function-plotter-code-multi/index.html at main · asyncker/function-plotter-code-multi · GitHub

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<!DOCTYPE html>
<html lang="ru">
<head>
<meta charset="UTF-8">
<title>Function Plotter with JS code Multi Graphics</title>
<meta name="keywords" content="plotter,function,multi,free,plotter,graphics,code">
<meta name="description" content="Function Plotter - with write JS code free, multi display graphics pix, gamma, special function!">
<style>
  * { margin:0; padding:0; box-sizing:border-box; }
  body { font-family:'Consolas',monospace; display:flex; height:100vh; background:#1e1e1e; color:#d4d4d4; }
  canvas { width:100%; height:100%; cursor:crosshair; display:block; }
  #editor { width:35%; display:flex; flex-direction:column; border-right:2px solid #333; }
  #graph { width:65%; position:relative; background:#fff; }
  #editor-header { background:#252526; padding:10px 15px; display:flex; justify-content:space-between; align-items:center; border-bottom:1px solid #333; }
  #editor-header h2 { font-size:14px; color:#4ec9b0; }
  #run-btn { background:#0e639c; color:white; border:none; padding:6px 20px; cursor:pointer; font-family:inherit; font-size:13px; border-radius:3px; }
  #run-btn:hover { background:#1177bb; }
  #code { flex:1; background:#1e1e1e; color:#d4d4d4; border:none; padding:15px; font-family:'Consolas',monospace; font-size:14px; resize:none; outline:none; line-height:1.6; }
  #controls { position:absolute; top:10px; right:10px; background:rgba(255,255,255,0.95); padding:8px; border-radius:5px; }
  #controls button { background:#f0f0f0; border:1px solid #ccc; padding:5px 10px; margin:2px; cursor:pointer; border-radius:3px; font-family:inherit; }
  #info { position:absolute; bottom:10px; left:10px; background:rgba(255,255,255,0.95); padding:8px 12px; border-radius:5px; font-size:12px; color:#333; }
  #msg { position:absolute; bottom:10px; right:10px; padding:8px 12px; border-radius:5px; font-size:12px; display:none; }
  #msg.err { background:rgba(255,0,0,0.9); color:white; }
  #msg.ok { background:rgba(0,200,0,0.9); color:black; }
  #toggle-editor { position:absolute; top:10px; left:10px; background:rgba(255,255,255,0.95); border:1px solid #ccc; padding:4px 10px; cursor:pointer; border-radius:3px; font-family:inherit; font-size:12px; z-index:10; }
  #toggle-editor:hover { background:#e0e0e0; }
</style>
</head>
<body>
<div id="editor">
  <div id="editor-header">
    <h2>📝 Editor</h2>
    <button id="run-btn" onclick="runCode()">▶ RUN</button>
  </div>
  <textarea id="code" spellcheck="false">
primes = primes(20000);
plot(x => pix(x, primes));
plot(x => ceil(x / ln(x)));
plot(x => floor(li(x)));
plot(x => ceil(x / ln(x) + x / pow(ln(x), 2)));

//plot(x => cgamma(complex(0, x)).y);

/*for (let i = 0; i < primes.length / 100; i++) {
  const p = primes[i];
  const f = (x) => x > p ? sin(x * (PI / p)) * p : 0;
  plot(x => f(x), { color: randomColor(), width: 1.5 });
}*/

/*for (let i = 0; i < 10.0; i += 0.05) {
  let ecolor = randomColor();
  plot(x => sqrt(pow(x, 3) - 2 * x + 2.0 / i), { color: ecolor });
  plot(x => -sqrt(pow(x, 3) - 2 * x + 2.0 / i), { color: ecolor });
}*/


