pathEffects.js
Area: Geometry
Punk, Bloat, PunkBloat, BloatPunk, Twirl, AntiTwirl, and Retract All effects for selected curves, plus Make Rectangle and Make Ellipse replacements. Handles are pushed toward or away from the object centre, the curves are rebuilt with CurveBuilder, and the result is applied with DocumentCommand.createSetCurves.
Source: pathEffects.js
Example scripts
pathEffects.js
pathEffects.js
/*
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Copyright (c) 2026, Canva Pty Ltd.
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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*/
'use strict';
// Path effects for selected curve objects (convert shapes or text to curves first).
//
// Punk: pushes all control handles toward the centre of the object.
// Bloat: pushes all control handles away from the centre.
// PunkBloat / BloatPunk: one handle toward the centre, the other away.
// Twirl / AntiTwirl: the outgoing (or incoming) handle toward the centre, the other unchanged.
// Retract All: retracts all control handles.
// Make Rectangle / Make Ellipse: replaces the curves with the bounding rectangle or ellipse.
const { AddChildNodesCommandBuilder, CompoundCommandBuilder, DocumentCommand } = require('/commands.js');
const { Dialog, DialogResult } = require('/dialog.js');
const { Document } = require('/document.js');
const { Curve, CurveBuilder, PolyCurve } = require('/geometry.js');
const { PolyCurveNodeDefinition } = require('/nodes.js');
const { UnitType } = require('/units.js');
const Effect = Object.freeze({
Punk: 0, Bloat: 1, PunkBloat: 2, BloatPunk: 3, Twirl: 4, AntiTwirl: 5, RetractAll: 6, MakeRectangle: 7, MakeEllipse: 8
});
const EffectNames = ["Punk", "Bloat", "PunkBloat", "BloatPunk", "Twirl", "AntiTwirl", "Retract All", "Make Rectangle", "Make Ellipse"];
function isOk(result) {
return (result?.value ?? result) == DialogResult.Ok.value;
}
function compound(cmds) {
if (cmds.length == 0)
return null;
const builder = CompoundCommandBuilder.create();
for (const cmd of cmds)
builder.addCommand(cmd);
return builder.createCommand();
}
function samePoint(a, b) {
return Math.abs(a.x - b.x) < 1e-6 && Math.abs(a.y - b.y) < 1e-6;
}
// Decomposes a curve into anchors with left (incoming) and right (outgoing) handles.
function decompose(curve) {
const bez = curve.beziers.toArray();
if (bez.length == 0)
return null;
const closed = curve.isClosed;
const wraps = closed && samePoint(bez[bez.length - 1].end, bez[0].start);
const pts = bez.map(b => ({ anchor: b.start, left: null, right: b.c1 }));
if (!wraps)
pts.push({ anchor: bez[bez.length - 1].end, left: null, right: null });
for (let i = 0; i < bez.length; ++i)
pts[(i + 1) % pts.length].left = bez[i].c2;
for (const p of pts) {
p.left ??= p.anchor;
p.right ??= p.anchor;
}
return { pts, closed };
}
function rebuild(pts, closed) {
const b = CurveBuilder.create().beginXY(pts[0].anchor.x, pts[0].anchor.y);
const segments = closed ? pts.length : pts.length - 1;
for (let i = 0; i < segments; ++i) {
const p = pts[i], q = pts[(i + 1) % pts.length];
b.addBezierXY(p.right.x, p.right.y, q.left.x, q.left.y, q.anchor.x, q.anchor.y);
}
if (closed)
b.close();
return b.createCurve();
}
function applyEffect(pts, effect, centre, amount) {
for (const p of pts) {
const a = p.anchor;
const dx = centre.x - a.x, dy = centre.y - a.y;
const x = dx * amount, y = dy * amount;
const toward = { x: centre.x - x, y: centre.y - y };
const away = { x: a.x - x, y: a.y - y };
const shifted = { x: a.x - (dx - x), y: a.y - (dy - y) };
switch (effect) {
case Effect.Punk: p.left = toward; p.right = toward; break;
case Effect.Bloat: p.left = away; p.right = away; break;
case Effect.PunkBloat: p.left = toward; p.right = shifted; break;
case Effect.BloatPunk: p.left = shifted; p.right = toward; break;
case Effect.Twirl: p.right = toward; break;
case Effect.AntiTwirl: p.left = toward; break;
case Effect.RetractAll: p.left = a; p.right = a; break;
}
}
}
function transformPolyCurve(polyCurve, effect, amount) {
const bounds = polyCurve.boundingBox;
const result = PolyCurve.create();
if (effect == Effect.MakeRectangle) {
result.addCurve(Curve.createRectangle(bounds));
return result;
}
if (effect == Effect.MakeEllipse) {
result.addCurve(Curve.createEllipse(bounds));
return result;
}
const centre = bounds.centre;
for (const curve of polyCurve.curves) {
const d = decompose(curve);
if (!d) {
result.addCurve(curve.clone());
continue;
}
applyEffect(d.pts, effect, centre, amount);
result.addCurve(rebuild(d.pts, d.closed));
}
return result;
}
// A new curve object carrying the node's fills and stroke, so "apply to a copy" is one command.
function copyDefinition(node, poly) {
const def = PolyCurveNodeDefinition.create(poly, node.brushFillDescriptor, node.penFillDescriptor,
node.lineStyleDescriptor, node.transparencyFillDescriptor);
def.transform = node.baseToSpreadTransform;
def.userDescription = node.description;
return def;
}
// Previews modify the nodes' curves, so always work from snapshots of the originals.
function createEffectCommand(sources, opts) {
const cmds = [];
const copies = AddChildNodesCommandBuilder.create();
let copyCount = 0;
for (const { node, original } of sources) {
const poly = transformPolyCurve(original, opts.effect, opts.amount);
if (poly.curveCount == 0)
continue;
if (opts.copyPath) {
copies.addNode(copyDefinition(node, poly));
++copyCount;
}
else {
cmds.push(DocumentCommand.createSetCurves(node.curvesInterface, poly));
}
}
if (copyCount > 0)
cmds.push(copies.createCommand(true));
return compound(cmds);
}
function readOptions(dlg) {
return {
effect: dlg.effect.selectedIndex,
amount: dlg.offset.value * 0.01,
copyPath: dlg.copyPath.value
};
}
function buildDialog() {
const dlg = Dialog.create("Path Effects");
const col = dlg.addColumn();
const effect = col.addGroup("Effect");
dlg.effect = effect.addRadioGroup("", EffectNames, Effect.Punk);
const opts = col.addGroup("Options");
dlg.offset = opts.addUnitValueEditor("Offset from centre %", UnitType.Number, UnitType.Number, 50, -1000, 1000).setPrecision(0);
dlg.copyPath = opts.addSwitch("Apply to a copy", false);
return dlg;
}
function main() {
const doc = Document.current;
if (!doc) {
alert("This script requires an open document");
return;
}
const nodes = doc.selection.nodes.filter(n => n.isPolyCurveNode).toArray();
if (nodes.length == 0) {
alert("Please select one or more curve objects (convert shapes or text to curves first)");
return;
}
const sources = nodes.map(node => ({ node, original: node.polyCurve.clone() }));
const dlg = buildDialog();
const update = (preview) => {
const cmd = createEffectCommand(sources, readOptions(dlg));
if (cmd)
doc.executeCommand(cmd, preview);
else
doc.clearPreviews();
};
dlg.onControlValueChangedHandler = () => update(true);
update(true);
if (isOk(dlg.runModal()))
update(false);
doc.clearPreviews();
}
module.exports.main = main;