# Follow2DRig

> Talos next · Since 0.6

## Signature

```ts
export class Follow2DRig implements CameraRig {
  readonly kind = "fixed" as const
  readonly inheritsFov = true
  readonly config: Follow2DConfig
  pose: CameraPose
  readonly yaw = 0
  readonly pitch = 0
  constructor(config: Partial<Follow2DConfig> = {})
  followTarget(ctx: Ctx): EntityHandle | null
  get center(): Vec2
  get leadOffset(): Vec2
  get pixelLens(): IntegerLens | null
  viewHalfSize(ctx: Ctx): Vec2 | null
  boundsRect(ctx: Ctx): Rect2 | null
  update(ctx: Ctx, dt: number, _input: RigInput): CameraPose
  engineParams(): Record<string, unknown>
}
```

Import: `import { Follow2DRig } from "@argus/gameplay"`

## Members

| Member | Signature | Description |
|---|---|---|
| `kind` | `readonly kind = "fixed" as const` |  |
| `inheritsFov` | `readonly inheritsFov = true` | No fov of its own: an orthographic lens ignores it, and a perspective one keeps the scene camera's. |
| `config` | `readonly config: Follow2DConfig` |  |
| `pose` | `pose: CameraPose` |  |
| `yaw` | `readonly yaw = 0` |  |
| `pitch` | `readonly pitch = 0` |  |
| `constructor` | `constructor(config: Partial<Follow2DConfig> = {})` |  |
| `followTarget` | `followTarget(ctx: Ctx): EntityHandle \| null` |  |
| `center` | `get center(): Vec2` | The view centre as of the last update, XY. |
| `leadOffset` | `get leadOffset(): Vec2` | The look-ahead offset in force, XY. |
| `pixelLens` | `get pixelLens(): IntegerLens \| null` | The whole-number lens `pixelScale` chose on the last update, or null. |
| `viewHalfSize` | `viewHalfSize(ctx: Ctx): Vec2 \| null` | Half the view's width and height, world units: the `pixelScale` lens when there is one, else `ctx.camera.viewSize`; null for a perspective lens. |
| `boundsRect` | `boundsRect(ctx: Ctx): Rect2 \| null` | The rectangle the view stays inside this tick, or null. |
| `update` | `update(ctx: Ctx, dt: number, _input: RigInput): CameraPose` |  |
| `engineParams` | `engineParams(): Record<string, unknown>` | The `pixelScale` lens as `ctx.camera.set` params: the box's `orthoSize`, and `pixelsPerUnit` as the art's texels a unit, so the engine picks the whole-number scale it is drawn at in the window. Nothing without one. |