wlr_damage_ring: Add wlr_damage_ring_contains_xxx functions

• Added wlr_damage_ring_contains_region to check if a pixman region is fully contained within the current damage tracked by the ring.
• Added wlr_damage_ring_contains_box to verify whether a wlr_box is fully contained within the current damage.

These functions help determine whether specific areas are already covered by the damage ring.

I'm having trouble understanding why these functions would be useful. They inherently make no sense because the damage will be different depending on which buffer is chosen from the swapchain.

Why not just call wlr_damage_ring_rotate_buffer() and check if things are contained depending on the returned region?

closed