Hi @Fudge,
The strategy to use depends on your visualization and platform. It’s challenging to have a solution that meets every case. For instance, on Android, you would use all the screen size but should decide how to adapt to a rotation of the screen. Are you going to apply a ratio to the whole viz to fit in the screen or are you going to clip it?
In any case, it’s possible on all platform to get the size of the containing window. You can then set the viz to that size and draw a rectangle of half the width.