quimbot/docs/gallery/waveinterference.html at main · milwrite/quimbot · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Wave Interference</title>
<style>
*{margin:0;padding:0;box-sizing:border-box}
html,body{height:100%;background:#04060e;overflow:hidden;display:flex;flex-direction:column}
canvas{display:block;flex:1;width:100%;touch-action:none}
.back{position:fixed;top:1rem;left:1rem;font:0.8rem/1 ui-monospace,SFMono-Regular,Menlo,monospace;color:#aaa;background:rgba(4,6,14,0.88);padding:0.5rem 0.8rem;border-radius:4px;text-decoration:none;border:1px solid #333;z-index:10;transition:border-color 0.2s}
.back:hover{border-color:#666;color:#fff}
.panel{background:#080d1a;border-top:1px solid #1a2235;padding:0.65rem 0.9rem;display:flex;justify-content:space-between;align-items:center;gap:0.75rem;font:0.75rem/1 ui-monospace,SFMono-Regular,Menlo,monospace;flex-wrap:wrap;flex-shrink:0}
.panel .meta{display:flex;align-items:center;gap:0.6rem;color:#7fa8d4}
.panel .hint{color:#3d5470}
.panel .controls{display:flex;align-items:center;gap:0.55rem;flex-wrap:wrap}
.panel label{display:flex;align-items:center;gap:0.35rem;color:#6a8fba}
.panel input[type=range]{width:90px;height:30px;accent-color:#4a7fa0}
.panel button{background:rgba(255,255,255,0.05);border:1px solid #2a3a50;color:#8ab0d4;font:0.75rem ui-monospace,SFMono-Regular,Menlo,monospace;padding:8px 14px;border-radius:4px;cursor:pointer;transition:all 0.2s;-webkit-tap-highlight-color:transparent}
.panel button:hover{background:rgba(255,255,255,0.1);color:#c0d8f0;border-color:#4a6888}
.in-iframe .back,.in-iframe .panel{display:none}
@media(max-width:760px){.panel{padding:0.5rem}.panel input[type=range]{width:70px}}
</style>
</head>
<body>
<a class="back" href="../gallery/">← gallery</a>
<canvas id="c"></canvas>
<div class="panel">
  <div class="meta">
    <span>Wave Interference</span>
    <span class="hint">drag sources · click empty space to add</span>
  </div>
  <div class="controls">
    <label>λ <input type="range" id="wl" min="20" max="150" value="70"></label>
    <label>speed <input type="range" id="spd" min="1" max="12" value="5"></label>
    <button id="addBtn">+ source</button>
    <button id="resetBtn">reset</button>
  </div>
</div>
<script>
if(window.self!==window.top) document.documentElement.classList.add('in-iframe');

const canvas=document.getElementById('c');
const ctx=canvas.getContext('2d');

// Lower-res offscreen canvas for the interference field
const off=document.createElement('canvas');
const octx=off.getContext('2d');

const SCALE=3; // render at 1/SCALE resolution then stretch
let W,H,rW,rH,imgData,data;

let sources=[];
let t=0;
let dragging=null;

function initSources(){
  sources=[
    {x:0.33,y:0.5},
    {x:0.67,y:0.5},
    {x:0.5, y:0.3}
  ];
}
initSources();

function resize(){
  const nw=canvas.offsetWidth;
  const nh=canvas.offsetHeight;
  if(nw<1||nh<1) return;
  if(nw===W&&nh===H) return;
  W=nw; H=nh;
  canvas.width=W;
  canvas.height=H;
  rW=Math.max(1,Math.ceil(W/SCALE));
  rH=Math.max(1,Math.ceil(H/SCALE));
  off.width=rW;
  off.height=rH;
  imgData=octx.createImageData(rW,rH);
  data=imgData.data;
}
window.addEventListener('resize',resize);

function getWL(){return +document.getElementById('wl').value;}
function getSpd(){return +document.getElementById('spd').value;}

function hslToRgb(h,s,l){
  // h 0-360, s 0-1, l 0-1
  const c=(1-Math.abs(2*l-1))*s;
  const x=c*(1-Math.abs((h/60)%2-1));
  const m=l-c/2;
  let r=0,g=0,b=0;
  if(h<60){r=c;g=x;}else if(h<120){r=x;g=c;}
  else if(h<180){g=c;b=x;}else if(h<240){g=x;b=c;}
  else if(h<300){r=x;b=c;}else{r=c;b=x;}
  return [Math.round((r+m)*255),Math.round((g+m)*255),Math.round((b+m)*255)];
}