/*for (let k = 0; k < 10.0; k += 0.1) {
  plot(x => cgammaphi(-k + 1, x).x);
}*/

/*
function realMandelbrot(c, n) {
  let z = 0;
  for (let i = 0; i < n; i++) {
    z = pow(z, 2) + c;
    //z = sin(z) + c;
  }
  return z;
}

for (let n = 20; n <= 100; n += 1) {
  plot(x => -realMandelbrot(x, n));
}
*/
</textarea>
</div>
<div id="graph">
  <canvas id="c"></canvas>
  <button id="toggle-editor" onclick="toggleEditor()">◀</button>
  <div id="controls">
    <button onclick="resetView()">⌂</button>
  </div>
  <div id="info">Graphics: <span id="cnt">0</span> | Scale: <span id="sc">1.0</span></div>
  <div id="msg"></div>
</div>

<script>
let editorVisible = true;

function toggleEditor() {
  const editor = document.getElementById('editor');
  const graph = document.getElementById('graph');
  const btn = document.getElementById('toggle-editor');
  editorVisible = !editorVisible;
  if (editorVisible) {
    editor.style.display = 'flex';
    editor.style.width = '35%';
    graph.style.width = '65%';
    btn.textContent = '◀';
  } else {
    editor.style.display = 'none';
    graph.style.width = '100%';
    btn.textContent = '▶';
  }
  setTimeout(resize, 200);
}

const savedCode = localStorage.getItem('plotter_code');
if (savedCode !== null && savedCode.length >= 6) { document.getElementById('code').value = savedCode; }

const canvas = document.getElementById('c');
const ctx = canvas.getContext('2d');
let scale = 50, cx = 0, cy = 0;
let graphs = [], dragging = false, lx = 0, ly = 0;

const sin=Math.sin, cos=Math.cos, tan=Math.tan, log=Math.log, log2=Math.log2, log10=Math.log10;
const sqrt=Math.sqrt, abs=Math.abs, exp=Math.exp, pow=Math.pow, PI=Math.PI, E=Math.E;
const asin=Math.asin, acos=Math.acos, atan=Math.atan, atan2=Math.atan2;
const sinh=Math.sinh, cosh=Math.cosh, tanh=Math.tanh;
const floor=Math.floor, ceil=Math.ceil, round=Math.round, sign=Math.sign;
const min=Math.min, max=Math.max, random=Math.random;
const step = (edge, x) => x >= edge ? 1.0 : 0.0;
const clamp = (v, mn, mx) => Math.max(mn, Math.min(mx, v));
const relumin = (x) => x >= 0 ? undefined : x;
const relumax = (x) => x <= 0 ? undefined : x;
function gcd(a, b) {
    while (b) {
        [a, b] = [b, a % b];
    }
    return a;
}
function primes(n) {
  const seq = [];
  for (let i = 2; i <= n; i++) {
    let isPrime = true;
    for (let j = 2; j * j <= i; j++) {
      if (i % j === 0) { isPrime = false; break; }
    }
    if (isPrime) { seq.push(i); }
  }
  return seq;
}

function factorial(n) {
    if (n <= 0) return [];
    const seq = [1];
    for (let i = 2; i <= n; i++) {
      seq.push(seq[seq.length - 1] * i);
    }
    return seq;
}

function isprime(x) {
    if (x < 2) { return false; }
    if (x <= 3) { return true; }
    if (x % 2 === 0 || x % 3 === 0) { return false; }
    for (let i = 5; i * i <= x; i += 6) {
        if (x % i === 0 || x % (i + 2) === 0) {
          return false;
        }
    }
    return true;
}

// According to this logic, almost all functions can be turned into prime versions. like fib-prime or mersenne-prime with add condition
function primorial(n) {
  if (n <= 0) return [];
  const seq = [1];
  for (let i = 2; i <= n; i++) {
    if (isprime(i)) { seq.push(seq[seq.length - 1] * i); }
  }
  return seq;
}

function fib(n) {
  if (n <= 0) return [];
  if (n === 1) return [0];
  const seq = [0, 1];
  for (let i = 2; i < n; i++) {
    seq.push(seq[i - 1] + seq[i - 2]);
  }
  return seq;
}

function mersenne(n) {
  const seq = [];
  for (let i = 1; i <= n; i++) {
    seq.push(Math.pow(2, i) - 1);
  }
  return seq;
}

function geometric(start, ratio, count) {
  const seq = [];
  for (let i = 0; i < count; i++) {
    seq.push(Math.pow(ratio, i) * start);
  }
  return seq;
}

