'>
        <button id="btn-prompt">Do</button>
      </div>
      <div id="prompt-log">Commands become pose clamps and depth moves; BP re-settles. Free-form uses Claude when this runs inside claude.ai; a local grammar otherwise.</div>
    </div>

    <div class="card">
      <h2>OVERLAYS</h2>
      <label class="tog"><input type="checkbox" id="ov-atoms" checked> atoms, colored by belief</label>
      <label class="tog"><input type="checkbox" id="ov-own"> ownership tint</label>
      <label class="tog"><input type="checkbox" id="ov-ent"> entropy border glow</label>
      <label class="tog"><input type="checkbox" id="ov-pose" checked> pose belief (crosshair + covariance)</label>
      <label class="tog"><input type="checkbox" id="ov-hints" checked> semantic hints</label>
    </div>

    <div class="card" id="ledger">
      <details>
        <summary>HONEST LEDGER</summary>
        <p><b>Verified in this build:</b> the BP core matches the SlapstackBet6 Python (transform 2e-16, render MSE 8.6e-8, identical binding); drag = pose clamp + re-settle; identity persists through occlusion; depth occlusion removes evidence honestly (marginals revert toward the prior, coverage releases when moved away); the semantic likelihood factor resolves the twins case (two identical stars: 0.05 acc on geometry alone, 0.99 with location priors) and a mildly wrong prior is overridden by evidence; image&rarr;layer fitting runs end to end on CPU. <b>Bet 9:</b> the eraser filters per-atom state (order-free, so undo is re-append), burn edits the template so erases survive rebuilds; the backdrop is pure presentation and persists across Bind/Scramble; band gains exploit render linearity (gain&middot;color &equiv; gain&middot;contribution), verified in tests_edit.js.</p>
        <p><span class="no">Not verified:</span> text&rarr;layer (SDS) and cross-attention matte are line-for-line adaptations of the verified Bet-5 GPU loop but have NOT been executed on a GPU — first run is a smoke test; SD attention maps flicker across seeds, which is why they enter BP as a prior with a weight, never as truth. Real-photo scene&rarr;atoms remains open. Painter compositing and the alpha matte are presentation choices, not the additive field model.</p>
      </details>
    </div>
  </aside>
</main>

<script>
/*CORE*/
</script>
<script>
/*STUDIO_CORE*/
</script>
<script>
const BUILTINS = /*BUILTINS*/null;
</script>
<script>
"use strict";
/* ============================ studio app ============================ */

const PALETTE = [
  ["#ff6b5e",[255,107,94]], ["#5ec8ff",[94,200,255]], ["#ffd35e",[255,211,94]],
  ["#7fd98a",[127,217,138]], ["#c86bff",[200,107,255]], ["#5effd0",[94,255,208]],
  ["#ff8fc7",[255,143,199]], ["#b0b8ff",[176,184,255]],
];
const OUTLIER_RGB = [120,128,143];
const RES = 192, OWN_RES = 128;
const NOISE_SCALE = [1,1,1,.3,.3,20,3,.5,.5,.5];
const HINT_W = 6.0, HINT_SIG = 0.4;

/* ------------- state ------------- */
const S = {
  phase: "soup",
  layers: [],            // {id,name,color,rgb,template,placed,pose,hidden,depth,hints:[]}
  selected: -1,          // index into layers
  obs: [], gt: [],       // gt = placed-order index, -1 clutter
  placed: [],            // layer indices in placed order (BP object order)
  marg: null, mu: null, Sig: null, assign: null,
  evid: [], covFrac: [],
  groupPre: [], groupAlpha: [],   // per placed group + clutter last
  ownField: null, coastT: [],
};
let nextDepth = 1, nextId = 1;

/* ---- Bet 9: eraser / backdrop / band-gain state ---- */
const GAINS = { band: [1, 1, 1], opacity: 1 };
const backdrop = { custom: false, rgb: [128, 128, 128], img: null }; // img: RGBA RES*RES
let bandPre = null, bandDirty = true;
const fieldAlpha = new Float32Array(RES * RES);
let eraseStack = [], lastCursor = null;
function toolMode(){ return document.querySelector('input[name=tool]:checked').value; }
function brushR(){ return +document.querySelector('input[name=brush]:checked').value; }
function updateEraseButtons(){
  document.getElementById("btn-undo-erase").disabled = !eraseStack.length;
  document.getElementById("btn-restore-erase").disabled = !eraseStack.length;
}

function addLayer(name, template, autoPlace) {
  const [color, rgb] = PALETTE[(S.layers.length) % PALETTE.length];
  const L = { id: nextId++, name, color, rgb, template, placed: false,
              pose: [0,0,0,Math.log(0.5)], hidden: false, depth: 0, hints: [] };
  S.layers.push(L);
  if (autoPlace) placeLayer(S.layers.length - 1);
  else { renderLibrary(); }
  return L;
}
function placeLayer(li) {
  const L = S.layers[li];
  L.placed = true; L.hidden = false; L.depth = nextDepth++;
  L.pose = [ -0.3 + 0.6*rand(), -0.3 + 0.6*rand(), -Math.PI + TAU*rand(),
             Math.log(0.45 + 0.2*rand()) ];
  rebuildScene();
}
function removeLayer(li) {
  S.layers[li].placed = false;
  rebuildScene();
}

/* ------------- scene construction ------------- */
let rngState = 22222;
function rand(){ rngState=(rngState*1103515245+12345)&0x7fffffff; return rngState/0x7fffffff; }

function rebuildScene() {
  S.placed = S.layers.map((L,i)=>L.placed?i:-1).filter(i=>i>=0);
  const noiseAmt = 0.006 * Math.pow(3, +document.getElementById("noise").value / 3);
  S.obs = []; S.gt = []; S.src = [];
  S.placed.forEach((li,k)=>{
    const tmpl = S.layers[li].template;
    const tr = transformAtoms(tmpl, S.layers[li].pose);
    for (let j = 0; j < tr.length; j++) {
      S.obs.push(tr[j]); S.gt.push(k); S.src.push({ li, ref: tmpl[j] });
    }
  });
  for (let i=0;i<12;i++){
    const su=0.04+0.08*rand();
    S.obs.push([-0.95+1.9*rand(),-0.95+1.9*rand(),-Math.PI/2+Math.PI*rand(),
      su,su*(0.4+0.5*rand()),4+10*rand(),TAU*rand(),rand(),rand(),rand()]);
    S.gt.push(-1); S.src.push(null);
  }
  for (const a of S.obs) for(let q=0;q<10;q++){
    const g=Math.sqrt(-2*Math.log(rand()+1e-9))*Math.cos(TAU*rand());
    a[q]+=g*noiseAmt*NOISE_SCALE[q];
  }
  for (const a of S.obs){a[3]=Math.max(a[3],.012);a[4]=Math.max(a[4],.008);a[5]=Math.max(a[5],.5);}
  S.marg=null; S.mu=null; S.Sig=null; S.assign=null;
  S.evid=S.obs.map(()=>true);
  S.covFrac=S.placed.map(()=>0);
  S.coastT=S.placed.map(()=>0);
  S.ownField=null;
  eraseStack=[]; updateEraseButtons();
  setPhase("soup");
  rebuildGroupBuffers();
  renderScene(); drawOverlay(); renderLayerList(); renderLibrary(); updatePanels();
}
function scramble(){
  for (const li of S.placed){
    S.layers[li].pose=[-0.35+0.7*rand(),-0.35+0.7*rand(),-Math.PI+TAU*rand(),
                       Math.log(0.4+0.25*rand())];
  }
  rebuildScene();
}

