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|
;****************************************************************************
; UpdatePSG
; Updates PSG output
;****************************************************************************
UpdatePSG:
ld hl, RAM_PSGData+48 ; PSG envelope data of *last* channel
ld b, 3 ; Go through all channels
.loop:
push bc
xor a
ld iyl, a
ld a, (hl) ; Get channel volume
or a
jp m, .noskip
ld b, $0F
inc l
jp .skip
.noskip:
and $7F
ld b, a
inc l ; Add global volume
ld a, (hl)
add b
ld b, a
PollPCM
push bc
inc l ; Get current address of envelope
ld c, (hl)
inc l
ld e, (hl)
inc l
ld d, (hl)
ex de, hl
.readenv:
PollPCM
call GetParam ; Get next byte
PollPCM
ld a, b
cp $FE ; Set loop point?
jp z, .envsetloop
cp $FF ; Loop envelope?
jp z, .envloop
ld iyl, b ; Keep byte safe somewhere...
PollPCM
ex de, hl ; Store new address
ld (hl), d
dec l
ld (hl), e
dec l
ld (hl), c
dec l
pop bc
PollPCM
db $FD,$7D ; ld a, iyl ; Mix envelope with volume
and $0F
add b
ld b, a
cp $10 ; Check for overflow
jr c, .notmute
ld b, $0F
.notmute:
.skip:
PollPCM
ld a, b ; Set PSG channel volume
rlca
rlca
rlca
pop bc
or b
rrca
rrca
rrca
or $90
ld ($7F11), a
PollPCM
push bc
ld a, l ; Get current semitone
add 11-1
ld l, a
ld b, (hl)
sub 11-1
ld l, a
ld a, b ; Oh, don't tocuh it?
inc a
jr z, .notone
PollPCM
db $FD,$7D ; ld a, iyl ; Get semitone shift
and $F0
rrca
rrca
rrca
rrca
ex de, hl
ld h, PSGShiftTable>>8
add PSGShiftTable&$FF
ld l, a
ld c, (hl)
ex de, hl
PollPCM
ld a, b ; Compute resulting semitone
add c
ex de, hl ; Get corresponding frequency
ld h, PSGFreqTable>>8
ld l, a
ld c, (hl)
inc l
ld b, (hl)
PollPCM
ld a, e ; Get PSG channel
and $30
add a
or c
ld hl, $7F11 ; Set new frequency
ld (hl), a
ld (hl), b
ex de, hl
PollPCM
.notone:
pop bc
ld a, l ; Go for next channel
sub 16+1
ld l, a
PollPCM
dec b
jp p, .loop
jp DoTick_PSGSkip ; End of subroutine
.envsetloop:
PollPCM
inc e ; Where we store the loop point
ex de, hl ; Store loop point
ld (hl), c
inc l
ld (hl), e
inc l
ld (hl), d
ex de, hl
dec e ; Back to where we were...
dec e
dec e
jp .readenv ; Go for next byte
.envloop:
PollPCM
inc e ; Where we store the loop point
ex de, hl ; Retrieve loop point
ld c, (hl)
inc l
ld e, (hl)
inc l
ld d, (hl)
ex de, hl
dec e ; Back to where we were...
dec e
dec e
jp .readenv ; Go for next byte
;****************************************************************************
; NoteOnPSG*
; Does a "note on" for a PSG channel
;****************************************************************************
NoteOnPSGSFX:
call NoteOnPSG ; We're just a wrapper
jp ProcessSFXRun ; End of subroutine
NoteOnPSGBGM:
ld b, a
PollPCM
ld a, b
push hl
and $03 ; Check if channel is free
ld hl, RAM_Locked+8
add l
ld l, a
ld a, (hl)
pop hl
or a
jp nz, ProcessBGMSkip1 ; Don't play if locked
ld a, b
call NoteOnPSG ; We're just a wrapper
jp ProcessBGMRun ; End of subroutine
NoteOnPSG:
and $03
ld b, a
;push af
ex af, af'
PollPCM
push hl ; Set channel volume
ld h, RAM_PSGData>>8
ld a, b
rrca
rrca
rrca
rrca
ld l, a
ld a, (hl)
or $80
ld (hl), a
PollPCM
push de
inc l ; Now we'll reset the envelope address...
