View difference between Paste ID: 9C32Exsf and v4NC3M5T

 
 TILE_BLACK EQU $10
 
 DIR_UP    EQU 0
 DIR_DOWN  EQU 1
 DIR_LEFT  EQU 2
 DIR_RIGHT EQU 3
 
 UP_KEY   EQU 6
 DOWN_KEY EQU 7
 
 	nop
 	nop
 Pong: ; xxx 0F:7BC8 Entry point, eventually in RAM
 	call ClearScreen
 ;	ld a, $0f
 ;	ld ($2000), a
 
 .waitingLoop
 	ld a, $ff
 	ld [wSerialExchangeNybbleReceiveData], a
 	call PlaySound ; mute music
 	ld a, 12
 	call LinkBattleExchangeData_PrintWaiting_ExchangeNybbles
 	ld a, [wSerialExchangeNybbleReceiveData]
 	cp 12
 	jr nz, .waitingLoop
 
 ; load the black tiles to VRAM
 	di
 .waitVblank
 	ldh a, [rSTAT]
 	cp $81
 	jr nz, .waitVblank
 	ld hl, $9100
 	ld bc, $16 * 3
 	ld a, $ff
 	call FillMemory
 	ei
 
 .newGame
 ; init game params
 	ld hl, wPad1Offset
 	ld a, 7
 	ld [hli], a ; wPad1Offset
 	ld [hli], a ; wPad2Offset
 	inc a
 	ld [hli], a ; wBallCoordY
 	ldh a, [hSerialConnectionStatus]
 	cp USING_INTERNAL_CLOCK
 	ld a, 1
 	ld c, 1 << DIR_UP + 1 << DIR_RIGHT
 	jr z, .notOppositeSide
 	ld a, 18
 	ld c, 1 << DIR_UP + 1 << DIR_LEFT
-.notOppositeSide
+.notOppositeSide
 	ld [hli], a ; wBallCoordX
 	ld a, [wRandomStartYFlag]
 	xor 1
 	ld [wRandomStartYFlag], a
 	and a
 	jr nz, .ok
 	inc c ; replace DIR_UP with DIR_DOWN
 .ok
 	ld [hl], c ; wBallDirection
 	call RefreshPadsAndBall
 	ld c, 12
 	call DelayFrames
 
 .mainLoop
 	call RefreshPadsAndBall
 	ld a, [wGameOver]
 	and a
 	jr z, .notGameOver
 	dec a
 	ld [wGameOver], a
 	jr z, .newGame
 .notGameOver
 	call HandleJoypadInput
 .skipJoypad
 	call SendPadOffset
 	call MoveBall
 	jr .mainLoop
 
 RefreshPadsAndBall:
 ; draw bg, horizontal walls, and vertical voids
 	call DrawBackground
 	call DrawVoids
 ; refresh player pad
 	ld hl, wTileMap
 	ld a, [wPad1Offset]
 	call DrawPadFromOffset
 ; refresh enemy pad
 	ld hl, wTileMap + 19
 	ld a, [wPad2Offset]
 	call DrawPadFromOffset
 ; refresh ball
 	ld hl, wTileMap
 	ld a, [wBallCoordX]
 	ld e, a
 	ld d, 0
 	add hl, de
 	ld a, [wBallCoordY]
 	ld bc, 20
 	call AddNTimes
 ;	xor a
 	ld [hl], a
 	ret
 
 DrawBackground:
 	ld hl, wTileMap
 	call .drawWall
 	ld a, TILE_BLACK
 	ld bc, 20 * (18 - 2)
 	call FillMemory
 ;	jr .drawWall
 .drawWall
 	ld bc, 20
-;	jp DrawFullVerticalBlackLine
+
 	jp FillMemory
 
 DrawVoids:
-	ld e, 18
+	ld hl, wTileMap + 20 * 1
 	call DrawFullVerticalBlackLine
 	ld hl, wTileMap + 20 * 1 + 19
 ;	jr DrawFullVerticalBlackLine
 
 DrawFullVerticalBlackLine:
 	ld a, TILE_BLACK
 	ld e, 16
 DrawVerticalLine:
 ; hl = start address
 ; e = how many tiles
 ; a = tile
 	ld bc, 20
 .loop
 	ld [hl], a
 	add hl, bc
 	dec e
 	ret z
-	jp DrawVerticalLine
+
 
 DrawPadFromOffset:
 	ld bc, 20
 	call AddNTimes
 	xor a
 	ld e, 4
 	jr DrawVerticalLine
 
 HandleJoypadInput:
 	ld bc, wPad1Offset
 	ld a, [bc]
 	ld hl, hJoyInput
 	bit UP_KEY, [hl]
 	jr z, .checkDown
 	dec a ; cp 1
 	ret z ; can't move up
 	ld [bc], a
 ;	ret
 .checkDown
 	bit DOWN_KEY, [hl]
 	ret z
 	cp 17 - 4
 	ret z
 	inc a
 	ld [bc], a
 	ret
 
 SendPadOffset:
 	ld a, [bc] ; wPad1Offset
 SendByte:
 	ld [wSerialExchangeNybbleSendData], a
 .syncLoop1
 	call Serial_ExchangeNybble
 	call DelayFrame
 	ld a, [wSerialExchangeNybbleReceiveData]
 	inc a
 	jr z, .syncLoop1
 	ld b, 5
 .syncLoop2
 	call DelayFrame
 	call Serial_ExchangeNybble
 	dec b
 	jr nz, .syncLoop2
 	ld a, [wSerialExchangeNybbleReceiveData]
 	ld [wPad2Offset], a
 	ret
 
 MoveBall:
 	ld hl, wBallCoordY ; handle vertical movement first
 	ld e, 2
 	ld a, [wBallDirection]
 .loop
 	rrca
 	jr nc, .notUpOrLeft
 	dec [hl]
 .notUpOrLeft
 	rrca
 	jr nc, .notDownOrRight
 	inc [hl]
 .notDownOrRight
 	dec e
 	inc hl ; wBallCoordX
-	jr z, .voidOrPad1
+
 ; handle collisions
 	dec hl
 	dec hl
 	ld a, [hl] ; wBallCoordY
 	cp 16
 	jr z, .wall
 	dec a ; cp 1
 	jr z, .wall
 .handleCorners
 	inc hl
-	xor (1 << DIR_UP + 1 << DIR_DOWN)
+
 	cp 18
 	jr z, .voidOrPad2
 	dec a ; cp 1
 	jr z, .voidOrPad1
 	ret
 .wall
 ; change Y movement
 	ld c, 1 << DIR_UP + 1 << DIR_DOWN
 	call .updateBallDirectionAndPlayClickSound
 ; properly handle the corners
 	jr .handleCorners
 .voidOrPad2
 	ld a, [wPad2Offset]
 	jr .voidOrPad
 .voidOrPad1
 	ld a, [wPad1Offset]
 .voidOrPad
 	dec hl ; wBallCoordY
 	ld e, 4
 .padBounceCheckLoop
 	cp [hl]
 	jr z, .pad
 	inc a ; next pad tile
-	xor (1 << DIR_LEFT + 1 << DIR_RIGHT)
+
 	jr nz, .padBounceCheckLoop
-	ret
+
 	ld a, 3
 	ld [wGameOver], a
 	ret
 .pad
 ; change X movement
 	ld c, 1 << DIR_LEFT + 1 << DIR_RIGHT
 ;	jr .updateBallDirectionAndPlayClickSound
 .updateBallDirectionAndPlayClickSound
 	ld a, [wBallDirection]
 	xor c
 	ld [wBallDirection], a
 	ld a, SFX_POUND
 	jp PlaySound