> ## Documentation Index
> Fetch the complete documentation index at: /llms.txt
> Use this file to discover all available pages before exploring further.

# Handwritten Write-On Title

> True glyph write-on: filled Caveat letterforms revealed by baked per-glyph centerline strokes traced in real stroke order with a curvature-adaptive pen-velocity ease (fast on straights, slow into curves, inter-stroke pen lifts); optional squiggle underline; boils

# Handwritten Write-On Title

True glyph write-on: filled Caveat letterforms revealed by baked per-glyph centerline strokes traced in real stroke order with a curvature-adaptive pen-velocity ease (fast on straights, slow into curves, inter-stroke pen lifts); optional squiggle underline; boils

**Handwritten Write-On Title**

```html hw-write-title.html
<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
    <script src="assets/baked/caveat-pen.js"></script>
    <style>
      /* Caveat is NOT auto-resolved by the renderer — bundle it. Asset paths
         are ROOT-relative. The glyph write-on itself renders BAKED outlines
         (no live font dependency); the bundled face serves the fallback path
         for characters outside the baked table. */
      @font-face {
        font-family: "Caveat";
        src: url("assets/fonts/Caveat-700-latin.woff2") format("woff2");
        font-weight: 700;
        font-display: block;
      }
      *,
      *::before,
      *::after {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
      }
      body {
        background: transparent;
        overflow: hidden;
      }
      /* ---- hw-write-title -------------------------------------------------
         TRUE glyph write-on: filled Caveat letterforms revealed by animated
         per-glyph centerline strokes (the AE mask-reveal classic — "a mask
         barely covering the line"), traced in real stroke order with a
         curvature-adaptive pen-velocity ease (fast on straights, slow into
         curves; inter-stroke pen lifts). Centerlines + outlines + stem widths
         ship baked (assets/baked/caveat-pen.js, generated deterministically
         from Caveat-700 — regeneration script in the PR).
         RULES: hwBoil owns x/y/rotation of the boil target; entrances/exits
         ride the outer wrapper. One timeline has ONE onUpdate (hwOnUpdate). */
      #hw-wt-root {
        --hw-font-print: "Caveat", cursive;
        --hw-ink: #f4f2ec;
        --hw-ink-dark: #26241f;
        --hw-accent-warm: #ffb020;

        position: relative;
        width: 1920px;
        height: 1080px;
        overflow: hidden;
        background: transparent; /* overlays footage or a board */
        font-family: var(--hw-font-print, "Caveat", cursive);
      }
      #hw-wt-wrap {
        position: absolute;
        pointer-events: none;
      }
      #hw-wt-svg {
        overflow: visible;
        display: block;
      }
      #hw-wt-under {
        overflow: visible;
        display: block;
        margin-top: -8px;
      }
      #hw-wt-under path {
        fill: none;
        stroke: var(--hw-accent-warm);
        stroke-width: 7;
        stroke-linecap: round;
      }
      .hw-wt-fallback {
        font-weight: 700;
        white-space: pre;
      }
    </style>
  </head>
  <body>
    <div
      id="hw-wt-root"
      data-composition-id="hw-write-title"
      data-start="0"
      data-duration="6"
      data-width="1920"
      data-height="1080"
    >
      <div id="hw-wt-move">
        <div id="hw-wt-boil">
          <div id="hw-wt-wrap">
            <svg id="hw-wt-svg"></svg>
            <svg id="hw-wt-under" width="10" height="40"><path id="hw-wt-under-path"></path></svg>
          </div>
        </div>
      </div>
      <div
        id="hw-wt-drv"
        class="clip"
        data-start="0"
        data-duration="6"
        data-track-index="0"
        style="position: absolute; width: 1px; height: 1px; opacity: 0; pointer-events: none"
      ></div>
    </div>
    <script>
      (function () {
        window.__timelines = window.__timelines || {};

        var CONFIG = {
          // ── Content (freely editable — not counted) ─────────────────────
          text: "write it on",
          fontSize: 170, // px; the word block auto-centers when x/y are null
          x: null,
          y: null,

          // ── Controls (family base + 2 item-specific; comment grammar is the published-parameter list) ──
