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|
;****************************************************************************
; PlaySFX [command $02]
; Plays a SFX
;****************************************************************************
PlaySFX:
PollPCM
call ClearSFX ; Clear SFX resources
PollPCM
ld a, (RAM_Status) ; Show SFX playback in Echo's status
or $01
ld (RAM_Status), a
PollPCM
ld hl, RAM_ComBank ; Get command parameters
ld c, (hl)
inc l
ld e, (hl)
inc l
ld d, (hl)
PollPCM
xor a ; Command parsed
ld (RAM_Command), a
ld hl, RAM_SFXData ; Set SFX as playing
ld (hl), $01
inc l ; No delays!
ld (hl), $01
inc l ; Store SFX start bank
ld (hl), c
inc l ; Store SFX start address (low)
ld (hl), e
inc l ; Store SFX start address (high)
ld (hl), d
PollPCM
ld hl, ProcessSFX ; Tell Echo to process SFX
ld (DoTick_SFX+1), hl
PollPCM
jp IdleLoop ; End of subroutine
;****************************************************************************
; ProcessSFX
; Processes a tick for a SFX
;****************************************************************************
ProcessSFX:
PollPCM
ld hl, RAM_SFXData+1 ; SFX data address
ld a, (hl) ; Delaying?
dec a
jp z, .nodelay
ld (hl), a
jp DoTick_SFXSkip ; End of subroutine
.nodelay:
PollPCM
inc l ; Get current address
ld c, (hl)
inc l
ld e, (hl)
inc l
ld d, (hl)
ex de, hl
ProcessSFXRun:
PollPCM ; Fetch next event
call GetParam
PollPCM
ld a, b ; Parse byte
cp $08
jp c, NoteOnFMSFX ; Events $00-$07: note on FM
cp $0B
jp c, NoteOnPSGSFX ; Events $08-$0A: note on PSG (square)
jp z, NoteOnNoiseSFX ; Event $0B: note on PSG (noise)
cp $0C
jp z, PlayPCMSFX ; Event $0C: note on PCM
PollPCM
ld a, b
cp $18
jp c, NoteOffFMSFX ; Events $10-$17: note off FM
cp $1C
jp c, NoteOffPSGSFX ; Events $18-$1B: note off PSG
jp z, StopPCMSFX ; Event $1C: note off PCM
PollPCM
ld a, b
cp $FE
jp z, SetDelaySFX ; Event $FE: set delay
cp $FF
jp z, StopSFXEvent ; Event $FF: stop SFX
PollPCM
ld a, b
cp $28
jp c, SetFMVolSFX ; Events $28-$2B: set FM volume
cp $2C
jp c, SetPSGVolSFX ; Events $28-$2B: set PSG volume
PollPCM
ld a, b
cp $38
jp c, SetNoteFMSFX ; Events $30-$37: set FM note
cp $3B
jp c, SetNotePSGSFX ; Events $38-$3A: set PSG note (square)
jp z, SetNoteNoiseSFX ; Event $3B: set PSG note (noise)
PollPCM
ld a, b
cp $48
jp c, LoadFMSFX ; Events $40-$47: load FM instrument
cp $4C
jp c, LoadPSGSFX ; Events $48-$4B: load PSG instrument
PollPCM
ld a, b
cp $E8
jp c, LockChannelFM ; Events $E0-$E7: lock FM channel
cp $EC
jp c, LockChannelPSG ; Events $E8-$EB: lock PSG channel
jp z, LockChannelPCM ; Event $EC: lock PCM channel
PollPCM
ld a, b
cp $F8 ; Events $F0-$F7: set FM parameters
jp c, SetFMParamSFX
;****************************************************************************
; StopSFX* [command $03, event $FF]
; Stops SFX playback
;****************************************************************************
StopSFXEvent:
call StopSFX ; We're just a wrapper
jp DoTick_SFXSkip ; End of subroutine
StopSFXCmd:
xor a ; Command parsed
ld (RAM_Command), a
call StopSFX ; We're just a wrapper
jp IdleLoop ; End of subroutine
StopSFX:
PollPCM
ld a, (RAM_Status) ; Hide SFX playback in Echo's status
and $FE
ld (RAM_Status), a
PollPCM
xor a ; Stop playback
ld (RAM_SFXPlaying), a
ld hl, DoTick_SFXSkip
ld (DoTick_SFX+1), hl
PollPCM
call ClearSFX ; Clear SFX resources
PollPCM
ret ; End of subroutine
;****************************************************************************
; ClearSFX
; Clears SFX resources
;****************************************************************************
ClearSFX:
ld a, (RAM_Locked+6) ; Stop PCM playback if needed
or a
call nz, StopPCM
;----------------------------------------------------------------------------
ld b, 4 ; Look for locked PSG channels
ld de, RAM_Locked+11
.unlockpsg:
PollPCM
ld a, (de) ; Check if this channel needs unlocking
or a
jr z, .psgfree
xor a
ld (de), a
PollPCM
ld a, b ; Restore BGM volume
rrca
rrca
rrca
rrca
dec a
ld h, RAM_PSGData>>8
ld l, a
ld c, (hl)
sub 15
ld l, a
ld (hl), c
PollPCM
push de
ld a, l ; Restore BGM envelope
add 8
ld l, a
add 12-8
ld e, a
ld d, h
PollPCM
ld a, (de)
ld (hl), a
inc l
inc e
ld a, (de)
ld (hl), a
inc l
inc e
ld a, (de)
ld (hl), a
pop de
PollPCM
.psgfree:
dec e ; Go for next PSG channel to unlock
djnz .unlockpsg
;----------------------------------------------------------------------------
ld b, 8 ; Look for locked FM channels
.unlockfm:
PollPCM
ld a, (de) ; Check if this channel needs unlocking
or a
jp z, .fmfree
xor a
ld (de), a
PollPCM
dec b ; Restore FM channel
call RestoreFM
inc b
.fmfree:
dec e ; Go for next FM channel to unlock
dec b
jp nz, .unlockfm
;----------------------------------------------------------------------------
ret ; End of subroutine
|
