UnitCircle/Primes at main · erinepshovel-code/UnitCircle · 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" />
  <title>Prime Rays — Flash & Stay</title>
  <style>
    html, body { margin:0; padding:0; background:#000; color:#ddd; }
    canvas { display:block; }
  </style>
</head>
<body>
<script src="https://cdn.jsdelivr.net/npm/p5@1.9.0/lib/p5.min.js"></script>
<script>
/**
 * Prime Rays (Flash & Stay)
 * - Top: 99 persistent rays (first 99 unique prime mod 360 degrees encountered)
 * - Rays flash on hit, then remain visible
 * - Bottom: unwrapped cylinder (360° x layers) fills permanently, flashes on new hits
 * - Twin primes (gap=2) flash white
 * - ROYGBIV hues on black
 *
 * Tweaks:
 *   PRIMES_TO_SHOW: how many primes to process total
 *   PRIMES_PER_FRAME: speed
 */

const PRIMES_TO_SHOW = 5000;
const PRIMES_PER_FRAME = 25;

const DISPLAY_RAYS = 99;
const FLASH_LEN = 10;
const TWIN_FLASH_LEN = 14;

class PrimeStream {
  constructor(){ this.primes=[]; this.candidate=2; }
  reset(){ this.primes=[]; this.candidate=2; }
  next(){
    while(true){
      const n=this.candidate++;
      if(n===2){ this.primes.push(2); return 2; }
      if(n%2===0) continue;
      const r=Math.floor(Math.sqrt(n));
      let ok=true;
      for(const p of this.primes){ if(p>r) break; if(n%p===0){ ok=false; break; } }
      if(ok){ this.primes.push(n); return n; }
    }
  }
}

// ROYGBIV-ish gradient across degrees using HSB
function roygbiv(deg, a=255){
  const stops=[{d:0,h:0},{d:60,h:30},{d:120,h:55},{d:180,h:120},{d:240,h:210},{d:300,h:250},{d:360,h:290}];
  let x=((deg%360)+360)%360, i=0;
  while(i<stops.length-1 && x>stops[i+1].d) i++;
  const A=stops[i], B=stops[i+1];
  const t=(x-A.d)/(B.d-A.d);
  const h=A.h+t*(B.h-A.h);
  colorMode(HSB,360,100,100,255);
  const c=color(h,90,100,a);
  colorMode(RGB,255);
  return c;
}

// ---------- State ----------
let stream = new PrimeStream();
let primeIndex = 0;
let lastPrime = null;

const hits = new Array(360).fill(0);
const flash = new Array(360).fill(0);      // countdown timers
const twinFlash = new Array(360).fill(0);  // countdown timers

const displaySet = new Set();
const displayList = []; // first 99 unique degrees, stable order

let cylinder = []; // array of Uint16Array(360)
let maxLayer = 0;

let rotation = 0;

function ensureLayer(L){
  while(cylinder.length <= L) cylinder.push(new Uint16Array(360));
}

function addPrime(){
  if(primeIndex >= PRIMES_TO_SHOW) return;

  const p = stream.next();
  primeIndex++;

  const d = ((p % 360) + 360) % 360;

  // Collect first 99 unique ray degrees for the unit-circle bones
  if(displayList.length < DISPLAY_RAYS && !displaySet.has(d)){
    displaySet.add(d);
    displayList.push(d);
  }

  // Always update stats
  hits[d]++;
  flash[d] = FLASH_LEN;

  // Twin primes flash white on both rays
  if(lastPrime !== null && (p - lastPrime) === 2){
    const d0 = ((lastPrime % 360) + 360) % 360;
    twinFlash[d0] = TWIN_FLASH_LEN;
    twinFlash[d]  = TWIN_FLASH_LEN;
  }
  lastPrime = p;

  // Cylinder
  const L = Math.floor((primeIndex - 1) / 360);
  ensureLayer(L);
  cylinder[L][d]++;
  if(L > maxLayer) maxLayer = L;

  // Rotate only while still collecting 99 rays
  if(displayList.length < DISPLAY_RAYS) rotation += 0.018;
}

function setup(){
  createCanvas(window.innerWidth, window.innerHeight);
  pixelDensity(1);
  background(0);
}

function windowResized(){
  resizeCanvas(window.innerWidth, window.innerHeight);
}

function draw(){
  background(0);

  // Advance primes
  for(let i=0; i<PRIMES_PER_FRAME; i++) addPrime();

  // Decrement flash timers
  for(let i=0; i<360; i++){
    if(flash[i] > 0) flash[i]--;
    if(twinFlash[i] > 0) twinFlash[i]--;
  }

  // Layout: vertical stack
  const pad = 16;
  const W = width - pad*2;
  const H = height - pad*2;

  const topH = Math.floor(H * 0.48);
  const botH = H - topH - 12;

  // ---------- TOP: Unit circle ----------
  const cx = pad + W/2;
  const cy = pad + topH*0.55;
  const r  = Math.min(W, topH) * 0.34;

  // Guide circle
  noFill(); stroke(90); strokeWeight(1);
  circle(cx, cy, r*2);

  // Rays (bones): flash then stay
  push();
  translate(cx, cy);
  rotate(rotation);

  for(const d of displayList){
    const f  = flash[d] / FLASH_LEN;               // 0..1
    const tf = twinFlash[d] / TWIN_FLASH_LEN;      // 0..1
    const a  = radians(d);

    // Always-on brightness + flash boost
    if(tf > 0){
      stroke(255, 255, 255, 160 + 95*tf);
    } else {
      stroke(roygbiv(d, Math.min(255, 210 + 45 + 160*f)));
    }

    // Always-on thickness + flash thickness
    strokeWeight(2.0 + 2.0*f + 2.5*tf);

    line(0, 0, Math.cos(a)*r, Math.sin(a)*r);
  }

  // Center dot
  noStroke(); fill(255);
  circle(0, 0, 4);

  pop();

  // ---------- BOTTOM: Cylinder unwrapped ----------
  const y0 = pad + topH + 12;
  const layers = Math.max(1, maxLayer + 1);

  const cw = W / 360.0;
  const ch = botH / layers;

  // Find max cell for intensity scaling
  let maxCell = 1;
  for(let L=0; L<layers; L++){
    const row = cylinder[L];
    if(!row) continue;
    for(let d=0; d<360; d++) maxCell = Math.max(maxCell, row[d]);
  }

  noStroke();
  for(let L=0; L<layers; L++){
    const row = cylinder[L];
    if(!row) continue;

    for(let d=0; d<360; d++){
      const v = row[d];
      if(v === 0 && flash[d] === 0 && twinFlash[d] === 0) continue;

      const f  = flash[d] / FLASH_LEN;
      const tf = twinFlash[d] / TWIN_FLASH_LEN;

      const vN = Math.sqrt(v / maxCell);
      const alpha = Math.min(255, 35 + 180*vN + 120*f);

      if(tf > 0){
        fill(255, 255, 255, 140 + 115*tf);
      } else {
        fill(roygbiv(d, alpha));
      }

      rect(pad + d*cw, y0 + L*ch, Math.max(1, cw + 0.2), Math.max(1, ch + 0.2));
    }
  }
}
</script>
</body>
</html>