          scheme: "chalk", //   variant: "chalk" | "ink" — selects the authored token set (family default "chalk")
          animationIn: true, // toggle: entrance on/off — write-on IS the entrance; false = hard-on at t=0 (pairs with animationOut; the pair counts as one control)
          animationOut: true, //  (exit fade; duration derived from DUR, never exposed)
          boil: "calm", //      variant: "off" | "calm" | "lively" — authored amp/rot pairs over the family-locked frameDrop 3; seed locked
          writeOn: "trace", //  variant: "trace" | "reveal" | "off" — trace = pen-traced glyph write-on (curvature-adaptive velocity, pen lifts); reveal = per-glyph staggered fade; off = hard-on; durations derived from stroke count, never exposed
          underline: true, //   toggle: seeded squiggle underline drawn after the write completes

          // ── Locked (edit the item source to change) ─────────────────────
          // seed, pen-velocity constants (kCurve 10, floor 0.22, lift 60ms),
          // trace-duration derivation, boil pose tables, all eases/durations
        };
        var SEED = 8; // locked — determinism
        var DUR = 6;

        function clamp(v, lo, hi) {
          return Math.min(hi, Math.max(lo, v));
        }
        var OUT = clamp(DUR * 0.06, 0.25, 0.6);

        /* ---- hw family runtime (copy identical across hw items) ---- */
        window.hwOnUpdate = function (tl, fn) {
          if (!tl.__hwRenders) {
            tl.__hwRenders = [];
            tl.eventCallback("onUpdate", function () {
              for (var i = 0; i < tl.__hwRenders.length; i++) tl.__hwRenders[i]();
            });
          }
          tl.__hwRenders.push(fn);
          fn();
        };
        window.hwHash = function (n, seed) {
          var x = Math.sin(n * 127.1 + (seed || 1) * 311.7) * 43758.5453;
          return (x - Math.floor(x)) * 2 - 1;
        };
        window.hwBoil = function (tl, target, opts) {
          opts = opts || {};
          var amp = opts.amp !== undefined ? opts.amp : 1.6;
          var rot = opts.rot !== undefined ? opts.rot : 0.5;
          var fps = opts.fps || 30;
          var drop = opts.frameDrop || 3;
          var seed = opts.seed || 1;
          var els = gsap.utils.toArray(target);
          window.hwOnUpdate(tl, function () {
            var step = Math.floor((tl.time() * fps) / drop);
            for (var i = 0; i < els.length; i++) {
              gsap.set(els[i], {
                x: window.hwHash(step * 3 + i * 97, seed) * amp,
                y: window.hwHash(step * 3 + 1 + i * 97, seed) * amp,
                rotation: (opts.baseRot || 0) + window.hwHash(step * 3 + 2 + i * 97, seed) * rot,
              });
            }
          });
        };
        // boil control: authored poses over the family-locked frameDrop.
        // Unknown pose → default + console error (bounded-controls law).
        window.hwBoilPose = function (tl, target, pose, opts) {
          opts = opts || {};
          var poses = { calm: { amp: 1.6, rot: 0.5 }, lively: { amp: 2.6, rot: 0.9 } };
          if (pose === "off") return;
          var p = poses[pose];
          if (!p) {
            console.error('hw: unknown boil pose "' + pose + '" — falling back to "calm"');
            p = poses.calm;
          }
          window.hwBoil(tl, target, { amp: p.amp, rot: p.rot, frameDrop: 3, seed: opts.seed || 1 });
        };

        /* ---- pen-velocity ease: pure function of the path geometry ----
           Sample 25–75 curvature-adaptive points, speed ∝ 1/(1+k·curvature)
           floored at 0.22 (a pen slows into curves, never stalls), integrate
           ds/speed, invert to a normalized time→distance ease. Seek-safe:
           no per-frame state. */
        window.hwPenEase = function (pathEl, opts) {
          opts = opts || {};
          var kCurve = opts.kCurve !== undefined ? opts.kCurve : 10;
          var L = pathEl.getTotalLength();
          if (L <= 0)
            return {
              ease: function (t) {
                return t;
              },
              samples: 2,
              inkTime: 1,
              len: 0,
            };
          var PRE = 48;
          var pts = [];
          for (var i = 0; i <= PRE; i++) pts.push(pathEl.getPointAtLength((L * i) / PRE));
          var curv = [0];
          for (i = 1; i < PRE; i++) {
            var ax = pts[i].x - pts[i - 1].x,
              ay = pts[i].y - pts[i - 1].y;
            var bx = pts[i + 1].x - pts[i].x,