/* ------------- believed grouping (persistent through occlusion) ------------- */
function believedGroup(i){ return S.assign ? S.assign[i] : -2; }
function updateAssign(){
  if(!S.marg){S.assign=null;return;}
  const K=S.placed.length;
  if(!S.assign) S.assign=new Array(S.obs.length).fill(-1);
  for(let i=0;i<S.obs.length;i++){
    if(S.assign[i]>=0 && !S.evid[i]) continue;      // no evidence: identity persists
    const m=S.marg[i]; let b=0;
    for(let k=1;k<=K;k++) if(m[k]>m[b]) b=k;
    S.assign[i]= b===K ? -1 : b;
  }
}
function groupAtomIdx(k){
  const out=[];
  for(let i=0;i<S.obs.length;i++) if(believedGroup(i)===k) out.push(i);
  return out;
}

/* ------------- rendering ------------- */
const stage=document.getElementById("stage");
const sceneC=document.getElementById("scene-canvas");
const overC=document.getElementById("overlay-canvas");
sceneC.width=sceneC.height=RES;
let CSS=600;
function fitStage(){
  const wrap=document.getElementById("stage-wrap");
  CSS=Math.max(280,Math.floor(Math.min(wrap.clientWidth,wrap.clientHeight)-8));
  stage.style.width=stage.style.height=CSS+"px";
  overC.width=overC.height=CSS*(window.devicePixelRatio||1);
  drawOverlay();
}
window.addEventListener("resize",fitStage);

function rebuildGroupBuffers(){
  const K=S.placed.length;
  S.groupPre=[]; S.groupAlpha=[];
  for(let g=0;g<=K;g++) S.groupPre.push(new Float32Array(3*RES*RES));
  const groupOf=i=>{ const g=S.marg?believedGroup(i):S.gt[i]; return g>=0?g:K; };
  for(let i=0;i<S.obs.length;i++){
    const g=groupOf(i);
    if(g<K && S.layers[S.placed[g]].hidden) continue;
    renderPre([S.obs[i]],RES,S.groupPre[g]);
  }
  for(let g=0;g<=K;g++) S.groupAlpha.push(alphaFromPre(S.groupPre[g],RES));
  bandDirty=true;
}
function rebuildOneGroup(k){
  S.groupPre[k]=new Float32Array(3*RES*RES);
  if(!S.layers[S.placed[k]].hidden)
    renderPre(groupAtomIdx(k).map(i=>S.obs[i]),RES,S.groupPre[k]);
  S.groupAlpha[k]=alphaFromPre(S.groupPre[k],RES);
  bandDirty=true;
}
/* frequency-band buffers, built lazily only when a band gain != 1.
   Same visibility rule as the group buffers; render is linear in atom color,
   so gain*color == gain*contribution and Σ_b gain_b·bandPre_b is exact. */
function rebuildBandBuffers(){
  const K=S.placed.length;
  bandPre=[new Float32Array(3*RES*RES),new Float32Array(3*RES*RES),new Float32Array(3*RES*RES)];
  const groupOf=i=>{ const g=S.marg?believedGroup(i):S.gt[i]; return g>=0?g:K; };
  for(let i=0;i<S.obs.length;i++){
    const g=groupOf(i);
    if(g<K && S.layers[S.placed[g]].hidden) continue;
    renderPre([S.obs[i]],RES,bandPre[bandOf(S.obs[i][5])]);
  }
  bandDirty=false;
}
const sceneCtx=sceneC.getContext("2d");
const compositePre=new Float32Array(3*RES*RES);
const sceneImg=new ImageData(RES,RES);
function compMode(){ return document.querySelector('input[name=comp]:checked').value; }
function renderScene(){
  const K=S.placed.length;
  const gb=GAINS.band, gainsOn=gb[0]!==1||gb[1]!==1||gb[2]!==1;
  const bgOn=backdrop.custom||backdrop.img||GAINS.opacity!==1;
  if(compMode()==="field"){
    compositePre.fill(0);
    if(gainsOn){
      if(bandDirty) rebuildBandBuffers();
      for(let b=0;b<3;b++){
        const g=gb[b]; if(!g) continue;
        const buf=bandPre[b];
        for(let i=0;i<compositePre.length;i++) compositePre[i]+=g*buf[i];
      }
    } else {
      for(const buf of S.groupPre)
        for(let i=0;i<compositePre.length;i++) compositePre[i]+=buf[i];
    }
    sigmoidField(compositePre,RES,sceneImg.data);
    if(bgOn){
      alphaFromPre(compositePre,RES,fieldAlpha);
      blendOverBackdrop(sceneImg.data,fieldAlpha,GAINS.opacity,backdrop.img||backdrop.rgb,RES);
    }
  } else {
    // painter: clutter at the back, then placed layers by depth
    const order=[K, ...S.placed.map((li,k)=>k)
      .sort((a,b)=>S.layers[S.placed[a]].depth-S.layers[S.placed[b]].depth)];
    compositePainter(order,S.groupPre,S.groupAlpha,RES,sceneImg.data);
    if(bgOn){
      // union alpha of everything rendered (band gains are field-mode only)
      for(let i=0;i<RES*RES;i++){
        let keep=1;
        for(let q=0;q<=K;q++) keep*=1-S.groupAlpha[q][i];
        fieldAlpha[i]=1-keep;
      }
      blendOverBackdrop(sceneImg.data,fieldAlpha,GAINS.opacity,backdrop.img||backdrop.rgb,RES);
    }
  }
  sceneCtx.putImageData(sceneImg,0,0);
}

