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8bitworkshop/presets/nes/famitone2.asm

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fixed NES audio; use setTimeout for animation loop; famitracker
2018-08-16 14:13:09 +00:00
;FamiTone2 v1.12
;settings, uncomment or put them into your main program; the latter makes possible updates easier
; FT_BASE_ADR = $0300 ;page in the RAM used for FT2 variables, should be $xx00
; FT_TEMP = $00 ;3 bytes in zeropage used by the library as a scratchpad
; FT_DPCM_OFF = $c000 ;$c000..$ffc0, 64-byte steps
; FT_SFX_STREAMS = 4 ;number of sound effects played at once, 1..4
; FT_DPCM_ENABLE ;undefine to exclude all DMC code
; FT_SFX_ENABLE ;undefine to exclude all sound effects code
; FT_THREAD ;undefine if you are calling sound effects from the same thread as the sound update call
; FT_PAL_SUPPORT ;undefine to exclude PAL support
; FT_NTSC_SUPPORT ;undefine to exclude NTSC support
;internal defines
IFCONST FT_PAL_SUPPORT
IFCONST FT_NTSC_SUPPORT
FT_PITCH_FIX equ 1 ;add PAL/NTSC pitch correction code only when both modes are enabled
ENDIF
ENDIF
FT_DPCM_PTR = (FT_DPCM_OFF&$3fff)>>6
;zero page variables
FT_TEMP_PTR = FT_TEMP ;word
FT_TEMP_PTR_L = FT_TEMP_PTR+0
FT_TEMP_PTR_H = FT_TEMP_PTR+1
FT_TEMP_VAR1 = FT_TEMP+2
FT_TEMP_SIZE = 3
;envelope structure offsets, 5 bytes per envelope, grouped by variable type
FT_ENVELOPES_ALL = 3+3+3+2 ;3 for the pulse and triangle channels, 2 for the noise channel
FT_ENV_STRUCT_SIZE = 5
FT_ENV_VALUE = FT_BASE_ADR+0*FT_ENVELOPES_ALL
FT_ENV_REPEAT = FT_BASE_ADR+1*FT_ENVELOPES_ALL
FT_ENV_ADR_L = FT_BASE_ADR+2*FT_ENVELOPES_ALL
FT_ENV_ADR_H = FT_BASE_ADR+3*FT_ENVELOPES_ALL
FT_ENV_PTR = FT_BASE_ADR+4*FT_ENVELOPES_ALL
;channel structure offsets, 7 bytes per channel
FT_CHANNELS_ALL = 5
FT_CHN_STRUCT_SIZE = 9
FT_CHN_PTR_L = FT_BASE_ADR+0*FT_CHANNELS_ALL
FT_CHN_PTR_H = FT_BASE_ADR+1*FT_CHANNELS_ALL
FT_CHN_NOTE = FT_BASE_ADR+2*FT_CHANNELS_ALL
FT_CHN_INSTRUMENT = FT_BASE_ADR+3*FT_CHANNELS_ALL
FT_CHN_REPEAT = FT_BASE_ADR+4*FT_CHANNELS_ALL
FT_CHN_RETURN_L = FT_BASE_ADR+5*FT_CHANNELS_ALL
FT_CHN_RETURN_H = FT_BASE_ADR+6*FT_CHANNELS_ALL
FT_CHN_REF_LEN = FT_BASE_ADR+7*FT_CHANNELS_ALL
FT_CHN_DUTY = FT_BASE_ADR+8*FT_CHANNELS_ALL
;variables and aliases
FT_ENVELOPES = FT_BASE_ADR
FT_CH1_ENVS = FT_ENVELOPES+0
FT_CH2_ENVS = FT_ENVELOPES+3
FT_CH3_ENVS = FT_ENVELOPES+6
FT_CH4_ENVS = FT_ENVELOPES+9
FT_CHANNELS = FT_ENVELOPES+FT_ENVELOPES_ALL*FT_ENV_STRUCT_SIZE
FT_CH1_VARS = FT_CHANNELS+0
FT_CH2_VARS = FT_CHANNELS+1
FT_CH3_VARS = FT_CHANNELS+2
FT_CH4_VARS = FT_CHANNELS+3
FT_CH5_VARS = FT_CHANNELS+4
FT_CH1_NOTE = FT_CH1_VARS+<(FT_CHN_NOTE)
FT_CH2_NOTE = FT_CH2_VARS+<(FT_CHN_NOTE)
FT_CH3_NOTE = FT_CH3_VARS+<(FT_CHN_NOTE)
FT_CH4_NOTE = FT_CH4_VARS+<(FT_CHN_NOTE)
FT_CH5_NOTE = FT_CH5_VARS+<(FT_CHN_NOTE)
