main.asm

INCLUDE "macros.asm"
INCLUDE "constants.asm"
INCLUDE "charmap.asm"

SECTION "rst 00", ROM0 [$00]
    ret

SECTION "rst 08", ROM0 [$08]
    ret

SECTION "rst 10", ROM0 [$10]
    ret

SECTION "rst 18", ROM0 [$18]
    jp JumpToFuncInTable

SECTION "rst 20", ROM0 [$20]
    ret

SECTION "rst 28", ROM0 [$28]
    ret

SECTION "rst 30", ROM0 [$30]
    ret

SECTION "rst 38", ROM0 [$38]
    ret

SECTION "VBlank", ROM0 [$40]
    jp VBlankInterruptHandler

SECTION "LCDC",ROM0[$48]
    reti

SECTION "Timer", ROM0 [$50]
    jp TimerInterruptHandler

SECTION "Serial",ROM0[$58]
    jp SerialInterruptHandler

SECTION "Joypad", ROM0 [$60]
    reti


SECTION "Entry", ROM0 [$100]

Entry: ; 0x100
	nop
	jp Start

SECTION "Header", ROM0 [$104]
	; The header is generated by rgbfix.
	; The space here is allocated to prevent code from being overwritten.
	ds $150 - $104

SECTION "Main", ROM0 [$150]

Start: ; 0x150
    di
    ld sp, $ffff
    xor a
    ld [rLCDC], a  ; Disable LCD Display
    ld hl, $c000
    ld bc, $2000
    call ClearData  ; Clear working RAM
    ld hl, vTiles0
    ld bc, $2000
    call ClearData  ; Clear VRAM
    ld hl, $fe00
    ld bc, $a0
    call ClearData  ; Clear OAM
    ld hl, $ff80
    ld bc, $7d  ; Clear HRAM
    call ClearData
    ld hl, GameGfx
    ld bc, $800
    ld de, vTiles0
    call LoadGfx
    ld a, %11100100
    ld [rBGP], a  ; Set Background palette
    ld [rOBP0], a ; Set Sprite Palette 0
    ld [rOBP1], a ; Set Sprite Palette 1

    call ClearOAMBuffer
    call ClearBackground

    ld sp, $dfff  ; Initialize stack pointer to end of working RAM

    call WriteDMACodeToHRAM

    xor a
    ld hl, wCurrentScreen
    ld [hli], a
    ld [hl], a

    ld a, $93
    ld [rLCDC], a   ; Enable LCD Display
    ld a,%00000001  ; Enable V-blank interrupt
    ld [rIE], a
    ei
    ld a, MUSIC_GAME
    call PlayMusic
    jp Main

JumpToFuncInTable:
; Jumps to a function in the pointer table immediately following
; a "rst $18" call.  Function must be in the same Bank as the pointer table.
    sla a
    pop hl
    push de
    ld e, a
    ld d, $0
    add hl, de
    ld e, [hl]
    inc hl
    ld d, [hl]
    ld l, e
    ld h, d
    pop de
    jp [hl]

VBlankInterruptHandler:
    push af
    push bc
    push de
    push hl
    call ReadJoypad
    call DrawCurrentScreen
    call Music2_UpdateMusic
    ld a, 1
    ld [VBlankFlag], a
    pop hl
    pop de
    pop bc
    pop af
    reti

DrawCurrentScreen:
    ld a, [wCurrentScreen]
    rst $18
DrawScreenFunctions:
    dw DrawTitlescreen
    dw DrawGame
    dw DrawGameOver

DrawTitlescreen:
    jp $ff80  ; OAM DMA transfer

DrawGame:
    call DrawScore
    call DrawPlayerPaddle
    call DrawComputerPaddle
    ; Draw OAM sprites
    call ClearOAMBuffer
    call DrawBall
    call DrawLasers
    jp $ff80  ; OAM DMA transfer

DrawGameOver:
    jp $ff80  ; OAM DMA transfer

TimerInterruptHandler:
    reti

SerialInterruptHandler:
    reti

; copies DMA routine to HRAM. By GB specifications, all DMA needs to be done in HRAM (no other memory section is available during DMA)
; This routine is taken from Pokemon Red Version.
WriteDMACodeToHRAM: ; 4bed (1:4bed)
    ld c, $80
    ld b, $a
    ld hl, DMARoutine
.copyLoop
    ld a, [hli]
    ld [$ff00+c], a
    inc c
    dec b
    jr nz, .copyLoop
    ret

DMARoutine: ; 4bfb (1:4bfb)
    ld a, (wOAMBuffer >> 8)
    ld [$ff00+$46], a   ; start DMA
    ld a, $28
.waitLoop               ; wait for DMA to finish
    dec a
    jr nz, .waitLoop
    ret

ClearData:
; Clears bc bytes starting at hl with value in a.
; bc can be a maximum of $7fff, since it checks bit 7 of b when looping.
    dec bc
.clearLoop
    ld [hli], a
    dec bc
    bit 7, b
    jr z, .clearLoop
    ret

CopyData:
; Copies bc bytes starting at hl to de.
    ld a, [hli]
    ld [de], a
    inc de
    dec bc
    ld a, b
    or c  ; have we copied all of the data?
    jr nz, CopyData
    ret

ClearOAMBuffer:
; Fills OAM buffer memory with $0.
    xor a
    ld hl, wOAMBuffer
    ld bc, $a0  ; size of OAM buffer
    jp ClearData

ClearBackground:
; Fills Background memory with $1.
    ld a, 1
    ld hl, vBGMap0
    ld bc,$800  ; size of background memory
    jp ClearData

ClearLasers:
; Deletes all lasers
    xor a
    ld hl, wLasers
    ld bc, (MAX_LASERS * 2 * 5)
    jp ClearData

LoadGfx:
; This loads data into VRAM. It waits for the LCD H-Blank to copy the data.
; input:  hl = source of data
;         de = destination for data
;         bc = number of bytes to copy
.waitForHBlank
    ld a, [$ff41] ; LCDC Status
    and $3
    jr nz, .waitForHBlank
    ld a, [hli]
    ld [de], a
    inc de
    dec bc
    ld a, b
    or c  ; have we copied all of the data?
    jr nz, .waitForHBlank
    ret

ClearGfx:
; Clear data in VRAM. It waits for the LCD H-Blank to clear the data.
; input:  hl = destination to clear
;         bc = number of bytes to clear
;          d = value to clear with
.waitForHBlank
    ld a, [$ff41] ; LCDC Status
    and $3
    jr nz, .waitForHBlank
    ld a, d
    ld [hli], a
    dec bc
    ld a, b
    or c  ; have we cleared all of the data?
    jr nz, .waitForHBlank
    ret

PrintText:
; Loads text graphics.
; input:  hl = pointer to "@"-terminated string
;         de = destination for data
    ld bc, $0000  ; Count number of bytes in string
    push hl
.loop
    ld a, [hli]
    cp "@"
    jr z, .finishedProcessingString
    inc bc
    jr .loop
.finishedProcessingString
    pop hl
    jp LoadGfx

ReadJoypad:
; Reads the current state of the joypad and saves the state into
; some registers the game uses during gameplay.
    ld a, $20
    ld [rJOYP], a
    ld a, [rJOYP]
    ld a, [rJOYP]
    and $f
    swap a
    ld b, a
    ld a, $30
    ld [rJOYP], a
    ld a, $10
    ld [rJOYP], a
    ld a, [rJOYP]
    ld a, [rJOYP]
    ld a, [rJOYP]
    ld a, [rJOYP]
    ld a, [rJOYP]
    ld a, [rJOYP]
    and $f
    or b
    cpl  ; a contains currently-pressed buttons
    ld [hJoypadState], a
    ret

ResetScores:
    xor a
    ld hl, wPlayerScore
    ld [hli], a
    ld [hl], a
    ret

InitPlayerPaddle:
; Initializes the player's paddle.
    ld hl, wPlayerY
    ld a, $00
    ld [hli], a
    ld a, $17
    ld [hl], a
    ld a, $18
    ld [wPlayerHeight], a
    ret

InitPlayerLasers:
; Initializes the player's lasers.
    xor a
    ld hl, wPlayerLasers
    ld bc, 5 * MAX_LASERS
    jp ClearData

InitComputerPaddle:
; Initializes the computer's paddle.
    ld hl, wComputerY
    ld a, $00
    ld [hli], a
    ld a, $17
    ld [hl], a
    ld a, $18
    ld [wComputerHeight], a
    ret

InitComputerLasers:
; Initializes the Computer's lasers.
    xor a
    ld hl, wComputerLasers
    ld bc, 5 * MAX_LASERS
    jp ClearData

DrawScore:
; Draws the score of the game.
    ld a, [wPlayerScore]
    cp 10
    jr c, .oneDigit
    push af
    ld a, $21
    hlCoord 2, 3, vBGMap0
    ld [hl], a
    pop af
    sub 10
.oneDigit
    add $20  ; base tile id for numbers
    hlCoord 3, 3, vBGMap0
    ld [hl], a
    ld a, [wComputerScore]
    cp 10
    jr c, .oneDigit2
    push af
    ld a, $21
    hlCoord 16, 3, vBGMap0
    ld [hl], a
    pop af
    sub 10
.oneDigit2
    add $20  ; base tile id for numbers
    hlCoord 17, 3, vBGMap0
    ld [hl], a
    ret

DrawPlayerPaddle:
; Draws the player's paddle to the screen.
; This also fills in blank tiles along the column where the player's paddle doesn't overlap.
    ld a, [wPlayerY + 1]
    push af
    srl a
    srl a
    srl a  ; Divide by 8 to get the tile index we need to start drawing at.
    hlCoord 0, 0, vBGMap0
    ld bc, $0020
    ld d, $00  ; Count which tile row we're on.
.addLoop
    ld [hl], $01
    and a
    jr z, .gotHLCoord
    inc d
    add hl, bc  ; Move the HL Coord down one row of tiles.
    dec a
    jr .addLoop
.gotHLCoord
    pop af  ; Reload player's paddle Y position
    and $7  ; Get the pixel offset in the tile. (Tiles are 8 pixels wide)
    jr z, .save8
    push af
    ld e, a
    ld a, 8
    sub e
    ld e, a
    pop af
    jr .drawTile
.save8
    ld e, 8
.drawTile
    add $10  ; a now contains tile id for the top tile
    ld [hl], a  ; Draw the top tile
    inc d
    ld a, [wPlayerHeight]
    sub e
.drawMiddleTiles
    add hl, bc
    cp a, 8
    jr c, .drawBottomTile
    sub 8
    ld [hl], $10  ; Tile id of the solid paddle tile.
    inc d
    jr .drawMiddleTiles
.drawBottomTile
    and a
    jr z, .clearRemainingTiles
    add $18
    ld [hl], a
    inc d
    ld a, d
.clearRemainingTiles
    cp 18 ; number of rows in the display
    jr z, .done
    add hl, bc
    ld [hl], $01  ; blank tile
    inc a
    jr .clearRemainingTiles
.done
    ret

DrawLasers:
; Loads the player's and the computer's laser sprites into the OAM buffer.
    ld hl, wLasers
    ld de, wLaserSprites    ; OAM buffer destination for laser sprites
    ld b, 1 + (MAX_LASERS * 2)  ; We're drawing both the player's and the computer's lasers
.loop
    dec b
    ret z
    ld a, [hli]  ; check if laser is active
    and a
    jr nz, .activeLaser
    ; Laser is inactive, so don't draw it
    push bc
    ld bc, $0004
    add hl, bc  ; Move to next laser struct
    pop bc
    jr .loop
.activeLaser
    inc hl  ; Skip over the low byte of the y position
    ld a, [hli]  ; y position (high byte)
    add 16 - 4  ; adjust for sprite screen offset (and center the sprite)
    ld [de], a
    inc de
    inc hl  ; Skip over the low byte of the x position
    ld a, [hli]  ; x position (high byte)
    add 8 - 4  ; adjust for sprite screen offset (and center the sprite)
    ld [de], a
    inc de
    ld a, $2  ; Laser tile id
    ld [de], a
    inc de
    ld a, %00000000  ; sprite attributes
    ld [de], a
    inc de
    jr .loop

DrawComputerPaddle:
; Draws the computer's paddle to the screen.
; This also fills in blank tiles along the column where the computer's paddle doesn't overlap.
    ld a, [wComputerY + 1]
    push af
    srl a
    srl a
    srl a  ; Divide by 8 to get the tile index we need to start drawing at.
    hlCoord 019, 0, vBGMap0
    ld bc, $0020
    ld d, $00  ; Count which tile row we're on.
.addLoop
    ld [hl], $01
    and a
    jr z, .gotHLCoord
    inc d
    add hl, bc  ; Move the HL Coord down one row of tiles.
    dec a
    jr .addLoop
.gotHLCoord
    pop af  ; Reload computer's paddle Y position
    and $7  ; Get the pixel offset in the tile. (Tiles are 8 pixels wide)
    jr z, .save8
    push af
    ld e, a
    ld a, 8
    sub e
    ld e, a
    pop af
    jr .drawTile
.save8
    ld e, 8
.drawTile
    add $10  ; a now contains tile id for the top tile
    ld [hl], a  ; Draw the top tile
    inc d
    ld a, [wComputerHeight]
    sub e
.drawMiddleTiles
    add hl, bc
    cp a, 8
    jr c, .drawBottomTile
    sub 8
    ld [hl], $10  ; Tile id of the solid paddle tile.
    inc d
    jr .drawMiddleTiles
.drawBottomTile
    and a
    jr z, .clearRemainingTiles
    add $18
    ld [hl], a
    inc d
    ld a, d
.clearRemainingTiles
    cp 18 ; number of rows in the display
    jr z, .done
    add hl, bc
    ld [hl], $01  ; blank tile
    inc a
    jr .clearRemainingTiles
.done
    ret

InitBall:
; Initializes the Pong ball
    ld hl, wBallY
    xor a
    ld [hli], a
    ld a, BASE_BALL_Y_POSITION
    ld [hli], a
    xor a
    ld [hli], a
    ld a, BASE_BALL_X_POSITION
    ld [hli], a
    ld a, (BASE_BALL_Y_SPEED & $ff)
    ld [hli], a
    ld a, (BASE_BALL_Y_SPEED >> 8)
    ld [hli], a
    ld a, (BASE_BALL_X_SPEED & $ff)
    ld [hli], a
    ld a, (BASE_BALL_X_SPEED >> 8)
    ld [hl], a
    ret