function w2p(x){return (x+1)/2*overC.width;}
function p2w(px){return px/overC.width*2-1;}

const ovAtoms=document.getElementById("ov-atoms"),ovOwn=document.getElementById("ov-own"),
      ovEnt=document.getElementById("ov-ent"),ovPose=document.getElementById("ov-pose"),
      ovHints=document.getElementById("ov-hints");
for(const el of [ovAtoms,ovOwn,ovEnt,ovPose,ovHints]) el.addEventListener("change",drawOverlay);
document.querySelectorAll('input[name=comp]').forEach(el=>
  el.addEventListener("change",()=>{renderScene();}));

function drawOverlay(){
  const ctx=overC.getContext("2d");
  ctx.clearRect(0,0,overC.width,overC.height);
  const px1=overC.width/CSS;
  const K=S.placed.length;
  const colOf=k=>S.layers[S.placed[k]];

  if(S.ownField && (ovOwn.checked||ovEnt.checked)){
    const {P,ent,support}=S.ownField;
    const im=ctx.createImageData(OWN_RES,OWN_RES);
    for(let i=0;i<OWN_RES*OWN_RES;i++){
      if(!support[i]) continue;
      let r=0,g=0,b=0,a=0;
      if(ovOwn.checked){
        let best=0;
        for(let k=1;k<=K;k++) if(P[k][i]>P[best][i]) best=k;
        const rgb=best===K?OUTLIER_RGB:colOf(best).rgb;
        r=rgb[0];g=rgb[1];b=rgb[2];a=90*P[best][i];
      }
      if(ovEnt.checked){
        const maxE=Math.log2(K+1);
        const e=Math.min(1,ent[i]/maxE), ea=160*e*e;
        if(ea>a){r=200;g=107;b=255;a=ea;}
      }
      im.data[4*i]=r;im.data[4*i+1]=g;im.data[4*i+2]=b;im.data[4*i+3]=a;
    }
    const tmp=document.createElement("canvas");
    tmp.width=tmp.height=OWN_RES;
    tmp.getContext("2d").putImageData(im,0,0);
    ctx.imageSmoothingEnabled=true;
    ctx.drawImage(tmp,0,0,overC.width,overC.height);
  }

  if(ovAtoms.checked){
    for(let i=0;i<S.obs.length;i++){
      const a=S.obs[i], g=believedGroup(i);
      if(g>=0 && S.layers[S.placed[g]].hidden) continue;
      let rgb=OUTLIER_RGB, alpha=0.5;
      if(g===-2){rgb=[150,155,168];alpha=0.55;}
      else if(g>=0){rgb=colOf(g).rgb;alpha=S.evid[i]?0.25+0.75*S.marg[i][g]:0.35;}
      else if(S.marg){alpha=0.25+0.55*S.marg[i][K];}
      const len=Math.max(3*px1,a[3]*overC.width*0.5);
      const cx=w2p(a[0]),cy=w2p(a[1]);
      const dx=Math.cos(a[2])*len/2,dy=Math.sin(a[2])*len/2;
      ctx.strokeStyle=`rgba(${rgb[0]},${rgb[1]},${rgb[2]},${alpha})`;
      ctx.lineWidth=1.6*px1;
      ctx.setLineDash(g>=0&&!S.evid[i]?[3*px1,3*px1]:[]);
      ctx.beginPath();ctx.moveTo(cx-dx,cy-dy);ctx.lineTo(cx+dx,cy+dy);ctx.stroke();
    }
    ctx.setLineDash([]);
  }

  if(ovHints.checked){
    for(let k=0;k<K;k++){
      const L=colOf(k);
      for(const h of L.hints){
        ctx.strokeStyle=L.color; ctx.lineWidth=1.2*px1; ctx.setLineDash([2*px1,3*px1]);
        ctx.beginPath();ctx.arc(w2p(h[0]),w2p(h[1]),HINT_SIG*overC.width/2,0,TAU);ctx.stroke();
        ctx.setLineDash([]);
        ctx.beginPath();ctx.arc(w2p(h[0]),w2p(h[1]),3*px1,0,TAU);
        ctx.fillStyle=L.color;ctx.fill();
      }
    }
  }

  if(ovPose.checked && S.mu){
    for(let k=0;k<K;k++){
      const mu=S.mu[k],Sg=S.Sig[k],L=colOf(k);
      const cx=w2p(mu[0]),cy=w2p(mu[1]);
      ctx.strokeStyle=L.color;ctx.lineWidth=1.2*px1;
      ctx.beginPath();
      ctx.moveTo(cx-7*px1,cy);ctx.lineTo(cx+7*px1,cy);
      ctx.moveTo(cx,cy-7*px1);ctx.lineTo(cx,cy+7*px1);ctx.stroke();
      const Ln=26*px1*Math.exp(mu[3]);
      ctx.beginPath();ctx.moveTo(cx,cy);
      ctx.lineTo(cx+Math.cos(mu[2])*Ln,cy+Math.sin(mu[2])*Ln);ctx.stroke();
      const coast=S.coastT[k], q=coast*coast*0.0012;
      const a11=Sg[0][0]+q,a12=Sg[0][1],a22=Sg[1][1]+q;
      const tr=a11+a22,det=a11*a22-a12*a12;
      const disc=Math.sqrt(Math.max(0,tr*tr/4-det));
      const l1=tr/2+disc,l2=Math.max(1e-12,tr/2-disc);
      const ang=Math.atan2(l1-a11,a12||1e-12);
      const ghost=L.hidden||S.covFrac[k]>0.7;
      ctx.save();ctx.translate(cx,cy);ctx.rotate(-ang+Math.PI/2);
      ctx.setLineDash(ghost?[5*px1,4*px1]:[]);
      ctx.beginPath();
      ctx.ellipse(0,0,2*Math.sqrt(l1)*overC.width/2,2*Math.sqrt(l2)*overC.width/2,0,0,TAU);
      ctx.stroke();ctx.restore();ctx.setLineDash([]);
      if(ghost){
        ctx.fillStyle=L.color;
        ctx.font=`${11*px1}px ${getComputedStyle(document.body).fontFamily}`;
        ctx.fillText("believed, unseen",cx+10*px1,cy-10*px1);
      }
    }
  }

  if(toolMode()==="erase"&&lastCursor){       // eraser brush cursor
    ctx.strokeStyle="rgba(255,120,110,0.9)";
    ctx.lineWidth=1.4*px1;ctx.setLineDash([4*px1,3*px1]);
    ctx.beginPath();
    ctx.arc(w2p(lastCursor[0]),w2p(lastCursor[1]),brushR()*overC.width/2,0,TAU);
    ctx.stroke();ctx.setLineDash([]);
  }
}

