; Furnace Command Stream player for 6502 architecture ; written by tildearrow ; usage: ; define the following constants: ; - FCS_MAX_CHAN: the number of channels in your stream ; - FCS_MAX_STACK: the maximum stack size ; - fcsAddrBase: player state address base ; - fcsZeroPage: player state address base for zero-page-mandatory variables ; - fcsGlobalStack: player stack (best placed in a page) ; - fcsPtr: pointer to command stream ; - fcsVolMax: pointer to max channel volume array ; - fcsCmdTableLow: low address of command table ; - fcsCmdTableHigh: high address of command table ; - see stream_example.i for an example ; call fcsInit - this sets A to 0 on success or 1 on failure ; call fcsTick on every frame/tick/whatever ; - call your dispatch implementation's tick function afterwards ; notes: ; - short pointers only ; - little-endian only! ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; calculated from player constants fcsDelays=fcsPtr+8 fcsSpeedDial=fcsPtr+24 ; variables ; these may be read by your command handling routines fcsArg0=fcsAddrBase ; int fcsArg1=fcsAddrBase+4 ; int ; something else fcsTicks=fcsAddrBase+8 ; short ; temporary variables fcsSendVolume=fcsAddrBase+10 ; char fcsSendPitch=fcsAddrBase+11 ; char fcsArpSpeed=fcsAddrBase+12 ; char fcsCmd=fcsAddrBase+16 ; char[8] fcsTempPtr=fcsZeroPage ; short ; channel state chanPC=fcsZeroPage+2 ; short chanTicks=fcsAddrBase+24 ; short chanStackPtr=fcsAddrBase+24+(FCS_MAX_CHAN*2) ; char chanNote=fcsAddrBase+24+(FCS_MAX_CHAN*2)+1 ; char chanVibratoPos=fcsAddrBase+24+(FCS_MAX_CHAN*4) ; char chanVibrato=fcsAddrBase+24+(FCS_MAX_CHAN*4)+1 ; char chanPitch=fcsAddrBase+24+(FCS_MAX_CHAN*6) ; char chanArp=fcsAddrBase+24+(FCS_MAX_CHAN*6)+1 ; char chanPortaSpeed=fcsAddrBase+24+(FCS_MAX_CHAN*8) ; char chanPortaTarget=fcsAddrBase+24+(FCS_MAX_CHAN*8)+1 ; char chanVol=fcsAddrBase+24+(FCS_MAX_CHAN*10) ; short chanVolSpeed=fcsAddrBase+24+(FCS_MAX_CHAN*12) ; short chanPan=fcsAddrBase+24+(FCS_MAX_CHAN*14) ; short ; may be used for driver detection fcsDriverInfo: .db "Furnace" .db 0 ; x: channel*2 ; a is set to next byte .MACRO fcsReadNext ; a=chanPC[x] lda (chanPC,x) ; increase PC inc chanPC,x bne + inc chanPC+1,x + .ENDM ; note on null fcsNoteOnNull: lda #0 sta chanVibratoPos,x ldy #$00 jsr fcsDispatchCmd rts ; note off, note off env, env release fcsNoArgDispatchB4: tya sec sbc #$b4 tay jsr fcsDispatchCmd rts fcsOneByteDispatchB4: tya pha fcsReadNext sta fcsArg0 pla sec sbc #$b4 tay jsr fcsDispatchCmd rts ; dispatch subroutines for full commands fcsNoArgDispatch: jsr fcsDispatchCmd rts fcsOneByteDispatch: tya pha fcsReadNext sta fcsArg0 pla tay jsr fcsDispatchCmd rts fcsTwoByteDispatch: tya pha fcsReadNext sta fcsArg0 fcsReadNext sta fcsArg1 pla tay jsr fcsDispatchCmd rts fcsOneShortDispatch: tya pha fcsReadNext sta fcsArg0 fcsReadNext sta fcsArg0+1 pla tay jsr fcsDispatchCmd rts fcsTwoShortDispatch: tya pha fcsReadNext sta fcsArg0 fcsReadNext sta fcsArg0+1 fcsReadNext sta fcsArg1 fcsReadNext sta fcsArg1+1 pla tay jsr fcsDispatchCmd rts fcsPrePorta: fcsReadNext pha and #$80 sta fcsArg0 pla and #$40 sta fcsArg1 ldy #$0c jsr fcsDispatchCmd rts fcsArpTime: fcsReadNext sta fcsArpSpeed rts fcsVibrato: fcsReadNext sta chanVibrato,x rts ; TODO fcsVibRange: fcsVibShape: fcsReadNext rts fcsPitch: fcsReadNext sta chanPitch,x