GUI rotation issue with ClipsDescendants

[buildthomas]

This is not a bug, this has been the case ever since rotation on GUI objects were released, and it has been made that way due to the fact that the paradigm (convex clipping) that could accomplish this is inefficient for real-time updates to the interface compared to clipping in axis-aligned GUI objects.

@zeuxcg

Stravant is correct - the reason this feature is not implemented atm is the requirement to change the UI code to work with arbitrary convex polygons everywhere instead of axis-aligned rectangles.

We can’t use scissor rectangles since they don’t provide full clipping support anyway as mentioned above; the only complete solution that does not need convex polygon clipping is stenciling, but it would require us to de-optimize current rendering code that aggressively merges geometry for visible UI elements to avoid CPU overhead.

We may end up implementing correct clipping some day but it would require a carefully optimized approach that only switches to slow convex clipping when absolutely necessary.

So probably not anywhere soon