View2D had some inconsistencies making it error prone in some cases.
- Inconstant checking for NULL x/y args.
Disallow NULL args for x/y destination pointers, instead add:
- UI_view2d_region_to_view_x/y
- UI_view2d_view_to_region_x/y
- '_no_clip' suffix wasn't always used for non-clipping conversion,
switch it around and use a '_clip' suffix for all funcs that clip.
- UI_view2d_text_cache_add now clips before adding cache.
- '_clip' funcs return a bool to quickly check if its in the view.
- add conversion for rectangles, since this is a common task:
- UI_view2d_view_to_region_rcti
- UI_view2d_region_to_view_rctf
9ae0e585b0