> ## Documentation Index
> Fetch the complete documentation index at: https://xrlive.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Window Sync

> Keep the operator viewport in sync with the game window size

The xRLive Launcher runs two windows in the same process — the **operator dashboard** and the **game window** (where the visual renders). The Window Sync system lets the game window broadcast its size to the operator viewport in real time so the preview stays correctly proportioned.

## How it works

The `xRLive Window Sync Subsystem` (a `UGameInstanceSubsystem`) acts as the message bus between the two windows. Since both windows share the same process and game instance, the subsystem is globally accessible from any Blueprint.

```
Game window resizes
    ↓
Publish Game Window Size (NewSize)  ← call this from your game window BP
    ↓
OnGameWindowSizeChanged delegate fires
    ↓
xRLive_Viewport updates its Size Box aspect ratio  ← handled automatically
```

## Getting the subsystem

```
Get Game Instance → Get Subsystem (xRLive Window Sync Subsystem)
```