/* ------------- semantic factor from hints ------------- */
function makeSemLL(){
  const K=S.placed.length;
  let any=false;
  for(const li of S.placed) if(S.layers[li].hints.length) any=true;
  if(!any) return null;
  return (i,k)=>{
    const hs=S.layers[S.placed[k]].hints;
    if(!hs.length) return 0;
    let best=0;
    for(const h of hs){
      const d2=(S.obs[i][0]-h[0])**2+(S.obs[i][1]-h[1])**2;
      best=Math.max(best,Math.exp(-0.5*d2/(HINT_SIG*HINT_SIG)));
    }
    return HINT_W*(best-0.5);
  };
}

/* ------------- BP wiring + depth occlusion ------------- */
function currentTemplates(){ return S.placed.map(li=>S.layers[li].template); }

function computeEvidence(){
  const K=S.placed.length;
  if(!document.getElementById("auto-occ").checked || !S.assign){
    S.evid=S.obs.map((_,i)=>{
      const g=believedGroup(i);
      return !(g>=0 && S.layers[S.placed[g]].hidden);
    });
    S.covFrac=S.placed.map((li,k)=>S.layers[li].hidden?1:0);
    return;
  }
  const layersMeta=S.placed.map(li=>({depth:S.layers[li].depth,hidden:S.layers[li].hidden}));
  const {mask,covFrac}=autoHidden(S.obs,S.assign,layersMeta,S.groupAlpha,RES);
  S.evid=mask.map(m=>!m);
  S.covFrac=covFrac;
}

function runBind(opts={}){
  const hiddenMask=S.evid.map(e=>!e);
  const frames=[];
  const res=bpBind(currentTemplates(),S.obs,{
    iters:opts.iters??40,
    clampPose:opts.clampPose??null,
    hiddenMask,
    semLL:makeSemLL(),
    onIter:(it,marg,mu,Sig)=>{ if(opts.animate) frames.push({
      marg,mu:mu.map(m=>m.slice()),Sig:Sig.map(M=>M.map(r=>r.slice()))}); },
  });
  return {res,frames};
}

function bind(animate=true){
  if(S.phase==="binding"||!S.placed.length) return;
  S.assign=null;
  eraseStack=[]; updateEraseButtons();   // erase history is stale once BP re-runs
  S.evid=S.obs.map(()=>true);      // full re-bind: everything is evidence again
  for(const li of S.placed) if(S.layers[li].hidden){
    // user-hidden layers stay evidence-free
    // (their atoms are excluded per-atom below via gt at soup time)
  }
  setPhase("binding");
  setTimeout(()=>{
    const {res,frames}=runBind({iters:40,animate});
    if(!animate){finishBind(res);return;}
    let f=0;
    const meter=document.querySelector("#bind-meter > div");
    const step=()=>{
      if(f<frames.length){
        S.marg=frames[f].marg;S.mu=frames[f].mu;S.Sig=frames[f].Sig;
        updateAssign();
        meter.style.width=(100*(f+1)/frames.length)+"%";
        document.getElementById("m-it").textContent=(f+1);
        drawOverlay();updatePanels();
        f++;requestAnimationFrame(step);
      } else finishBind(res);
    };
    step();
  },30);
}
function finishBind(res){
  S.marg=res.marg;S.mu=res.mu;S.Sig=res.Sig;
  updateAssign();
  rebuildGroupBuffers();
  occlusionRefresh(true);
  renderScene();refreshOwnership();
  setPhase("bound");
  drawOverlay();updatePanels();renderLayerList();
}

/* recompute evidence from the depth stack; if it changed, refresh marginals
   with all poses clamped (occlusion changes evidence, not where things are) */
function occlusionRefresh(silent){
  const before=S.evid.join("");
  computeEvidence();
  if(S.evid.join("")===before) return;
  const clamp=S.mu.map(m=>m.slice());
  const {res}=runBind({iters:8,clampPose:clamp});
  S.marg=res.marg;
  updateAssign();
  // coasting for heavily covered layers
  for(let k=0;k<S.placed.length;k++)
    S.coastT[k]=(S.covFrac[k]>0.7||S.layers[S.placed[k]].hidden)?S.coastT[k]+1:0;
  if(!silent){drawOverlay();updatePanels();renderLayerList();}
}

function refreshOwnership(){
  if(!S.marg){S.ownField=null;return;}
  const K=S.placed.length;
  const vis=[],visMarg=[];
  for(let i=0;i<S.obs.length;i++){
    const g=believedGroup(i);
    if(g>=0&&S.layers[S.placed[g]].hidden) continue;
    vis.push(S.obs[i]);visMarg.push(S.marg[i]);
  }
  S.ownField=ownershipField(vis,visMarg,K,OWN_RES);
}

function resettle(k,clampXi){
  const clamp=S.placed.map(()=>null);clamp[k]=clampXi;
  const {res}=runBind({iters:10,clampPose:clamp});
  S.marg=res.marg;S.mu=res.mu;S.Sig=res.Sig;
  S.mu[k]=clampXi.slice();
  updateAssign();
  rebuildGroupBuffers();
  occlusionRefresh(true);
  renderScene();refreshOwnership();
  drawOverlay();updatePanels();renderLayerList();
  document.getElementById("m-it").textContent="10 (re-settle)";
}

/* ------------- interventions ------------- */
function applyGesture(k,g){
  for(const i of groupAtomIdx(k)) S.obs[i]=transformAtoms([S.obs[i]],g)[0];
  S.mu[k]=composePose(g,S.mu[k]);
  rebuildOneGroup(k);
  renderScene();drawOverlay();updatePanels();
}

