These typedefs don't save much typing compared to the full `Ref<Resource>`
and `Ref<RefCounted>`, yet they sometimes introduce confusion among
new contributors.
Didn't commit all the changes where it wants to initialize a struct
with `{}`. Should be reviewed in a separate PR.
Option `IgnoreArrays` enabled for now to be conservative, can be
disabled to see if it proposes more useful changes.
Also fixed manually a handful of other missing initializations / moved
some from constructors.
The validation layers were complaining that we use DEFAULT_RD_TEXTURE_WHITE (which is RGBA8) in places where it's sampled as a depth texture. This commit adds the new default texture DEFAULT_RD_TEXTURE_DEPTH and uses it where needed.