pixijs-performance

What this skill does

Profile before optimizing. PixiJS handles a lot of content well out of the box; browser DevTools Performance + GPU profiling should be your first move. Once you've found the bottleneck, apply the targeted pattern below (destroy, pool, batch, cache, or cull).

## Quick Start

```ts
container.cacheAsTexture(true);
container.updateCacheTexture();
container.cacheAsTexture(false);
container.destroy({ children: true });

import { CullerPlugin, extensions } from "pixi.js";
extensions.add(CullerPlugin);

offscreenContainer.cullable = true;
offscreenContainer.cullArea = new Rectangle(0, 0, 256, 256);

// Tune GC via init options (ms). The `textureGC.*` properties are
// deprecated since 8.15.0 — use these on the Application init instead.
await app.init({ gcMaxUnusedTime: 60_000, gcFrequency: 30_000 });
```

**Related skills:** `pixijs-scene-container` (destroy options), `pixijs-scene-core-concepts` (render groups, layers, culling), `pixijs-scene-text` (BitmapText for dynamic content), `pixijs-assets` (atlasing), `pixijs-custom-rendering` (custom batchers).

## Core Patterns

### Proper destroy with cleanup

```ts
import { Sprite, Assets } from "pixi.js";

const texture = await Assets.load("character.png");
const sprite = new Sprite(texture);

// Destroy sprite only (preserve texture for reuse)
sprite.destroy();

// Destroy sprite AND its texture
sprite.destroy({ children: true, texture: true, textureSource: true });
```

When done with a loaded asset entirely:

```ts
Assets.unload("character.png");
```

This removes it from the cache and unloads the GPU resource.

### Application destroy/recreate cycle

```ts
import { Application } from "pixi.js";

// Correct destroy that cleans global pools
app.destroy({ releaseGlobalResources: true });

const newApp = new Application();
await newApp.init({ width: 800, height: 600 });
```

Without `releaseGlobalResources: true`, pooled objects (batches, textures) from the old app leak into the new one, causing flickering and corruption.

### Texture garbage collection

PixiJS auto-collects unused textures and GPU resources via `GCSystem`. Defaults: checks every 30 seconds, removes resources idle for 60 seconds. These are time-based (milliseconds).

```ts
import { Application } from "pixi.js";

const app = new Application();

await app.init({
  gcActive: true,
  gcMaxUnusedTime: 120000, // idle time before cleanup in ms (default: 60000)
  gcFrequency: 60000, // check interval in ms (default: 30000)
});
```

For manual control:

```ts
texture.source.unload(); // immediate GPU memory release
```

### PrepareSystem for GPU upload

Upload textures and graphics to GPU before rendering to avoid first-frame hitches:

```ts
import "pixi.js/prepare";
import { Application, Assets } from "pixi.js";

const app = new Application();
await app.init();

// Don't render until assets are uploaded
app.stop();

const texture = await Assets.load("large-scene.png");

// Upload to GPU ahead of time
await app.renderer.prepare.upload(app.stage);

// Now rendering won't hitch on first frame
app.start();
```

`prepare.upload()` accepts a Container (uploads all textures, text, and graphics in the subtree) or individual resources.

### cacheAsTexture for performance

`cacheAsTexture()` renders a container's subtree to a single texture, reducing draw calls for complex static content. Internally it creates a render group and caches the result.

**When to use:**

- Many static children (UI panels, decorative backgrounds, complex Graphics)
- Containers with expensive filters (cache the filter result)
- Large subtrees that rarely change

**Tradeoffs:**

- Uses GPU memory for the cached texture (larger containers = more memory)
- Max texture size is GPU-dependent (typically 4096x4096; check `renderer.texture.maxTextureSize`)
- Must call `updateCacheTexture()` after modifying children
- Combining with masks is fragile (see the masking skill)

```ts
import { Container, Sprite } from "pixi.js";

const panel = new Container();
// ... add many static children ...

panel.cacheAsTexture(true);

// With options
panel.cacheAsTexture({ resolution: 2, antialias: true });

// Refresh after changes
panel.updateCacheTexture();

// MUST disable before destroying (see Common Mistakes below)
panel.cacheAsTexture(false);
panel.destroy();
```

**Avoid:** toggling on/off repeatedly (constant re-caching negates benefits), caching sparse containers (negligible gain), caching containers larger than 4096x4096.