/* ------------- eraser (Bet 9) -------------
   Deleting an atom = filtering every per-atom parallel array by the brush
   mask. Order of atoms carries no meaning anywhere (additive render, per-atom
   marginals), so undo can simply re-append the removed records.
   Undo is valid until the next Bind/Scramble/place/remove (those rebuild or
   re-infer the per-atom state). "Burn" additionally removes the source atom
   from the layer TEMPLATE, so the erase survives scene rebuilds. */
function eraseAt(wx,wy,stroke){
  const skip=i=>{ const g=believedGroup(i); return g>=0&&S.layers[S.placed[g]].hidden; };
  const mask=eraseMask(S.obs,wx,wy,brushR(),skip);
  let any=false; for(const m of mask) if(m){any=true;break;}
  if(!any) return;
  const kObs=[],kGt=[],kSrc=[],kEvid=[],
        kAssign=S.assign?[]:null, kMarg=S.marg?[]:null;
  for(let i=0;i<S.obs.length;i++){
    if(mask[i]){
      stroke.atoms.push({a:S.obs[i],gt:S.gt[i],src:S.src[i],evid:S.evid[i],
        assign:S.assign?S.assign[i]:null, marg:S.marg?S.marg[i]:null});
    } else {
      kObs.push(S.obs[i]);kGt.push(S.gt[i]);kSrc.push(S.src[i]);kEvid.push(S.evid[i]);
      if(kAssign)kAssign.push(S.assign[i]);
      if(kMarg)kMarg.push(S.marg[i]);
    }
  }
  S.obs=kObs;S.gt=kGt;S.src=kSrc;S.evid=kEvid;
  if(kAssign)S.assign=kAssign;
  if(kMarg)S.marg=kMarg;
  rebuildGroupBuffers();renderScene();drawOverlay();updatePanels();
}
function commitStroke(stroke){
  if(!stroke.atoms.length) return;
  if(document.getElementById("erase-burn").checked){
    for(const rec of stroke.atoms){
      if(!rec.src) continue;                       // clutter has no template
      const L=S.layers[rec.src.li];
      const idx=L.template.indexOf(rec.src.ref);
      if(idx>=0){L.template.splice(idx,1);stroke.tmpl.push(rec.src);}
    }
  }
  eraseStack.push(stroke);
  updateEraseButtons();
  refreshOwnership();drawOverlay();renderLayerList();renderLibrary();
}
function undoErase(redraw=true){
  const stroke=eraseStack.pop();
  if(!stroke) return;
  for(const t of stroke.tmpl) S.layers[t.li].template.push(t.ref);
  for(const rec of stroke.atoms){
    S.obs.push(rec.a);S.gt.push(rec.gt);S.src.push(rec.src);S.evid.push(rec.evid);
    if(S.assign)S.assign.push(rec.assign??-1);
    if(S.marg)S.marg.push(rec.marg);
  }
  updateEraseButtons();
  if(redraw){
    rebuildGroupBuffers();renderScene();refreshOwnership();
    drawOverlay();updatePanels();renderLayerList();renderLibrary();
  }
}
function restoreAllErases(){
  while(eraseStack.length) undoErase(false);
  rebuildGroupBuffers();renderScene();refreshOwnership();
  drawOverlay();updatePanels();renderLayerList();renderLibrary();
}

/* ------------- pointer interaction ------------- */
let drag=null;
overC.addEventListener("pointerdown",e=>{
  const rect=overC.getBoundingClientRect();
  const wx=p2w((e.clientX-rect.left)*overC.width/rect.width);
  const wy=p2w((e.clientY-rect.top)*overC.width/rect.width);
  if(e.shiftKey){                       // semantic hint for the selected layer
    const li=S.selected;
    if(li>=0&&S.layers[li].placed){
      S.layers[li].hints.push([wx,wy]);
      drawOverlay();renderLayerList();
      document.getElementById("prompt-log").textContent=
        `hint added for ${S.layers[li].name} — Bind applies it as a location prior.`;
    }
    return;
  }
  if(toolMode()==="erase"){                 // erase works in soup AND bound
    drag={erase:true,stroke:{atoms:[],tmpl:[]}};
    overC.setPointerCapture(e.pointerId);
    lastCursor=[wx,wy];
    eraseAt(wx,wy,drag.stroke);
    return;
  }
  if(S.phase!=="bound") return;
  let best=-1,bd=0.12*0.12;
  for(let i=0;i<S.obs.length;i++){
    const g=believedGroup(i);
    if(g<0) continue;
    if(S.layers[S.placed[g]].hidden) continue;
    const d=(S.obs[i][0]-wx)**2+(S.obs[i][1]-wy)**2;
    if(d<bd){bd=d;best=i;}
  }
  let k=best>=0?believedGroup(best):-1;
  if(k<0) for(let kk=0;kk<S.placed.length;kk++)
    if((S.layers[S.placed[kk]].hidden||S.covFrac[kk]>0.7)&&
       (S.mu[kk][0]-wx)**2+(S.mu[kk][1]-wy)**2<0.05*0.05) k=kk;
  if(k<0) return;
  drag={k,lx:wx,ly:wy,moved:false};
  overC.classList.add("dragging");
  overC.setPointerCapture(e.pointerId);
});
overC.addEventListener("pointermove",e=>{
  const rect=overC.getBoundingClientRect();
  const wx=p2w((e.clientX-rect.left)*overC.width/rect.width);
  const wy=p2w((e.clientY-rect.top)*overC.width/rect.width);
  if(toolMode()==="erase") lastCursor=[wx,wy];
  if(!drag){ if(toolMode()==="erase") drawOverlay(); return; }
  if(drag.erase){ eraseAt(wx,wy,drag.stroke); return; }
  const dx=wx-drag.lx,dy=wy-drag.ly;
  if(dx||dy){applyGesture(drag.k,gestureTranslate(dx,dy));drag.lx=wx;drag.ly=wy;drag.moved=true;}
});
overC.addEventListener("pointerup",e=>{
  if(!drag) return;
  if(drag.erase){ commitStroke(drag.stroke); drag=null; return; }
  overC.classList.remove("dragging");
  if(drag.moved) resettle(drag.k,S.mu[drag.k]);
  drag=null;
});
overC.addEventListener("pointerleave",()=>{
  if(lastCursor){ lastCursor=null; drawOverlay(); }
});
overC.addEventListener("wheel",e=>{
  if(S.phase!=="bound") return;
  const rect=overC.getBoundingClientRect();
  const wx=p2w((e.clientX-rect.left)*overC.width/rect.width);
  const wy=p2w((e.clientY-rect.top)*overC.width/rect.width);
  let k=-1,bd=0.16*0.16;
  for(let kk=0;kk<S.placed.length;kk++){
    const d=(S.mu[kk][0]-wx)**2+(S.mu[kk][1]-wy)**2;
    if(d<bd){bd=d;k=kk;}
  }
  if(k<0) return;
  e.preventDefault();
  const c=[S.mu[k][0],S.mu[k][1]];
  const g=e.shiftKey?gestureScaleAbout(c,e.deltaY>0?-0.05:0.05)
                    :gestureRotateAbout(c,e.deltaY>0?0.08:-0.08);
  applyGesture(k,g);
  clearTimeout(overC._wt);
  overC._wt=setTimeout(()=>resettle(k,S.mu[k]),350);
},{passive:false});