inc l
ld d, h
ld a, l
add 6
ld e, a
PollPCM
ld a, (de) ; Reset envelope address
ld (hl), a
inc l
inc e
ld a, (de)
ld (hl), a
inc l
inc e
ld a, (de)
ld (hl), a
ld a, e
pop de
pop hl
ex af, af'
PollPCM
call GetParam ; Get note
PollPCM
ex af, af'
SetSemitonePSG:
push hl ; Store new semitone
inc a
ld h, RAM_PSGData>>8
ld l, a
ld (hl), b
pop hl
ret ; End of subroutine
;****************************************************************************
; NoteOnNoise*
; Does a "note on" for the noise PSG channel
;****************************************************************************
NoteOnNoiseSFX:
call NoteOnNoise ; We're just a wrapper
jp ProcessSFXRun ; End of subroutine
NoteOnNoiseBGM:
ld a, (RAM_Locked+11) ; Check if channel is free
or a
jp nz, ProcessBGMSkip1 ; Don't play if locked
call NoteOnNoise ; We're just a wrapper
jp ProcessBGMRun ; End of subroutine
NoteOnNoise:
PollPCM
push hl
ld hl, RAM_PSGData+48 ; Set channel volume
ld a, (hl)
or $80
ld (hl), a
PollPCM
push de
inc l ; Now we'll reset the envelope address...
inc l
ld d, h
ld a, l
add 6
ld e, a
PollPCM
ld a, (de) ; Reset envelope address
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
pop hl
SetNoteNoise:
PollPCM
call GetParam ; Get noise type
PollPCM
ld a, $E0 ; Set new noise type
or b
ld ($7F11), a
ret ; End of subroutine
;****************************************************************************
; NoteOffPSG*
; Does a "note off" for a PSG channel
;****************************************************************************
NoteOffPSGSFX:
call NoteOffPSG ; We're just a wrapper
jp ProcessSFXRun ; End of subroutine
NoteOffPSGBGM:
ld b, a
PollPCM
ld a, b
push hl
and $03 ; Check if channel is free
ld hl, RAM_Locked+8
add l
ld l, a
ld a, (hl)
pop hl
or a
jp nz, ProcessBGMRun ; Don't stop if locked
ld a, b
call NoteOffPSG ; We're just a wrapper
jp ProcessBGMRun ; End of subroutine
NoteOffPSG:
and $03
ld b, a
PollPCM
push hl ; Mark channel as not playing
ld h, RAM_PSGData>>8
ld a, b
rrca
rrca
rrca
rrca
ld l, a
ld a, (hl)
and $7F
ld (hl), a
PollPCM
ld a, l ; Don't waste time with semitone shifting
add 11
ld l, a
ld a, $FF
ld (hl), a
pop hl
ret ; End of subroutine
;****************************************************************************
; SetPSGVol*
; Sets the volume of a PSG channel
;****************************************************************************
SetPSGVolSFX:
and $03 ; Get channel ID
ex af, af'
PollPCM
call GetParam ; Get volume
PollPCM
ex af, af'
push hl
ld h, RAM_PSGData>>8 ; Set new volume
rrca
rrca
rrca
rrca
ld l, a
ld a, (hl)
and $80
or b
ld (hl), a
pop hl
jp ProcessSFXRun ; End of subroutine
SetPSGVolBGM:
and $03 ; Get channel ID
ex af, af'
PollPCM
call GetParam ; Get volume
PollPCM
ex af, af'
push de
push hl
push af
ld de, RAM_Locked+8 ; Check if channel is locked
add e ; Keep results for later
ld e, a
ld a, (de)
ld e, a
PollPCM
pop af
ld h, RAM_PSGData>>8 ; Store new volume
rrca
rrca
rrca
rrca
add 15
ld l, a
ld (hl), b
PollPCM
ld a, e ; Is channel locked?
