Another step towards a cleaner API, with a cleaner separation of purposes.
Also avoids wasting a whopping one third of the flag space on what really
shouldn't have been a flag to begin with.
I pre-emptively decided to separate the scaler selection between "scaler"
and "scaler_sub", the latter defining what's used for things like 4:2:0
subsampling.
This allows us to get rid of the awkwardly defined SWS_BICUBLIN flag, in favor
of that just being the natural consequence of using a different scaler_sub.
Lastly, I also decided to pre-emptively axe the poorly defined and
questionable SWS_X scaler, which I doubt ever saw much use. The old flag
is still available as a deprecated flag, anyhow.
Sponsored-by: Sovereign Tech Fund
Signed-off-by: Niklas Haas <git@haasn.dev>
3503b19711