              by = pts[i + 1].y - pts[i].y;
            var la = Math.hypot(ax, ay) || 1e-6,
              lb = Math.hypot(bx, by) || 1e-6;
            var dot = Math.max(-1, Math.min(1, (ax * bx + ay * by) / (la * lb)));
            curv.push(Math.acos(dot) / ((la + lb) / 2));
          }
          curv.push(0);
          var mass = 0;
          for (i = 0; i < curv.length; i++) mass += curv[i];
          var N = Math.max(25, Math.min(75, Math.round(25 + mass * 18)));
          var seg = L / N;
          var times = [0];
          var t = 0;
          for (i = 1; i <= N; i++) {
            var u = ((i - 0.5) / N) * PRE;
            var i0 = Math.floor(u),
              f = u - i0;
            var c = curv[Math.min(i0, PRE)] * (1 - f) + curv[Math.min(i0 + 1, PRE)] * f;
            var speed = Math.max(1 / (1 + kCurve * c * 14), 0.22);
            t += seg / speed;
            times.push(t);
          }
          var total = times[N];
          for (i = 0; i <= N; i++) times[i] /= total;
          var easeFn = function (p) {
            if (p <= 0) return 0;
            if (p >= 1) return 1;
            var lo = 0,
              hi = N;
            while (hi - lo > 1) {
              var mid = (lo + hi) >> 1;
              if (times[mid] <= p) lo = mid;
              else hi = mid;
            }
            var span = times[hi] - times[lo] || 1e-9;
            return (lo + (p - times[lo]) / span) / N;
          };
          return { ease: easeFn, samples: N, inkTime: total, len: L };
        };

        /* ---- word assembly from the baked table ----
           Each glyph: <mask> of centerline strokes (stroke-width = the glyph's
           baked stem × 1.35) over the filled outline. Characters missing from
           the table fall back to live Caveat text revealed by fade (+ console
           warning) — the bundled face exists for exactly this path. */
        function buildWord(svg, text) {
          // everything in GLYPH UNITS (upem 1000, y-down, baseline 0) — the
          // svg viewBox maps units → px, no scale transform needed
          var table = window.__hwPenCaveat;
          var ns = "http://www.w3.org/2000/svg";
          // scheme control: bounded lookup — unknown → default + console error
          var schemes = { chalk: "var(--hw-ink)", ink: "var(--hw-ink-dark)" };
          if (!(CONFIG.scheme in schemes)) {
            console.error('hw: unknown scheme "' + CONFIG.scheme + '" — falling back to "chalk"');
          }
          var ink = schemes[CONFIG.scheme] || schemes.chalk;
          var g = document.createElementNS(ns, "g");
          var x = 0;
          var strokes = [];
          var fallbacks = [];
          var gi = 0;
          for (var ci = 0; ci < text.length; ci++) {
            var ch = text[ci];
            var gl = table.glyphs[ch];
            if (ch === " ") {
              x += 340;
              continue;
            }
            if (!gl) {
              console.warn(
                'hw-write-title: "' + ch + '" not in the baked table — Caveat fallback fade',
              );
              var ft = document.createElementNS(ns, "text");
              ft.setAttribute("x", x);
              ft.setAttribute("y", 0);
              ft.setAttribute("class", "hw-wt-fallback");
              ft.setAttribute("font-size", "1000");
              ft.setAttribute("fill", ink);
              ft.textContent = ch;
              g.appendChild(ft);
              fallbacks.push(ft);
              x += 450;
              continue;
            }
            var gg = document.createElementNS(ns, "g");
            gg.setAttribute("transform", "translate(" + x + ",0)");
            var maskId = "hw-wt-m" + gi;
            var mask = document.createElementNS(ns, "mask");
            mask.setAttribute("id", maskId);
            mask.setAttribute("maskUnits", "userSpaceOnUse");
            mask.setAttribute("x", "-200");
            mask.setAttribute("y", "-900");
            mask.setAttribute("width", gl.adv + 400);
            mask.setAttribute("height", "1400");
            for (var si = 0; si < gl.strokes.length; si++) {
              var mp = document.createElementNS(ns, "path");
              mp.setAttribute("d", gl.strokes[si]);
              mp.setAttribute("fill", "none");
              mp.setAttribute("stroke", "#fff");
              mp.setAttribute("stroke-width", Math.max(30, Math.round(gl.stem * 1.35)));
              mp.setAttribute("stroke-linecap", "round");