PlayerScorePoint:
    ld a, [wPlayerScore]
    inc a
    ld [wPlayerScore], a
    ld a, START_PLAY_TIME
    ld [wStartPlayTimer], a
    call InitPlayerPaddle
    call InitComputerPaddle
    call InitBall
    ld hl, wBallY
    xor a
    ld [hli], a
    ld a, BASE_BALL_Y_POSITION
    ld [hli], a
    xor a
    ld [hli], a
    ld a, BASE_BALL_X_POSITION
    ld [hli], a
    ld a, (BASE_BALL_Y_SPEED & $ff)
    ld [hli], a
    ld a, (BASE_BALL_Y_SPEED >> 8)
    ld [hli], a
    ld a, (BASE_BALL_X_SPEED_NEGATIVE & $ff)
    ld [hli], a
    ld a, (BASE_BALL_X_SPEED_NEGATIVE >> 8)
    ld [hl], a
    call ClearLasers
    call CheckForGameFinished
    ret

ComputerScorePoint:
    ld a, [wComputerScore]
    inc a
    ld [wComputerScore], a
    ld a, START_PLAY_TIME
    ld [wStartPlayTimer], a
    call InitPlayerPaddle
    call InitComputerPaddle
    call InitBall
    ld hl, wBallY
    xor a
    ld [hli], a
    ld a, BASE_BALL_Y_POSITION
    ld [hli], a
    xor a
    ld [hli], a
    ld a, BASE_BALL_X_POSITION
    ld [hli], a
    ld a, (BASE_BALL_Y_SPEED & $ff)
    ld [hli], a
    ld a, (BASE_BALL_Y_SPEED >> 8)
    ld [hli], a
    ld a, (BASE_BALL_X_SPEED & $ff)
    ld [hli], a
    ld a, (BASE_BALL_X_SPEED >> 8)
    ld [hl], a
    call ClearLasers
    call CheckForGameFinished
    ret

CheckForGameFinished:
    ld a, [wComputerScore]
    cp POINTS_TO_WIN
    jr c, .checkPlayer
    ; Computer won the game
    ; TODO: do stuff when game is won
    ld a, 2  ; computer won
    ld [wWinner], a
    xor a
    ld [wScreenState], a
    ld a, SCREEN_GAME_OVER
    ld [wCurrentScreen], a
    ret
.checkPlayer
    ld a, [wPlayerScore]
    cp POINTS_TO_WIN
    ret c
    ; Player won the game
    ld a, 1  ; player won
    ld [wWinner], a
    xor a
    ld [wScreenState], a
    ld a, SCREEN_GAME_OVER
    ld [wCurrentScreen], a
    ret

DrawBall:
; Draws the Pong ball sprite to OAM.
    ld hl, wBallSprite
    ld a, [wBallY + 1]
    add 16 - 4  ; Add 16 to adjust for the screen offset for sprites.
    ld [hli], a
    ld a, [wBallX + 1]
    add 8 - 4  ; Add 8 to adjust for the screen offset for sprites.
    ld [hli], a
    ld a, $0  ; tile id for ball's sprite
    ld [hli], a
    ld a, %00000000
    ld [hl], a
    ret

MoveBall:
; Updates the ball's position according to its speed.
    call UpdateBallYPosition
    call UpdateBallXPosition
    ret

UpdateBallYPosition:
    ld a, [wBallY]
    ld l, a
    ld a, [wBallY + 1]
    ld h, a  ; hl contains ball's y position
    ld a, [wBallYSpeed]
    ld c, a
    ld a, [wBallYSpeed + 1]
    ld b, a  ; bc contains ball's y speed
    cp $80
    jr c, .movingDown
    ; Ball is moving up because y speed is negative
    add hl, bc
    ; Check if new position is beyond the top of the screen
    ld a, h
    cp 220  ; Arbitrary large number so we can detect underflow
    jr c, .saveYPosition
    ; Invert the y speed, and set the y position equal to the top of the screen
    call InvertBC
    ; bc now contains inverted y speed
    ld a, c
    ld [wBallYSpeed], a
    ld a, b
    ld [wBallYSpeed + 1], a
    ld hl, $0000
    jr .saveYPosition
.movingDown
    ; Ball is moving down because y speed is positive
    add hl, bc
    ; Check if new position is beyond the bottom of the screen
    ld a, h
    cp 144
    jr c, .saveYPosition
    ; Invert the y speed, and set the y position equal to the bottom of the screen 
    call InvertBC
    ; bc now contains inverted y speed
    ld a, c
    ld [wBallYSpeed], a
    ld a, b
    ld [wBallYSpeed + 1], a
    ld h, 144
    ld l, 0
.saveYPosition
    ld a, l
    ld [wBallY], a
    ld a, h
    ld [wBallY + 1], a
    ret

UpdateBallXPosition:
    ld a, [wBallX]
    ld l, a
    ld a, [wBallX + 1]
    ld h, a  ; hl contains ball's x position
    ld a, [wBallXSpeed]
    ld c, a
    ld a, [wBallXSpeed + 1]
    ld b, a  ; bc contains ball's x speed
    cp $80
    jr c, .movingRight
    ; Ball is moving left because x speed is negative
    add hl, bc
    ; Check if it hit the player's wall
    ld a, h
    cp 220 ; Arbitrary large number to check for underflow
    jr c, .notTouchingLeftWall
    ; Computer scored a point!
    call ComputerScorePoint
    ret
.notTouchingLeftWall
    ; Check if the ball is hitting the player's paddle
    ld a, h
    sub 4
    cp 4
    jp c, .saveXPosition
    cp 8
    jp nc, .saveXPosition
    ld a, [wBallY + 1]
    ld e, a
    ld a, [wPlayerY + 1]
    cp e
    jp nc, .saveXPosition
    ld d, a
    ld a, [wPlayerHeight]
    add d
    cp e
    jp c, .saveXPosition
    ; Ball is hitting player's paddle
    ; Invert the x speed, and set the x position equal to the right side of player's paddle.
    ; Also set the x speed to its base speed.
    ld bc, BASE_BALL_X_SPEED
    ld a, c
    ld [wBallXSpeed], a
    ld a, b
    ld [wBallXSpeed + 1], a
    ; Increase or decrease y speed based on where it hit the paddle
    ld a, [wBallY + 1]
    ld b, a
    ld a, [wPlayerY + 1]
    ld c, a
    ld a, [wPlayerHeight]
    srl a
    add c  ; a is midpoint of player's paddle
    cp b
    jr c, .bottomOfPlayerPaddle
    ; ball is hitting top half of player's paddle
    ld a, [wBallYSpeed + 1]
    cp $80
    jr c, .decreaseBallYSpeed
    jr .increaseBallYSpeed
.bottomOfPlayerPaddle
    ; ball is hitting bottom half of player's paddle
    ld a, [wBallYSpeed + 1]
    cp $80
    jr c, .increaseBallYSpeed
    jr .decreaseBallYSpeed
.increaseBallYSpeed
    call IncreaseBallYSpeed
    jr .doneChangingYSpeed
.decreaseBallYSpeed
    call DecreaseBallYSpeed
.doneChangingYSpeed
    ld hl, $0c00
    jr .saveXPosition
.movingRight
    add hl, bc
    ; Check if it hit the computer's wall
    ld a, h
    cp 160 ; Pixel position of right-side wall
    jr c, .notTouchingRightWall
    ; Player scored a point!
    call PlayerScorePoint
    ret
.notTouchingRightWall
    ; Check if the ball is hitting the computer's paddle
    ld a, h
    add 4
    cp 152
    jr c, .saveXPosition
    cp 156
    jr nc, .saveXPosition
    ld a, [wBallY + 1]
    ld e, a
    ld a, [wComputerY + 1]
    cp e
    jr nc, .saveXPosition
    ld d, a
    ld a, [wComputerHeight]
    add d
    cp e
    jr c, .saveXPosition
    ; Ball is hitting computer's paddle
    ; Invert the x speed, and set the x position equal to the left side of computer's paddle.
    ; Also set the x speed to its base speed.
    ld bc, BASE_BALL_X_SPEED_NEGATIVE
    ld a, c
    ld [wBallXSpeed], a
    ld a, b
    ld [wBallXSpeed + 1], a
    ; Increase or decrease y speed based on where it hit the paddle
    ld a, [wBallY + 1]
    ld b, a
    ld a, [wComputerY + 1]
    ld c, a
    ld a, [wComputerHeight]
    srl a
    add c  ; a is midpoint of Computer's paddle
    cp b
    jr c, .bottomOfComputerPaddle
    ; ball is hitting top half of Computer's paddle
    ld a, [wBallYSpeed + 1]
    cp $80
    jr c, .decreaseBallYSpeed2
    jr .increaseBallYSpeed2
.bottomOfComputerPaddle
    ; ball is hitting bottom half of Computer's paddle
    ld a, [wBallYSpeed + 1]
    cp $80
    jr c, .increaseBallYSpeed2
    jr .decreaseBallYSpeed2
.increaseBallYSpeed2
    call IncreaseBallYSpeed
    jr .doneChangingYSpeed2
.decreaseBallYSpeed2
    call DecreaseBallYSpeed
.doneChangingYSpeed2
    ld hl, $9400
.saveXPosition
    ld a, l
    ld [wBallX], a
    ld a, h
    ld [wBallX + 1], a
    ret

InvertBC:
; Inverts the 16-bit value in bc
    ld a, b
    cpl
    ld b, a
    ld a, c
    cpl
    ld c, a
    inc c
    ret nz
    inc b
    ret

MoveLasers:
; Updates laser positions according to their speeds.
    call MovePlayerLasers
    jp MoveComputerLasers

MovePlayerLasers:
    ld hl, wPlayerLasers
    ld b, MAX_LASERS + 1
.loop
    dec b
    ret z
    ld a, [hli]
    and a
    jr nz, .activeLaser
    inc hl
    inc hl
    inc hl
    inc hl  ; Move to next laser struct
    jr .loop
.activeLaser
    inc hl
    inc hl
    push hl  ; Save pointer to y position
    ld a, [hli]
    ld e, a
    ld a, [hl]
    ld d, a  ; de contains laser x position
    ld hl, BASE_LASER_SPEED_RIGHT
    add hl, de
    ld d, h
    ld e, l
    pop hl
    ld a, e
    ld [hli], a
    ld a, d
    ld [hli], a
    jr .loop

MoveComputerLasers:
    ld hl, wComputerLasers
    ld b, MAX_LASERS + 1
.loop
    dec b
    ret z
    ld a, [hli]
    and a
    jr nz, .activeLaser
    inc hl
    inc hl
    inc hl
    inc hl  ; Move to next laser struct
    jr .loop
.activeLaser
    inc hl
    inc hl
    push hl  ; Save pointer to y position
    ld a, [hli]
    ld e, a
    ld a, [hl]
    ld d, a  ; de contains laser x position
    ld hl, BASE_LASER_SPEED_LEFT
    add hl, de
    ld d, h
    ld e, l
    pop hl
    ld a, e
    ld [hli], a
    ld a, d
    ld [hli], a
    jr .loop

ShootLasers:
    call ShootPlayerLasers
    call ShootComputerLasers
    ret

ShootPlayerLasers:
; If player is pressing "shoot" button, fire a laser.
    ld a, [hJoypadState]
    bit BIT_A_BUTTON, a
    jr z, .done
    ld a, [wPlayerLaserCooldown]
    and a
    jr nz, .done
    ld hl, wPlayerLasers
    ld b, MAX_LASERS + 1
    ; Loop to find the first inactive laser, if there is one
.loop
    dec b
    jr z, .done  ; Maximum number of lasers are currently in play
    ld a, [hl]
    and a
    jr z, .foundInactiveLaser
    ; Check the next laser
    inc hl
    inc hl
    inc hl
    inc hl
    inc hl
    jr .loop
.foundInactiveLaser
    ld a, 1
    ld [hli], a  ; Set laser state to "active"
    ; Set laser's position in front of the player's paddle
    xor a
    ld [hli], a  ; Set low byte of laser's y position
    ld a, [wPlayerY + 1]
    ld c, a
    ld a, [wPlayerHeight]
    srl a
    add c  ; a is now the y-midpoint of the player's paddle
    ld [hli], a
    xor a
    ld [hli], a
    ld a, $a
    ld [hli], a  ; Set the laser's x position just to the right of the player's paddle
    ; Player has to wait awhile before firing another laser
    ld a, LASER_COOLDOWN
    ld [wPlayerLaserCooldown], a
    ret
.done
    ; Decrement the cooldown counter
    ld a, [wPlayerLaserCooldown]
    and a
    ret z
    dec a
    ld [wPlayerLaserCooldown], a
    ret

ShootComputerLasers:
; TODO: Do some logic to determine if computer should shoot a laser
    ld a, [wComputerLaserCooldown]
    and a
    jr nz, .done
    ld hl, wComputerLasers
    ld b, MAX_LASERS + 1
    ; Loop to find the first inactive laser, if there is one
.loop
    dec b
    jr z, .done  ; Maximum number of lasers are currently in play
    ld a, [hl]
    and a
    jr z, .foundInactiveLaser
    ; Check the next laser
    inc hl
    inc hl
    inc hl
    inc hl
    inc hl
    jr .loop
.foundInactiveLaser
    ld a, 1
    ld [hli], a  ; Set laser state to "active"
    ; Set laser's position in front of the computer's paddle
    xor a
    ld [hli], a  ; Set low byte of laser's y position
    ld a, [wComputerY + 1]
    ld c, a
    ld a, [wComputerHeight]
    srl a
    add c  ; a is now the y-midpoint of the computer's paddle
    ld [hli], a
    xor a
    ld [hli], a
    ld a, $96
    ld [hli], a  ; Set the laser's x position just to the left of the computer's paddle
    ; Computer has to wait awhile before firing another laser
    ld a, LASER_COOLDOWN
    ld [wComputerLaserCooldown], a
    ret
.done
    ; Decrement the cooldown counter
    ld a, [wComputerLaserCooldown]
    and a
    ret z
    dec a
    ld [wComputerLaserCooldown], a
    ret

HandleLaserCollisions:
    call HandlePlayerLaserCollisions
    call HandleComputerLaserCollisions
    jp HandleLaserPairCollisions