/* ------------- panels ------------- */
function setPhase(p){
  S.phase=p;
  const lamp=document.getElementById("state-lamp");
  lamp.className=p==="soup"?"soup":p==="binding"?"binding":"bound";
  lamp.textContent=p==="soup"?"ATOM SOUP":p==="binding"?"BELIEFS SETTLING":"BOUND — GRABBABLE";
  document.getElementById("btn-bind").disabled=p==="binding"||!S.placed.length;
}

function renderLayerList(){
  const el=document.getElementById("layer-list");
  el.innerHTML="";
  const byDepth=[...S.placed].map((li,k)=>({li,k}))
    .sort((a,b)=>S.layers[b.li].depth-S.layers[a.li].depth);
  for(const {li,k} of byDepth){
    const L=S.layers[li];
    const idx=S.assign?groupAtomIdx(k):[];
    const conf=idx.length?idx.reduce((a,i)=>a+(S.evid[i]?S.marg[i][k]:0),0)/Math.max(1,idx.filter(i=>S.evid[i]).length):0;
    const cov=S.covFrac[k]||0;
    const d=document.createElement("div");
    d.className="layer"+(S.selected===li?" sel":"");
    d.innerHTML=`
      <div class="name" data-li="${li}">
        <span class="swatch" style="background:${L.color}"></span>
        <span>${L.name}</span>
        <span class="dim">${idx.length||L.template.length} atoms${L.hints.length?` · ${L.hints.length} hint${L.hints.length>1?"s":""}`:""}</span>
        <span class="spacer"></span>
        <div class="belief-bar"><div style="width:${100*conf}%"></div></div>
      </div>
      <div class="pose">${S.mu?`t=(${S.mu[k][0].toFixed(2)}, ${S.mu[k][1].toFixed(2)}) \u03c1=${(S.mu[k][2]*180/Math.PI).toFixed(0)}\u00b0 s=${Math.exp(S.mu[k][3]).toFixed(2)}`:"pose: unbound"}${cov>0.05?` · <span style="color:var(--entropy)">${(100*cov).toFixed(0)}% occluded${S.coastT[k]?`, coasting ${S.coastT[k]}`:""}</span>`:""}</div>
      <div class="ctl">
        <button data-li="${li}" data-op="rotl">&#8634;</button>
        <button data-li="${li}" data-op="rotr">&#8635;</button>
        <button data-li="${li}" data-op="grow">+</button>
        <button data-li="${li}" data-op="shrink">&minus;</button>
        <button data-li="${li}" data-op="front">front</button>
        <button data-li="${li}" data-op="back">back</button>
        <button data-li="${li}" data-op="hide">${L.hidden?"reveal":"hide"}</button>
        ${L.hints.length?`<button data-li="${li}" data-op="clearhints">hints&nbsp;&#10005;</button>`:""}
        <button data-li="${li}" data-op="remove">&#10005;</button>
      </div>`;
    el.appendChild(d);
  }
  if(!byDepth.length)
    el.innerHTML='<div class="dim" style="font-size:11px">no layers placed — place from the library or spawn one</div>';
}
document.getElementById("layer-list").addEventListener("click",e=>{
  const nm=e.target.closest(".name");
  if(nm&&!e.target.closest("button")){
    S.selected=+nm.dataset.li===S.selected?-1:+nm.dataset.li;
    renderLayerList();return;
  }
  const b=e.target.closest("button");if(!b)return;
  const li=+b.dataset.li,op=b.dataset.op;
  const k=S.placed.indexOf(li);
  if(op==="remove"){removeLayer(li);return;}
  if(op==="clearhints"){S.layers[li].hints=[];drawOverlay();renderLayerList();return;}
  if(op==="front"||op==="back"){
    S.layers[li].depth=op==="front"?nextDepth++:(Math.min(...S.placed.map(x=>S.layers[x].depth))-1);
    if(S.phase==="bound"){rebuildGroupBuffers();occlusionRefresh(false);renderScene();refreshOwnership();}
    renderLayerList();return;
  }
  if(S.phase!=="bound")return;
  if(op==="hide"){
    S.layers[li].hidden=!S.layers[li].hidden;
    rebuildGroupBuffers();occlusionRefresh(false);renderScene();refreshOwnership();drawOverlay();renderLayerList();
    return;
  }
  const c=[S.mu[k][0],S.mu[k][1]];
  if(op==="rotl"){applyGesture(k,gestureRotateAbout(c,-Math.PI/12));resettle(k,S.mu[k]);}
  if(op==="rotr"){applyGesture(k,gestureRotateAbout(c,Math.PI/12));resettle(k,S.mu[k]);}
  if(op==="grow"){applyGesture(k,gestureScaleAbout(c,0.12));resettle(k,S.mu[k]);}
  if(op==="shrink"){applyGesture(k,gestureScaleAbout(c,-0.12));resettle(k,S.mu[k]);}
});

function renderLibrary(){
  const el=document.getElementById("library");
  el.innerHTML="";
  S.layers.forEach((L,li)=>{
    if(L.placed) return;
    const c=document.createElement("span");
    c.className="chip";
    c.innerHTML=`<span class="swatch" style="background:${L.color}"></span>${L.name}
      <span class="dim">${L.template.length}</span>
      <button data-li="${li}" data-op="place" title="place">+</button>`;
    el.appendChild(c);
  });
}
document.getElementById("library").addEventListener("click",e=>{
  const b=e.target.closest("button");if(!b)return;
  placeLayer(+b.dataset.li);
});

function updatePanels(){
  document.getElementById("m-n").textContent=S.obs.length;
  const K=S.placed.length;
  if(!S.marg){
    document.getElementById("m-acc").textContent="—";
    document.getElementById("m-ent").textContent="—";
    return;
  }
  let correct=0;
  for(let i=0;i<S.gt.length;i++) if(believedGroup(i)===S.gt[i]) correct++;
  document.getElementById("m-acc").textContent=(100*correct/S.gt.length).toFixed(1)+"%";
  const ent=atomEntropy(S.marg);
  document.getElementById("m-ent").textContent=
    (ent.reduce((a,x)=>a+x,0)/ent.length).toFixed(2)+" bits";
}

