Thanks Manel! Your instructions made it simple to implement the replayer.
Is the C register meant to be loaded with the sample's priority value (0-15) in this routine? The comments on ayFX_INIT say so, but it doesn't seem to be working. Is the sample's priority meant to be defined another way? 
Call FX:
LD HL,"name.afb" LD A,200 LD (ayFX_VOLUME),A CALL ayFX_SETUP XOR A LD C,1 CALL ayFX_INIT XOR A LD (ayFX_VOLUME),A RET
I guess this is effective for PSG music. With msx music or opl4, it surely doesn't work.
I say it by logic, but I'm not sure.
@Tangent
Yeah, the C register is meant to be used as a priority for the sfx.
I have found 5 different ayfx replayers online, and not all of them support this priority setting.
Some of them seem to rotate the 3 psg registers, allowing 3 sfx to be played at the same time.
In this case you don't need the priority setting at all.
Let me know what your findings are, I'm also trying my best to understand what is happening.
I don't yet understand the code completely
I was able to get the priorities working well (tested with 2 sounds) by calling my sound effects this way:
PLAY_FX_EXPLODE:
; A = Index of sample in bank
LD A,2
; C = Priority (0-15) of sample
LD C,2
CALL ayFX_INIT
RET
PLAY_FX_SHOOT:
LD A,1
LD C,1
CALL ayFX_INIT
RETI set up the replayer with:
; Load FX bank to ayFX replayer
LD HL,FX_BANK
CALL ayFX_SETUP
FX_BANK:
INCBIN "FX.AFB"
And added to my VDP interrupt routine:
CALL PT3_ROUT
CALL PT3_PLAY
CALL ayFX_PLAY
I used the ROM version of the ayFX Replayer v1.31 provided by theNestruo here. According to the readme this should be all that's required to set up and call the replayer.
As far as I can tell, the channel rotation is intended to prevent interference with music. A sample with a higher priority will interrupt one which is playing at a lower priority, but only one sound will play at a time. I would be interested to see if this is not the case however. :)
The version I'm using plays back multiple sound effect at the same time.
3 max obviously.
I think it also uses channel rotation to cause less interference with the music.
If you are interested I can copy the code.
So far I really like it.
I'm interested. What about music? Wich tools do you use to compose and replay it as bgm?
Alright,
This is the sfx code:
;;;;;;;;;;;;;;;;based on Shiru's, modified by Artrag in April 6 2014
; map 0C000h
DATA_AREA: ;$
afxNoisePeriod: ds 1
afxBnkAdr: ds 2
AYREGS: ds 14
; descriptors channels 11 bytes to the channel:
; 0 (2) the current address (the channel is free, if the high byte = $ 00)
; 2 (2) Time effect
; 4 (1) the volume
; 5 (1) bits of the mixer
; 6 (2) pitch period
; 8 (1) looping effect if != $00
; 9 (2) starting point if looping
afxChData: ds 3*11
END_DATA_AREA: ;$
; endmap
TonA: EQU 0
TonB: EQU 2
TonC: EQU 4
Noise: EQU 6
Mixer: EQU 7
AmplA: EQU 8
AmplB: EQU 9
AmplC: EQU 10
loopingsfx: equ 0 ; sfx with $ up to loopingsfx (excluded) will loop, the higher $ will go once
; ------------------------------------------------- ------------- ;
; Initialization player effects. ;
; Turns off all channels , sets variables . ;
