This started as a fixing a misalignment issue, but I got carried away.
Was originally 41 bytes (overflowing it's expected 40 bytes by 1 bit).
Now it's 27 bytes plus 8 bits of padding (ready for future expansion).
The savings come from:
- Removing UV usage from components, it can be reconstructed from
texcoord_elem_count (saved 8 bits)
- Removed the 8 unused bits from texMtxInfo_n_projection (saved 8 bits)
- Removing unused bit from from start of components (saved 1 bit)
- Removed extra bit from inputform, texgentype and sourcerow
- packed texMtxInfo_n_projection and texcoord_elem_count back into
the per texgen info space freed up above. (saved 24 bits)
- Overlayed postMtx index and Emboss mode shifts into a union based on
texgentype (saved 56 bits)
- Move to a single-bit union tag, freeing up an extra bit for regular
texgens.
- Move PotMtx normalize into the freed up space (saved 8 bits)
Total savings: 105 bits of data
EDIT: Even worse, MSVC wasn't respecting pack(1) for bitfields at all,
so on windows this struct was actually quite a bit larger.
Something like 80 bytes, if not more.
Fixed this by dropping the size of any enums used in these
bit structs to u8. Our Common::BitField allows for the underlying
type to be explicitly specified to something larger.
msvc's bitfield packing appears to be completely braindead, can't
mix sizes at all.
Scott Mansell
e5eabd08f5