              mp.setAttribute("stroke-linejoin", "round");
              mask.appendChild(mp);
              strokes.push({ path: mp, glyph: gi });
            }
            gg.appendChild(mask);
            var op = document.createElementNS(ns, "path");
            op.setAttribute("d", gl.outline);
            op.setAttribute("fill", ink);
            op.setAttribute("mask", "url(#" + maskId + ")");
            gg.appendChild(op);
            g.appendChild(gg);
            x += gl.adv;
            gi++;
          }
          svg.appendChild(g);
          return { el: g, widthUnits: x, strokes: strokes, fallbacks: fallbacks };
        }

        /* ---- trace choreography: per-stroke reveals, pen-velocity eases,
           60ms pen lifts; duration DERIVED from stroke count (writeOn owns
           it — never exposed). One dispatcher-registered render applies the
           dashoffsets. */
        function writeOnTrace(tl, built, at) {
          var strokes = built.strokes;
          if (!strokes.length) return at;
          var lift = 0.06;
          var metas = [];
          var inkSum = 0;
          for (var i = 0; i < strokes.length; i++) {
            var pe = window.hwPenEase(strokes[i].path);
            var len = strokes[i].path.getTotalLength();
            metas.push({ pe: pe, len: len, st: { p: 0 } });
            inkSum += pe.inkTime;
            strokes[i].path.setAttribute("stroke-dasharray", len + " " + len);
            strokes[i].path.setAttribute("stroke-dashoffset", len);
            strokes[i].path.style.opacity = "0"; // no round-cap nub pre-draw
          }
          var dur = clamp(0.55 + 0.22 * strokes.length, 1.2, 4);
          var drawTotal = Math.max(0.1, dur - lift * (strokes.length - 1));
          var t = at;
          for (i = 0; i < metas.length; i++) {
            var d = (metas[i].pe.inkTime / inkSum) * drawTotal;
            metas[i].d = d;
            tl.to(metas[i].st, { p: 1, duration: d, ease: metas[i].pe.ease }, t);
            t += d + lift;
          }
          window.hwOnUpdate(tl, function () {
            for (var i = 0; i < metas.length; i++) {
              var m = metas[i];
              strokes[i].path.style.strokeDashoffset = m.len * (1 - m.st.p);
              strokes[i].path.style.opacity = m.st.p > 0 ? "1" : "0";
            }
          });
          for (i = 0; i < built.fallbacks.length; i++) {
            gsap.set(built.fallbacks[i], { opacity: 0 });
            tl.to(
              built.fallbacks[i],
              { opacity: 1, duration: 0.4, ease: "power2.out" },
              at + dur * 0.5,
            );
          }
          return t - lift;
        }

        /* writeOn pose control — unknown → "trace" + console error */
        function writeOnPose(tl, built, at, pose) {
          if (pose !== "trace" && pose !== "reveal" && pose !== "off") {
            console.error('hw: unknown writeOn pose "' + pose + '" — falling back to "trace"');
            pose = "trace";
          }
          var all = built.strokes
            .map(function (s) {
              return s.path;
            })
            .concat(built.fallbacks);
          if (pose === "off") {
            for (var i = 0; i < all.length; i++) {
              all[i].style.opacity = "0";
              tl.set(all[i], { opacity: 1 }, at);
            }
            return at;
          }
          if (pose === "reveal") {
            // per-glyph staggered fade (the family sweep grammar); derived timing
            var byGlyph = {};
            for (var j = 0; j < built.strokes.length; j++) {
              (byGlyph[built.strokes[j].glyph] = byGlyph[built.strokes[j].glyph] || []).push(
                built.strokes[j].path,
              );
            }
            var keys = Object.keys(byGlyph);
            for (var k = 0; k < keys.length; k++) {
              var paths = byGlyph[keys[k]];
              for (var m = 0; m < paths.length; m++) {
                gsap.set(paths[m], { opacity: 0 });
                tl.to(paths[m], { opacity: 1, duration: 0.3, ease: "power2.out" }, at + k * 0.12);
              }
            }
            for (var f = 0; f < built.fallbacks.length; f++) {
              gsap.set(built.fallbacks[f], { opacity: 0 });
              tl.to(
                built.fallbacks[f],
                { opacity: 1, duration: 0.3, ease: "power2.out" },
                at + keys.length * 0.06,
              );
            }
            return at + keys.length * 0.12 + 0.3;