; ------------------------------------------------- ------------- ;
AFXINIT:
; ld hl, sfxBank_miz
; ld de,miz_buffer
; call mom_depack_rom
AFXSTOP:
ld hl,DATA_AREA
ld b,END_DATA_AREA-DATA_AREA
.loop:
ld (hl),0
inc hl
djnz .loop
; LD HL,DATA_AREA
; LD (HL),0
; LD DE,DATA_AREA+1
; LD BC,END_DATA_AREA-DATA_AREA+1
; LDIR
ld hl,$4000 ;miz_buffer
inc hl
ld (afxBnkAdr), hl; reserve table address offsets
xor a
ld (afxNoisePeriod), a
ld hl, afxChData; mark all channels as empty
ld de, $00ff
ld b, 3
afxInit0:
ld (hl), d
inc hl
ld (hl), d
inc hl
ld (hl), e
inc hl
ld (hl), e
inc hl
ld (hl), d
inc hl
ld (hl), e
inc hl
ld (hl), d
inc hl
ld (hl), d
inc hl
ld (hl), d
inc hl
ld (hl), d
inc hl
ld (hl), d
inc hl
djnz afxInit0
ret
; ------------------------------------------------- ------------- ;
; Playback of the current frame . ;
; With no parameters . ;
; ------------------------------------------------- ------------- ;
AFXFRAME:
;out buffered sfx data
xor a ; --- FIXES BITS 6 AND 7 OF MIXER ---
ld hl,AYREGS+Mixer
set 7,(hl)
res 6,(hl)
ld c,$a0
ld hl,AYREGS
.sfxloop:
out (c),a
inc c
outi
dec c
inc a
cp 13
jr nz,.sfxloop
;/out buffered sfx data
;out buffered sfx data
; xor a ; --- FIXES BITS 6 AND 7 OF MIXER ---
; ld hl,AYREGS+Mixer
; set 7,(hl)
; res 6,(hl)
; ld c,$A1
; ld hl,AYREGS
;.sfxloop:
; out ($A0),A
; inc a
; outi
; cp 13
; jr nz,.sfxloop
;/out buffered sfx data
ld ix, afxChData
ld b, 3
afxFrameLoop:
ld a, (ix +1) ; significant byte addresses effect
or a ; if 0, the channel is not active
jr z, afxFrameChSkip
ld h, a
ld l, (ix +0) ; low byte address effect
ld a, (hl) ; read information bytes
inc hl
ld c, a
ld (ix +5), a ; remember bits mixer
and 15
ld (ix +4), a ; remember volume
bit 5 , c ; changing pitch period
jr z, afxFrameNoTone
ld a, (hl) ; remember period
inc hl
ld (ix +6), a
ld a, (hl)
inc hl
ld (ix +7), a
afxFrameNoTone:
bit 6 , c ; period change noise
jr z, afxFrameNoNoise
ld a, (hl) ; period obtain
cp $20 ; if it is more than 31 , the effect is over
jr c, afxFrameNoise
ld a,(ix+ 8)
and a
jr z,a1
; looping effect
ld l,(ix+ 9) ; restart the effect from the beginning
ld h,(ix+ 10)
ld (ix +0), l ; remember address
ld (ix +1), h
inc (ix +2) ; increment the playing time
jr nz, afxFrameLoop
inc (ix +3)
jr afxFrameLoop
a1: ; no loop
xor a ; vanishes high byte address and the volume
ld (ix +1), a
ld (ix +4), a
jr afxFrameChSkip
afxFrameNoise:
inc hl ; remember period noise
ld (afxNoisePeriod), a
afxFrameNoNoise:
ld (ix +0), l ; remember address
ld (ix +1), h
inc (ix +2) ; increment the playing time
jr nz, afxFrameChSkip
inc (ix +3)
afxFrameChSkip:
ld de, 11 ; the next channel
add ix, de
djnz afxFrameLoop
; ld a, (AYREGS + AmplA)
; ld c, a
ld a, (afxChData +0 * 11 +4)
; cp c
; jr c, afxSkipCh0
ld (AYREGS + AmplA), a
ld a, (afxChData +0 * 11 + 6 )
ld (AYREGS + TonA +0), a
ld a, (afxChData +0 * 11 +7 )
ld (AYREGS + TonA +1), a
ld a, (AYREGS + Mixer)
and %11110110
ld c, a
ld a, (afxChData +0 * 11 + 5 )
rra
rra
rra
rra
and %00001001
or c
ld (AYREGS + Mixer), a
afxSkipCh0:
; ld a, (AYREGS + AmplB)
; ld c, a
ld a, (afxChData +1 * 11 +4)