HandlePlayerLaserCollisions:
    ld hl, wPlayerLasers
    ld b, MAX_LASERS + 1
.loop
    dec b
    ret z
    ld a, [hli]
    and a
    jr nz, .activeLaser
    inc hl
    inc hl
    inc hl
    inc hl  ; Move to next laser struct
    jr .loop
.activeLaser
    push hl
    ; Check if laser is moving the opposite direction of the pong ball
    ld a, [wBallXSpeed + 1]
    cp $80
    jr c, .checkForWall
    ; Check if laser is hitting the pong ball
    inc hl
    ld a, [hl]  ; Y position of laser (high byte)
    ld c, a
    ld a, [wBallY + 1]
    cp c
    jr c, .laserYIsGreater
    sub c
    jr .gotYDifference
.laserYIsGreater
    ld d, a
    ld a, c
    sub d
.gotYDifference
    ; a contains difference between laser and ball y coordinates
    cp 7  ; TODO: make this a constant
    jr nc, .checkForWall
    inc hl
    inc hl
    ld a, [hl]  ; X position of laser (high byte)
    ld c, a
    ld a, [wBallX + 1]
    cp c
    jr c, .laserXIsGreater
    sub c
    jr .gotXDifference
.laserXIsGreater
    ld d, a
    ld a, c
    sub d
.gotXDifference
    ; a contains difference between laser and ball x coordinates
    cp 7  ; TODO: make this a constant
    jr nc, .checkForWall
    ; Laser is hitting ball!
    ; Deactivate laser and change the ball's direction/speed
    pop hl
    dec hl
    xor a
    ld [hl], a  ; deactivate laser
    inc hl
    inc hl
    inc hl
    inc hl
    inc hl
    call IncreaseBallYSpeed
    call IncreaseBallXSpeed
    call FlipBallDirection
    jr .loop
.checkForWall
    pop hl
    ; Check if laser is past the computer's wall
    inc hl
    inc hl
    inc hl
    ld a, [hl]  ; X position (high byte)
    cp 164
    jr c, .checkForPaddle
    ; Set laser to inactive
    push hl
    dec hl
    dec hl
    dec hl
    dec hl
    xor a
    ld [hl], a
    pop hl
    inc hl
    jr .loop
.checkForPaddle
    ; a contains x position
    cp 156
    jr nc, .continue
    cp 152
    jr c, .continue
    dec hl
    dec hl
    ld a, [hl]  ; high byte of laser's y position
    ld c, a
    ld a, [wComputerY + 1]
    cp c
    inc hl
    inc hl
    jr nc, .continue
    ld d, a
    ld a, [wComputerHeight]
    add d
    cp c
    jr c, .continue
    ; Laser is colliding with computer's paddle
    push hl
    dec hl
    dec hl
    dec hl
    dec hl
    xor a
    ld [hli], a  ; Deactivate laser
    call LaserHitComputerPaddle
    pop hl
.continue
    inc hl
    jp .loop

LaserHitComputerPaddle:
; Shrink the paddle.
    ld a, [wComputerY + 1]
    ld b, a
    ld a, [wComputerHeight]
    sub 4
    inc b
    inc b
    cp MIN_PADDLE_HEIGHT
    jr nc, .done
    dec b
    dec b
    ld a, MIN_PADDLE_HEIGHT
.done
    ld [wComputerHeight], a
    ld a, b
    ld [wComputerY + 1], a
    ret

HandleComputerLaserCollisions:
    ld hl, wComputerLasers
    ld b, MAX_LASERS + 1
.loop
    dec b
    ret z
    ld a, [hli]
    and a
    jr nz, .activeLaser
    inc hl
    inc hl
    inc hl
    inc hl  ; Move to next laser struct
    jr .loop
.activeLaser
    push hl
    ; Check if laser is moving the opposite direction of the pong ball
    ld a, [wBallXSpeed + 1]
    cp $80
    jr nc, .checkForWall
    ; Check if laser is hitting the pong ball
    inc hl
    ld a, [hl]  ; Y position of laser (high byte)
    ld c, a
    ld a, [wBallY + 1]
    cp c
    jr c, .laserYIsGreater
    sub c
    jr .gotYDifference
.laserYIsGreater
    ld d, a
    ld a, c
    sub d
.gotYDifference
    ; a contains difference between laser and ball y coordinates
    cp 7  ; TODO: make this a constant
    jr nc, .checkForWall
    inc hl
    inc hl
    ld a, [hl]  ; X position of laser (high byte)
    ld c, a
    ld a, [wBallX + 1]
    cp c
    jr c, .laserXIsGreater
    sub c
    jr .gotXDifference
.laserXIsGreater
    ld d, a
    ld a, c
    sub d
.gotXDifference
    ; a contains difference between laser and ball x coordinates
    cp 7  ; TODO: make this a constant
    jr nc, .checkForWall
    ; Laser is hitting ball!
    ; Deactivate laser and change the ball's direction/speed
    pop hl
    dec hl
    xor a
    ld [hl], a  ; deactivate laser
    inc hl
    inc hl
    inc hl
    inc hl
    inc hl
    call IncreaseBallYSpeed
    call IncreaseBallXSpeed
    call FlipBallDirection
    jr .loop
.checkForWall
    pop hl
    ; Check if laser is past the computer's wall
    inc hl
    inc hl
    inc hl
    ld a, [hl]  ; X position (high byte)
    cp 252
    jr c, .checkForPaddle
    ; Set laser to inactive
    push hl
    dec hl
    dec hl
    dec hl
    dec hl
    xor a
    ld [hl], a
    pop hl
    inc hl
    jr .loop
.checkForPaddle
    ; a contains x position
    cp 4
    jr c, .continue
    cp 8
    jr nc, .continue
    dec hl
    dec hl
    ld a, [hl]  ; high byte of laser's y position
    ld c, a
    ld a, [wPlayerY + 1]
    cp c
    inc hl
    inc hl
    jr nc, .continue
    ld d, a
    ld a, [wPlayerHeight]
    add d
    cp c
    jr c, .continue
    ; Laser is colliding with player's paddle
    push hl
    dec hl
    dec hl
    dec hl
    dec hl
    xor a
    ld [hli], a  ; Deactivate laser
    call LaserHitPlayerPaddle
    pop hl
.continue
    inc hl
    jp .loop

LaserHitPlayerPaddle:
; Shrink the paddle.
    ld a, [wPlayerY + 1]
    ld b, a
    ld a, [wPlayerHeight]
    sub 4
    inc b
    inc b
    cp MIN_PADDLE_HEIGHT
    jr nc, .done
    dec b
    dec b
    ld a, MIN_PADDLE_HEIGHT
.done
    ld [wPlayerHeight], a
    ld a, b
    ld [wPlayerY + 1], a
    ret

FlipBallDirection:
; Flips the x speed of the ball
    ld a, [wBallXSpeed]
    ld c, a
    ld a, [wBallXSpeed + 1]
    ld b, a
    call InvertBC
    ld a, c
    ld [wBallXSpeed], a
    ld a, b
    ld [wBallXSpeed + 1], a
    ret

DecreaseBallYSpeed:
; Makes ball's y speed slower
    ld a, [wBallYSpeed]
    ld c, a
    ld a, [wBallYSpeed + 1]
    ld b, a
    cp $80
    jr c, .movingDown
    ; ball is moving upward
    ld a, c
    add BALL_Y_SPEED_DELTA
    jr nc, .noCarry
    inc b
.noCarry
    ld c, a
    ; bc is new speed
    ld a, b
    jr .saveSpeed
.movingDown
    ; ball is moving downward
    ld a, c
    sub BALL_Y_SPEED_DELTA
    jr nc, .noCarry2
    dec b
.noCarry2
    ld c, a
.saveSpeed
    ; bc is new speed
    ld a, c
    ld [wBallYSpeed], a
    ld a, b
    ld [wBallYSpeed + 1], a
    ret

IncreaseBallYSpeed:
; Makes ball's y speed faster
    ld a, [wBallYSpeed]
    ld c, a
    ld a, [wBallYSpeed + 1]
    ld b, a
    cp $80
    jr c, .movingDown
    ; ball is moving upward
    ld a, c
    sub BALL_Y_SPEED_DELTA
    jr nc, .noCarry
    dec b
.noCarry
    ld c, a
    ; bc is new speed
    ld a, b
    cp MIN_Y_SPEED
    jr nc, .saveSpeed
    ld b, MIN_Y_SPEED
    ld c, 0
    jr .saveSpeed
.movingDown
    ; ball is moving downward
    ld a, c
    add BALL_Y_SPEED_DELTA
    jr nc, .noCarry2
    inc b
.noCarry2
    ld c, a
    ; bc is new speed
    ld a, b
    cp MAX_Y_SPEED
    jr c, .saveSpeed
    ld b, MAX_Y_SPEED
    ld c, 0
.saveSpeed
    ; bc is the Y speed to save
    ld a, c
    ld [wBallYSpeed], a
    ld a, b
    ld [wBallYSpeed + 1], a
    ret

IncreaseBallXSpeed:
; Makes ball's x speed faster
    ld a, [wBallXSpeed]
    ld c, a
    ld a, [wBallXSpeed + 1]
    ld b, a
    cp $80
    jr c, .movingRight
    ; Ball is moving left
    ld a, c
    sub BALL_X_SPEED_DELTA
    jr nc, .noCarry
    dec b
.noCarry
    ld c, a
    ; bc is new x speed
    ld a, b
    cp MIN_X_SPEED
    jr nc, .saveSpeed
    ld b, MIN_X_SPEED
    ld c, 0
    jr .saveSpeed
.movingRight
    ; ball is moving right
    ld a, c
    add BALL_X_SPEED_DELTA
    jr nc, .noCarry2
    inc b
.noCarry2
    ld c, a
    ; bc is new speed
    ld a, b
    cp MAX_X_SPEED
    jr c, .saveSpeed
    ld b, MAX_X_SPEED
    ld c, 0
.saveSpeed
    ; bc is the X speed to save
    ld a, c
    ld [wBallXSpeed], a
    ld a, b
    ld [wBallXSpeed + 1], a
    ret

HandleLaserPairCollisions:
; Checks every pair of active lasers.
; If two lasers are colliding, disable them both.
    ld hl, wPlayerLasers
    ld a, MAX_LASERS
    ld [wScratch], a
.loopPlayerLasers
    ld a, [wScratch]
    dec a
    cp $ff  ; check for underflow
    ret z  ; return if we're done checking all of player's lasers
    ld [wScratch], a
    ; Check if laser is enabled
    ld a, [hl]
    and a
    jr nz, .checkComputerLasers
    ; Player laser is disabled, move the to the next one
    ld bc, 5
    add hl, bc
    jr .loopPlayerLasers
.checkComputerLasers
    ; Check all of the computer lasers for collision
    ld de, wComputerLasers
    ld a, MAX_LASERS
    ld [wScratch2], a
    push hl  ; save player laser pointer
.loopComputerLasers
    ld a, [wScratch2]
    dec a
    cp $ff  ; check for underflow
    ld [wScratch2], a
    jr nz, .checkEnabled
    ; advance to next player laser
    pop hl  ; pop player laser position
    ld bc, 5
    add hl, bc
    jr .loopPlayerLasers
.checkEnabled
    ; Check if computer laser is enabled
    ld a, [de]
    and a
    jr nz, .computerLaserEnabled
    ; advance to next computer laser
    inc de
    inc de
    inc de
    inc de
    inc de
    jr .loopComputerLasers
.computerLaserEnabled
    inc hl
    inc hl
    inc de
    inc de
    ; hl = high byte of player laser y position 
    ; de = high byte of computer laser y position
    ld a, [de]
    ld b, a
    ld a, [hl]
    cp b
    jr c, .playerIsLess
    ; computer's laser is above the player's laser
    sub b
    jr .gotYDifference
.playerIsLess
    ; player's laser is above the computer's laser
    ld c, a
    ld a, b
    sub c
.gotYDifference
    ; a = y pixel difference
    cp 5
    jr c, .checkForXDifference
    ; advance to next computer laser
    dec hl
    dec hl
    inc de
    inc de
    inc de
    jr .loopComputerLasers
.checkForXDifference
    ; Check for x difference
    inc hl
    inc hl
    inc de
    inc de
    ; hl = high byte of player laser x position
    ; de = high byte of computer laser x position
    ld a, [hl]
    ld b, a
    ld a, [de]
    sub b
    cp 5
    jr c, .lasersColliding
    ; advance to next computer laser
    dec hl
    dec hl
    dec hl
    dec hl
    inc de
    jr .loopComputerLasers
.lasersColliding
    ; disable both lasers
    ; de = high byte of computer laser x position
    pop hl  ; pop player laser enabled byte
    dec de
    dec de
    dec de
    dec de
    xor a
    ld [hl], a
    ld [de], a
    ; advance to next player laser
    ld bc, 5
    add hl, bc
    jr .loopPlayerLasers

WaitForNextFrame:
    ld hl, VBlankFlag
    xor a
    ld [hl], a
.wait
    ld a, [hl]
    and a
    jr z, .wait
    ret

Main:
; Master control loop for the game.
    call RunCurrentScreen
    jr Main

RunCurrentScreen:
    ld a, [wCurrentScreen]
    rst $18  ; Call function in the following pointer table
ScreenFunctions:
    dw RunTitlescreen  ; SCREEN_TITLESCREEN
    dw RunGame         ; SCREEN_GAME
    dw RunGameOver     ; SCREEN_GAME_OVER

RunTitlescreen:
    ld a, [wScreenState]
    rst $18
TitlescreenFunctions:
    dw LoadTitlescreenGraphics
    dw MainTitlescreen

LoadTitlescreenGraphics:
    ld d, 1
    ld hl, vBGMap0
    ld bc, $400
    call ClearGfx
    call ClearOAMBuffer
    hlCoord 5, 7, vBGMap0
    ld d, h
    ld e, l
    ld hl, TitlescreenMainText
    call PrintText
    hlCoord 4, 12, vBGMap0
    ld d, h
    ld e, l
    ld hl, AuthorText
    call PrintText
    ; advance to next titlescreen state
    ld a, 1
    ld [wScreenState], a
    ret

TitlescreenMainText:
    db "LAZERPONG@"

AuthorText:
    db "BY SHANTYTOWN@"

MainTitlescreen:
; Main titlescreen loop.
; Go to the game when player pressed START or A
    ld a, [hJoypadState]
    bit BIT_A_BUTTON, a
    jr nz, .exitTitlescreen
    bit BIT_START, a
    jr z, .stayOnTitlescreen
.exitTitlescreen
    xor a
    ld [wScreenState], a
    ld a, SCREEN_GAME
    ld [wCurrentScreen], a
    ret
.stayOnTitlescreen
    jr MainTitlescreen

RunGame:
    ld a, [wScreenState]
    rst $18
GameFunctions:
    dw InitGame
    dw GameLoop

InitGame:
; Initializes paddles, lasers, ball, etc.
    call ResetScores
    call InitPlayerPaddle
    call InitPlayerLasers
    call InitComputerPaddle
    call InitComputerLasers
    call InitBall
    ld a, START_PLAY_TIME
    ld [wStartPlayTimer], a
    ld d, 1
    ld hl, vBGMap0
    ld bc, $400
    call ClearGfx
    ld a, 1
    ld [wScreenState], a  ; Advance to GameLoop state
    ret

GameLoop:
; Main game loop.
    call WaitForNextFrame
    call MovePlayerPaddle
    call MoveComputerPaddle
    ld a, [wStartPlayTimer]
    and a
    jr z, .currentlyPlaying
    dec a
    ld [wStartPlayTimer], a
    ret
.currentlyPlaying
    call ShootLasers
    call MoveLasers
    call MoveBall
    call HandleLaserCollisions
    ret