function arithmetic(start, diff, count) {
  const seq = [];
  for (let i = 0; i < count; i++) {
    seq.push(start + i * diff);
  }
  return seq;
}

function primePolynomial(n, coff1, coff2, coff3) { /// 11, 17, 41
  const seq = [];
  for (let i = 0; i <= n; i++) {
    seq.push(coff1 * i * i + coff2 * i + coff3);
  }
  return seq;
}

function catalan(n) {
  if (n <= 0) return [];
  const seq = [1];
  for (let i = 1; i < n; i++) {
    seq.push(seq[i-1] * 2 * (2 * i - 1) / (i + 1));
  }
  return seq;
}

function eulerTotient(n) {
    const seq = [];
    for (let i = 1; i <= n; i++) {
        let count = 0;
        for (let j = 1; j <= i; j++) {
            if (gcd(i, j) === 1) count++;
        }
        seq.push(count);
    }
    return seq;
}

function binomial(n, k) {
  if (k < 0 || k > n) return 0;
  let result = 1;
  for (let i = 1; i <= k; i++) {
    result = result * (n - i + 1) / i;
  }
  return result;
}

function bell(n) {
  if (n <= 0) return [];
  const seq = [1];
  for (let i = 1; i < n; i++) {
    let prev = seq[i-1];
    let sum = 0;
    for (let j = 0; j < i; j++) {
      sum += binomial(i-1, j) * seq[j];
    }
    seq.push(sum);
  }
  return seq;
}

function lucas(n) {
  if (n <= 0) return [];
  if (n === 1) return [2];
  const seq = [2, 1];
  for (let i = 2; i < n; i++) {
    seq.push(seq[i-1] + seq[i-2]);
  }
  return seq;
}

function tribonacci(n) { //n-bonacci
  if (n <= 0) return [];
  if (n === 1) return [0];
  if (n === 2) return [0, 1];
  const seq = [0, 1, 1];
  for (let i = 3; i < n; i++) {
    seq.push(seq[i-1] + seq[i-2] + seq[i-3]);
  }
  return seq;
}

function pell(n) {
  if (n <= 0) return [];
  if (n === 1) return [0];
  const seq = [0, 1];
  for (let i = 2; i < n; i++) {
    seq.push(2 * seq[i-1] + seq[i-2]);
  }
  return seq;
}

function golomb(n) {
  if (n <= 0) return [];
  const seq = [1, 2, 2];
  for (let i = 3; i < n; i++) {
    let count = 0;
    for (let j = 0; j < seq[i-1]; j++) {
      count++;
    }
    seq.push(count);
  }
  return seq;
}

function stirlingSecond(n, k) {
  if (k === 0 || k > n) return 0;
  if (k === 1 || k === n) return 1;
  const dp = Array.from({length: n+1}, () => Array(k+1).fill(0));
  for (let i = 1; i <= n; i++) {
    for (let j = 1; j <= Math.min(i, k); j++) {
      if (j === 1 || j === i) {
        dp[i][j] = 1;
      } else {
        dp[i][j] = j * dp[i-1][j] + dp[i-1][j-1];
      }
    }
  }
  return dp[n][k];
}

function collatz(n) {
  if (n <= 0) return [];
  const seq = [n];
  while (n !== 1) {
    if (n % 2 === 0) { n = n / 2; }
    else { n = (3 * n + 1); } // /2
    seq.push(n);
  }
  return seq;
}

function perfectNumbers(limit) {
  const seq = [];
  for (let n = 2; n <= limit; n++) {
    let sum = 1;
    for (let i = 2; i * i <= n; i++) {
      if (n % i === 0) {
        sum += i;
        if (i !== n / i) sum += n / i;
      }
    }
    if (sum === n && n > 1) seq.push(n);
  }
  return seq;
}

function armstrongNumbers(limit) {
  const seq = [];
  for (let n = 0; n <= limit; n++) {
    const str = String(n);
    const len = str.length;
    let sum = 0;
    for (const digit of str) {
      sum += Math.pow(parseInt(digit), len);
    }
    if (sum === n) seq.push(n);
  }
  return seq;
}

