@sveltecraft/p5-svelte

A Svelte component wrapper for p5.js sketches.

Installation

⚠️ Warning p5.js 2.0+ has a slightly different API than older versions. In the new version, asset preloading is done in setup instead of the preload function.

npm i @sveltecraft/p5-svelte p5

Global Mode

If you want to copy-paste standard p5.js examples without the p. prefix, use the p5 attachment function with Svelte's {@attach} directive:

<script>
    import { p5 } from '@sveltecraft/p5-svelte';

    let x = 0;
    let y = 0;
    let diameter = $state(50);

    function setup() {
        createCanvas(800, 600);
        noStroke();
    }

    function draw() {
        background(10);
        x = lerp(x, mouseX, 0.05);
        y = lerp(y, mouseY, 0.05);
        fill(255);
        circle(x, y, diameter);
    }
</script>

<div {@attach p5({ setup, draw })}></div>

<label>
    diameter
    <input type="range" bind:value={diameter} min={10} max={200} />
    {diameter}
</label>

The p5() function runs p5 in its native global mode — all p5 methods (createCanvas, background, fill, …) and properties (mouseX, mouseY, width, height, …) are available as globals. The attachment lifecycle is managed automatically by Svelte (mounts with the element, cleans up on unmount).

TypeScript: p5 global functions are injected at runtime, so your editor may report them as unknown. Install @types/p5 and add /// <reference types="@types/p5/global" /> to your entry point for full type support.

Instance Mode

Import the P5Sketch component and the optional Sketch type. After that create a sketch function with a setup and draw function. Since we're using instance mode we have to prefix any p5 method with p which we receive as an argument:

<script lang="ts">
    import P5Sketch, { type Sketch } from '@sveltecraft/p5-svelte';

    let x = 0;
    let y = 0;
    let diameter = $state(50);

    const sketch: Sketch = (p) => {
        p.setup = () => {
            p.createCanvas(800, 600);
            p.noStroke();
        };
        p.draw = () => {
            p.background(4);
            x = p.lerp(x, p.mouseX, 0.05);
            y = p.lerp(y, p.mouseY, 0.05);
            p.fill(255);
            p.circle(x, y, diameter);
        };
    };
</script>

<P5Sketch {sketch} />

<label>
    diameter
    <input type="range" bind:value={diameter} min={10} max={200} />
    {diameter}
</label>

Multiple Sketches

You can create as many sketches as you want:

<script lang="ts">
    import P5Sketch, { type Sketch } from '@sveltecraft/p5-svelte';

    const walker: Sketch = (p) => {
        // ...
    };

    const randomNumberDistribution: Sketch = (p) => {
        // ...
    };
</script>

<!-- walker -->
<P5Sketch sketch={walker} />

<!-- random number distribution -->
<P5Sketch sketch={randomNumberDistribution} />

Abstracting Code

If you want to abstract your code into a class or function keep in mind you have to pass the p5 object to it:

<script lang="ts">
    import type p5 from 'p5';

    class Walker {
        p: p5;
        x = 0;
        y = 0;

        constructor(p: p5) {
            this.p = p;
            this.x = this.p.width / 2;
            this.y = this.p.height / 2;
        }

        show() {
            this.p.stroke(255);
            this.p.point(this.x, this.y);
        }

        step() {
            let xstep = this.p.random(-1, 1);
            let ystep = this.p.random(-1, 1);
            this.x += xstep;
            this.y += ystep;
        }
    }

    const sketch: Sketch = (p) => {
        let walker: Walker;
        p.setup = () => {
            walker = new Walker(p);
            p.createCanvas(400, 400);
            p.background(10);
        };
        p.draw = () => {
            walker.step();
            walker.show();
        };
    };
</script>

<P5Sketch {sketch} />

Addons

This section shows how to use legacy addons that only work with a global p5 instance and ones that support instance mode. You have to install addons using npm instead of using a CDN.

Legacy Global Mode Addons

Addons like p5.sound work only in global mode, so we have to load them using the addons array before the sketch initializes:

<script lang="ts">
    import P5Sketch, { type Sketch } from '@sveltecraft/p5-svelte';

    // 🚫 this doesn't work
    import 'p5.sound';

    // 👍 pass your legacy addons here
    const addons = [() => import('p5.sound')];

    const sketch: Sketch = (p) => {
        let sound: any;
        p.setup = async () => {
            sound = await (p as any).loadSound('/sfx.mp3');
            p.createCanvas(400, 400);
        };
        p.draw = () => {
            p.background(10);
        };
        p.mousePressed = () => {
            sound.play();
        };
    };
</script>

<!-- pass the addons -->
<P5Sketch {sketch} {addons} />

Addons like p5.sound look for window.p5 at load time to extend the library. By passing addons as an array, the component:

1. Loads p5 dynamically
2. Assigns p5 to window.p5 before loading addons
3. Waits for all addons to load
4. Then initializes your sketch

This ensures addons are properly registered before your sketch runs.

Instance Mode Addons

Addons like p5.brush support global and instance mode. You can learn how to use it by reading their docs. Here's an example of using the p5.brush addon:

<script lang="ts">
    import P5Sketch, { type Sketch } from '@sveltecraft/p5-svelte';
    import * as brush from 'p5.brush';

    const sketch: Sketch = (p) => {
        brush.instance(p);

        p.setup = () => {
            p.createCanvas(400, 400, p.WEBGL);
        };

        p.draw = () => {
            // ...
        };
    };
</script>

<P5Sketch {sketch} />

API

P5Sketch Props

• sketch (required): A function that receives a p5 instance and defines setup and draw methods
• addons (optional): Array of async functions that load p5 addons
• style (optional): CSS styles to apply to the canvas container
• class (optional): CSS class to apply to the canvas container

p5() Options (Global Mode)

• setup (optional): p5 setup function using global p5 methods
• draw (optional): p5 draw function using global p5 methods
• addons (optional): Array of async functions that load p5 addons