/* ------------- spawn: server endpoints ------------- */
const spawnStatus=document.getElementById("spawn-status");
async function gradioCall(name,data){
  const base=location.pathname.includes("/studio/")?"..":"";
  const r=await fetch(`${base}/gradio_api/call/${name}`,{
    method:"POST",headers:{"Content-Type":"application/json"},
    body:JSON.stringify({data})});
  const {event_id}=await r.json();
  const resp=await fetch(`${base}/gradio_api/call/${name}/${event_id}`);
  const text=await resp.text();
  const lines=text.split("\n").filter(l=>l.startsWith("data:"));
  if(!lines.length) throw new Error("no data from server");
  const payload=JSON.parse(lines[lines.length-1].slice(5));
  if(payload==null||payload.error) throw new Error(payload?.error||"server error");
  return JSON.parse(payload[0]);
}
function addGenerated(layer,fallbackName){
  const name=(layer.ledger&&layer.ledger.prompt)
    ? (layer.ledger.attention&&layer.ledger.attention.token!=="(all content tokens)"
        ? layer.ledger.attention.token : layer.ledger.prompt.split(/[ ,]/)[1]||fallbackName)
    : fallbackName;
  addLayer(name,layer.atoms,true);
  spawnStatus.textContent=`layer "${name}": ${layer.atoms.length} atoms · ${layer.ledger.status}`+
    (layer.ledger.attention?` · matte kept ${layer.ledger.attention.atoms_after_matte}/${layer.ledger.attention.atoms_before_matte}`:"");
}
document.getElementById("btn-spawn-text").addEventListener("click",async()=>{
  const prompt=document.getElementById("spawn-prompt").value.trim();
  const token=document.getElementById("spawn-token").value.trim();
  if(!prompt){spawnStatus.textContent="write a prompt first";return;}
  spawnStatus.textContent="distilling on the server (GPU, minutes)\u2026";
  try{
    const layer=await gradioCall("layer_from_text",[prompt,"",192,900,30,token,0.35]);
    addGenerated(layer,"generated");
  }catch(err){spawnStatus.textContent="distill failed: "+err.message+
    " (needs a GPU Space; on CPU use Fit or paste JSON)";}
});
document.getElementById("btn-spawn-img").addEventListener("click",async()=>{
  const f=document.getElementById("spawn-file").files[0];
  if(!f){spawnStatus.textContent="choose an image first";return;}
  spawnStatus.textContent="fitting atoms to the image (CPU, ~1 min)\u2026";
  try{
    const b64=await new Promise((res,rej)=>{
      const img=new Image();
      img.onload=()=>{
        const c=document.createElement("canvas");
        const s=Math.min(1,160/Math.max(img.width,img.height));
        c.width=Math.round(img.width*s);c.height=Math.round(img.height*s);
        c.getContext("2d").drawImage(img,0,0,c.width,c.height);
        res(c.toDataURL("image/png").split(",")[1]);
      };
      img.onerror=rej;
      img.src=URL.createObjectURL(f);
    });
    const layer=await gradioCall("layer_from_image_b64",[b64,140,400]);
    addGenerated(layer,f.name.replace(/\.[^.]+$/,""));
  }catch(err){spawnStatus.textContent="fit failed: "+err.message+
    " (is this page running from the Space? standalone files can only paste JSON)";}
});
document.getElementById("btn-spawn-json").addEventListener("click",()=>{
  try{
    const raw=JSON.parse(document.getElementById("spawn-json").value);
    const atoms=raw.atoms||raw;
    if(!Array.isArray(atoms)||atoms[0].length!==10) throw new Error("expect [[10 fields]...]");
    addLayer("pasted-"+nextId,atoms,true);
    spawnStatus.textContent=`pasted layer: ${atoms.length} atoms`;
    document.getElementById("spawn-json").value="";
  }catch(err){spawnStatus.textContent="bad JSON: "+err.message;}
});

