Selection tool dual behaviour

The Select box tool currently works the same way whatever the direction of the mouse: from top-left to bottom-right, or reverse.

I propose the following: If you click and drag to the right (a window selection), you select only what’s completely inside the box. If you click and drag to the left (a crossing selection), anything completely or partially inside the box becomes selected.

So, when lots of small objects are front of a bigger one (a background plane for example), and you just want to select the small ones, doing a window selection won't pick the big object. While doing a crossing selection will select them all.

This behaviour is currently used in Sketchup and is very intuitive.