FT_CH1_INSTRUMENT = FT_CH1_VARS+<(FT_CHN_INSTRUMENT)
FT_CH2_INSTRUMENT = FT_CH2_VARS+<(FT_CHN_INSTRUMENT)
FT_CH3_INSTRUMENT = FT_CH3_VARS+<(FT_CHN_INSTRUMENT)
FT_CH4_INSTRUMENT = FT_CH4_VARS+<(FT_CHN_INSTRUMENT)
FT_CH5_INSTRUMENT = FT_CH5_VARS+<(FT_CHN_INSTRUMENT)
FT_CH1_DUTY = FT_CH1_VARS+<(FT_CHN_DUTY)
FT_CH2_DUTY = FT_CH2_VARS+<(FT_CHN_DUTY)
FT_CH3_DUTY = FT_CH3_VARS+<(FT_CHN_DUTY)
FT_CH4_DUTY = FT_CH4_VARS+<(FT_CHN_DUTY)
FT_CH5_DUTY = FT_CH5_VARS+<(FT_CHN_DUTY)
FT_CH1_VOLUME = FT_CH1_ENVS+<(FT_ENV_VALUE)+0
FT_CH2_VOLUME = FT_CH2_ENVS+<(FT_ENV_VALUE)+0
FT_CH3_VOLUME = FT_CH3_ENVS+<(FT_ENV_VALUE)+0
FT_CH4_VOLUME = FT_CH4_ENVS+<(FT_ENV_VALUE)+0
FT_CH1_NOTE_OFF = FT_CH1_ENVS+<(FT_ENV_VALUE)+1
FT_CH2_NOTE_OFF = FT_CH2_ENVS+<(FT_ENV_VALUE)+1
FT_CH3_NOTE_OFF = FT_CH3_ENVS+<(FT_ENV_VALUE)+1
FT_CH4_NOTE_OFF = FT_CH4_ENVS+<(FT_ENV_VALUE)+1
FT_CH1_PITCH_OFF = FT_CH1_ENVS+<(FT_ENV_VALUE)+2
FT_CH2_PITCH_OFF = FT_CH2_ENVS+<(FT_ENV_VALUE)+2
FT_CH3_PITCH_OFF = FT_CH3_ENVS+<(FT_ENV_VALUE)+2
FT_VARS = FT_CHANNELS+FT_CHANNELS_ALL*FT_CHN_STRUCT_SIZE
FT_PAL_ADJUST = FT_VARS+0
FT_SONG_LIST_L = FT_VARS+1
FT_SONG_LIST_H = FT_VARS+2
FT_INSTRUMENT_L = FT_VARS+3
FT_INSTRUMENT_H = FT_VARS+4
FT_TEMPO_STEP_L = FT_VARS+5
FT_TEMPO_STEP_H = FT_VARS+6
FT_TEMPO_ACC_L = FT_VARS+7
FT_TEMPO_ACC_H = FT_VARS+8
FT_SONG_SPEED = FT_CH5_INSTRUMENT
FT_PULSE1_PREV = FT_CH3_DUTY
FT_PULSE2_PREV = FT_CH5_DUTY
FT_DPCM_LIST_L = FT_VARS+9
FT_DPCM_LIST_H = FT_VARS+10
FT_DPCM_EFFECT = FT_VARS+11
FT_OUT_BUF = FT_VARS+12 ;11 bytes
;sound effect stream variables, 2 bytes and 15 bytes per stream
;when sound effects are disabled, this memory is not used
FT_SFX_ADR_L = FT_VARS+23
FT_SFX_ADR_H = FT_VARS+24
FT_SFX_BASE_ADR = FT_VARS+25
FT_SFX_STRUCT_SIZE = 15
FT_SFX_REPEAT = FT_SFX_BASE_ADR+0
FT_SFX_PTR_L = FT_SFX_BASE_ADR+1
FT_SFX_PTR_H = FT_SFX_BASE_ADR+2
FT_SFX_OFF = FT_SFX_BASE_ADR+3
FT_SFX_BUF = FT_SFX_BASE_ADR+4 ;11 bytes
FT_BASE_SIZE = FT_SFX_BUF+11-FT_BASE_ADR
;aliases for sound effect channels to use in user calls
FT_SFX_CH0 = FT_SFX_STRUCT_SIZE*0
FT_SFX_CH1 = FT_SFX_STRUCT_SIZE*1
FT_SFX_CH2 = FT_SFX_STRUCT_SIZE*2
FT_SFX_CH3 = FT_SFX_STRUCT_SIZE*3
;aliases for the APU registers
APU_PL1_VOL = $4000
APU_PL1_SWEEP = $4001
APU_PL1_LO = $4002
APU_PL1_HI = $4003
APU_PL2_VOL = $4004
APU_PL2_SWEEP = $4005
APU_PL2_LO = $4006
APU_PL2_HI = $4007
APU_TRI_LINEAR = $4008
APU_TRI_LO = $400a
APU_TRI_HI = $400b
APU_NOISE_VOL = $400c
APU_NOISE_LO = $400e
APU_NOISE_HI = $400f
APU_DMC_FREQ = $4010
APU_DMC_RAW = $4011
APU_DMC_START = $4012
APU_DMC_LEN = $4013
APU_SND_CHN = $4015
;aliases for the APU registers in the output buffer
IFNCONST FT_SFX_ENABLE ;if sound effects are disabled, write to the APU directly
FT_MR_PULSE1_V = APU_PL1_VOL
FT_MR_PULSE1_L = APU_PL1_LO
FT_MR_PULSE1_H = APU_PL1_HI
