From 2b4a5bdd8d9c711d8a8ad8dc822539f969744329 Mon Sep 17 00:00:00 2001 From: yenatch Date: Mon, 9 Sep 2013 12:47:02 -0400 Subject: [PATCH] comment flag predef this is like FlagAction but with index c instead of de --- main.asm | 58 ++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 37 insertions(+), 21 deletions(-) diff --git a/main.asm b/main.asm index 29f8e3174..1a8ef637e 100644 --- a/main.asm +++ b/main.asm @@ -11988,7 +11988,7 @@ PredefPointers: ; 856b dwb Function6508, BANK(Function6508) dwb Function747a, BANK(Function747a) dwb Functionc658, BANK(Functionc658) - dwb Function4d7c1, BANK(Function4d7c1) + dwb FlagPredef, BANK(FlagPredef) dwb Functionc699, BANK(Functionc699) dwb FillPP, BANK(FillPP) dwb Functiond88c, BANK(Functiond88c) @@ -52635,57 +52635,73 @@ INCBIN "baserom.gbc", $4d580, $4d596 - $4d580 Tilesets: INCLUDE "tilesets/tileset_headers.asm" -Function4d7c1: ; 4d7c1 + +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 + ld b, 0 add hl, bc pop bc + +; Which bit we want from the byte ld a, c - and $7 + and 7 ld c, a - ld a, $1 - jr z, .asm_4d7da -.asm_4d7d6 + +; Shift left until we can mask the bit + ld a, 1 + jr z, .shifted +.shift add a dec c - jr nz, .asm_4d7d6 - -.asm_4d7da + jr nz, .shift +.shifted ld c, a + +; What are we doing to this flag? dec b - jr z, .asm_4d7e7 + jr z, .set ; 1 dec b - jr z, .asm_4d7ec + jr z, .check ; 2 + +.reset ld a, c cpl and [hl] ld [hl], a - jr .asm_4d7f9 + jr .done -.asm_4d7e7 +.set ld a, [hl] or c ld [hl], a - jr .asm_4d7f9 + jr .done -.asm_4d7ec +.check ld a, d - cp $0 - jr nz, .asm_4d7f5 + cp 0 + jr nz, .farcheck + ld a, [hl] and c - jr .asm_4d7f9 + jr .done -.asm_4d7f5 +.farcheck call GetFarByte and c -.asm_4d7f9 +.done pop bc pop hl ld c, a