MovePlayerPaddle:
; Moves the player's paddle up/down based on the buttons being pressed.
    ld a, [hJoypadState]
    bit BIT_D_UP, a
    jr nz, .pressingUp
    bit BIT_D_DOWN, a
    ret z
    ; pressing Down
    ld a, [wPlayerY]
    ld l, a
    ld a, [wPlayerY + 1]
    ld h, a
    ld bc, BASE_PADDLE_DOWN_SPEED
    add hl, bc
    push hl
    ; Check if the new paddle position is hitting the bottom of the screen
    ld a, [wPlayerHeight]
    add h
    cp 144 + 1  ; Bottom of the screen (pixels)
    pop hl
    jr c, .savePosition
    ; Set the paddle's position so it's touching the bottom of the screen
    sub h
    ld b, a  ; Save paddle height into b
    ld a, 144
    sub b
    ld h, a
    ld l, 0
    jr .savePosition
.pressingUp
    ld a, [wPlayerY]
    ld l, a
    ld a, [wPlayerY + 1]
    ld h, a
    ld bc, BASE_PADDLE_UP_SPEED
    add hl, bc
    ; Check if the new paddle position it hitting the top of the screen
    ld a, h
    cp 220  ; Arbitrary large number. We're just checking if the y position had underflow.
    jr c, .savePosition
    ; Set the paddle's position so it's touching the top of the screen
    ld hl, $0000
.savePosition
    ld a, l
    ld [wPlayerY], a
    ld a, h
    ld [wPlayerY + 1], a
    ret

MoveComputerPaddle:
    ; If ball is moving away from computer, move towards middle.
    ; Else, move towards ball.
    ld a, [wBallXSpeed + 1]
    cp $80
    jr c, .movingTowardsComputer
    ; ball is moving away computer
    ld a, [wComputerY + 1]
    ld b, a
    ld a, [wComputerHeight]
    srl a
    add b
    cp $48
    jr c, .aboveHalf
    sub $48
    jr .gotDiff
.aboveHalf
    ld b, a
    ld a, $48
    sub b
.gotDiff
    cp $4
    ret c
    ld a, [wComputerY + 1]
    ld b, a
    ld a, [wComputerHeight]
    srl a
    add b
    cp $48
    jr c, .upperHalf
    ; computer paddle is in lower half, so move up
.moveUp
    ld a, [wComputerY]
    ld l, a
    ld a, [wComputerY + 1]
    ld h, a
    ld bc, BASE_PADDLE_UP_SPEED
    add hl, bc
    ld a, h
    cp 220  ; arbitrary large number to check for underflow
    jr c, .noUnderflow
    xor a
    ld h, a
    ld l, a
.noUnderflow
    ld a, l
    ld [wComputerY], a
    ld a, h
    ld [wComputerY + 1], a
    ret
.upperHalf
    ; computer paddle is in upper half, so move down
.moveDown
    ld a, [wComputerY]
    ld l, a
    ld a, [wComputerY + 1]
    ld h, a
    ld bc, BASE_PADDLE_DOWN_SPEED
    add hl, bc
    ld a, [wPlayerHeight]
    add h
    cp 144 + 1  ; Bottom of the screen (pixels)
    jr c, .noOverflow
    sub h
    ld b, a  ; Save paddle height into b
    ld a, 144
    sub b
    ld h, a
    ld l, 0
.noOverflow
    ld a, l
    ld [wComputerY], a
    ld a, h
    ld [wComputerY + 1], a
    ret
.movingTowardsComputer
    ld a, [wComputerY + 1]
    ld b, a
    ld a, [wComputerHeight]
    srl a
    add b
    ld b, a ; b = computer paddle middle y position
    ld a, [wBallY + 1]
    cp b
    jr c, .moveUp
    jr .moveDown

RunGameOver:
; Display the winner of the game.
    ld d, 1
    ld hl, vBGMap0
    ld bc, $400
    call ClearGfx
    call ClearOAMBuffer
    ld a, [wWinner]
    cp 2
    jr z, .computerWon
    ; player won
    hlCoord 3, 8, vBGMap0
    ld d, h
    ld e, l
    ld hl, PlayerWonText
    call PrintText
    hlCoord 3, 10, vBGMap0
    ld d, h
    ld e, l
    ld hl, PlayerWonText2
    call PrintText
    jr .loadedGraphics
.computerWon
    hlCoord 3, 8, vBGMap0
    ld d, h
    ld e, l
    ld hl, ComputerWonText
    call PrintText
    hlCoord 3, 10, vBGMap0
    ld d, h
    ld e, l
    ld hl, ComputerWonText2
    call PrintText
.loadedGraphics
    ; wait for a few seconds, then return to titlescreen
    ld b, 240  ; 240 frames
.waitLoop
    call WaitForNextFrame
    dec b
    jr nz, .waitLoop
    xor a
    ld [wScreenState], a
    ld a, SCREEN_TITLESCREEN
    ld [wCurrentScreen], a
    ret

PlayerWonText:
    db "PLAYER WON@"

PlayerWonText2:
    db "COMPUTER IS BAD@"

ComputerWonText:
    db "COMPUTER WON@"

ComputerWonText2:
    db "PLAYER IS BAD@"

GameGfx:
    INCBIN "gfx/game.2bpp"












SECTION "Bank 1",ROMX,BANK[$1]

; This audio engine is taken from Pokemon Red/Blue Version (pokered disassembly)

SFX_Headers_02::
    db $ff, $ff, $ff ; padding

SFX_02_01:: ; 8003 (2:4003)
    db CH7
    dw SFX_02_01_Ch1

SFX_02_02:: ; 8006 (2:4006)
    db CH7
    dw SFX_02_02_Ch1

SFX_02_03:: ; 8009 (2:4009)
    db CH7
    dw SFX_02_03_Ch1

SFX_02_04:: ; 800c (2:400c)
    db CH7
    dw SFX_02_04_Ch1

SFX_02_05:: ; 800f (2:400f)
    db CH7
    dw SFX_02_05_Ch1

SFX_02_06:: ; 8012 (2:4012)
    db CH7
    dw SFX_02_06_Ch1

SFX_02_07:: ; 8015 (2:4015)
    db CH7
    dw SFX_02_07_Ch1

SFX_02_08:: ; 8018 (2:4018)
    db CH7
    dw SFX_02_08_Ch1

SFX_02_09:: ; 801b (2:401b)
    db CH7
    dw SFX_02_09_Ch1

SFX_02_0a:: ; 801e (2:401e)
    db CH7
    dw SFX_02_0a_Ch1

SFX_02_0b:: ; 8021 (2:4021)
    db CH7
    dw SFX_02_0b_Ch1

SFX_02_0c:: ; 8024 (2:4024)
    db CH7
    dw SFX_02_0c_Ch1

SFX_02_0d:: ; 8027 (2:4027)
    db CH7
    dw SFX_02_0d_Ch1

SFX_02_0e:: ; 802a (2:402a)
    db CH7
    dw SFX_02_0e_Ch1

SFX_02_0f:: ; 802d (2:402d)
    db CH7
    dw SFX_02_0f_Ch1

SFX_02_10:: ; 8030 (2:4030)
    db CH7
    dw SFX_02_10_Ch1

SFX_02_11:: ; 8033 (2:4033)
    db CH7
    dw SFX_02_11_Ch1

SFX_02_12:: ; 8036 (2:4036)
    db CH7
    dw SFX_02_12_Ch1

SFX_02_13:: ; 8039 (2:4039)
    db CH7
    dw SFX_02_13_Ch1

SFX_02_14:: ; 803c (2:403c)
    db ( $80 | CH4 )
    dw SFX_02_14_Ch1
    db CH5
    dw SFX_02_14_Ch2
    db CH7
    dw SFX_02_14_Ch3

SFX_02_15:: ; 8045 (2:4045)
    db ( $80 | CH4 )
    dw SFX_02_15_Ch1
    db CH5
    dw SFX_02_15_Ch2
    db CH7
    dw SFX_02_15_Ch3

SFX_02_16:: ; 804e (2:404e)
    db ( $80 | CH4 )
    dw SFX_02_16_Ch1
    db CH5
    dw SFX_02_16_Ch2
    db CH7
    dw SFX_02_16_Ch3

SFX_02_17:: ; 8057 (2:4057)
    db ( $80 | CH4 )
    dw SFX_02_17_Ch1
    db CH5
    dw SFX_02_17_Ch2
    db CH7
    dw SFX_02_17_Ch3

SFX_02_18:: ; 8060 (2:4060)
    db ( $80 | CH4 )
    dw SFX_02_18_Ch1
    db CH5
    dw SFX_02_18_Ch2
    db CH7
    dw SFX_02_18_Ch3

SFX_02_19:: ; 8069 (2:4069)
    db ( $80 | CH4 )
    dw SFX_02_19_Ch1
    db CH5
    dw SFX_02_19_Ch2
    db CH7
    dw SFX_02_19_Ch3

SFX_02_1a:: ; 8072 (2:4072)
    db ( $80 | CH4 )
    dw SFX_02_1a_Ch1
    db CH5
    dw SFX_02_1a_Ch2
    db CH7
    dw SFX_02_1a_Ch3

SFX_02_1b:: ; 807b (2:407b)
    db ( $80 | CH4 )
    dw SFX_02_1b_Ch1
    db CH5
    dw SFX_02_1b_Ch2
    db CH7
    dw SFX_02_1b_Ch3

SFX_02_1c:: ; 8084 (2:4084)
    db ( $80 | CH4 )
    dw SFX_02_1c_Ch1
    db CH5
    dw SFX_02_1c_Ch2
    db CH7
    dw SFX_02_1c_Ch3

SFX_02_1d:: ; 808d (2:408d)
    db ( $80 | CH4 )
    dw SFX_02_1d_Ch1
    db CH5
    dw SFX_02_1d_Ch2
    db CH7
    dw SFX_02_1d_Ch3

SFX_02_1e:: ; 8096 (2:4096)
    db ( $80 | CH4 )
    dw SFX_02_1e_Ch1
    db CH5
    dw SFX_02_1e_Ch2
    db CH7
    dw SFX_02_1e_Ch3

SFX_02_1f:: ; 809f (2:409f)
    db ( $80 | CH4 )
    dw SFX_02_1f_Ch1
    db CH5
    dw SFX_02_1f_Ch2
    db CH7
    dw SFX_02_1f_Ch3

SFX_02_20:: ; 80a8 (2:40a8)
    db ( $80 | CH4 )
    dw SFX_02_20_Ch1
    db CH5
    dw SFX_02_20_Ch2
    db CH7
    dw SFX_02_20_Ch3

SFX_02_21:: ; 80b1 (2:40b1)
    db ( $80 | CH4 )
    dw SFX_02_21_Ch1
    db CH5
    dw SFX_02_21_Ch2
    db CH7
    dw SFX_02_21_Ch3

SFX_02_22:: ; 80ba (2:40ba)
    db ( $80 | CH4 )
    dw SFX_02_22_Ch1
    db CH5
    dw SFX_02_22_Ch2
    db CH7
    dw SFX_02_22_Ch3

SFX_02_23:: ; 80c3 (2:40c3)
    db ( $80 | CH4 )
    dw SFX_02_23_Ch1
    db CH5
    dw SFX_02_23_Ch2
    db CH7
    dw SFX_02_23_Ch3

SFX_02_24:: ; 80cc (2:40cc)
    db ( $80 | CH4 )
    dw SFX_02_24_Ch1
    db CH5
    dw SFX_02_24_Ch2
    db CH7
    dw SFX_02_24_Ch3

SFX_02_25:: ; 80d5 (2:40d5)
    db ( $80 | CH4 )
    dw SFX_02_25_Ch1
    db CH5
    dw SFX_02_25_Ch2
    db CH7
    dw SFX_02_25_Ch3

SFX_02_26:: ; 80de (2:40de)
    db ( $80 | CH4 )
    dw SFX_02_26_Ch1
    db CH5
    dw SFX_02_26_Ch2
    db CH7
    dw SFX_02_26_Ch3

SFX_02_27:: ; 80e7 (2:40e7)
    db ( $80 | CH4 )
    dw SFX_02_27_Ch1
    db CH5
    dw SFX_02_27_Ch2
    db CH7
    dw SFX_02_27_Ch3

SFX_02_28:: ; 80f0 (2:40f0)
    db ( $80 | CH4 )
    dw SFX_02_28_Ch1
    db CH5
    dw SFX_02_28_Ch2
    db CH7
    dw SFX_02_28_Ch3

SFX_02_29:: ; 80f9 (2:40f9)
    db ( $80 | CH4 )
    dw SFX_02_29_Ch1
    db CH5
    dw SFX_02_29_Ch2
    db CH7
    dw SFX_02_29_Ch3

SFX_02_2a:: ; 8102 (2:4102)
    db ( $80 | CH4 )
    dw SFX_02_2a_Ch1
    db CH5
    dw SFX_02_2a_Ch2
    db CH7
    dw SFX_02_2a_Ch3

SFX_02_2b:: ; 810b (2:410b)
    db ( $80 | CH4 )
    dw SFX_02_2b_Ch1
    db CH5
    dw SFX_02_2b_Ch2
    db CH7
    dw SFX_02_2b_Ch3

SFX_02_2c:: ; 8114 (2:4114)
    db ( $80 | CH4 )
    dw SFX_02_2c_Ch1
    db CH5
    dw SFX_02_2c_Ch2
    db CH7
    dw SFX_02_2c_Ch3

SFX_02_2d:: ; 811d (2:411d)
    db ( $80 | CH4 )
    dw SFX_02_2d_Ch1
    db CH5
    dw SFX_02_2d_Ch2
    db CH7
    dw SFX_02_2d_Ch3

SFX_02_2e:: ; 8126 (2:4126)
    db ( $80 | CH4 )
    dw SFX_02_2e_Ch1
    db CH5
    dw SFX_02_2e_Ch2
    db CH7
    dw SFX_02_2e_Ch3

SFX_02_2f:: ; 812f (2:412f)
    db ( $80 | CH4 )
    dw SFX_02_2f_Ch1
    db CH5
    dw SFX_02_2f_Ch2
    db CH7
    dw SFX_02_2f_Ch3

SFX_02_30:: ; 8138 (2:4138)
    db ( $80 | CH4 )
    dw SFX_02_30_Ch1
    db CH5
    dw SFX_02_30_Ch2
    db CH7
    dw SFX_02_30_Ch3

SFX_02_31:: ; 8141 (2:4141)
    db ( $80 | CH4 )
    dw SFX_02_31_Ch1
    db CH5
    dw SFX_02_31_Ch2
    db CH7
    dw SFX_02_31_Ch3

SFX_02_32:: ; 814a (2:414a)
    db ( $80 | CH4 )
    dw SFX_02_32_Ch1
    db CH5
    dw SFX_02_32_Ch2
    db CH7
    dw SFX_02_32_Ch3

SFX_02_33:: ; 8153 (2:4153)
    db ( $80 | CH4 )
    dw SFX_02_33_Ch1
    db CH5
    dw SFX_02_33_Ch2
    db CH7
    dw SFX_02_33_Ch3