function btn(minusKey, plusKey) {
  let value = 0;
  const minusBtn = document.getElementById(minusKey) || document.querySelector(`[data-key="${minusKey}"]`);
  const plusBtn = document.getElementById(plusKey) || document.querySelector(`[data-key="${plusKey}"]`);
  const getBtn = (key) => {
    const el = document.getElementById(key);
    if (el) return el;
    return {
      addEventListener: (event, handler) => {
        document.addEventListener('keydown', (e) => {
          if (e.key === key) handler(e);
        });
      }
    };
  };
  const minus = getBtn(minusKey);
  const plus = getBtn(plusKey);
  const num = () => value;
  num.valueOf = () => value;
  num.toString = () => String(value);
  const update = (newVal) => {
    value = newVal;
    if (window.render) window.render(value);
    return value;
  };
  minus.addEventListener('click', () => update(value - 1));
  plus.addEventListener('click', () => update(value + 1));
  document.addEventListener('keydown', (e) => {
    if (e.key === minusKey) update(value - 1);
    if (e.key === plusKey) update(value + 1);
  });
  return num;
}

function pix(x, primes) {
  let left = 0;
  let right = primes.length - 1;
  let result = 0;
  while (left <= right) {
    const mid = Math.floor((left + right) / 2);
    if (primes[mid] <= x) {
      result = mid + 1;
      left = mid + 1;
    } else {
      right = mid - 1;
    }
  }
  return result;
}

function li(x) {
  if (x < 2) return 0;
  const a = 2;
  const b = x;
  const n = 1000;
  if (b <= a) return 0;
  const h = (b - a) / n;
  let sum = 0;
  const f = (t) => {
    if (t <= 1) return 0;
    const ln_t = Math.log(t);
    if (Math.abs(ln_t) < 1e-10) return 0;
    return 1 / ln_t;
  };
  for (let i = 0; i <= n; i++) {
    const t = a + i * h;
    const val = f(t);
    if (i === 0 || i === n) {
      sum += val;
    } else if (i % 2 === 1) {
      sum += 4 * val;
    } else {
      sum += 2 * val;
    }
  }

  return (h / 3) * sum;
}

function complex(x, y) {
  return {
    x, y,
    add(w) { return complex(this.x + w.x, this.y + w.y); },
    sub(w) { return complex(this.x - w.x, this.y - w.y); },
    mul(w) { return complex(this.x * w.x - this.y * w.y, this.x * w.y + this.y * w.x); },
    dot(w) { return complex(this.x * w.x + this.y * w.y, this.y * w.x - this.x * w.y); },
    scale(k) { return complex(this.x * k, this.y * k); },
    conj() { return complex(this.x, -this.y); },
    inv() { const denom = this.x * this.x + this.y * this.y; return complex(this.x / denom, -this.y / denom); },
    abs() { return Math.sqrt(this.x * this.x + this.y * this.y); }
  };
}

function toComplex(a, b) {
  if (a && typeof a === 'object' && 'x' in a && 'y' in a) {
    return a;
  }
  if (typeof a === 'number' && typeof b === 'number') {
    return complex(a, b);
  }
  if (typeof a === 'number' && b === undefined) {
    return complex(a, 0);
  }
  return complex(0, 0);
}

function cmul_i(x, y) { const z = toComplex(x, y); return complex(-z.y, z.x); }
function conj(x, y) { const z = toComplex(x, y); return complex(z.x, -z.y); }
function cinv(x, y) { const z = toComplex(x, y); return z.inv(); }
function cexp(x, y) { const z = toComplex(x, y); const ex = Math.exp(z.x); return complex(ex * Math.cos(z.y), ex * Math.sin(z.y)); }
function clog(x, y) { const z = toComplex(x, y); return complex(Math.log(z.x * z.x + z.y * z.y) * 0.5, Math.atan2(z.y, z.x)); }
function csin(x, y) { const z = toComplex(x, y); return complex(Math.sin(z.x) * Math.cosh(z.y), Math.cos(z.x) * Math.sinh(z.y)); }
function ccos(x, y) { const z = toComplex(x, y); return complex(Math.cos(z.x) * Math.cosh(z.y), -Math.sin(z.x) * Math.sinh(z.y)); }
function cadd(z, w) { return z.add(w); }
function csub(z, w) { return z.sub(w); }
function cmul(z, w) { return z.mul(w); }
function cdiv(z, w) { return z.mul(w.inv()); }
function cpow(z, w) { return cexp(w.mul(clog(z))); }
function cdot(z, w) { return z.dot(w); }
function cmulcomp(z, w) { return complex(z.x * w.x, z.y * w.y); }
function cscale(z, k) { return z.scale(k); }

