ref: 59e6baee1eba3ad659d86f5fff6b73d367b12203
dir: /engine/routines/flagpredef.asm/
FlagPredef: ; 4d7c1 ; Perform action b on flag c in flag array hl. ; If checking a flag, check flag array d:hl unless d is 0. ; For longer flag arrays, see FlagAction. push hl push bc ; Divide by 8 to get the byte we want. push bc srl c srl c srl c ld b, 0 add hl, bc pop bc ; Which bit we want from the byte ld a, c and 7 ld c, a ; Shift left until we can mask the bit ld a, 1 jr z, .shifted .shift add a dec c jr nz, .shift .shifted ld c, a ; What are we doing to this flag? dec b jr z, .set ; 1 dec b jr z, .check ; 2 .reset ld a, c cpl and [hl] ld [hl], a jr .done .set ld a, [hl] or c ld [hl], a jr .done .check ld a, d cp 0 jr nz, .farcheck ld a, [hl] and c jr .done .farcheck call GetFarByte and c .done pop bc pop hl ld c, a ret