SFX_02_34:: ; 815c (2:415c)
    db ( $80 | CH4 )
    dw SFX_02_34_Ch1
    db CH5
    dw SFX_02_34_Ch2
    db CH7
    dw SFX_02_34_Ch3

SFX_02_35:: ; 8165 (2:4165)
    db ( $80 | CH4 )
    dw SFX_02_35_Ch1
    db CH5
    dw SFX_02_35_Ch2
    db CH7
    dw SFX_02_35_Ch3

SFX_02_36:: ; 816e (2:416e)
    db ( $80 | CH4 )
    dw SFX_02_36_Ch1
    db CH5
    dw SFX_02_36_Ch2
    db CH7
    dw SFX_02_36_Ch3

SFX_02_37:: ; 8177 (2:4177)
    db ( $80 | CH4 )
    dw SFX_02_37_Ch1
    db CH5
    dw SFX_02_37_Ch2
    db CH7
    dw SFX_02_37_Ch3

SFX_02_38:: ; 8180 (2:4180)
    db ( $80 | CH4 )
    dw SFX_02_38_Ch1
    db CH5
    dw SFX_02_38_Ch2
    db CH7
    dw SFX_02_38_Ch3

SFX_02_39:: ; 8189 (2:4189)
    db ( $80 | CH4 )
    dw SFX_02_39_Ch1
    db CH5
    dw SFX_02_39_Ch2
    db CH7
    dw SFX_02_39_Ch3

SFX_02_3a:: ; 8192 (2:4192)
    db ( $80 | CH4 )
    dw SFX_02_3a_Ch1
    db CH5
    dw SFX_02_3a_Ch2
    db CH6
    dw SFX_02_3a_Ch3

SFX_02_3b:: ; 819b (2:419b)
    db ( $80 | CH4 )
    dw SFX_02_3b_Ch1
    db CH5
    dw SFX_02_3b_Ch2
    db CH6
    dw SFX_02_3b_Ch3

SFX_02_3c:: ; 81a4 (2:41a4)
    db CH4
    dw SFX_02_3c_Ch1

SFX_02_3d:: ; 81a7 (2:41a7)
    db CH4
    dw SFX_02_3d_Ch1

SFX_02_3e:: ; 81aa (2:41aa)
    db CH4
    dw SFX_02_3e_Ch1

SFX_02_3f:: ; 81ad (2:41ad)
    db CH7
    dw SFX_02_3f_Ch1

SFX_02_40:: ; 81b0 (2:41b0)
    db CH4
    dw SFX_02_40_Ch1

SFX_02_41:: ; 81b3 (2:41b3)
    db ( $80 | CH4 )
    dw SFX_02_41_Ch1
    db CH5
    dw SFX_02_41_Ch2
    db CH6
    dw SFX_02_41_Ch3

SFX_02_42:: ; 81bc (2:41bc)
    db ( $80 | CH4 )
    dw SFX_02_42_Ch1
    db CH5
    dw SFX_02_42_Ch2
    db CH6
    dw SFX_02_42_Ch3

SFX_02_43:: ; 81c5 (2:41c5)
    db CH4
    dw SFX_02_43_Ch1

SFX_02_44:: ; 81c8 (2:41c8)
    db CH4
    dw SFX_02_44_Ch1

SFX_02_45:: ; 81cb (2:41cb)
    db CH4
    dw SFX_02_45_Ch1

SFX_02_46:: ; 81ce (2:41ce)
    db CH4
    dw SFX_02_46_Ch1

SFX_02_47:: ; 81d1 (2:41d1)
    db CH4
    dw SFX_02_47_Ch1

SFX_02_48:: ; 81d4 (2:41d4)
    db CH4
    dw SFX_02_48_Ch1

SFX_02_49:: ; 81d7 (2:41d7)
    db CH4
    dw SFX_02_49_Ch1

SFX_02_4a:: ; 81da (2:41da)
    db CH4
    dw SFX_02_4a_Ch1

SFX_02_4b:: ; 81dd (2:41dd)
    db CH4
    dw SFX_02_4b_Ch1

SFX_02_4c:: ; 81e0 (2:41e0)
    db CH4
    dw SFX_02_4c_Ch1

SFX_02_4d:: ; 81e3 (2:41e3)
    db CH4
    dw SFX_02_4d_Ch1

SFX_02_4e:: ; 81e6 (2:41e6)
    db CH4
    dw SFX_02_4e_Ch1

SFX_02_4f:: ; 81e9 (2:41e9)
    db CH7
    dw SFX_02_4f_Ch1

SFX_02_50:: ; 81ec (2:41ec)
    db CH7
    dw SFX_02_50_Ch1

SFX_02_51:: ; 81ef (2:41ef)
    db ( $40 | CH4 )
    dw SFX_02_51_Ch1
    db CH5
    dw SFX_02_51_Ch2

SFX_02_52:: ; 81f5 (2:41f5)
    db CH4
    dw SFX_02_52_Ch1

SFX_02_53:: ; 81f8 (2:41f8)
    db CH7
    dw SFX_02_53_Ch1

SFX_02_54:: ; 81fb (2:41fb)
    db ( $40 | CH4 )
    dw SFX_02_54_Ch1
    db CH5
    dw SFX_02_54_Ch2

SFX_02_55:: ; 8201 (2:4201)
    db CH4
    dw SFX_02_55_Ch1

SFX_02_56:: ; 8204 (2:4204)
    db CH7
    dw SFX_02_56_Ch1

SFX_02_57:: ; 8207 (2:4207)
    db CH7
    dw SFX_02_57_Ch1

SFX_02_58:: ; 820a (2:420a)
    db ( $40 | CH4 )
    dw SFX_02_58_Ch1
    db CH5
    dw SFX_02_58_Ch2

SFX_02_59:: ; 8210 (2:4210)
    db ( $40 | CH4 )
    dw SFX_02_59_Ch1
    db CH5
    dw SFX_02_59_Ch2

SFX_02_5a:: ; 8216 (2:4216)
    db ( $40 | CH4 )
    dw SFX_02_5a_Ch1
    db CH5
    dw SFX_02_5a_Ch2

SFX_02_5b:: ; 821c (2:421c)
    db CH4
    dw SFX_02_5b_Ch1

SFX_02_5c:: ; 821f (2:421f)
    db CH7
    dw SFX_02_5c_Ch1

SFX_02_5d:: ; 8222 (2:4222)
    db ( $40 | CH4 )
    dw SFX_02_5d_Ch1
    db CH5
    dw SFX_02_5d_Ch2

SFX_02_5e:: ; 8228 (2:4228)
    db CH2
    dw SFX_02_5e_Ch1

SFX_02_5f:: ; 822b (2:422b)
    db CH4
    dw SFX_02_5f_Ch1

Music_Game::
    db ( $C0 | CH0 )
    dw Music_Game_Ch1
    db CH1
    dw Music_Game_Ch2
    db CH2
    dw Music_Game_Ch3
    db CH3
    dw Music_Game_Ch4

PlayMusic::
    ld b, a
    ld [wc0ee], a
    xor a
    ld [wMusicHeaderPointer], a
    ld [wc0f0], a
    ld a, b

; plays music specified by a. If value is $ff, music is stopped
PlaySound::
    push hl
    push de
    push bc
    ld b, a
    ld a, [wc0ee]
    and a
    jr z, .asm_23c8
    xor a
    ld [wc02a], a
    ld [wc02b], a
    ld [wc02c], a
    ld [wc02d], a
.asm_23c8
    ld a, [wMusicHeaderPointer]
    and a
    jr z, .asm_23e3
    ld a, [wc0ee]
    and a
    jr z, .asm_2425
    xor a
    ld [wc0ee], a
    ld a, [wcfca]
    cp $ff
    jr nz, .asm_2414
    xor a
    ld [wMusicHeaderPointer], a
.asm_23e3
    xor a
    ld [wc0ee], a
    ld a, b
    call Func_9876
    jr .asm_2425
.asm_2414
    ld a, b
    ld [wcfca], a
    ld a, [wMusicHeaderPointer]
    ld [wcfc8], a
    ld [wcfc9], a
    ld a, b
    ld [wMusicHeaderPointer], a
.asm_2425
    pop bc
    pop de
    pop hl
    ret

Music2_UpdateMusic::
    ld c, CH0
.loop
    ld b, $0
    ld hl, wc026
    add hl, bc
    ld a, [hl]
    and a
    jr z, .nextChannel
    ld a, c
    cp CH4
    jr nc, .asm_912e ; if sfx channel
    ld a, [wc002]
    and a
    jr z, .asm_912e
    bit 7, a
    jr nz, .nextChannel
    set 7, a
    ld [wc002], a
    xor a
    ld [$ff25], a
    ld [$ff1a], a
    ld a, $80
    ld [$ff1a], a
    jr .nextChannel
.asm_912e
    call Music2_ApplyMusicAffects
.nextChannel
    ld a, c
    inc c ; inc channel number
    cp CH7
    jr nz, .loop
    ret

; this routine checks flags for music effects currently applied
; to the channel and calls certain functions based on flags.
; known flags for wc02e:
;   0: toggleperfectpitch has been used
;   1: call has been used
;   3: a toggle used only by this routine for vibrato
;   4: pitchbend flag
;   6: dutycycle flag
Music2_ApplyMusicAffects:
    ld b, $0
    ld hl, wc0b6 ; delay until next note
    add hl, bc
    ld a, [hl]
    cp $1 ; if the delay is 1, play next note
    jp z, Music2_PlayNextNote
    dec a ; otherwise, decrease the delay timer
    ld [hl], a
    ld a, c
    cp CH4
    jr nc, .startChecks ; if a sfx channel
    ld hl, wc02a
    add hl, bc
    ld a, [hl]
    and a
    jr z, .startChecks
    ret
.startChecks
    ld hl, wc02e
    add hl, bc
    bit 6, [hl] ; dutycycle
    jr z, .checkForExecuteMusic
    call Music2_ApplyDutyCycle
.checkForExecuteMusic
    ld b, $0
    ld hl, wc036
    add hl, bc
    bit 0, [hl]
    jr nz, .checkForPitchBend
    ld hl, wc02e
    add hl, bc
    bit 2, [hl]
    jr nz, .disablePitchBendVibrato
.checkForPitchBend
    ld hl, wc02e
    add hl, bc
    bit 4, [hl] ; pitchbend
    jr z, .checkVibratoDelay
    jp Music2_ApplyPitchBend
.checkVibratoDelay
    ld hl, wc04e ; vibrato delay
    add hl, bc
    ld a, [hl]
    and a ; check if delay is over
    jr z, .checkForVibrato
    dec [hl] ; otherwise, dec delay
.disablePitchBendVibrato
    ret
.checkForVibrato
    ld hl, wc056 ; vibrato rate
    add hl, bc
    ld a, [hl]
    and a
    jr nz, .vibrato
    ret ; no vibrato
.vibrato
    ld d, a
    ld hl, wc05e
    add hl, bc
    ld a, [hl]
    and $f
    and a
    jr z, .vibratoAlreadyDone
    dec [hl] ; apply vibrato pitch change
    ret
.vibratoAlreadyDone
    ld a, [hl]
    swap [hl]
    or [hl]
    ld [hl], a ; reset the vibrato value and start again
    ld hl, wc066
    add hl, bc
    ld e, [hl] ; get note pitch
    ld hl, wc02e
    add hl, bc
    bit 3, [hl] ; this is the only code that sets/resets bit three so
    jr z, .unset ; it continuously alternates which path it takes
    res 3, [hl]
    ld a, d
    and $f
    ld d, a
    ld a, e
    sub d
    jr nc, .noCarry
    ld a, $0
.noCarry
    jr .done
.unset
    set 3, [hl]
    ld a, d
    and $f0
    swap a
    add e
    jr nc, .done
    ld a, $ff
.done
    ld d, a
    ld b, $3
    call Func_9838
    ld [hl], d
    ret

; this routine executes all music commands that take up no time,
; like tempo changes, duty changes etc. and doesn't return
; until the first note is reached
Music2_PlayNextNote:
    ld hl, wc06e
    add hl, bc
    ld a, [hl]
    ld hl, wc04e
    add hl, bc
    ld [hl], a
    ld hl, wc02e
    add hl, bc
    res 4, [hl]
    res 5, [hl]
    call Music2_endchannel
    ret

Music2_endchannel:
    call Music2_GetNextMusicByte
    ld d, a
    cp $ff ; is this command an endchannel?
    jp nz, Music2_callchannel ; no
    ld b, $0 ; yes
    ld hl, wc02e
    add hl, bc
    bit 1, [hl]
    jr nz, .returnFromCall
    ld a, c
    cp CH3
    jr nc, .noiseOrSfxChannel
    jr .asm_923f
.noiseOrSfxChannel
    res 2, [hl]
    ld hl, wc036
    add hl, bc
    res 0, [hl]
    cp CH6
    jr nz, .notSfxChannel3
    ld a, $0
    ld [$ff1a], a
    ld a, $80
    ld [$ff1a], a
.notSfxChannel3
    jr nz, .asm_9222
    ld a, [wc003]
    and a
    jr z, .asm_9222
    xor a
    ld [wc003], a
    jr .asm_923f
.asm_9222
    jr .asm_9248
.returnFromCall
    res 1, [hl]
    ld d, $0
    ld a, c
    add a
    ld e, a
    ld hl, wc006
    add hl, de
    push hl ; store current channel address
    ld hl, wc016
    add hl, de
    ld e, l
    ld d, h
    pop hl
    ld a, [de]
    ld [hli], a
    inc de
    ld a, [de]
    ld [hl], a ; loads channel address to return to
    jp Music2_endchannel
.asm_923f
    ld hl, Unknown_9b1f
    add hl, bc
    ld a, [$ff25]
    and [hl]
    ld [$ff25], a
.asm_9248
    ld a, [wc02a]
    cp $14
    jr nc, .asm_9251
    jr .asm_926e
.asm_9251
    ld a, [wc02a]
    cp $86
    jr z, .asm_926e
    jr c, .asm_925c
    jr .asm_926e
.asm_925c
    ld a, c
    cp CH4
    jr z, .asm_9265
    call Func_96c7
    ret c
.asm_9265
    ld a, [wc005]
    ld [$ff24], a
    xor a
    ld [wc005], a
.asm_926e
    ld hl, wc026
    add hl, bc
    ld [hl], b
    ret

Music2_callchannel:
    cp $fd ; is this command a callchannel?
    jp nz, Music2_loopchannel ; no
    call Music2_GetNextMusicByte ; yes
    push af
    call Music2_GetNextMusicByte
    ld d, a
    pop af
    ld e, a
    push de ; store pointer
    ld d, $0
    ld a, c
    add a
    ld e, a
    ld hl, wc006
    add hl, de
    push hl
    ld hl, wc016
    add hl, de
    ld e, l
    ld d, h
    pop hl
    ld a, [hli]
    ld [de], a
    inc de
    ld a, [hld]
    ld [de], a ; copy current channel address
    pop de
    ld [hl], e
    inc hl
    ld [hl], d ; overwrite current address with pointer
    ld b, $0
    ld hl, wc02e
    add hl, bc
    set 1, [hl] ; set the call flag
    jp Music2_endchannel

