[truetype] Refactor compensation color.

* src/truetype/ttinterp.h (TT_Round_Func): Change the last argument.
* src/truetype/ttinterp.c (Ins_ROUND, Ins_NROUND, Ins_MDAP, Ins_MIAP,
Ins_MDRP, Ins_MIRP): Move compensation retrieval from here...
(Round_*): ... to here.
* src/truetype/ttobjs.c (tt_size_init_bytecode): Reserve zero
compensation at color index 3.
4 files changed