Identify hardware register bits (#469)

Author: Rangi42

constants/hardware_constants.asm

@@ -81,8 +81,14 @@ DEF rWave_d           EQU $ff3d
 DEF rWave_e           EQU $ff3e
 DEF rWave_f           EQU $ff3f
 DEF rLCDC             EQU $ff40 ; LCD Control (R/W)
-DEF rLCDC_ENABLE      EQU 7
-DEF rLCDC_ENABLE_MASK EQU 1 << rLCDC_ENABLE
+DEF rLCDC_BG_PRIORITY    EQU 0
+DEF rLCDC_SPRITES_ENABLE EQU 1
+DEF rLCDC_SPRITE_SIZE    EQU 2
+DEF rLCDC_BG_TILEMAP     EQU 3
+DEF rLCDC_TILE_DATA      EQU 4
+DEF rLCDC_WINDOW_ENABLE  EQU 5
+DEF rLCDC_WINDOW_TILEMAP EQU 6
+DEF rLCDC_ENABLE         EQU 7
 DEF rSTAT             EQU $ff41 ; LCDC Status (R/W)
 DEF rSCY              EQU $ff42 ; Scroll Y (R/W)
 DEF rSCX              EQU $ff43 ; Scroll X (R/W)
@@ -111,3 +117,8 @@ DEF rSVBK             EQU $ff70 ; CGB Mode Only - WRAM Bank
 DEF rPCM12            EQU $ff76 ; Channels 1 & 2 Amplitude (R)
 DEF rPCM34            EQU $ff77 ; Channels 3 & 4 Amplitude (R)
 DEF rIE               EQU $ffff ; Interrupt Enable (R/W)
+DEF rIE_VBLANK EQU 0
+DEF rIE_LCD    EQU 1
+DEF rIE_TIMER  EQU 2
+DEF rIE_SERIAL EQU 3
+DEF rIE_JOYPAD EQU 4

engine/movie/hall_of_fame.asm

@@ -12,7 +12,7 @@ AnimateHallOfFame:
 	call FillMemory
 	call EnableLCD
 	ld hl, rLCDC
-	set 3, [hl]
+	set rLCDC_BG_TILEMAP, [hl]
 	xor a
 	ld hl, wHallOfFame
 	ld bc, HOF_TEAM
@@ -88,7 +88,7 @@ AnimateHallOfFame:
 	xor a
 	ldh [hWY], a
 	ld hl, rLCDC
-	res 3, [hl]
+	res rLCDC_BG_TILEMAP, [hl]
 	ret
 
 HallOfFameText:

engine/movie/intro.asm

@@ -319,8 +319,8 @@ PlayShootingStar:
 	call LoadIntroGraphics
 	call EnableLCD
 	ld hl, rLCDC
-	res 5, [hl]
-	set 3, [hl]
+	res rLCDC_WINDOW_ENABLE, [hl]
+	set rLCDC_BG_TILEMAP, [hl]
 	ld c, 64
 	call DelayFrames
 	farcall AnimateShootingStar

home/init.asm

@@ -8,7 +8,6 @@ SoftReset::
 Init::
 ;  Program init.
 
-DEF rLCDC_DEFAULT EQU %11100011
 ; * LCD enabled
 ; * Window tile map at $9C00
 ; * Window display enabled
@@ -17,6 +16,7 @@ DEF rLCDC_DEFAULT EQU %11100011
 ; * 8x8 OBJ size
 ; * OBJ display enabled
 ; * BG display enabled
+DEF rLCDC_DEFAULT EQU (1 << rLCDC_ENABLE) | (1 << rLCDC_WINDOW_TILEMAP) | (1 << rLCDC_WINDOW_ENABLE) | (1 << rLCDC_SPRITES_ENABLE) | (1 << rLCDC_BG_PRIORITY)
 
 	di
 
@@ -35,7 +35,7 @@ DEF rLCDC_DEFAULT EQU %11100011
 	ldh [rOBP0], a
 	ldh [rOBP1], a
 
-	ld a, rLCDC_ENABLE_MASK
+	ld a, 1 << rLCDC_ENABLE
 	ldh [rLCDC], a
 	call DisableLCD
 

home/lcd.asm

@@ -3,7 +3,7 @@ DisableLCD::
 	ldh [rIF], a
 	ldh a, [rIE]
 	ld b, a
-	res 0, a
+	res rIE_VBLANK, a
 	ldh [rIE], a
 
 .wait
@@ -12,7 +12,7 @@ DisableLCD::
 	jr nz, .wait
 
 	ldh a, [rLCDC]
-	and ~rLCDC_ENABLE_MASK
+	and ~(1 << rLCDC_ENABLE)
 	ldh [rLCDC], a
 	ld a, b
 	ldh [rIE], a

home/load_font.asm

@@ -1,6 +1,6 @@
 LoadFontTilePatterns::
 	ldh a, [rLCDC]
-	bit 7, a ; is the LCD enabled?
+	bit rLCDC_ENABLE, a
 	jr nz, .on
 .off
 	ld hl, FontGraphics
@@ -16,7 +16,7 @@ LoadFontTilePatterns::
 
 LoadTextBoxTilePatterns::
 	ldh a, [rLCDC]
-	bit 7, a ; is the LCD enabled?
+	bit rLCDC_ENABLE, a
 	jr nz, .on
 .off
 	ld hl, TextBoxGraphics
@@ -32,7 +32,7 @@ LoadTextBoxTilePatterns::
 
 LoadHpBarAndStatusTilePatterns::
 	ldh a, [rLCDC]
-	bit 7, a ; is the LCD enabled?
+	bit rLCDC_ENABLE, a
 	jr nz, .on
 .off
 	ld hl, HpBarAndStatusGraphics