Music2_loopchannel:
    cp $fe ; is this command a loopchannel?
    jp nz, Music2_notetype ; no
    call Music2_GetNextMusicByte ; yes
    ld e, a
    and a
    jr z, .infiniteLoop
    ld b, $0
    ld hl, wc0be
    add hl, bc
    ld a, [hl]
    cp e
    jr nz, .loopAgain
    ld a, $1 ; if no more loops to make,
    ld [hl], a
    call Music2_GetNextMusicByte ; skip pointer
    call Music2_GetNextMusicByte
    jp Music2_endchannel
.loopAgain ; inc loop count
    inc a
    ld [hl], a
    ; fall through
.infiniteLoop ; overwrite current address with pointer
    call Music2_GetNextMusicByte
    push af
    call Music2_GetNextMusicByte
    ld b, a
    ld d, $0
    ld a, c
    add a
    ld e, a
    ld hl, wc006
    add hl, de
    pop af
    ld [hli], a
    ld [hl], b
    jp Music2_endchannel

Music2_notetype:
    and $f0
    cp $d0 ; is this command a notetype?
    jp nz, Music2_toggleperfectpitch ; no
    ld a, d ; yes
    and $f
    ld b, $0
    ld hl, wc0c6
    add hl, bc
    ld [hl], a ; store low nibble as speed
    ld a, c
    cp CH3
    jr z, .noiseChannel ; noise channel has 0 params
    call Music2_GetNextMusicByte
    ld d, a
    ld a, c
    cp CH2
    jr z, .musicChannel3
    cp CH6
    jr nz, .notChannel3
    ld hl, wc0e7
    jr .sfxChannel3
.musicChannel3
    ld hl, wc0e6
.sfxChannel3
    ld a, d
    and $f
    ld [hl], a ; store low nibble of param as duty
    ld a, d
    and $30
    sla a
    ld d, a
    ; fall through

    ; if channel 3, store high nibble as volume
    ; else, store volume (high nibble) and fade (low nibble)
.notChannel3
    ld b, $0
    ld hl, wc0de
    add hl, bc
    ld [hl], d
.noiseChannel
    jp Music2_endchannel

Music2_toggleperfectpitch:
    ld a, d
    cp $e8 ; is this command a toggleperfectpitch?
    jr nz, Music2_vibrato ; no
    ld b, $0 ; yes
    ld hl, wc02e
    add hl, bc
    ld a, [hl]
    xor $1
    ld [hl], a ; flip bit 0 of wc02e
    jp Music2_endchannel

Music2_vibrato:
    cp $ea ; is this command a vibrato?
    jr nz, Music2_pitchbend ; no
    call Music2_GetNextMusicByte ; yes
    ld b, $0
    ld hl, wc04e
    add hl, bc
    ld [hl], a ; store delay
    ld hl, wc06e
    add hl, bc
    ld [hl], a ; store delay
    call Music2_GetNextMusicByte
    ld d, a
    and $f0
    swap a
    ld b, $0
    ld hl, wc056
    add hl, bc
    srl a
    ld e, a
    adc b
    swap a
    or e
    ld [hl], a ; store rate as both high and low nibbles
    ld a, d
    and $f
    ld d, a
    ld hl, wc05e
    add hl, bc
    swap a
    or d
    ld [hl], a ; store depth as both high and low nibbles
    jp Music2_endchannel

Music2_pitchbend:
    cp $eb ; is this command a pitchbend?
    jr nz, Music2_duty ; no
    call Music2_GetNextMusicByte ; yes
    ld b, $0
    ld hl, wc076
    add hl, bc
    ld [hl], a ; store first param
    call Music2_GetNextMusicByte
    ld d, a
    and $f0
    swap a
    ld b, a
    ld a, d
    and $f
    call Func_9858
    ld b, $0
    ld hl, wc0a6
    add hl, bc
    ld [hl], d ; store unknown part of second param
    ld hl, wc0ae
    add hl, bc
    ld [hl], e ; store unknown part of second param
    ld b, $0
    ld hl, wc02e
    add hl, bc
    set 4, [hl] ; set pitchbend flag
    call Music2_GetNextMusicByte
    ld d, a
    jp Music2_notelength

Music2_duty:
    cp $ec ; is this command a duty?
    jr nz, Music2_tempo ; no
    call Music2_GetNextMusicByte ; yes
    rrca
    rrca
    and $c0
    ld b, $0
    ld hl, wc03e
    add hl, bc
    ld [hl], a ; store duty
    jp Music2_endchannel

Music2_tempo:
    cp $ed ; is this command a tempo?
    jr nz, Music2_stereopanning ; no
    ld a, c ; yes
    cp CH4
    jr nc, .sfxChannel
    call Music2_GetNextMusicByte
    ld [wc0e8], a ; store first param
    call Music2_GetNextMusicByte
    ld [wc0e9], a ; store second param
    xor a
    ld [wc0ce], a ; clear RAM
    ld [wc0cf], a
    ld [wc0d0], a
    ld [wc0d1], a
    jr .musicChannelDone
.sfxChannel
    call Music2_GetNextMusicByte
    ld [wc0ea], a ; store first param
    call Music2_GetNextMusicByte
    ld [wc0eb], a ; store second param
    xor a
    ld [wc0d2], a ; clear RAM
    ld [wc0d3], a
    ld [wc0d4], a
    ld [wc0d5], a
.musicChannelDone
    jp Music2_endchannel

Music2_stereopanning:
    cp $ee ; is this command a stereopanning?
    jr nz, Music2_unknownmusic0xef ; no
    call Music2_GetNextMusicByte ; yes
    ld [wc004], a ; store panning
    jp Music2_endchannel

Music2_unknownmusic0xef:
    cp $ef ; is this command an unknownmusic0xef?
    jr nz, Music2_dutycycle ; no
    call Music2_GetNextMusicByte ; yes
    push bc
    call Func_9876
    pop bc
    ld a, [wc003]
    and a
    jr nz, .skip
    ld a, [wc02d]
    ld [wc003], a
    xor a
    ld [wc02d], a
.skip
    jp Music2_endchannel

Music2_dutycycle:
    cp $fc ; is this command a dutycycle?
    jr nz, Music2_volume ; no
    call Music2_GetNextMusicByte ; yes
    ld b, $0
    ld hl, wc046
    add hl, bc
    ld [hl], a ; store full cycle
    and $c0
    ld hl, wc03e
    add hl, bc
    ld [hl], a ; store first duty
    ld hl, wc02e
    add hl, bc
    set 6, [hl] ; set dutycycle flag
    jp Music2_endchannel

Music2_volume:
    cp $f0 ; is this command a volume?
    jr nz, Music2_executemusic ; no
    call Music2_GetNextMusicByte ; yes
    ld [$ff24], a ; store volume
    jp Music2_endchannel

Music2_executemusic:
    cp $f8 ; is this command an executemusic?
    jr nz, Music2_octave ; no
    ld b, $0 ; yes
    ld hl, wc036
    add hl, bc
    set 0, [hl]
    jp Music2_endchannel

Music2_octave:
    and $f0
    cp $e0 ; is this command an octave?
    jr nz, Music2_unknownsfx0x20 ; no
    ld hl, wc0d6 ; yes
    ld b, $0
    add hl, bc
    ld a, d
    and $f
    ld [hl], a ; store low nibble as octave
    jp Music2_endchannel

Music2_unknownsfx0x20:
    cp $20 ; is this command an unknownsfx0x20?
    jr nz, Music2_unknownsfx0x10 ; no
    ld a, c
    cp CH3 ; is this a noise or sfx channel?
    jr c, Music2_unknownsfx0x10 ; no
    ld b, $0
    ld hl, wc036
    add hl, bc
    bit 0, [hl]
    jr nz, Music2_unknownsfx0x10 ; no
    call Music2_notelength ; yes
    ld d, a
    ld b, $0
    ld hl, wc03e
    add hl, bc
    ld a, [hl]
    or d
    ld d, a
    ld b, $1
    call Func_9838
    ld [hl], d
    call Music2_GetNextMusicByte
    ld d, a
    ld b, $2
    call Func_9838
    ld [hl], d
    call Music2_GetNextMusicByte
    ld e, a
    ld a, c
    cp CH7
    ld a, $0
    jr z, .sfxNoiseChannel ; only two params for noise channel
    push de
    call Music2_GetNextMusicByte
    pop de
.sfxNoiseChannel
    ld d, a
    push de
    call Func_9629
    call Func_95f8
    pop de
    call Func_964b
    ret

Music2_unknownsfx0x10:
    ld a, c
    cp CH4
    jr c, Music2_note ; if not a sfx
    ld a, d
    cp $10 ; is this command a unknownsfx0x10?
    jr nz, Music2_note ; no
    ld b, $0
    ld hl, wc036
    add hl, bc
    bit 0, [hl]
    jr nz, Music2_note ; no
    call Music2_GetNextMusicByte ; yes
    ld [$ff10], a
    jp Music2_endchannel

Music2_note:
    ld a, c
    cp CH3
    jr nz, Music2_notelength ; if not noise channel
    ld a, d
    and $f0
    cp $b0 ; is this command a dnote?
    jr z, Music2_dnote ; yes
    jr nc, Music2_notelength ; no
    swap a
    ld b, a
    ld a, d
    and $f
    ld d, a
    ld a, b
    push de
    push bc
    jr asm_94fd

Music2_dnote:
    ld a, d
    and $f
    push af
    push bc
    call Music2_GetNextMusicByte ; get dnote instrument
asm_94fd
    ld d, a
    ld a, [wc003]
    and a
    jr nz, .asm_9508
    ld a, d
    call Func_9876
.asm_9508
    pop bc
    pop de

Music2_notelength:
    ld a, d
    push af
    and $f
    inc a
    ld b, $0
    ld e, a  ; store note length (in 16ths)
    ld d, b
    ld hl, wc0c6
    add hl, bc
    ld a, [hl]
    ld l, b
    call Func_9847
    ld a, c
    cp CH4
    jr nc, .sfxChannel
    ld a, [wc0e8]
    ld d, a
    ld a, [wc0e9]
    ld e, a
    jr .skip
.sfxChannel
    ld d, $1
    ld e, $0
    cp CH7
    jr z, .skip ; if noise channel
    call Func_9693
    ld a, [wc0ea]
    ld d, a
    ld a, [wc0eb]
    ld e, a
.skip
    ld a, l
    ld b, $0
    ld hl, wc0ce
    add hl, bc
    ld l, [hl]
    call Func_9847
    ld e, l
    ld d, h
    ld hl, wc0ce
    add hl, bc
    ld [hl], e
    ld a, d
    ld hl, wc0b6
    add hl, bc
    ld [hl], a
    ld hl, wc036
    add hl, bc
    bit 0, [hl]
    jr nz, Music2_notepitch
    ld hl, wc02e
    add hl, bc
    bit 2, [hl]
    jr z, Music2_notepitch
    pop hl
    ret

Music2_notepitch:
    pop af
    and $f0
    cp $c0 ; compare to rest
    jr nz, .notRest
    ld a, c
    cp CH4
    jr nc, .sfxChannel
    ld hl, wc02a
    add hl, bc
    ld a, [hl]
    and a
    jr nz, .done
    ; fall through
.sfxChannel
    ld a, c
    cp CH2
    jr z, .musicChannel3
    cp CH6
    jr nz, .notSfxChannel3
.musicChannel3
    ld b, $0
    ld hl, Unknown_9b1f
    add hl, bc
    ld a, [$ff25]
    and [hl]
    ld [$ff25], a
    jr .done
.notSfxChannel3
    ld b, $2
    call Func_9838
    ld a, $8
    ld [hli], a
    inc hl
    ld a, $80
    ld [hl], a
.done
    ret
.notRest
    swap a
    ld b, $0
    ld hl, wc0d6
    add hl, bc
    ld b, [hl]
    call Func_9858
    ld b, $0
    ld hl, wc02e
    add hl, bc
    bit 4, [hl]
    jr z, .asm_95b8
    call Func_978f
.asm_95b8
    push de
    ld a, c
    cp CH4
    jr nc, .skip ; if sfx channel
    ld hl, wc02a
    ld d, $0
    ld e, a
    add hl, de
    ld a, [hl]
    and a
    jr nz, .asm_95cb
    jr .skip
.asm_95cb
    pop de
    ret
.skip
    ld b, $0
    ld hl, wc0de
    add hl, bc
    ld d, [hl]
    ld b, $2
    call Func_9838
    ld [hl], d
    call Func_9629
    call Func_95f8
    pop de
    ld b, $0
    ld hl, wc02e
    add hl, bc
    bit 0, [hl]   ; has toggleperfectpitch been used?
    jr z, .skip2
    inc e         ; if yes, increment the pitch by 1
    jr nc, .skip2
    inc d
.skip2
    ld hl, wc066
    add hl, bc
    ld [hl], e
    call Func_964b
    ret

Func_95f8:
    ld b, $0
    ld hl, Unknown_9b27
    add hl, bc
    ld a, [$ff25]
    or [hl]
    ld d, a
    ld a, c
    cp CH7
    jr z, .sfxNoiseChannel
    cp CH4
    jr nc, .skip ; if sfx channel
    ld hl, wc02a
    add hl, bc
    ld a, [hl]
    and a
    jr nz, .skip
.sfxNoiseChannel
    ld a, [wc004]
    ld hl, Unknown_9b27
    add hl, bc
    and [hl]
    ld d, a
    ld a, [$ff25]
    ld hl, Unknown_9b1f
    add hl, bc
    and [hl]
    or d
    ld d, a
.skip
    ld a, d
    ld [$ff25], a
    ret

Func_9629:
    ld b, $0
    ld hl, wc0b6
    add hl, bc
    ld d, [hl]
    ld a, c
    cp CH2
    jr z, .channel3 ; if music channel 3
    cp CH6
    jr z, .channel3 ; if sfx channel 3
    ld a, d
    and $3f
    ld d, a
    ld hl, wc03e
    add hl, bc
    ld a, [hl]
    or d
    ld d, a
.channel3
    ld b, $1
    call Func_9838
    ld [hl], d
    ret

