Plot boxed zoom

[nongiach]

Hello,

Very happy to make my first contribution here!

This adds boxed zooming feature on plots.
demo: https://www.youtube.com/watch?v=oUSWUgdFBCs

To allow the feature to work I added:

• Plot::allow_boxed_zoom(bool). Default true
• Plot::boxed_zoom_pointer(PointerButton). Default: Secondary
• PlotMemory::last_click_pos_for_zoom: Option<Pos2>, Default None
• ScreenTransform::bounds_mut(&mut self) -> &mut PlotBounds

Also changelog has been updated, check.sh is passing. And next time I will make sure to create an issue first.

I had a little non related issue in check.sh so double check for me please.

Regards,

[emilk]

Nice! Please add instructions for this in the "Instructions" tab in the pot demo. It would also be good to document in the docstring for Plot.

[Bromeon]

This is a great feature! 👍

I wonder, if instead of a bool yes/no, it would make sense to have different modes?

enum RegionZoom {
   None,     // disallow
   Rect,     // rect/box, like current PR
   XRange,   // only horizontal, along X axis
   YRange,   // only vertical, along Y axis
}

The X/Y ones are for scaling only along one axis:

[nongiach]

@emilk tests are passing my side, I updated with all your comments.
Let me know if we need additional update on this.

👍

[emilk]

awesome!