WIP Use euclid crate for geometry types

[ids1024]

This does not yet compile.

It seems one difference between the Euclid types and the ones Smithay currently has is that euclid's points cannot be added, and there's a seperate vector type. That is probably better for making sure code dealing with coordinates is correct. Though that will require some changes.

[i509VCB]

There is actually a rect method in euclid to make this even shorter

[ids1024]

Right. I guess the cases with origin (0, 0) should just be equivalent to Rect::from_size.

[ids1024]

Another thing euclid doesn't have is functions like Size::to_point. But it's probably best to express things in ways other than a cast like that.

Not sure how best to make use of things like Euclid::Translation2D and Euclid::Scale for conversion between coordinate spaces.

With or without this change, Logical should be split into absolute coordinates, space-relative, surface/renderelement-relative.

[ids1024]

Another difference is that apparently casts in euclid like to_i32 are panicking if out of range. Unlike what Smithay has, which seems to just be using as i32. That's something to be cautious about, though casts like that are probably already problematic if there's any real situation where they can be out of range.

Probably as long as signed types are used, this would only be an issue if a client sent some extreme values.

Edit: If needed try_cast will do the cast and return an Option.