Consolidate BG Map & OAM attribute flags (#1078)

pret · Jan 7, 2024 · 0266f64 · 0266f64
1 parent e0c278a
commit 0266f64
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diff --git a/constants/hardware_constants.asm b/constants/hardware_constants.asm
@@ -32,20 +32,19 @@ DEF SERIAL     EQU 3
 DEF JOYPAD     EQU 4
 DEF IE_DEFAULT EQU (1 << SERIAL) | (1 << TIMER) | (1 << LCD_STAT) | (1 << VBLANK)
 
-; OAM attribute flags
-DEF OAM_TILE_BANK EQU 3
-DEF OAM_OBP_NUM   EQU 4 ; non CGB Mode Only
-DEF OAM_X_FLIP    EQU 5
-DEF OAM_Y_FLIP    EQU 6
-DEF OAM_PRIORITY  EQU 7 ; 0: OBJ above BG, 1: OBJ behind BG (colors 1-3)
+; BG Map & OAM attribute flags
+DEF TILE_BANK_F EQU 3
+DEF OBP_NUM_F   EQU 4 ; OAM attribute only, non CGB Mode Only
+DEF X_FLIP_F    EQU 5
+DEF Y_FLIP_F    EQU 6
+DEF PRIORITY_F  EQU 7 ; BG priority overrides OBJ priority. Otherwise, for OBJ: 0: OBJ above BG, 1: OBJ behind BG (colors 1-3)
 
-; BG Map attribute flags
-DEF PALETTE_MASK EQU %111
-DEF VRAM_BANK_1  EQU 1 << OAM_TILE_BANK ; $08
-DEF OBP_NUM      EQU 1 << OAM_OBP_NUM   ; $10
-DEF X_FLIP       EQU 1 << OAM_X_FLIP    ; $20
-DEF Y_FLIP       EQU 1 << OAM_Y_FLIP    ; $40
-DEF PRIORITY     EQU 1 << OAM_PRIORITY  ; $80
+DEF PALETTE_MASK EQU %111 ; For BG Map: which of BGP0–7 to use. For OAM: which of OBP0–7 to use (CGB mode only).
+DEF VRAM_BANK_1  EQU 1 << TILE_BANK_F ; $08
+DEF OBP1         EQU 1 << OBP_NUM_F   ; $10
+DEF X_FLIP       EQU 1 << X_FLIP_F    ; $20
+DEF Y_FLIP       EQU 1 << Y_FLIP_F    ; $40
+DEF PRIORITY     EQU 1 << PRIORITY_F  ; $80
 
 ; Hardware registers
 DEF rJOYP                EQU $ff00 ; Joypad (R/W)