; cp c
; jr c, afxSkipCh1
ld (AYREGS + AmplB), a
ld a, (afxChData +1 * 11 + 6 )
ld (AYREGS + TonB +0), a
ld a, (afxChData +1 * 11 +7 )
ld (AYREGS + TonB +1), a
ld a, (AYREGS + Mixer)
and %11101101
ld c, a
ld a, (afxChData +1 * 11 + 5 )
rra
rra
rra
and %00010010
or c
ld (AYREGS + Mixer), a
afxSkipCh1:
; ld a, (AYREGS + AmplC)
; ld c, a
ld a, (afxChData +2 * 11 +4)
; cp c
; jr c, afxSkipCh2
ld (AYREGS + AmplC), a
ld a, (afxChData +2 * 11 + 6 )
ld (AYREGS + TonC +0), a
ld a, (afxChData +2 * 11 +7 )
ld (AYREGS + TonC +1), a
ld a, (AYREGS + Mixer)
and %11011011
ld c, a
ld a, (afxChData +2 * 11 + 5 )
rra
rra
and %00100100
or c
ld (AYREGS + Mixer), a
afxSkipCh2:
ld ix, afxChData
ld a,(ix +0 * 11 +5)
and (ix +1 * 11 +5)
and (ix +2 * 11 +5)
rla
jr c, afxNoNoise
ld a, (afxNoisePeriod)
ld (AYREGS + Noise), a
afxNoNoise:
ret
; ------------------------------------------------- ------------- ;
; Running effect on the free channel. In the absence ;
; free channels selects the most long -sounding . ;
; Input : A = number of effect 0 .. 255 ;
; ------------------------------------------------- ------------- ;
AFXPLAY:
push ix
push iy
ex af,af'
ld ix, afxChData ; empty channel search
ld de,11
ld b,3
b1: ld a,(ix +1)
or a
jr z,freechan
add ix,de
djnz b1
; no free channels
ld iy, afxChData ; search the channel that plays from more time
ld ix, afxChData ; in case of 3 looping channels use channel A
ld de, 0 ; in de the longest time while searching
ld bc,11
ld a, 3
afxPlay0:
inc (iy+8)
dec (iy+8)
jr nz, afxPlay1 ; skip channels with looping effects
ld l, (iy+2) ; compare time channel with the highest
ld h, (iy+3)
sbc hl,de
jr c, afxPlay1
add hl,de ; remember the longest time
ex de,hl
push iy ; remember the address of the channel in ix
pop ix
afxPlay1:
add iy,bc
dec a
jr nz,afxPlay0
; expect to address the effect
freechan:
ld h, a
ex af,af'
ld l, a
add hl, hl
ld bc, (afxBnkAdr) ; address offset table effects
add hl, bc
ld c, (hl)
inc hl
ld b, (hl)
add hl, bc ; effect address obtained in hl
ld (ix+0), l ; record in the channel descriptor
ld (ix+1), h
ld (ix+2), 0 ; reset execution Time
ld (ix+3), 0
ld (ix+8), 0 ; reset looping flag
cp loopingsfx ; up to sfx $loopingsfx-1 will loop
jr nc,c1
ld (ix+ 8), -1 ; set looping flag
ld (ix+ 9), l ; record in the channel descriptor for later use
ld (ix+10), h
c1:
pop iy
pop ix
ret
ROUT:
xor A ; --- FIXES BITS 6 AND 7 OF MIXER ---
LD HL,AYREGS+Mixer
set 7,( hl)
res 6,( hl)
LD C,0xA1
LD HL,AYREGS
d1: OUT (0xA0),A
INC A
OUTI
CP 13
JR NZ,d1
RET
in the code you see:
ld hl,$4000 ;miz_buffer
This is the address where I have stored my sfx bank.
Of course you can change this to any address you want.
I really love the fact that this code can play 3 sfx at the same time, and really barely interferes with the music.
For music I use MBPLAY. Moonblaster songs.
Ops! I plan to use only PSG for both BGM and SFX. So better I use only one channel for SFX, I think... (but I'll look this code anyway, I have a lot to learn)
this is the same code above on github
https://github.com/artrag/Uridium-msx1/blob/master/MSX_Shiru...