lda #1 sta fcsSendPitch rts fcsArpeggio: fcsReadNext sta chanArp,x rts fcsVolume: fcsReadNext sta chanVol+1,x lda #0 sta chanVol,x lda #1 sta fcsSendVolume rts fcsVolSlide: fcsReadNext sta chanVolSpeed,x fcsReadNext sta chanVolSpeed+1,x rts fcsPorta: fcsReadNext sta chanPortaTarget,x fcsReadNext sta chanPortaSpeed,x rts fcsLegato: fcsReadNext sta chanNote,x sta fcsArg0 ldy #11 jsr fcsDispatchCmd rts fcsVolSlideTarget: fcsReadNext sta chanVolSpeed,x fcsReadNext sta chanVolSpeed+1,x ; TODO: we don't support this yet... fcsReadNext fcsReadNext rts fcsNoOpOneByte: fcsReadNext rts fcsPan: fcsReadNext sta chanPan,x sta fcsArg0 fcsReadNext sta chanPan+1,x sta fcsArg1 ldy #10 jsr fcsDispatchCmd rts fcsOptPlaceholder: fcsReadNext fcsReadNext fcsReadNext rts fcsCallI: ; get address and relocate it fcsReadNext clc adc #fcsPtr pha ; ignore next two bytes jsr fcsIgnoreNext jsr fcsIgnoreNext jsr fcsPushCall pla sta chanPC+1,x pla sta chanPC,x rts fcsOffWait: ldy #0 sty chanTicks+1,x iny sty chanTicks,x jsr fcsDispatchCmd rts fcsFullCmd: ; read command fcsReadNext tay lda fcsFullCmdTable-28,y tay lda fcsCmdReadTableLow,y sta fcsTempPtr lda fcsCmdReadTableHigh,y sta fcsTempPtr+1 jmp (fcsTempPtr) fcsSpeedDialCmd: lda fcsSpeedDial-224,y tay lda fcsFullCmdTable-28,y tay lda fcsCmdReadTableLow,y sta fcsTempPtr lda fcsCmdReadTableHigh,y sta fcsTempPtr+1 jmp (fcsTempPtr) fcsCall: ; get address and relocate it fcsReadNext clc adc #fcsPtr pha jsr fcsPushCall pla sta chanPC+1,x pla sta chanPC,x rts ; push channel PC to stack fcsPushCall: lda chanStackPtr,x tay lda chanPC,x sta fcsGlobalStack,y iny lda chanPC+1,x sta fcsGlobalStack,y iny tya sta chanStackPtr,x rts ; retrieve channel PC from stack fcsRet: lda chanStackPtr,x tay dey lda fcsGlobalStack,y sta chanPC+1,x dey lda fcsGlobalStack,y sta chanPC,x tya sta chanStackPtr,x rts fcsJump: ; get address and relocate it fcsReadNext clc adc #fcsPtr pha ; ignore next two bytes jsr fcsIgnoreNext jsr fcsIgnoreNext pla sta chanPC+1,x pla sta chanPC,x rts ; TODO fcsTickRate: rts fcsWaitS: fcsReadNext sta chanTicks,x fcsReadNext sta chanTicks+1,x rts fcsWaitC: fcsReadNext sta chanTicks,x lda #0 sta chanTicks+1,x rts fcsWait1: ldy #1 sty chanTicks,x dey sty chanTicks+1,x rts fcsStop: lda #0 sta chanPC,x sta chanPC+1,x rts fcsNoOp: rts ; x: channel*2 ; y: command fcsDispatchCmd: ; read command call table lda fcsCmdTableLow,y sta fcsTempPtr lda fcsCmdTableHigh,y sta fcsTempPtr+1 ; check for zero lda fcsTempPtr ora fcsTempPtr beq + ; get out ; handle command in dispatch code jmp (fcsTempPtr) ; only if pointer is zero + rts ; x: channel*2 fcsIgnoreNext: ; increase PC inc chanPC,x bne + inc chanPC+1,x + rts ; x: channel*2 (for speed... char variables are interleaved) ; read commands fcsChannelCmd: ; read next byte fcsReadNext and #$ff ; touch flags ; process and read arguments ; if (a<0xb3) bpl fcsNote ; handle $00-$7f cmp #$b4 bpl fcsCheckOther ; this is a note fcsNote: sta fcsArg0 sta chanNote,x lda #0 tay sta chanVibratoPos,x ; call DIV_CMD_NOTE_ON jsr fcsDispatchCmd rts ; check other instructions fcsCheckOther: ; check for preset delays cmp #$f0 bmi fcsOther ; handler for preset delays fcsPresetDelay: ; load preset delay and store it tay lda fcsPtr+8-240,y sta chanTicks,x lda #0 sta chanTicks+1,x rts ; other instructions fcsOther: ; call respective handler tay lda fcsInsTableLow-180,y sta fcsTempPtr lda fcsInsTableHigh-180,y sta fcsTempPtr+1 jmp (fcsTempPtr) ; x: channel*2 ; stuff that goes after command reading fcsChannelPost: ; do volume ; do pitch ; do portamento ; do arpeggio ; end rts ; x: channel*2 fcsDoChannel: ; initialize lda #0 sta fcsSendVolume sta fcsSendPitch ; check whether this channel is halted (PC = 0) lda chanPC,x ora chanPC+1,x bne + rts ; channel not halted... begin processing ; chanTicks-- + lda chanTicks,x sec sbc #1 sta chanTicks,x bne + ; skip if our counter isn't zero ; ticks lower is zero; check upper byte ldy chanTicks+1,x beq fcsDoChannelLoop ; go to read commands if it's zero as well ; decrease ticks upper dey sty chanTicks+1,x ; process channel stuff jsr fcsChannelPost rts ; ticks is zero... read commands until chanTicks is set fcsDoChannelLoop: lda chanTicks,x ora chanTicks+1,x bne + ; get out if chanTicks is no longer zero jsr fcsChannelCmd ; read next command jmp fcsDoChannelLoop + jsr fcsChannelPost ; end rts fcsTick: ; update channel state ; for (x=0; xfcsPtr sta chanPC,x inx cpx #(FCS_MAX_CHAN*2) bne - ; initialize channel stacks lda #0 ldx #0 - sta chanStackPtr,x clc adc #FCS_MAX_STACK inx inx cpx #(FCS_MAX_CHAN*2) bne - ; set volumes ; TODO ; success lda #0 rts ; floor(127*sin((x/64)*(2*pi))) fcsVibTable: .db 0, 12, 24, 36, 48, 59, 70, 80, 89, 98, 105, 112, 117, 121, 124, 126 .db 127, 126, 124, 121, 117, 112, 105, 98, 89, 80, 70, 59, 48, 36, 24, 12 .db 0, -12, -24, -36, -48, -59, -70, -80, -89, -98, -105, -112, -117, -121, -124, -126 .db -126, -126, -124, -121, -117, -112, -105, -98, -89, -80, -70, -59, -48, -36, -24, -12 ; COMMAND TABLE ; $b4 fcsNoArgDispatch, ; $b5 fcsNoArgDispatch, ; $b6 fcsNoArgDispatch, ; $b7 fcsNoArgDispatch, ; $b8 fcsOneByteDispatch, ; $b9 fcsNoOp, ; $ba fcsNoOp, ; $bb fcsNoOp, ; $bc fcsNoOp, ; $bd fcsNoOp, ; $be fcsNoOp, ; $bf fcsNoOp, ; $c0 fcsPrePorta, ; $c1 fcsArpTime, ; $c2 fcsVibrato, ; $c3 fcsVibRange, ; $c4 fcsVibShape, ; $c5 fcsPitch, ; $c6 fcsArpeggio, ; $c7 fcsVolume, ; $c8 fcsVolSlide, ; $c9 fcsPorta, ; $ca fcsLegato, ; $cb fcsVolSlideTarget, ; $cc fcsNoOpOneByte, ; $cd fcsNoOpOneByte, ; $ce fcsNoOpOneByte, ; $cf fcsPan, ; $d0 fcsOptPlaceholder, ; $d1 fcsNoOp, ; $d2 fcsNoOp, ; $d3 fcsNoOp, ; $d4 fcsNoOp, ; $d5 fcsCallI, ; $d6 fcsOffWait, ; $d7 fcsFullCmd, ; $d8 fcsCall, ; $d9 fcsRet, ; $da fcsJump, ; $db fcsTickRate, ; $dc fcsWaitS, ; $dd fcsWaitC, ; $de fcsWait1, ; $df fcsStop, fcsInsTableHigh: .db >fcsNoArgDispatchB4, >fcsNoArgDispatchB4, >fcsNoArgDispatchB4, >fcsNoArgDispatchB4, >fcsOneByteDispatchB4, >fcsNoOp, >fcsNoOp, >fcsNoOp, >fcsNoOp, >fcsNoOp, >fcsNoOp, >fcsNoOp .db >fcsPrePorta, >fcsArpTime, >fcsVibrato, >fcsVibRange, >fcsVibShape, >fcsPitch, >fcsArpeggio, >fcsVolume, >fcsVolSlide, >fcsPorta, >fcsLegato, >fcsVolSlideTarget, >fcsNoOpOneByte, >fcsNoOpOneByte, >fcsNoOpOneByte, >fcsPan .db >fcsOptPlaceholder, >fcsNoOp, >fcsNoOp, >fcsNoOp, >fcsNoOp, >fcsCallI, >fcsOffWait, >fcsFullCmd, >fcsCall, >fcsRet, >fcsJump, >fcsTickRate, >fcsWaitS, >fcsWaitC, >fcsWait1, >fcsStop .db >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd, >fcsSpeedDialCmd fcsInsTableLow: .db fcsNoArgDispatch .db >fcsOneByteDispatch .db >fcsTwoByteDispatch .db >fcsOneShortDispatch .db >fcsTwoShortDispatch fcsCmdReadTableLow: .db