FT_MR_PULSE2_V = APU_PL2_VOL
FT_MR_PULSE2_L = APU_PL2_LO
FT_MR_PULSE2_H = APU_PL2_HI
FT_MR_TRI_V = APU_TRI_LINEAR
FT_MR_TRI_L = APU_TRI_LO
FT_MR_TRI_H = APU_TRI_HI
FT_MR_NOISE_V = APU_NOISE_VOL
FT_MR_NOISE_F = APU_NOISE_LO
ELSE ;otherwise write to the output buffer
FT_MR_PULSE1_V = FT_OUT_BUF
FT_MR_PULSE1_L = FT_OUT_BUF+1
FT_MR_PULSE1_H = FT_OUT_BUF+2
FT_MR_PULSE2_V = FT_OUT_BUF+3
FT_MR_PULSE2_L = FT_OUT_BUF+4
FT_MR_PULSE2_H = FT_OUT_BUF+5
FT_MR_TRI_V = FT_OUT_BUF+6
FT_MR_TRI_L = FT_OUT_BUF+7
FT_MR_TRI_H = FT_OUT_BUF+8
FT_MR_NOISE_V = FT_OUT_BUF+9
FT_MR_NOISE_F = FT_OUT_BUF+10
ENDIF
;------------------------------------------------------------------------------
; reset APU, initialize FamiTone
; in: A 0 for PAL, not 0 for NTSC
; X,Y pointer to music data
;------------------------------------------------------------------------------
FamiToneInit: subroutine
stx FT_SONG_LIST_L ;store music data pointer for further use
sty FT_SONG_LIST_H
stx <FT_TEMP_PTR_L
sty <FT_TEMP_PTR_H
IFCONST FT_PITCH_FIX
tax ;set SZ flags for A
beq .pal
lda #64
.pal:
ELSE
IFCONST FT_PAL_SUPPORT
lda #0
ENDIF
IFCONST FT_NTSC_SUPPORT
lda #64
ENDIF
ENDIF
sta FT_PAL_ADJUST
jsr FamiToneMusicStop ;initialize channels and envelopes
ldy #1
lda (FT_TEMP_PTR),y ;get instrument list address
sta FT_INSTRUMENT_L
iny
lda (FT_TEMP_PTR),y
sta FT_INSTRUMENT_H
iny
lda (FT_TEMP_PTR),y ;get sample list address
sta FT_DPCM_LIST_L
iny
lda (FT_TEMP_PTR),y
sta FT_DPCM_LIST_H
lda #$ff ;previous pulse period MSB, to not write it when not changed
sta FT_PULSE1_PREV
sta FT_PULSE2_PREV
lda #$0f ;enable channels, stop DMC
sta APU_SND_CHN
lda #$80 ;disable triangle length counter
sta APU_TRI_LINEAR
lda #$00 ;load noise length
sta APU_NOISE_HI
lda #$30 ;volumes to 0
sta APU_PL1_VOL
sta APU_PL2_VOL
sta APU_NOISE_VOL
lda #$08 ;no sweep
sta APU_PL1_SWEEP
sta APU_PL2_SWEEP
;jmp FamiToneMusicStop
;------------------------------------------------------------------------------
; stop music that is currently playing, if any
; in: none
;------------------------------------------------------------------------------
FamiToneMusicStop: subroutine
lda #0
sta FT_SONG_SPEED ;stop music, reset pause flag
sta FT_DPCM_EFFECT ;no DPCM effect playing
ldx #<(FT_CHANNELS) ;initialize channel structures
.set_channels:
lda #0
sta FT_CHN_REPEAT,x
sta FT_CHN_INSTRUMENT,x
sta FT_CHN_NOTE,x
sta FT_CHN_REF_LEN,x
lda #$30
sta FT_CHN_DUTY,x
inx ;next channel
cpx #<(FT_CHANNELS)+FT_CHANNELS_ALL
bne .set_channels
ldx #<(FT_ENVELOPES) ;initialize all envelopes to the dummy envelope
.set_envelopes:
lda #< (_FT2DummyEnvelope)
sta FT_ENV_ADR_L,x
lda #>(_FT2DummyEnvelope)
sta FT_ENV_ADR_H,x
lda #0
sta FT_ENV_REPEAT,x
sta FT_ENV_VALUE,x
inx
cpx #<(FT_ENVELOPES)+FT_ENVELOPES_ALL
bne .set_envelopes
jmp FamiToneSampleStop