/* ------------- prompt as intervention ------------- */
const promptLog=document.getElementById("prompt-log");
function layerByName(part){
  for(let k=0;k<S.placed.length;k++)
    if(part.includes(S.layers[S.placed[k]].name.toLowerCase())) return k;
  return -1;
}
function localParse(text){
  const t=text.toLowerCase(),ops=[];
  for(const part of t.split(/,|;| and /)){
    const k=layerByName(part);
    if(k<0) continue;
    if(/hide|occlude/.test(part)){ops.push({op:"hide",k});continue;}
    if(/show|reveal|unhide/.test(part)){ops.push({op:"show",k});continue;}
    if(/front|top|forward/.test(part)&&/bring|put|move|send/.test(part)){ops.push({op:"front",k});continue;}
    if(/back|behind|bottom/.test(part)&&/send|put|move|push/.test(part)){ops.push({op:"back",k});continue;}
    const deg=part.match(/(-?\d+)\s*(deg|\u00b0)?/);
    if(/rotate|turn|spin/.test(part))
      ops.push({op:"rotate",k,deg:deg?+deg[1]:30*(/left|counter|ccw/.test(part)?-1:1)});
    if(/scale|grow|bigger|larger|shrink|smaller/.test(part))
      ops.push({op:"scale",k,ds:/shrink|smaller/.test(part)?-0.15:0.15});
    if(/move|push|slide|put|drag/.test(part)){
      let dx=0,dy=0;const step=0.22;
      if(/left/.test(part))dx-=step;
      if(/right/.test(part))dx+=step;
      if(/up|top/.test(part))dy-=step;
      if(/down|bottom/.test(part))dy+=step;
      if(/center|middle/.test(part))ops.push({op:"moveto",k,x:0,y:0});
      else if(dx||dy)ops.push({op:"move",k,dx,dy});
    }
  }
  return ops;
}
async function claudeParse(text){
  const names=S.placed.map(li=>S.layers[li].name);
  const sceneDesc=S.placed.map((li,k)=>
    `${S.layers[li].name}: t=(${S.mu[k][0].toFixed(2)},${S.mu[k][1].toFixed(2)}) rho=${S.mu[k][2].toFixed(2)} scale=${Math.exp(S.mu[k][3]).toFixed(2)} depth=${S.layers[li].depth} hidden=${S.layers[li].hidden}`).join("; ");
  const resp=await fetch("https://api.anthropic.com/v1/messages",{
    method:"POST",headers:{"Content-Type":"application/json"},
    body:JSON.stringify({model:"claude-sonnet-4-6",max_tokens:1000,
      messages:[{role:"user",content:
`You control a probabilistic layered scene editor. Coordinates x,y in [-1,1], y grows DOWNWARD. Higher depth = in front. Layers: ${sceneDesc}.
User command: "${text}"
Respond ONLY with a JSON array (no prose, no fences) of ops:
{"op":"move","object":<name>,"dx":n,"dy":n} {"op":"moveto","object":<name>,"x":n,"y":n}
{"op":"rotate","object":<name>,"deg":n} {"op":"scale","object":<name>,"factor":n}
{"op":"front","object":<name>} {"op":"back","object":<name>}
{"op":"hide","object":<name>} {"op":"show","object":<name>}
Valid names: ${JSON.stringify(names)}`}]})});
  const data=await resp.json();
  const txt=data.content.filter(c=>c.type==="text").map(c=>c.text).join("");
  const arr=JSON.parse(txt.replace(/```json|```/g,"").trim());
  return arr.map(o=>{
    const k=S.placed.findIndex(li=>S.layers[li].name===o.object);
    if(k<0)return null;
    if(o.op==="move")return{op:"move",k,dx:o.dx,dy:o.dy};
    if(o.op==="moveto")return{op:"moveto",k,x:o.x,y:o.y};
    if(o.op==="rotate")return{op:"rotate",k,deg:o.deg};
    if(o.op==="scale")return{op:"scale",k,ds:Math.log(o.factor)};
    return{op:o.op,k};
  }).filter(Boolean);
}
function execOps(ops){
  if(!ops.length){promptLog.textContent="Parsed no intervention. Layers: "+
    S.placed.map(li=>S.layers[li].name).join(", ")+". Verbs: move/rotate/scale/hide/show/front/back.";return;}
  const touched=new Set();
  for(const o of ops){
    const li=S.placed[o.k];
    if(o.op==="hide"&&!S.layers[li].hidden){S.layers[li].hidden=true;continue;}
    if(o.op==="show"&&S.layers[li].hidden){S.layers[li].hidden=false;continue;}
    if(o.op==="front"){S.layers[li].depth=nextDepth++;continue;}
    if(o.op==="back"){S.layers[li].depth=Math.min(...S.placed.map(x=>S.layers[x].depth))-1;continue;}
    const c=[S.mu[o.k][0],S.mu[o.k][1]];
    if(o.op==="move"){applyGesture(o.k,gestureTranslate(o.dx,o.dy));touched.add(o.k);}
    if(o.op==="moveto"){applyGesture(o.k,gestureTranslate(o.x-c[0],o.y-c[1]));touched.add(o.k);}
    if(o.op==="rotate"){applyGesture(o.k,gestureRotateAbout(c,o.deg*Math.PI/180));touched.add(o.k);}
    if(o.op==="scale"){applyGesture(o.k,gestureScaleAbout(c,o.ds));touched.add(o.k);}
  }
  for(const k of touched) resettle(k,S.mu[k]);
  rebuildGroupBuffers();occlusionRefresh(true);renderScene();refreshOwnership();
  drawOverlay();updatePanels();renderLayerList();
  promptLog.textContent="Clamped: "+ops.map(o=>`${o.op} ${S.layers[S.placed[o.k]].name}`).join(", ")+
    " — beliefs re-settled around the intervention.";
}
async function doPrompt(){
  if(S.phase!=="bound"){promptLog.textContent="Bind first — there is nothing to address in a soup.";return;}
  const text=document.getElementById("prompt").value.trim();
  if(!text)return;
  let ops=localParse(text);
  if(!ops.length){
    promptLog.textContent="Local grammar found nothing; asking Claude\u2026";
    try{ops=await claudeParse(text);}
    catch{promptLog.textContent="Claude unavailable outside claude.ai — try: move/rotate/scale/hide/front/back + a layer name.";return;}
  }
  execOps(ops);
}
document.getElementById("btn-prompt").addEventListener("click",doPrompt);
document.getElementById("prompt").addEventListener("keydown",e=>{if(e.key==="Enter")doPrompt();});
document.getElementById("auto-occ").addEventListener("change",()=>{
  if(S.phase==="bound"){occlusionRefresh(false);renderScene();}
});

/* ------------- edit & look wiring (Bet 9) ------------- */
document.getElementById("btn-undo-erase").addEventListener("click",()=>undoErase());
document.getElementById("btn-restore-erase").addEventListener("click",restoreAllErases);
document.querySelectorAll('input[name=tool]').forEach(el=>el.addEventListener("change",()=>{
  stage.classList.toggle("erasing",toolMode()==="erase");
  if(toolMode()!=="erase") lastCursor=null;
  drawOverlay();
}));
document.querySelectorAll('input[name=brush]').forEach(el=>el.addEventListener("change",drawOverlay));
document.getElementById("bg-color").addEventListener("input",e=>{
  const h=e.target.value;
  backdrop.rgb=[parseInt(h.slice(1,3),16),parseInt(h.slice(3,5),16),parseInt(h.slice(5,7),16)];
  backdrop.custom=true;renderScene();
});
document.getElementById("bg-file").addEventListener("change",e=>{
  const f=e.target.files[0];if(!f)return;
  const img=new Image();
  img.onload=()=>{
    const c=document.createElement("canvas");c.width=c.height=RES;
    const sc=Math.max(RES/img.width,RES/img.height);      // cover-crop
    c.getContext("2d").drawImage(img,(RES-img.width*sc)/2,(RES-img.height*sc)/2,img.width*sc,img.height*sc);
    backdrop.img=c.getContext("2d").getImageData(0,0,RES,RES).data;
    backdrop.custom=true;renderScene();
    URL.revokeObjectURL(img.src);
  };
  img.src=URL.createObjectURL(f);
});
document.getElementById("btn-bg-clear").addEventListener("click",()=>{
  backdrop.img=null;document.getElementById("bg-file").value="";
  renderScene();
});
for(const [id,set] of [
  ["g-coarse",v=>GAINS.band[0]=v],["g-mid",v=>GAINS.band[1]=v],
  ["g-fine",v=>GAINS.band[2]=v],["g-op",v=>GAINS.opacity=v]]){
  const el=document.getElementById(id);
  el.addEventListener("input",()=>{
    const v=el.value/100; set(v);
    document.getElementById(id+"-v").textContent=v.toFixed(2);
    renderScene();
  });
}

/* ------------- boot ------------- */
document.getElementById("btn-scramble").addEventListener("click",scramble);
document.getElementById("btn-bind").addEventListener("click",()=>bind(true));
addLayer("tractor",BUILTINS.tractor,false);
addLayer("star",BUILTINS.star,false);
addLayer("boat",BUILTINS.boat,false);
S.layers[0].placed=true;S.layers[0].depth=nextDepth++;S.layers[0].pose=[0.3,-0.25,0.3,Math.log(0.55)];
S.layers[1].placed=true;S.layers[1].depth=nextDepth++;S.layers[1].pose=[-0.4,0.35,-0.9,Math.log(0.5)];
fitStage();
rebuildScene();
</script>
</body>
</html>