or a
jr nz, .nosetvol
ld a, l ; Set new volume
sub 15
ld l, a
ld a, (hl)
and $80
or b
ld (hl), a
PollPCM
.nosetvol:
pop hl
pop de
jp ProcessBGMRun ; End of subroutine
;****************************************************************************
; LoadPSG*
; Loads a PSG instrument
;****************************************************************************
LoadPSGSFX:
and $03 ; Get channel number
ex af, af'
PollPCM
call GetParam ; Get instrument ID
PollPCM
ex af, af'
push de
push hl
ld d, RAM_PointerList>>8 ; Get position in pointer list
ld e, b
ld h, RAM_PSGData>>8 ; Where to store address
rrca
rrca
rrca
rrca
add 8+2+(RAM_PSGData&$FF)
ld l, a
PollPCM
ld a, (de) ; Store PSG envelope start address
ld (hl), a
inc d
dec l
ld a, (de)
ld (hl), a
inc d
dec l
ld a, (de)
ld (hl), a
PollPCM
ld a, l ; Reset volume
sub 8
ld l, a
ld (hl), $00
pop hl
pop de
jp ProcessSFXRun ; End of subroutine
;----------------------------------------------------------------------------
LoadPSGBGM:
and $03 ; Get channel number
ex af, af'
PollPCM
call GetParam ; Get instrument ID
PollPCM
ex af, af'
push de
push hl
ld d, RAM_PointerList>>8 ; Get position in pointer list
ld e, b
ld hl, RAM_Locked+8 ; Get if channel is locked
push af
add l
ld l, a
pop af
ld b, (hl)
ld h, RAM_PSGData>>8 ; Where to store BGM instrument data
rrca
rrca
rrca
rrca
add 15
ld l, a
PollPCM
ld (hl), a ; Reset volume for BGM
dec l
ld a, (de) ; Store PSG envelope address for BGM
ld (hl), a
inc d
dec l
ld a, (de)
ld (hl), a
inc d
dec l
ld a, (de)
ld (hl), a
PollPCM
ld a, b ; Don't set PSG envelope if locked
or a
jp z, .noloadlocked
pop hl
pop de
jp ProcessBGMRun
.noloadlocked:
PollPCM
ld d, h ; Set PSG envelope
ld a, l
sub 12-8
ld e, a
ld a, (hl)
ld (de), a
inc l
inc e
ld a, (hl)
ld (de), a
inc l
inc e
ld a, (hl)
ld (de), a
PollPCM
ld a, l ; Reset volume
sub 8
ld l, a
ld (hl), $00
pop hl
pop de
jp ProcessBGMRun ; End of subroutine
;****************************************************************************
; SetNotePSG*
; Sets the note of a PSG channel without "note on"
;****************************************************************************
SetNotePSGSFX:
call SetNotePSG ; We're just a wrapper
jp ProcessSFXRun ; End of subroutine
SetNotePSGBGM:
ld b, a
PollPCM
ld a, b
push hl
and $0F ; Check if channel is free
ld h, RAM_Locked>>8
add RAM_Locked&$FF
ld l, a
ld a, (hl)
pop hl
or a
jp nz, ProcessBGMSkip2 ; Don't play if locked
ld a, b
call SetNotePSG ; We're just a wrapper
jp ProcessBGMRun ; End of subroutine
SetNotePSG:
and $03 ; Get channel number
ex af, af'
PollPCM
call GetParam ; Get first byte
PollPCM
ld a, b ; Select by semitone?
add a, a
jp c, .freqtone
ex af, af'
push hl ; Mark semitone as not valid
ld l, a
ex af, af'
PollPCM
ld a, l
rrca
rrca
rrca
rrca
add a, 11
ld l, a
ld h, RAM_PSGData>>8
ld (hl), $FF
pop hl
PollPCM
ex af, af'
push de ; PSG port address
ld de, $7F11
rrca ; Set first frequency byte
rrca
rrca
or b
or $80
ld (de), a
PollPCM
call GetParam ; Get second byte
PollPCM
ex de, hl
ld (hl), b ; Set second frequency byte
ex de, hl
pop de
ret ; End of subroutine
;----------------------------------------------------------------------------
.freqtone:
ld b, a
PollPCM
ex af, af'
rrca
rrca
rrca
rrca
add 10
jp SetSemitonePSG
;****************************************************************************
; SetNoteNoise*
; Sets the note of the noise PSG channel without "note on"
;****************************************************************************
SetNoteNoiseSFX:
call SetNoteNoise ; We're just a wrapper
jp ProcessSFXRun ; End of subroutine
SetNoteNoiseBGM:
ld a, (RAM_Locked+11) ; Check if channel is free
or a
jp nz, ProcessBGMSkip1 ; Don't play if locked
call SetNoteNoise ; We're just a wrapper
jp ProcessBGMRun ; End of subroutine
;****************************************************************************
; LockChannelPSG [events $E8-$EB]
; Locks a PSG channel
;****************************************************************************
LockChannelPSG:
and $03
ld b, a
PollPCM
push hl
ld h, RAM_Locked>>8 ; Get address of channel to lock
ld a, b
add (RAM_Locked&$FF)+8
ld l, a
ld (hl), $01 ; Lock channel
PollPCM
ld a, b ; Stop channel
rrca
rrca
rrca
rrca
ld l, a
ld h, RAM_PSGData>>8
ld (hl), $00
pop hl
jp ProcessSFXRun ; End of subroutine
|