function render(){
  const wl=getWL()/SCALE;
  const n=sources.length;
  const TAU=Math.PI*2;

  for(let y=0;y<rH;y++){
    for(let x=0;x<rW;x++){
      let amp=0;
      for(let s=0;s<n;s++){
        const sx=sources[s].x*rW;
        const sy=sources[s].y*rH;
        const dx=x-sx,dy=y-sy;
        const dist=Math.sqrt(dx*dx+dy*dy);
        // Amplitude falls off with distance
        const falloff=1/(1+dist*0.02);
        amp+=falloff*Math.sin(TAU*dist/wl-t);
      }
      amp/=n;

      // Map amp (-1..1) to a cyan-blue-violet palette
      // Positive: cyan (180°) through blue (240°)
      // Negative: blue (240°) through violet (280°)
      const norm=(amp+1)*0.5; // 0..1
      const hue=180+norm*100;  // 180=cyan ... 280=violet
      const sat=0.8+norm*0.2;
      const lit=0.08+Math.abs(amp)*0.55;

      const [r,g,b]=hslToRgb(hue,sat,Math.min(lit,1));
      const idx=(y*rW+x)*4;
      data[idx]=r; data[idx+1]=g; data[idx+2]=b; data[idx+3]=255;
    }
  }

  octx.putImageData(imgData,0,0);
  ctx.imageSmoothingEnabled=false;
  ctx.drawImage(off,0,0,W,H);

  // Draw source markers (hidden in iframe via CSS on .back/.panel but we also skip here)
  if(!document.documentElement.classList.contains('in-iframe')){
    for(let s=0;s<sources.length;s++){
      const sx=sources[s].x*W;
      const sy=sources[s].y*H;
      ctx.beginPath();
      ctx.arc(sx,sy,10,0,Math.PI*2);
      ctx.strokeStyle='rgba(255,255,255,0.5)';
      ctx.lineWidth=1.5;
      ctx.stroke();
      ctx.beginPath();
      ctx.arc(sx,sy,3,0,Math.PI*2);
      ctx.fillStyle='rgba(255,255,255,0.9)';
      ctx.fill();
    }
  }
}

function loop(){
  resize();
  if(W<1||H<1||!data){requestAnimationFrame(loop);return;}
  t+=getSpd()*0.04;
  render();
  requestAnimationFrame(loop);
}
// Defer start so flexbox layout has resolved offsetWidth/Height
requestAnimationFrame(function(){requestAnimationFrame(loop);});

// Pointer interaction
function cpos(e){
  const r=canvas.getBoundingClientRect();
  const cx=((e.touches?e.touches[0].clientX:e.clientX)-r.left);
  const cy=((e.touches?e.touches[0].clientY:e.clientY)-r.top);
  return{x:cx/W,y:cy/H};
}

function nearSource(px,py){
  const thr=24/Math.max(W,H);
  for(let i=sources.length-1;i>=0;i--){
    const dx=sources[i].x-px,dy=sources[i].y-py;
    if(Math.sqrt(dx*dx+dy*dy)<thr) return i;
  }
  return -1;
}

canvas.addEventListener('pointerdown',e=>{
  const p=cpos(e);
  const idx=nearSource(p.x,p.y);
  if(idx>=0){dragging=idx;canvas.setPointerCapture(e.pointerId);}
  else if(sources.length<8) sources.push({x:p.x,y:p.y});
});
canvas.addEventListener('pointermove',e=>{
  if(dragging===null) return;
  const p=cpos(e);
  sources[dragging].x=Math.max(0,Math.min(1,p.x));
  sources[dragging].y=Math.max(0,Math.min(1,p.y));
});
canvas.addEventListener('pointerup',()=>{dragging=null;});

document.getElementById('addBtn').addEventListener('click',()=>{
  if(sources.length<8) sources.push({x:0.25+Math.random()*0.5,y:0.25+Math.random()*0.5});
});
document.getElementById('resetBtn').addEventListener('click',()=>{initSources();t=0;});
</script>
</body>
</html>