function cgamma_right(z) {
    const w = complex(z.x - 1.0, z.y);
    const t = complex(w.x + 7.5, w.y);
    let x = complex(0.99999999999980993, 0.0);
    x = x.add(complex(w.x + 1.0, w.y).inv().scale(676.5203681218851));
    x = x.add(complex(w.x + 2.0, w.y).inv().scale(-1259.1392167224028));
    x = x.add(complex(w.x + 3.0, w.y).inv().scale(771.32342877765313));
    x = x.add(complex(w.x + 4.0, w.y).inv().scale(-176.61502916214059));
    x = x.add(complex(w.x + 5.0, w.y).inv().scale(12.507343278686905));
    x = x.add(complex(w.x + 6.0, w.y).inv().scale(-0.13857109526572012));
    x = x.add(complex(w.x + 7.0, w.y).inv().scale(9.9843695780195716e-6));
    x = x.add(complex(w.x + 8.0, w.y).inv().scale(1.5056327351493116e-7));
    return cmul(x, cexp(cadd(cmul(clog(t), complex(0.5 + w.x, w.y)), t.scale(-1.0)))).scale(2.50662827463);
}
function cgamma_left(z) { return (cmul(csin(z.scale(Math.PI)), cgamma_right(complex(1.0 - z.x, -z.y)))).inv().scale(Math.PI); }
function cgamma(x, y) { let z = toComplex(x, y); z = complex(z.x + 1.0, z.y); return z.x < 0.5 ? cgamma_left(z) : cgamma_right(z); }

const EULER_GAMMA = 0.5772156649015329;
function cgammaw(x, y) {
  let z = toComplex(x, y); z = complex(z.x + 1.0, z.y);
  const one = complex(1.0, 0.0);
  let result = cmul(z, cexp(z.scale(EULER_GAMMA)));
  for (let n = 1; n <= 256; n++) {
    const invn = 1.0 / n;
    result = cmul(result, cmul(z.scale(invn).add(one), cexp(z.scale(-invn))));
  }
  return result.inv();
}

function cgammap(x, y) {
  let z = toComplex(x, y); z = complex(z.x + 1.0, z.y);
  const one = complex(1.0, 0.0);
  let result = cmul(z, cexp(z.scale(EULER_GAMMA)));
  const primesv = primes(256);
  for (let n = 0; n < primesv.length; n++) {
    const invn = 1.0 / primesv[n];
    result = cmul(result, cmul(z.scale(invn).add(one), cexp(z.scale(-invn))));
  }
  return result.inv();
}

function randomColor() { const h = Math.floor(Math.random() * 360); return `hsl(${h},70%,55%)`; }

function extractReal(value) { return value && typeof value === 'object' && 'x' in value && 'y' in value ? value.x : value; }

const print = (fn, opts={}) => {
  if (Array.isArray(fn)) {
    const arr = fn;
    fn = x => (x > arr.length - 1 ? 0 : arr[floor(x)]);
  }
  const wrappedFn = (x) => extractReal(fn(x));
  graphs.push({
    fn: wrappedFn,
    color: opts.color || randomColor(),
    width: opts.width || 2,
    opacity: opts.opacity ?? 0.8
  });
};

const plot = print;