          }
          return writeOnTrace(tl, built, at);
        }

        /* ---- build ---- */
        var table = window.__hwPenCaveat;
        var scalePx = CONFIG.fontSize / 1000;
        var svg = document.getElementById("hw-wt-svg");
        var built = buildWord(svg, CONFIG.text);
        var wUnits = built.widthUnits;
        var hUnits = table.meta.ascent - table.meta.descent;
        var wPx = wUnits * scalePx;
        var hPx = hUnits * scalePx;
        svg.setAttribute("width", Math.ceil(wPx));
        svg.setAttribute("height", Math.ceil(hPx));
        svg.setAttribute("viewBox", "0 " + -table.meta.ascent + " " + wUnits + " " + hUnits);

        var wrap = document.getElementById("hw-wt-wrap");
        var move = document.getElementById("hw-wt-move");
        move.style.position = "absolute";
        move.style.left = (CONFIG.x === null ? Math.round((1920 - wPx) / 2) : CONFIG.x) + "px";
        move.style.top = (CONFIG.y === null ? Math.round((1080 - hPx) / 2) : CONFIG.y) + "px";

        var tl = gsap.timeline({ paused: true });

        var startAt = CONFIG.animationIn ? 0.35 : 0;
        var writeEnd = startAt;
        if (CONFIG.animationIn) {
          writeEnd = writeOnPose(tl, built, startAt, CONFIG.writeOn);
        } else {
          // hard-on pose regardless of writeOn (animationIn=false = instant-on)
          writeEnd = writeOnPose(tl, built, 0, "off");
        }

        /* squiggle underline (accent), drawn as the write lands */
        var underPath = document.getElementById("hw-wt-under-path");
        if (CONFIG.underline) {
          var uw = Math.round(wPx);
          var usvg = document.getElementById("hw-wt-under");
          usvg.setAttribute("width", uw);
          usvg.setAttribute("viewBox", "0 0 " + uw + " 40");
          var segs = Math.max(6, Math.round(uw / 90));
          var d = "M 2 " + (18 + window.hwHash(0, SEED) * 4).toFixed(1);
          for (var i = 1; i <= segs; i++) {
            var x2 = (uw / segs) * i;
            var y2 = 18 + window.hwHash(i * 5 + 1, SEED) * 6;
            var cxp = x2 - uw / segs / 2 + window.hwHash(i * 5 + 2, SEED) * 10;
            var cyp = 18 + (i % 2 ? -1 : 1) * (9 + window.hwHash(i * 5 + 3, SEED) * 4);
            d +=
              " Q " +
              cxp.toFixed(1) +
              " " +
              cyp.toFixed(1) +
              " " +
              x2.toFixed(1) +
              " " +
              y2.toFixed(1);
          }
          underPath.setAttribute("d", d);
          var ulen = underPath.getTotalLength();
          gsap.set(underPath, {
            strokeDasharray: ulen + " " + ulen,
            strokeDashoffset: ulen,
            opacity: 0,
          });
          var uAt = Math.min(writeEnd + 0.1, DUR - 1.2);
          tl.set(underPath, { opacity: 1 }, uAt);
          tl.to(underPath, { strokeDashoffset: 0, duration: 0.7, ease: "power2.inOut" }, uAt);
        } else {
          document.getElementById("hw-wt-under").style.display = "none";
        }

        /* the boil rides its own wrapper; entrances/exits ride #hw-wt-move */
        window.hwBoilPose(tl, "#hw-wt-boil", CONFIG.boil, { seed: SEED });

        if (CONFIG.animationOut) {
          tl.to(move, { opacity: 0, duration: OUT, ease: "power2.in" }, DUR - OUT - 0.05);
        }
        tl.set("#hw-wt-root", { visibility: "hidden" }, DUR - 0.02);

        window.__timelines["hw-write-title"] = tl;
      })();
    </script>
  </body>
</html>
```

Copy npx hyperframes add hw-write-title to the clipboard

That writes `compositions/hw-write-title.html`, plus 2 supporting files under `assets/baked/` and `assets/fonts/`.

## Add it to your video

It runs for 6 seconds at 1920×1080. Paste this into your composition:

```html index.html
<div
  data-composition-id="hw-write-title"
  data-composition-src="compositions/hw-write-title.html"
  data-start="0"
  data-duration="6"
  data-track-index="1"
  data-width="1920"
  data-height="1080"
></div>
```

Move it in time with `data-start`. Put it on a different timeline row with
`data-track-index`. See [data attributes](/concepts/data-attributes.md) for the rest.

{/* hf:generated-footer */}

Tagged `handwritten` `typography` `title-card` `write-on` `overlay`.

## Related topics

* [Browse the complete Catalog](/catalog.md)
* [Add assets and Catalog items in the browser editor](/studio/assets-and-blocks.md)
* [Put blocks together into one video](/concepts/compositions.md)
