Initial upload, Echo 0.8 UNSTABLE VERSION

1 files changed, 316 insertions, 0 deletions

diff --git a/src-z80/core/sfx.z80 b/src-z80/core/sfx.z80
new file mode 100644
index 0000000..b7e26aa
--- /dev/null
+++ b/src-z80/core/sfx.z80
@@ -0,0 +1,316 @@
+;****************************************************************************
+; 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
+
+    dec b                         ; Mute FM channel
+    ld (ix+0), $28
+    ld (ix+1), b
+
+    PollPCM
+    
+    ld a, b
+    and $04                       ; Determine which port to write
+    rrca
+    ld iyl, a
+    
+    ld a, b                     ; Kill ADSR
+    call KillFM
+
+    PollPCM
+
+    ld hl, RAM_BGMFMVol           ; Restore BGM FM volume
+    ld a, b
+    add l
+    ld l, a
+    ld c, (hl)
+    ld a, l
+    add 8
+    ld l, a
+    ld (hl), c
+
+    PollPCM
+
+    ld a, l                       ; Restore BGM FM instrument
+    sub 8*2
+    ld l, a
+    push bc
+    push de
+    push hl
+    ld a, b
+    ld b, (hl)
+    call LoadFMDirect
+    pop hl
+    pop de
+    pop bc
+
+    PollPCM
+    inc b
+.fmfree:
+    PollPCM
+    dec e                         ; Go for next FM channel to unlock
+    dec b
+    jp nz, .unlockfm
+
+;----------------------------------------------------------------------------
+
+    ret                         ; End of subroutine