;------------------------------------------------------------------------------
; play music
; in: A number of subsong
;------------------------------------------------------------------------------
FamiToneMusicPlay: subroutine
ldx FT_SONG_LIST_L
stx <FT_TEMP_PTR_L
ldx FT_SONG_LIST_H
stx <FT_TEMP_PTR_H
ldy #0
cmp (FT_TEMP_PTR),y ;check if there is such sub song
bcs .skip
asl ;multiply song number by 14
sta <FT_TEMP_PTR_L ;use pointer LSB as temp variable
asl
tax
asl
adc <FT_TEMP_PTR_L
stx <FT_TEMP_PTR_L
adc <FT_TEMP_PTR_L
adc #5 ;add offset
tay
lda FT_SONG_LIST_L ;restore pointer LSB
sta <FT_TEMP_PTR_L
jsr FamiToneMusicStop ;stop music, initialize channels and envelopes
ldx #<(FT_CHANNELS) ;initialize channel structures
.set_channels:
lda (FT_TEMP_PTR),y ;read channel pointers
sta FT_CHN_PTR_L,x
iny
lda (FT_TEMP_PTR),y
sta FT_CHN_PTR_H,x
iny
lda #0
sta FT_CHN_REPEAT,x
sta FT_CHN_INSTRUMENT,x
sta FT_CHN_NOTE,x
sta FT_CHN_REF_LEN,x
lda #$30
sta FT_CHN_DUTY,x
inx ;next channel
cpx #<(FT_CHANNELS)+FT_CHANNELS_ALL
bne .set_channels
lda FT_PAL_ADJUST ;read tempo for PAL or NTSC
beq .pal
iny
iny
.pal:
lda (FT_TEMP_PTR),y ;read the tempo step
sta FT_TEMPO_STEP_L
iny
lda (FT_TEMP_PTR),y
sta FT_TEMPO_STEP_H
lda #0 ;reset tempo accumulator
sta FT_TEMPO_ACC_L
lda #6 ;default speed
sta FT_TEMPO_ACC_H
sta FT_SONG_SPEED ;apply default speed, this also enables music
.skip:
rts
;------------------------------------------------------------------------------
; pause and unpause current music
; in: A 0 or not 0 to play or pause
;------------------------------------------------------------------------------
FamiToneMusicPause: subroutine
tax ;set SZ flags for A
beq .unpause
.pause:
jsr FamiToneSampleStop
lda #0 ;mute sound
sta FT_CH1_VOLUME
sta FT_CH2_VOLUME
sta FT_CH3_VOLUME
sta FT_CH4_VOLUME
lda FT_SONG_SPEED ;set pause flag
ora #$80
bne .done
.unpause:
lda FT_SONG_SPEED ;reset pause flag
and #$7f
.done:
sta FT_SONG_SPEED
rts
;------------------------------------------------------------------------------
; update FamiTone state, should be called every NMI
; in: none
;------------------------------------------------------------------------------
FamiToneUpdate: subroutine
IFCONST FT_THREAD
lda FT_TEMP_PTR_L
pha
lda FT_TEMP_PTR_H
pha
ENDIF
lda FT_SONG_SPEED ;speed 0 means that no music is playing currently
bmi .pause ;bit 7 set is the pause flag
bne .update
.pause:
jmp .update_sound
.update:
clc ;update frame counter that considers speed, tempo, and PAL/NTSC
lda FT_TEMPO_ACC_L
adc FT_TEMPO_STEP_L
sta FT_TEMPO_ACC_L
lda FT_TEMPO_ACC_H
adc FT_TEMPO_STEP_H
cmp FT_SONG_SPEED
bcs .update_row ;overflow, row update is needed
sta FT_TEMPO_ACC_H ;no row update, skip to the envelopes update
jmp .update_envelopes
.update_row:
sec
sbc FT_SONG_SPEED
sta FT_TEMPO_ACC_H