Func_964b:
    ld a, c
    cp CH2
    jr z, .channel3
    cp CH6
    jr nz, .notSfxChannel3
    ; fall through
.channel3
    push de
    ld de, wc0e6
    cp CH2
    jr z, .musicChannel3
    ld de, wc0e7
.musicChannel3
    ld a, [de]
    add a
    ld d, $0
    ld e, a
    ld hl, Music2_WavePointers
    add hl, de
    ld e, [hl]
    inc hl
    ld d, [hl]
    ld hl, $ff30
    ld b, $f
    ld a, $0
    ld [$ff1a], a
.loop
    ld a, [de]
    inc de
    ld [hli], a
    ld a, b
    dec b
    and a
    jr nz, .loop
    ld a, $80
    ld [$ff1a], a
    pop de
.notSfxChannel3
    ld a, d
    or $80
    and $c7
    ld d, a
    ld b, $3
    call Func_9838
    ld [hl], e
    inc hl
    ld [hl], d
    call Func_96b5
    ret

Func_9693:
    call Func_96e5
    jr nc, .asm_96ab
    ld d, $0
    ld a, [wc0f2]
    add $80
    jr nc, .asm_96a2
    inc d
.asm_96a2
    ld [wc0eb], a
    ld a, d
    ld [wc0ea], a
    jr .asm_96b4
.asm_96ab
    xor a
    ld [wc0eb], a
    ld a, $1
    ld [wc0ea], a
.asm_96b4
    ret

Func_96b5:
    call Func_96e5
    jr nc, .asm_96c6
    ld a, [wc0f1]
    add e
    jr nc, .asm_96c1
    inc d
.asm_96c1
    dec hl
    ld e, a
    ld [hl], e
    inc hl
    ld [hl], d
.asm_96c6
    ret

Func_96c7:
    call Func_96e5
    jr nc, .asm_96e2
    ld hl, wc006
    ld e, c
    ld d, $0
    sla e
    rl d
    add hl, de
    ld a, [hl]
    sub $1
    ld [hl], a
    inc hl
    ld a, [hl]
    sbc $0
    ld [hl], a
    scf
    ret
.asm_96e2
    scf
    ccf
    ret

Func_96e5:
    ld a, [wc02a]
    cp $14
    jr nc, .asm_96ee
    jr .asm_96f4
.asm_96ee
    cp $86
    jr z, .asm_96f4
    jr c, .asm_96f7
.asm_96f4
    scf
    ccf
    ret
.asm_96f7
    scf
    ret

Music2_ApplyPitchBend: ; 0x96f9
    ld hl, wc02e
    add hl, bc
    bit 5, [hl]
    jp nz, .asm_9740
    ld hl, wc09e
    add hl, bc
    ld e, [hl]
    ld hl, wc096
    add hl, bc
    ld d, [hl]
    ld hl, wc07e
    add hl, bc
    ld l, [hl]
    ld h, b
    add hl, de
    ld d, h
    ld e, l
    ld hl, wc08e
    add hl, bc
    push hl
    ld hl, wc086
    add hl, bc
    ld a, [hl]
    pop hl
    add [hl]
    ld [hl], a
    ld a, $0
    adc e
    ld e, a
    ld a, $0
    adc d
    ld d, a
    ld hl, wc0a6
    add hl, bc
    ld a, [hl]
    cp d
    jp c, .asm_9786
    jr nz, .asm_9773
    ld hl, wc0ae
    add hl, bc
    ld a, [hl]
    cp e
    jp c, .asm_9786
    jr .asm_9773
.asm_9740
    ld hl, wc09e
    add hl, bc
    ld a, [hl]
    ld hl, wc096
    add hl, bc
    ld d, [hl]
    ld hl, wc07e
    add hl, bc
    ld e, [hl]
    sub e
    ld e, a
    ld a, d
    sbc b
    ld d, a
    ld hl, wc086
    add hl, bc
    ld a, [hl]
    add a
    ld [hl], a
    ld a, e
    sbc b
    ld e, a
    ld a, d
    sbc b
    ld d, a
    ld hl, wc0a6
    add hl, bc
    ld a, d
    cp [hl]
    jr c, .asm_9786
    jr nz, .asm_9773
    ld hl, wc0ae
    add hl, bc
    ld a, e
    cp [hl]
    jr c, .asm_9786
.asm_9773
    ld hl, wc09e
    add hl, bc
    ld [hl], e
    ld hl, wc096
    add hl, bc
    ld [hl], d
    ld b, $3
    call Func_9838
    ld a, e
    ld [hli], a
    ld [hl], d
    ret
.asm_9786
    ld hl, wc02e
    add hl, bc
    res 4, [hl]
    res 5, [hl]
    ret

Func_978f: ; 0x978f
    ld hl, wc096
    add hl, bc
    ld [hl], d
    ld hl, wc09e
    add hl, bc
    ld [hl], e
    ld hl, wc0b6
    add hl, bc
    ld a, [hl]
    ld hl, wc076
    add hl, bc
    sub [hl]
    jr nc, .asm_97a7
    ld a, $1
.asm_97a7
    ld [hl], a
    ld hl, wc0ae
    add hl, bc
    ld a, e
    sub [hl]
    ld e, a
    ld a, d
    sbc b
    ld hl, wc0a6
    add hl, bc
    sub [hl]
    jr c, .asm_97c3
    ld d, a
    ld b, $0
    ld hl, wc02e
    add hl, bc
    set 5, [hl]
    jr .asm_97e6
.asm_97c3
    ld hl, wc096
    add hl, bc
    ld d, [hl]
    ld hl, wc09e
    add hl, bc
    ld e, [hl]
    ld hl, wc0ae
    add hl, bc
    ld a, [hl]
    sub e
    ld e, a
    ld a, d
    sbc b
    ld d, a
    ld hl, wc0a6
    add hl, bc
    ld a, [hl]
    sub d
    ld d, a
    ld b, $0
    ld hl, wc02e
    add hl, bc
    res 5, [hl]
.asm_97e6
    ld hl, wc076
    add hl, bc
.asm_97ea
    inc b
    ld a, e
    sub [hl]
    ld e, a
    jr nc, .asm_97ea
    ld a, d
    and a
    jr z, .asm_97f8
    dec a
    ld d, a
    jr .asm_97ea
.asm_97f8
    ld a, e
    add [hl]
    ld d, b
    ld b, $0
    ld hl, wc07e
    add hl, bc
    ld [hl], d
    ld hl, wc086
    add hl, bc
    ld [hl], a
    ld hl, wc08e
    add hl, bc
    ld [hl], a
    ret

Music2_ApplyDutyCycle:
    ld b, $0
    ld hl, wc046
    add hl, bc
    ld a, [hl]
    rlca
    rlca
    ld [hl], a
    and $c0
    ld d, a
    ld b, $1
    call Func_9838
    ld a, [hl]
    and $3f
    or d
    ld [hl], a
    ret

Music2_GetNextMusicByte:
    ld d, $0
    ld a, c
    add a
    ld e, a
    ld hl, wc006
    add hl, de
    ld a, [hli]
    ld e, a
    ld a, [hld]
    ld d, a
    ld a, [de] ; get next music command
    inc de
    ld [hl], e ; store address of next command
    inc hl
    ld [hl], d
    ret

Func_9838:
    ld a, c
    ld hl, Unknown_9b17
    add l
    jr nc, .noCarry
    inc h
.noCarry
    ld l, a
    ld a, [hl]
    add b
    ld l, a
    ld h, $ff
    ret

Func_9847:
    ld h, $0
.loop
    srl a
    jr nc, .noCarry
    add hl, de
.noCarry
    sla e
    rl d
    and a
    jr z, .done
    jr .loop
.done
    ret

Func_9858:
    ld h, $0
    ld l, a
    add hl, hl
    ld d, h
    ld e, l
    ld hl, Music2_Pitches
    add hl, de
    ld e, [hl]
    inc hl
    ld d, [hl]
    ld a, b
.loop
    cp $7
    jr z, .done
    sra d
    rr e
    inc a
    jr .loop
.done
    ld a, $8
    add d
    ld d, a
    ret

Func_9876::
    ld [wc001], a
    cp $ff
    jp z, Func_9a34
    cp $b9
    jp z, Func_994e
    jp c, Func_994e
    cp $fe
    jr z, .asm_988d
    jp nc, Func_994e
.asm_988d
    xor a
    ld [wc000], a
    ld [wc003], a
    ld [wc0e9], a
    ld [wc0e6], a
    ld [wc0e7], a
    ld d, $8
    ld hl, wc016
    call FillMusicRAM2
    ld hl, wc006
    call FillMusicRAM2
    ld d, $4
    ld hl, wc026
    call FillMusicRAM2
    ld hl, wc02e
    call FillMusicRAM2
    ld hl, wc03e
    call FillMusicRAM2
    ld hl, wc046
    call FillMusicRAM2
    ld hl, wc04e
    call FillMusicRAM2
    ld hl, wc056
    call FillMusicRAM2
    ld hl, wc05e
    call FillMusicRAM2
    ld hl, wc066
    call FillMusicRAM2
    ld hl, wc06e
    call FillMusicRAM2
    ld hl, wc036
    call FillMusicRAM2
    ld hl, wc076
    call FillMusicRAM2
    ld hl, wc07e
    call FillMusicRAM2
    ld hl, wc086
    call FillMusicRAM2
    ld hl, wc08e
    call FillMusicRAM2
    ld hl, wc096
    call FillMusicRAM2
    ld hl, wc09e
    call FillMusicRAM2
    ld hl, wc0a6
    call FillMusicRAM2
    ld hl, wc0ae
    call FillMusicRAM2
    ld a, $1
    ld hl, wc0be
    call FillMusicRAM2
    ld hl, wc0b6
    call FillMusicRAM2
    ld hl, wc0c6
    call FillMusicRAM2
    ld [wc0e8], a
    ld a, $ff
    ld [wc004], a
    xor a
    ld [$ff24], a
    ld a, $8
    ld [$ff10], a
    ld a, $0
    ld [$ff25], a
    xor a
    ld [$ff1a], a
    ld a, $80
    ld [$ff1a], a
    ld a, $77
    ld [$ff24], a
    jp Func_9a8f

Func_994e:
    ld l, a
    ld e, a
    ld h, $0
    ld d, h
    add hl, hl
    add hl, de
    ld de, SFX_Headers_02
    add hl, de
    ld a, h
    ld [wc0ec], a
    ld a, l
    ld [wc0ed], a
    ld a, [hl]
    and $c0
    rlca
    rlca
    ld c, a
.asm_9967
    ld d, c
    ld a, c
    add a
    add c
    ld c, a
    ld b, $0
    ld a, [wc0ec]
    ld h, a
    ld a, [wc0ed]
    ld l, a
    add hl, bc
    ld c, d
    ld a, [hl]
    and $f
    ld e, a
    ld d, $0
    ld hl, wc026
    add hl, de
    ld a, [hl]
    and a
    jr z, .asm_99a3
    ld a, e
    cp $7
    jr nz, .asm_999a
    ld a, [wc001]
    cp $14
    jr nc, .asm_9993
    ret
.asm_9993
    ld a, [hl]
    cp $14
    jr z, .asm_99a3
    jr c, .asm_99a3
.asm_999a
    ld a, [wc001]
    cp [hl]
    jr z, .asm_99a3
    jr c, .asm_99a3
    ret
.asm_99a3
    xor a
    push de
    ld h, d
    ld l, e
    add hl, hl
    ld d, h
    ld e, l
    ld hl, wc016
    add hl, de
    ld [hli], a
    ld [hl], a
    ld hl, wc006
    add hl, de
    ld [hli], a
    ld [hl], a
    pop de
    ld hl, wc026
    add hl, de
    ld [hl], a
    ld hl, wc02e
    add hl, de
    ld [hl], a
    ld hl, wc03e
    add hl, de
    ld [hl], a
    ld hl, wc046
    add hl, de
    ld [hl], a
    ld hl, wc04e
    add hl, de
    ld [hl], a
    ld hl, wc056
    add hl, de
    ld [hl], a
    ld hl, wc05e
    add hl, de
    ld [hl], a
    ld hl, wc066
    add hl, de
    ld [hl], a
    ld hl, wc06e
    add hl, de
    ld [hl], a
    ld hl, wc076
    add hl, de
    ld [hl], a
    ld hl, wc07e
    add hl, de
    ld [hl], a
    ld hl, wc086
    add hl, de
    ld [hl], a
    ld hl, wc08e
    add hl, de
    ld [hl], a
    ld hl, wc096
    add hl, de
    ld [hl], a
    ld hl, wc09e
    add hl, de
    ld [hl], a
    ld hl, wc0a6
    add hl, de
    ld [hl], a
    ld hl, wc0ae
    add hl, de
    ld [hl], a
    ld hl, wc036
    add hl, de
    ld [hl], a
    ld a, $1
    ld hl, wc0be
    add hl, de
    ld [hl], a
    ld hl, wc0b6
    add hl, de
    ld [hl], a
    ld hl, wc0c6
    add hl, de
    ld [hl], a
    ld a, e
    cp $4
    jr nz, .asm_9a2b
    ld a, $8
    ld [$ff10], a
.asm_9a2b
    ld a, c
    and a
    jp z, Func_9a8f
    dec c
    jp .asm_9967

Func_9a34:
    ld a, $80
    ld [$ff26], a
    ld [$ff1a], a
    xor a
    ld [$ff25], a
    ld [$ff1c], a
    ld a, $8
    ld [$ff10], a
    ld [$ff12], a
    ld [$ff17], a
    ld [$ff21], a
    ld a, $40
    ld [$ff14], a
    ld [$ff19], a
    ld [$ff23], a
    ld a, $77
    ld [$ff24], a
    xor a
    ld [wc000], a
    ld [wc003], a
    ld [wc002], a
    ld [wc0e9], a
    ld [wc0eb], a
    ld [wc0e6], a
    ld [wc0e7], a
    ld d, $a0
    ld hl, wc006
    call FillMusicRAM2
    ld a, $1
    ld d, $18
    ld hl, wc0b6
    call FillMusicRAM2
    ld [wc0e8], a
    ld [wc0ea], a
    ld a, $ff
    ld [wc004], a
    ret

; fills d bytes at hl with a
FillMusicRAM2:
    ld b, d
.loop
    ld [hli], a
    dec b
    jr nz, .loop
    ret