function resize() {
  const p = document.getElementById('graph');
  canvas.width = p.clientWidth;
  canvas.height = p.clientHeight;
  render();
}
window.addEventListener('resize', resize);
canvas.addEventListener('mousedown', e => { dragging=true; lx=e.clientX; ly=e.clientY; });
canvas.addEventListener('mousemove', e => {
  if (!dragging) return;
  cx -= (e.clientX-lx)/scale;
  cy += (e.clientY-ly)/scale;
  lx=e.clientX; ly=e.clientY;
  render();
});
canvas.addEventListener('mouseup', () => dragging=false);
canvas.addEventListener('mouseleave', () => dragging=false);
canvas.addEventListener('wheel', e => { e.preventDefault(); zoom(e.deltaY>0?0.9:1.1); });

function zoom(f) { scale *= f; render(); }
function resetView() { scale=50; cx=0; cy=0; render(); }
function toScreen(x, y) { return [(x-cx)*scale + canvas.width/2, canvas.height/2 - (y-cy)*scale]; }
function toMath(px, py) { return [(px - canvas.width/2)/scale + cx, -(py - canvas.height/2)/scale + cy]; }

function render() {
  const W = canvas.width, H = canvas.height;
  ctx.clearRect(0, 0, W, H);
  ctx.fillStyle = '#1a1a1a';
  ctx.fillRect(0, 0, W, H);
  const [xMin, yMax] = toMath(0, 0);
  const [xMax, yMin] = toMath(W, H);
  let gridStep;
  const targetPixels = 60;
  const rawStep = targetPixels / scale;
  const magnitude = Math.pow(10, Math.floor(Math.log10(rawStep)));
  const normalized = rawStep / magnitude;
  if (normalized < 1.5) gridStep = magnitude;
  else if (normalized < 3.5) gridStep = 2 * magnitude;
  else if (normalized < 7.5) gridStep = 5 * magnitude;
  else gridStep = 10 * magnitude;
  ctx.strokeStyle = '#2d2d2d';
  ctx.lineWidth = 1.0;
  ctx.beginPath();
  const startX = Math.ceil(xMin / gridStep) * gridStep;
  for (let x = startX; x <= xMax; x += gridStep) {
    const px = (x - cx) * scale + W / 2;
    if (px < -10 || px > W + 10) continue;
    ctx.moveTo(px, 0);
    ctx.lineTo(px, H);
  }
  const startY = Math.ceil(yMin / gridStep) * gridStep;
  for (let y = startY; y <= yMax; y += gridStep) {
    const py = H / 2 - (y - cy) * scale;
    if (py < -10 || py > H + 10) continue;
    ctx.moveTo(0, py);
    ctx.lineTo(W, py);
  }
  ctx.stroke();
  const labelStep = gridStep * (scale > 200 ? 1 : scale > 80 ? 2 : 4);
  ctx.fillStyle = '#777';
  ctx.textAlign = 'center';
  const [, axisY_px] = toScreen(0, 0);
  for (let x = Math.ceil(xMin / labelStep) * labelStep; x <= xMax; x += labelStep) {
    if (Math.abs(x) < 1e-9) continue;
    const px = (x - cx) * scale + W / 2;
    if (px < 10 || px > W - 10) continue;
    const labelY = Math.min(H - 4, Math.max(14, axisY_px + 16));
    ctx.fillText(parseFloat(x.toFixed(6)).toString(), px, labelY);
  }
  ctx.textAlign = 'right';
  const [axisX_px] = toScreen(0, 0);
  for (let y = Math.ceil(yMin / labelStep) * labelStep; y <= yMax; y += labelStep) {
    if (Math.abs(y) < 1e-9) continue;
    const py = H / 2 - (y - cy) * scale;
    if (py < 10 || py > H - 10) continue;
    const labelX = Math.min(W - 4, Math.max(20, axisX_px - 8));
    ctx.fillText(parseFloat(y.toFixed(6)).toString(), labelX, py + 4);
  }
  ctx.strokeStyle = '#545454';
  ctx.lineWidth = 1.5;
  ctx.beginPath();
  if (axisY_px >= 0 && axisY_px <= H) {
    ctx.moveTo(0, axisY_px); ctx.lineTo(W, axisY_px);
  }
  if (axisX_px >= 0 && axisX_px <= W) {
    ctx.moveTo(axisX_px, H); ctx.lineTo(axisX_px, 0);
  }
  ctx.stroke();
  const W_half = W / 2;
  const H_half = H / 2;
  const inv_scale = 1 / scale;
  function findDomainEdge(fn, xValid, xInvalid) {
    let a = xValid, b = xInvalid;
    for (let i = 0; i < 16; i++) {
      const mid = (a + b) * 0.5;
      if (Number.isFinite(fn(mid))) a = mid;
      else b = mid;
    }
    return a;
  }

