Pixijs Ticker

`app.ticker` runs registered callbacks every frame and drives `app.render()` at `UPDATE_PRIORITY.LOW`. Each callback receives the Ticker instance; read `deltaTime` as a frame-rate-independent multiplier (≈1.0 at 60fps) or `deltaMS` for real-time calculations.

## Quick Start

```ts
app.ticker.add((ticker) => {
  sprite.rotation += 0.01 * ticker.deltaTime;
  sprite.x += (200 / 1000) * ticker.deltaMS;
});

app.ticker.add(
  (ticker) => {
    updatePhysics(ticker.deltaMS);
  },
  undefined,
  UPDATE_PRIORITY.HIGH,
);

app.ticker.maxFPS = 30;
app.ticker.speed = 0.5;

sprite.onRender = () => {
  sprite.scale.x = Math.sin(performance.now() / 500);
};
```

**Related skills:** `pixijs-application` (Application setup and sharedTicker option), `pixijs-performance` (frame rate optimization), `pixijs-migration-v8` (v7 ticker signature changes).

## Core Patterns

### Time units

The Ticker exposes three timing values, each for different use cases:

| Property    | Type                          | Scaled by speed? | Capped by minFPS? | Use case                                     |
| ----------- | ----------------------------- | ---------------- | ----------------- | -------------------------------------------- |
| `deltaTime` | dimensionless (~1.0 at 60fps) | yes              | yes               | Frame-rate-independent animation multipliers |
| `deltaMS`   | milliseconds                  | yes              | yes               | Time-based calculations (pixels/sec)         |
| `elapsedMS` | milliseconds                  | no               | no                | Raw measurement, profiling                   |

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

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

app.ticker.add((ticker) => {
  // deltaTime: dimensionless scalar, ~1.0 at 60fps
  sprite.rotation += 0.1 * ticker.deltaTime;

  // deltaMS: real milliseconds (speed-scaled, capped)
  sprite.x += (200 / 1000) * ticker.deltaMS; // 200 pixels per second

  // elapsedMS: raw milliseconds (no scaling, no cap)
  console.log(`Raw frame time: ${ticker.elapsedMS}ms`);
});
```

**Tension note:** `deltaTime` is not milliseconds. It is `deltaMS * Ticker.targetFPMS` where targetFPMS is 0.06 (i.e. 1/16.67). At exactly 60fps, deltaTime is 1.0. At 30fps, deltaTime is 2.0. This catches people who treat it as a time value.

### Priority ordering and context binding

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

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

// INTERACTION (50) > HIGH (25) > NORMAL (0) > LOW (-25) > UTILITY (-50)
// app.render() is registered at LOW by the TickerPlugin

app.ticker.add(
  (ticker) => {
    // Physics runs before normal-priority callbacks
    updatePhysics(ticker.deltaMS);
  },
  undefined,
  UPDATE_PRIORITY.HIGH,
);

app.ticker.add((ticker) => {
  // Default priority (NORMAL = 0), runs after HIGH but before render
  updateAnimations(ticker.deltaTime);
});

// Pass `this` as the second argument to preserve context on class methods
class GameSystem {
  public speed = 5;
  public position = 0;

  public update(ticker: Ticker): void {
    this.position += this.speed * ticker.deltaTime;
  }
}

const system = new GameSystem();
app.ticker.add(system.update, system);
app.ticker.remove(system.update, system); // must match both fn and context
```

### Frame rate capping

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

const ticker = new Ticker();

ticker.maxFPS = 30; // Cap at 30fps (skips frames to mainta