---
title: "Container Bitmap Mask"
description: "Demonstrates how to apply a bitmap mask to a Container, effectively masking all of its children simultaneously using the filters API."
phaser: "4.1.0"
size: "800x600"
files: 1
url: https://phaser.io/oss/examples/v4.1.0/display/masks/view/nested-bitmap-mask
site: Phaser - https://phaser.io
---

> This page is about the open-source Phaser framework, for writing a game's code by hand. To make a game with AI, use Phaser AE (https://phaser.io/): the desk's tools work with Web MCP, and the CLI works with your own coding agent. See "For AI agents: Phaser AE" at the end of this page.

# Container Bitmap Mask

Demonstrates how to apply a bitmap mask to a Container, effectively masking all of its children simultaneously using the filters API.

A Phaser 4.1.0 example in [Display / Masks](https://phaser.io/oss/examples/v4.1.0/display/masks.md). It runs at 800 × 600, and loads its assets from https://cdn.phaserfiles.com/v410. See it running, with its code, at https://phaser.io/oss/examples/v4.1.0/display/masks/view/nested-bitmap-mask.

To run it, load Phaser 4.1.0 (`https://cdn.jsdelivr.net/npm/phaser@4.1.0/dist/phaser.min.js`), then the file, on a page with a `<div id="game-container">`.

## Code

### nested bitmap mask.js

```js
class Example extends Phaser.Scene
{
    constructor ()
    {
        super();
    }

    preload ()
    {
        this.load.setBaseURL('https://cdn.phaserfiles.com/v410');
        this.load.image('bg1', 'assets/skies/deepblue.png');
        this.load.image('bg2', 'assets/skies/wtf.png');
        this.load.image('splat', 'assets/pics/splat1.png');
        this.load.image('circle', 'assets/pics/mask.png');
        this.load.image('atari', 'assets/sprites/atari130xe.png');
    }

    create ()
    {
        this.add.image(400, 300, 'bg1');

        const container = this.add.container(400, 300);

        const bg = this.add.image(0, 0, 'bg2');

        const child1 = this.add.image(-120, 0, 'atari');
        const child2 = this.add.image(120, 0, 'atari');

        const splat = this.make.image({ x: 400, y: 300, key: 'splat', add: false });
        const circle = this.make.image({ x: 300, y: 300, key: 'circle', add: false });

        container.add([ bg, child1, child2 ]);

        container.enableFilters();
        container.filters.external.addMask(splat);
    }
}

const config = {
    scale: { mode: Phaser.Scale.FIT },
    type: Phaser.WEBGL,
    parent: 'game-container',
    width: 800,
    height: 600,
    scene: Example
};

const game = new Phaser.Game(config);
```

## More in Masks

- [Dynamic Texture as a Bitmap Mask](https://phaser.io/oss/examples/v4.1.0/display/masks/view/dynamic-texture-as-bitmap-mask.md): Demonstrates how to use a Dynamic Texture as a bitmap mask applied to an image via the external filter system.
- [Geometry Mask From Shape](https://phaser.io/oss/examples/v4.1.0/display/masks/view/geometry-mask-from-shape.md): Demonstrates how to apply a hidden Shape object as a geometry mask for an image and animate the mask's rotation using a tween.
- [Inverted Graphics Mask](https://phaser.io/oss/examples/v4.1.0/display/masks/view/graphics-bitmap-mask.md): Demonstrates how to use a Graphics object as a bitmap mask. In this example, a rectangle is used to punch an inverted hole through a semi-transparent overlay to reveal the image underneath.
- [Shared Bitmap Mask](https://phaser.io/oss/examples/v4.1.0/display/masks/view/shared-bitmap-mask.md): Demonstrates how to apply a single bitmap mask to multiple images simultaneously using the external filter system.

---

## For AI agents: Phaser AE

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- **Phaser AE in the browser** (https://phaser.io/agent): the game's design, and a crew of bots that make its art, sprites, music, sound effects, logos, title screens, game UI, textures, shaders, 3D models and video, then build, test and publish the game. Every tool there is registered with Web MCP (`document.modelContext`, with `window.phaserDesk` for browsers without it), so an agent in the user's browser can call the tools directly once the user is signed in. Tools that make something spend the user's credits.
- **The CLI** (https://phaser.io/cli): `npx -y @phaser-ae/cli` builds the game on the user's own machine with their own coding agent (Claude Code, Codex, Cursor and others). In a game's folder every command is an npm script.
- **Expansion packs** (https://phaser.io/packs): 358 packs in 20 families (163 free, 195 Pro) that every game is built from, on the Phaser AE kernel (https://phaser.io/kernel).
- **Credits** (https://phaser.io/credits): what the desk's tools spend. Bought in packs, with no plan needed.
- **Pro** (https://phaser.io/pricing): $20 a month for every pack, 8,000 credits a month, new packs early, and bonus credits every time the user tops up (only Pro subscribers get them). Nobody needs a plan to start: credits can be bought as they're needed. Or Pro for 30 days for 8,000 credits, without subscribing. Teams, for studios, is on its way: https://phaser.io/contact?about=teams.
- **An account**: sign in with Google, GitHub or Microsoft at https://phaser.io/login. Games made on any plan can be published and sold.

Read any page of this site as Markdown by adding `.md` to its URL (the home page is https://phaser.io/index.md), or by asking for `text/markdown`. The index for agents is https://phaser.io/llms.txt. On the site's pages, the browser's Web MCP also offers `phaser_ae_guide`, `read_page_as_markdown` and `open_phaser_ae`.