# GUI Rendering

The GUI aims to be somewhat similar to immediate mode rendering, where the screen is re-rendered each sweep.
This is due to a few aims:

1. Functions should try and contain their state to the context struct (helps keep state usage flatter)
2. Allows external events to change the state
3. Means state can be read/write over BLE or other external control interfaces

## Transitions

When changing the view to a new view it can be preferable to transition using an animation.
The tooling provides for left, right and down animations at this point.
The use of these gives a notion of "direction" when navigating the menu.

```
<TODO>

```

The downside of supporting transitions is that for these to work, the code should render the screen _first_ then return the new state.
This ensures there is a good working copy in the buffer before the transition changes the view.

## TODO notes

On settings menu exit:

```
      OLED::useSecondaryFramebuffer(true);
      showExitMenuTransition = true;

```