Func_9a8f:
    ld a, [wc001]
    ld l, a
    ld e, a
    ld h, $0
    ld d, h
    add hl, hl
    add hl, de
    ld de, SFX_Headers_02
    add hl, de
    ld e, l
    ld d, h
    ld hl, wc006
    ld a, [de] ; get channel number
    ld b, a
    rlca
    rlca
    and $3
    ld c, a
    ld a, b
    and $f
    ld b, c
    inc b
    inc de
    ld c, $0
.asm_9ab1
    cp c
    jr z, .asm_9ab9
    inc c
    inc hl
    inc hl
    jr .asm_9ab1
.asm_9ab9
    push hl
    push bc
    push af
    ld b, $0
    ld c, a
    ld hl, wc026
    add hl, bc
    ld a, [wc001]
    ld [hl], a
    pop af
    cp $3
    jr c, .asm_9ad2
    ld hl, wc02e
    add hl, bc
    set 2, [hl]
.asm_9ad2
    pop bc
    pop hl
    ld a, [de] ; get channel pointer
    ld [hli], a
    inc de
    ld a, [de]
    ld [hli], a
    inc de
    inc c
    dec b
    ld a, b
    and a
    ld a, [de]
    inc de
    jr nz, .asm_9ab1
    ld a, [wc001]
    cp $14
    jr nc, .asm_9aeb
    jr .asm_9b15
.asm_9aeb
    ld a, [wc001]
    cp $86
    jr z, .asm_9b15
    jr c, .asm_9af6
    jr .asm_9b15
.asm_9af6
    ld hl, wc02a
    ld [hli], a
    ld [hli], a
    ld [hli], a
    ld [hl], a
    ld hl, wc012 ; sfx noise channel pointer
    ld de, Noise2_endchannel
    ld [hl], e
    inc hl
    ld [hl], d ; overwrite pointer to point to endchannel
    ld a, [wc005]
    and a
    jr nz, .asm_9b15
    ld a, [$ff24]
    ld [wc005], a
    ld a, $77
    ld [$ff24], a
.asm_9b15
    ret

Noise2_endchannel:
    endchannel

Unknown_9b17:
    db $10, $15, $1A, $1F ; channels 0-3
    db $10, $15, $1A, $1F ; channels 4-7

Unknown_9b1f:
    db $EE, $DD, $BB, $77 ; channels 0-3
    db $EE, $DD, $BB, $77 ; channels 4-7

Unknown_9b27:
    db $11, $22, $44, $88 ; channels 0-3
    db $11, $22, $44, $88 ; channels 4-7

Music2_Pitches:
    dw $F82C ; C_
    dw $F89D ; C#
    dw $F907 ; D_
    dw $F96B ; D#
    dw $F9CA ; E_
    dw $FA23 ; F_
    dw $FA77 ; F#
    dw $FAC7 ; G_
    dw $FB12 ; G#
    dw $FB58 ; A_
    dw $FB9B ; A#
    dw $FBDA ; B_

Music2_WavePointers:
    dw .wave0
    dw .wave1
    dw .wave2
    dw .wave3
    dw .wave4

; these are the definitions for the channel 3 instruments
; each instrument definition is made up of 32 points (nibbles) that form
; the graph of the wave
; the current instrument is copied to $FF30
.wave0
    db $02,$46,$8A,$CE,$FF,$FE,$ED,$DC,$CB,$A9,$87,$65,$44,$33,$22,$11

.wave1
    db $02,$46,$8A,$CE,$EF,$FF,$FE,$EE,$DD,$CB,$A9,$87,$65,$43,$22,$11

.wave2
    db $13,$69,$BD,$EE,$EE,$FF,$FF,$ED,$DE,$FF,$FF,$EE,$EE,$DB,$96,$31

.wave3
    db $02,$46,$8A,$CD,$EF,$FE,$DE,$FF,$EE,$DC,$BA,$98,$76,$54,$32,$10

.wave4
    db $01,$23,$45,$67,$8A,$CD,$EE,$F7,$7F,$EE,$DC,$A8,$76,$54,$32,$10

Music_Game_Ch1:: ; b6c7 (2:76c7)
    tempo 130
    volume 7, 7
    duty 3
    notetype 12, 8, 0

Music_Game_Ch1_b0::
    octave 2
    C_ 1
    D# 1
    G_ 1
    octave 3
    C_ 1
    D# 1
    G_ 1
    octave 4
    C_ 1
    D# 1
    G_ 1
    D# 1
    C_ 1
    octave 3
    G_ 1
    D# 1
    C_ 1
    octave 2
    G_ 1
    D# 1
    D# 1
    G_ 1
    A# 1
    octave 3
    D# 1
    G_ 1
    A# 1
    octave 4
    D# 1
    G_ 1
    A# 1
    G_ 1
    D# 1
    octave 3
    A# 1
    G_ 1
    D# 1
    octave 2
    A# 1
    G_ 1
    A# 1
    octave 2
    D_ 1
    F_ 1
    A# 1
    octave 3
    D_ 1
    F_ 1
    A# 1
    octave 4
    D_ 1
    F_ 1
    D_ 1
    octave 3
    A# 1
    F_ 1
    D_ 1
    octave 2
    A# 1
    F_ 1
    D_ 1
    G# 1
    octave 2
    C_ 1
    D# 1
    G# 1
    octave 3
    C_ 1
    D# 1
    G# 1
    octave 4
    C_ 1
    D# 1
    C_ 1
    octave 3
    G# 1
    D# 1
    C_ 1
    octave 2
    G# 1
    D# 1
    C_ 1
    loopchannel 0, Music_Game_Ch1_b0

Music_Game_Ch2::
    duty 2
    notetype 12, 12, 0
    vibrato 15, 4, 2

Music_Game_Ch2_b0::
    rest 16
    rest 16
    rest 16
    rest 16
    callchannel Music_Game_Ch2_b1
    callchannel Music_Game_Ch2_b1
    rest 16
    rest 16
    rest 16
    rest 16
    loopchannel 0, Music_Game_Ch2_b0

Music_Game_Ch2_b1::
    octave 3
    G_ 1
    rest 1
    octave 4
    C_ 3
    rest 1
    D_ 1
    rest 1
    D# 3
    rest 1
    D_ 1
    rest 1
    C_ 1
    rest 1
    octave 3
    A# 8
    G_ 1
    rest 1
    A# 1
    rest 1
    G_ 1
    rest 1
    D# 1
    rest 1
    F_ 8
    A# 1
    rest 1
    octave 4
    C_ 1
    rest 1
    D_ 1
    rest 1
    C_ 16
    rest 2
    octave 3
    G_ 1
    rest 1
    octave 4
    C_ 3
    rest 1
    D_ 1
    rest 1
    D# 3
    rest 1
    D_ 1
    rest 1
    D# 1
    rest 1
    F_ 6
    rest 2
    D# 1
    rest 1
    F_ 1
    rest 1
    D# 1
    rest 1
    C_ 1
    rest 1
    D_ 7
    rest 1
    octave 3
    A# 1
    rest 1
    octave 4
    C_ 1
    rest 1
    D_ 1
    rest 1
    C_ 14
    rest 4
    D# 3
    rest 1
    D# 1
    rest 1
    D_ 1
    rest 1
    C_ 3
    rest 1
    D_ 1
    rest 1
    D# 1
    rest 1
    octave 3
    A# 7
    rest 1
    F_ 1
    rest 1
    G_ 3
    rest 1
    A# 1
    rest 1
    F_ 7
    rest 1
    octave 4
    C_ 1
    rest 1
    D_ 1
    rest 1
    D# 1
    rest 1
    C_ 16
    rest 2
    endchannel

Music_Game_Ch3::
    notetype 12, 1, 3

Music_Game_Ch3_b0::
    callchannel Music_Game_Ch3_b1
    callchannel Music_Game_Ch3_b1
    callchannel Music_Game_Ch3_b1
    callchannel Music_Game_Ch3_b1
    rest 16
    rest 16
    rest 16
    rest 16
    callchannel Music_Game_Ch3_b1
    callchannel Music_Game_Ch3_b1
    callchannel Music_Game_Ch3_b1
    loopchannel 0, Music_Game_Ch3_b0

Music_Game_Ch3_b1::
    octave 2
    C_ 2
    octave 3
    C_ 2
    octave 2
    C_ 2
    octave 3
    C_ 2
    octave 2
    C_ 2
    octave 3
    C_ 2
    octave 2
    C_ 2
    octave 3
    C_ 2
    octave 2
    D# 2
    octave 3
    D# 2
    octave 2
    D# 2
    octave 3
    D# 2
    octave 2
    D# 2
    octave 3
    D# 2
    octave 2
    D# 2
    octave 3
    D# 2
    octave 1
    A# 2
    octave 2
    A# 2
    octave 1
    A# 2
    octave 2
    A# 2
    octave 1
    A# 2
    octave 2
    A# 2
    octave 1
    A# 2
    octave 2
    A# 2
    octave 1
    G# 2
    octave 2
    G# 2
    octave 1
    G# 2
    octave 2
    G# 2
    octave 1
    G# 2
    octave 2
    G# 2
    octave 1
    G# 2
    octave 2
    G# 2
    endchannel

Music_Game_Ch4::
    dspeed 12

Music_Game_Ch4_b0::
    rest 16
    rest 16
    rest 16
    snare4 4
    snare4 4
    snare4 2
    snare4 2
    rest 4
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    callchannel Music_Game_Ch4_b1
    loopchannel 0, Music_Game_Ch4_b0

Music_Game_Ch4_b1::
    snare4 2
    snare4 2
    rest 2
    snare4 1
    triangle1 1
    rest 1
    snare4 1
    triangle1 1
    rest 5
    endchannel

INCLUDE "audio/sfx/sfx_02_01.asm"
INCLUDE "audio/sfx/sfx_02_02.asm"
INCLUDE "audio/sfx/sfx_02_03.asm"
INCLUDE "audio/sfx/sfx_02_04.asm"
INCLUDE "audio/sfx/sfx_02_05.asm"
INCLUDE "audio/sfx/sfx_02_06.asm"
INCLUDE "audio/sfx/sfx_02_07.asm"
INCLUDE "audio/sfx/sfx_02_08.asm"
INCLUDE "audio/sfx/sfx_02_09.asm"
INCLUDE "audio/sfx/sfx_02_0a.asm"
INCLUDE "audio/sfx/sfx_02_0b.asm"
INCLUDE "audio/sfx/sfx_02_0c.asm"
INCLUDE "audio/sfx/sfx_02_0d.asm"
INCLUDE "audio/sfx/sfx_02_0e.asm"
INCLUDE "audio/sfx/sfx_02_0f.asm"
INCLUDE "audio/sfx/sfx_02_10.asm"
INCLUDE "audio/sfx/sfx_02_11.asm"
INCLUDE "audio/sfx/sfx_02_12.asm"
INCLUDE "audio/sfx/sfx_02_13.asm"
INCLUDE "audio/sfx/sfx_02_14.asm"
INCLUDE "audio/sfx/sfx_02_15.asm"
INCLUDE "audio/sfx/sfx_02_16.asm"
INCLUDE "audio/sfx/sfx_02_17.asm"
INCLUDE "audio/sfx/sfx_02_18.asm"
INCLUDE "audio/sfx/sfx_02_19.asm"
INCLUDE "audio/sfx/sfx_02_1a.asm"
INCLUDE "audio/sfx/sfx_02_1b.asm"
INCLUDE "audio/sfx/sfx_02_1c.asm"
INCLUDE "audio/sfx/sfx_02_1d.asm"
INCLUDE "audio/sfx/sfx_02_1e.asm"
INCLUDE "audio/sfx/sfx_02_1f.asm"
INCLUDE "audio/sfx/sfx_02_20.asm"
INCLUDE "audio/sfx/sfx_02_21.asm"
INCLUDE "audio/sfx/sfx_02_22.asm"
INCLUDE "audio/sfx/sfx_02_23.asm"
INCLUDE "audio/sfx/sfx_02_24.asm"
INCLUDE "audio/sfx/sfx_02_25.asm"
INCLUDE "audio/sfx/sfx_02_26.asm"
INCLUDE "audio/sfx/sfx_02_27.asm"
INCLUDE "audio/sfx/sfx_02_28.asm"
INCLUDE "audio/sfx/sfx_02_29.asm"
INCLUDE "audio/sfx/sfx_02_2a.asm"
INCLUDE "audio/sfx/sfx_02_2b.asm"
INCLUDE "audio/sfx/sfx_02_2c.asm"
INCLUDE "audio/sfx/sfx_02_2d.asm"
INCLUDE "audio/sfx/sfx_02_2e.asm"
INCLUDE "audio/sfx/sfx_02_2f.asm"
INCLUDE "audio/sfx/sfx_02_30.asm"
INCLUDE "audio/sfx/sfx_02_31.asm"
INCLUDE "audio/sfx/sfx_02_32.asm"
INCLUDE "audio/sfx/sfx_02_33.asm"
INCLUDE "audio/sfx/sfx_02_34.asm"
INCLUDE "audio/sfx/sfx_02_35.asm"
INCLUDE "audio/sfx/sfx_02_36.asm"
INCLUDE "audio/sfx/sfx_02_37.asm"
INCLUDE "audio/sfx/sfx_02_38.asm"
INCLUDE "audio/sfx/sfx_02_39.asm"
INCLUDE "audio/sfx/sfx_02_3a.asm"
INCLUDE "audio/sfx/sfx_02_3b.asm"
INCLUDE "audio/sfx/sfx_02_3c.asm"
INCLUDE "audio/sfx/sfx_02_3d.asm"
INCLUDE "audio/sfx/sfx_02_3e.asm"
INCLUDE "audio/sfx/sfx_02_3f.asm"
INCLUDE "audio/sfx/sfx_02_40.asm"
INCLUDE "audio/sfx/sfx_02_41.asm"
INCLUDE "audio/sfx/sfx_02_42.asm"
INCLUDE "audio/sfx/sfx_02_43.asm"
INCLUDE "audio/sfx/sfx_02_44.asm"
INCLUDE "audio/sfx/sfx_02_45.asm"
INCLUDE "audio/sfx/sfx_02_46.asm"
INCLUDE "audio/sfx/sfx_02_47.asm"
INCLUDE "audio/sfx/sfx_02_48.asm"
INCLUDE "audio/sfx/sfx_02_49.asm"
INCLUDE "audio/sfx/sfx_02_4a.asm"
INCLUDE "audio/sfx/sfx_02_4b.asm"
INCLUDE "audio/sfx/sfx_02_4c.asm"
INCLUDE "audio/sfx/sfx_02_4d.asm"
INCLUDE "audio/sfx/sfx_02_4e.asm"
INCLUDE "audio/sfx/sfx_02_4f.asm"
INCLUDE "audio/sfx/sfx_02_50.asm"
INCLUDE "audio/sfx/sfx_02_51.asm"
INCLUDE "audio/sfx/sfx_02_52.asm"
INCLUDE "audio/sfx/sfx_02_53.asm"
INCLUDE "audio/sfx/sfx_02_54.asm"
INCLUDE "audio/sfx/sfx_02_55.asm"
INCLUDE "audio/sfx/sfx_02_56.asm"
INCLUDE "audio/sfx/sfx_02_57.asm"
INCLUDE "audio/sfx/sfx_02_58.asm"
INCLUDE "audio/sfx/sfx_02_59.asm"
INCLUDE "audio/sfx/sfx_02_5a.asm"
INCLUDE "audio/sfx/sfx_02_5b.asm"
INCLUDE "audio/sfx/sfx_02_5c.asm"
INCLUDE "audio/sfx/sfx_02_5d.asm"
INCLUDE "audio/sfx/sfx_02_5e.asm"
INCLUDE "audio/sfx/sfx_02_5f.asm"
INCLUDE "audio/sfx/sfx_02_unused.asm"