for(let size=2;size<=n;size<<=1){ const h=size>>1, st=n/size;
        for(let s=0;s<n;s+=size) for(let k=0;k<h;k++){ const c=cs[k*st], si=sn[k*st], a=s+k, b=a+h, tr=re[b]*c-im[b]*si, ti=re[b]*si+im[b]*c;
          re[b]=re[a]-tr; im[b]=im[a]-ti; re[a]+=tr; im[a]+=ti; } }
      for(let k=0;k<half;k++){ sm[k]=0.45*sm[k]+0.55*Math.hypot(re[k],im[k])/n; out[k]=sm[k]>0?20*Math.log10(sm[k]):-1000; } } }; }
const breathe=()=>new Promise(r=>{ const c=new MessageChannel(); c.port1.onmessage=()=>{ c.port1.close(); r(); }; c.port2.postMessage(0); });
const mmss=s=>{ s=Math.max(0,Math.round(s)); return Math.floor(s/60)+':'+String(s%60).padStart(2,'0'); };
let renderStop=false;
async function renderVideo(){
  if(rendering){ renderStop=true; stat.textContent='stopping the render…'; return; }
  if(!SONG||!SONG.buf){ stat.textContent='LOAD a song first'; return; }
  if(recording){ stat.textContent='a take is recording: stop it first'; return; }
  if(typeof CleanRec==='undefined'||!CleanRec.render||!CleanRec.ok()){ stat.textContent='this browser cannot render (it needs WebCodecs: Chrome or Edge on a computer)'; return; }

  const P=CleanRec.plan?await CleanRec.plan({dur:SONG.buf.duration,pos:(SONG.aud&&SONG.aud.currentTime)||0,fps:FPS,head:HEAD,tail:TAIL,say:t=>{ stat.textContent=t; }})
                       :{light:false,size:RS.size,mbps:mbps(),from:0,len:SONG.buf.duration,whole:true,slow:''};
  if(!P) return; const slow=P.slow||'';
  pauseAll(''); const fps=FPS, per=Math.max(1,Math.round(SIM/fps)), buf=SONG.buf, len=buf.duration, sr=buf.sampleRate;
  const ch=Math.min(2,buf.numberOfChannels), pcm=[...Array(ch)].map((_,c)=>buf.getChannelData(c));
  rendering=true; renderStop=false; renderBtn.classList.add('on'); renderBtn.textContent='■ STOP RENDER'; stat.textContent='⏺ RENDER — getting the encoder ready…';
  const keep={AN,SPEC,TD}; let msg='', R=null, sleep=()=>{};
  try{ if(CleanRec.awake) sleep=await CleanRec.awake(); }catch(e){}
  try{
    const STEPS=Math.ceil((HEAD+len+TAIL)*SIM), K0=P.whole||!(P.from>0)?0:Math.round((HEAD+P.from)*SIM/per)*per, KEND=P.whole?STEPS:Math.min(STEPS,K0+Math.round((P.len+(K0?0:HEAD))*SIM));
    R=await CleanRec.render({canvas:cv,w:P.size,h:P.size,fps,mbps:P.mbps,head:HEAD-K0/SIM,audio:{pcm,sr,ch}});
    if(!R){ msg='this browser cannot render '+P.size+'² at '+fps+' fps'; return; }
    const ears=makeEars(buf); AN=ears; SPEC=new Float32Array(ears.frequencyBinCount); TD=new Float32Array(ears.fftSize);
    sizeTo(P.size); freshScene(); PLATE.S.D2=RENDER_D2; playing=false;
    const steps=Math.ceil((HEAD+len+TAIL)*SIM), hk=Math.round(HEAD*SIM), frames=Math.ceil((KEND-K0)/per), w0=performance.now(); let f=0, ok=true, pure=false;
    for(let k=0;k<KEND;k++){ const t=k/SIM;
      if(k===hk) begin(len,t,true);
      ears.seek(t-HEAD); pure=advance(1/SIM,t,t);
      if(k%per===0){ drawScene(t); if(k>=K0){ ok=await R.frame(f++); if(!ok) break; } }
      if(k%30===0){ const done=f/frames, el=(performance.now()-w0)/1000;
        stat.textContent=k<K0?'⏺ RENDER — getting to '+mmss(K0/SIM)+' (nothing filmed yet) · '+mmss(t)+slow:'⏺ RENDER'+(P.light?' LIGHT':'')+' · '+Math.round(done*100)+'% · '+mmss(t)+' of '+mmss(KEND/SIM)+' · '+fps+' fps'+(done>0.02?' · about '+mmss(el/done*(1-done))+' left':'')+slow;
        if(playing) readout(t,pure); else read('<b>THE DRUM</b> · at rest');
        await breathe(); if(renderStop) break; } }
    if(renderStop||!ok){ R.cancel(); msg=renderStop?'render stopped · nothing was saved':'the encoder stopped at frame '+f+' · nothing was saved'; return; }
    stat.textContent='⏺ RENDER — closing the file…';
    const res=await R.finish(f/fps);
    if(!res||!res.blob){ msg='the MP4 could not be closed'+(res&&res.err?': '+res.err:''); return; }
    const url=URL.createObjectURL(res.blob), a=document.createElement('a'); a.href=url; a.download='render-DRUM-'+new Date().toISOString().replace(/[:.]/g,'-')+(P.light?'-light-'+P.size:'')+'.mp4'; a.click(); setTimeout(()=>URL.revokeObjectURL(url),4000);
    msg='rendered · MP4 · '+res.fps+' fps · '+res.frames+' frames · '+mmss(res.frames/res.fps)+' · in '+mmss((performance.now()-w0)/1000)+' · nothing skipped'+(res.aerr?' · ⚠ the sound encoder complained':'')+' · nothing uploaded';
  }catch(e){ try{ if(R) R.cancel(); }catch(_){} msg='the render stopped: '+(e&&e.message||e); }
  finally{ sleep(); AN=keep.AN; SPEC=keep.SPEC; TD=keep.TD; delete PLATE.S.D2; playing=false; rendering=false; PLATE.rest(false);
    renderBtn.classList.remove('on'); renderBtn.textContent='⏺ RENDER'; last=performance.now()/1000; fit(); stat.textContent=msg; } }
renderBtn.onclick=renderVideo;
window.__PLATE=PLATE; window.__D=D; window.__E=E; window.__VOICE=VOICE; window.__VOICES=VOICES; window.__BES=BES;
})();
</script>
</body>
</html>