### Object recycling

Reuse objects by changing their properties instead of destroy/recreate:

```ts
import { Sprite, Container, Texture } from "pixi.js";

class BulletPool {
  private _pool: Sprite[] = [];
  private _container: Container;

  constructor(container: Container) {
    this._container = container;
  }

  public get(texture: Texture): Sprite {
    let bullet = this._pool.pop();

    if (!bullet) {
      bullet = new Sprite(texture);
      this._container.addChild(bullet);
    }

    bullet.texture = texture;
    bullet.position.set(0, 0);
    bullet.rotation = 0;
    bullet.scale.set(1);
    bullet.alpha = 1;
    bullet.tint = 0xffffff;
    bullet.blendMode = "normal";
    bullet.visible = true;
    return bullet;
  }

  public release(bullet: Sprite): void {
    bullet.visible = false;
    this._pool.push(bullet);
  }
}
```

Destroying and recreating is significantly more expensive than toggling `visible` and updating properties. GPU resources stay allocated; only scene graph visibility changes.

### Batching optimization

PixiJS batches similar consecutive objects into single draw calls. Batch breaks occur on:

- Object type change (Sprite vs Graphics)
- Texture source change (beyond the per-batch texture limit, typically 16)
- Blend mode change
- Topology change

Optimize draw order:

```ts
import { Sprite, Graphics, Container } from "pixi.js";

// 4 draw calls: type alternates
const bad = new Container();
bad.addChild(new Sprite(t1));
bad.addChild(new Graphics().rect(0, 0, 10, 10).fill(0xff0000));
bad.addChild(new Sprite(t2));
bad.addChild(new Graphics().rect(0, 0, 10, 10).fill(0x00ff00));

// 2 draw calls: types grouped
const good = new Container();
good.addChild(new Sprite(t1));
good.addChild(new Sprite(t2));
good.addChild(new Graphics().rect(0, 0, 10, 10).fill(0xff0000));
good.addChild(new Graphics().rect(0, 0, 10, 10).fill(0x00ff00));
```

Same principle applies to blend modes: `screen/normal/screen/normal` = 4 draws; `screen/screen/normal/normal` = 2 draws.

### Spritesheets over individual textures

```ts
import { Assets, Sprite } from "pixi.js";

// Load a spritesheet (single texture atlas)
const sheet = await Assets.load("game-atlas.json");

// All frames share one GPU texture; enables batching
const hero = new Sprite(sheet.textures["hero.png"]);
const enemy = new Sprite(sheet.textures["enemy.png"]);
const coin = new Sprite(sheet.textures["coin.png"]);
```

Individual textures each require their own GPU upload and break batches when the texture limit is exceeded. Spritesheets consolidate many frames into one atlas texture.

Use `@0.5x` filename suffix on half-resolution sheets so PixiJS auto-scales them.

### Text performance

Text and HTMLText re-render to a canvas and re-upload to the GPU on every change. Never update them per frame unconditionally:

```ts
import { BitmapText, Text } from "pixi.js";

// Wrong: re-renders canvas + GPU upload every frame
app.ticker.add(() => {
  scoreText.text = `Score: ${score}`;
});

// Correct: use BitmapText for frequently changing content
const scoreText = new BitmapText({
  text: "Score: 0",
  style: { fontFamily: "Arial", fontSize: 24, fill: 0xffffff },
});

app.ticker.add(() => {
  scoreText.text = `Score: ${score}`;
});
```

BitmapText renders from a pre-generated glyph atlas. Updates only reposition quads; no canvas re-render or GPU upload. Use it for scores, timers, counters, and anything that changes frequently.

If you must use canvas Text, guard updates so they only happen when the value changes:

```ts