Hints to indicate compositor how to deal with a conflict between the dimensions for the surface and the dimensions of the output. As a hint the compositor is free to ignore this parameter.

"default" The client has no preference on fullscreen behavior, policies are determined by compositor.

"scale" The client prefers scaling by the compositor. Scaling would always preserve surface's aspect ratio with surface centered on the output

"driver" The client wants to switch video mode to the smallest mode that can fit the client buffer. If the sizes do not match the compositor must add black borders.

"fill" The surface is centered on the output on the screen with no scaling. If the surface is of insufficient size the compositor must add black borders.