  for (let g = 0; g < graphs.length; g++) {
    const g_fn = graphs[g].fn;
    ctx.strokeStyle = graphs[g].color;
    ctx.lineWidth = graphs[g].width;
    ctx.globalAlpha = graphs[g].opacity;
    ctx.beginPath();
    let inPath = false;
    let prevPx = 0, prevPy = 0, prevX = 0, prevY = 0;
    for (let px = 0; px <= W; px++) {
      const x = (px - W_half) * inv_scale + cx;
      const y = g_fn(x);
      const isValid = Number.isFinite(y);
      if (isValid) {
        const py = H_half - (y - cy) * scale;
        if (!inPath) {
          const prevX_math = ((px - 1) - W_half) * inv_scale + cx;
          const edgeX = findDomainEdge(g_fn, x, prevX_math);
          const edgePx = (edgeX - cx) * scale + W_half;
          const edgeY = g_fn(edgeX);
          const edgePy = H_half - ((Number.isFinite(edgeY) ? edgeY : 0) - cy) * scale;
          ctx.moveTo(edgePx, edgePy);
          ctx.lineTo(px, py);
          inPath = true;
        } else {
          if (Math.abs(py - prevPy) > H * 0.8 && Math.sign(y) !== Math.sign(prevY)) {
            ctx.moveTo(px, py);
          } else {
            ctx.lineTo(px, py);
          }
        }
        prevPx = px; prevPy = py; prevX = x; prevY = y;
      } else {
        if (inPath) {
          const edgeX = findDomainEdge(g_fn, prevX, x);
          const edgePx = (edgeX - cx) * scale + W_half;
          const edgeY = g_fn(edgeX);
          const edgePy = H_half - ((Number.isFinite(edgeY) ? edgeY : 0) - cy) * scale;
          ctx.lineTo(edgePx, edgePy);
          inPath = false;
        }
      }
    }
    ctx.stroke();
  }

  ctx.globalAlpha = 1;
  document.getElementById('sc').textContent = (scale / 50).toFixed(2);
}

function showMsg(text, type) {
  const m = document.getElementById('msg');
  m.textContent = text;
  m.className = type;
  m.style.display = 'block';
  setTimeout(() => m.style.display = 'none', 3000);
}

function runCode() {
  const code = document.getElementById('code').value;
  graphs = [];
  try {
    const fn = new Function('randomColor','sin','cos','tan','log','ln','log2','log10',
      'sqrt','abs','exp','pow','PI','E','asin','acos','atan','atan2',
      'sinh','cosh','tanh','floor','ceil','round','sign','min','max','random','primes','pix','li','complex',
      'cgamma','csin','cexp','clog','cinv','cpow',
      code);
    fn(randomColor,sin,cos,tan,log,log,log2,log10,sqrt,abs,exp,pow,PI,E,
       asin,acos,atan,atan2, sinh,cosh,tanh, floor,ceil,round,sign,min,max,random,primes,pix,li,complex,cgamma,csin,cexp,clog,cinv,cpow);
    document.getElementById('cnt').textContent = graphs.length;
    render();
    showMsg(`✓ Build: ${graphs.length}`, 'ok');
    try {
      localStorage.setItem('plotter_code', code);
    } catch(e) {}
  } catch(e) {
    showMsg(`✗ ${e.message}`, 'err');
  }
}

document.getElementById('code').addEventListener('keydown', e => {
  if (e.ctrlKey && e.key === 'Enter') runCode();
});

resize();
setTimeout(runCode, 100);
</script>
<script src="./zeta-fast.js"></script>
</body>
</html>