ldx #<(FT_CH1_VARS) ;process channel 1
jsr _FT2ChannelUpdate
bcc .no_new_note1
ldx #<(FT_CH1_ENVS)
lda FT_CH1_INSTRUMENT
jsr _FT2SetInstrument
sta FT_CH1_DUTY
.no_new_note1:
ldx #<(FT_CH2_VARS) ;process channel 2
jsr _FT2ChannelUpdate
bcc .no_new_note2
ldx #<(FT_CH2_ENVS)
lda FT_CH2_INSTRUMENT
jsr _FT2SetInstrument
sta FT_CH2_DUTY
.no_new_note2:
ldx #<(FT_CH3_VARS) ;process channel 3
jsr _FT2ChannelUpdate
bcc .no_new_note3
ldx #<(FT_CH3_ENVS)
lda FT_CH3_INSTRUMENT
jsr _FT2SetInstrument
.no_new_note3:
ldx #<(FT_CH4_VARS) ;process channel 4
jsr _FT2ChannelUpdate
bcc .no_new_note4
ldx #<(FT_CH4_ENVS)
lda FT_CH4_INSTRUMENT
jsr _FT2SetInstrument
sta FT_CH4_DUTY
.no_new_note4:
IFCONST FT_DPCM_ENABLE
ldx #<(FT_CH5_VARS) ;process channel 5
jsr _FT2ChannelUpdate
bcc .no_new_note5
lda FT_CH5_NOTE
bne .play_sample
jsr FamiToneSampleStop
bne .no_new_note5 ;A is non-zero after FamiToneSampleStop
.play_sample:
jsr FamiToneSamplePlayM
.no_new_note5:
ENDIF
.update_envelopes:
ldx #<(FT_ENVELOPES) ;process 11 envelopes
.env_process:
lda FT_ENV_REPEAT,x ;check envelope repeat counter
beq .env_read ;if it is zero, process envelope
dec FT_ENV_REPEAT,x ;otherwise decrement the counter
bne .env_next
.env_read:
lda FT_ENV_ADR_L,x ;load envelope data address into temp
sta <FT_TEMP_PTR_L
lda FT_ENV_ADR_H,x
sta <FT_TEMP_PTR_H
ldy FT_ENV_PTR,x ;load envelope pointer
.env_read_value:
lda (FT_TEMP_PTR),y ;read a byte of the envelope data
bpl .env_special ;values below 128 used as a special code, loop or repeat
clc ;values above 128 are output value+192 (output values are signed -63..64)
adc #256-192
sta FT_ENV_VALUE,x ;store the output value
iny ;advance the pointer
bne .env_next_store_ptr ;bra
.env_special:
bne .env_set_repeat ;zero is the loop point, non-zero values used for the repeat counter
iny ;advance the pointer
lda (FT_TEMP_PTR),y ;read loop position
tay ;use loop position
jmp .env_read_value ;read next byte of the envelope
.env_set_repeat:
iny
sta FT_ENV_REPEAT,x ;store the repeat counter value
.env_next_store_ptr:
tya ;store the envelope pointer
sta FT_ENV_PTR,x
.env_next:
inx ;next envelope
cpx #<(FT_ENVELOPES)+FT_ENVELOPES_ALL
bne .env_process
.update_sound:
;convert envelope and channel output data into APU register values in the output buffer
lda FT_CH1_NOTE
beq .ch1cut
clc
adc FT_CH1_NOTE_OFF
IFCONST FT_PITCH_FIX
ora FT_PAL_ADJUST
ENDIF
tax
lda FT_CH1_PITCH_OFF
tay
adc _FT2NoteTableLSB,x
sta FT_MR_PULSE1_L
tya ;sign extension for the pitch offset
ora #$7f
bmi .ch1sign
lda #0
.ch1sign:
adc _FT2NoteTableMSB,x
IFNCONST FT_SFX_ENABLE
cmp FT_PULSE1_PREV
beq .ch1prev
sta FT_PULSE1_PREV
ENDIF
sta FT_MR_PULSE1_H
.ch1prev:
lda FT_CH1_VOLUME
.ch1cut:
ora FT_CH1_DUTY
sta FT_MR_PULSE1_V
lda FT_CH2_NOTE
beq .ch2cut
clc
adc FT_CH2_NOTE_OFF
IFCONST FT_PITCH_FIX
ora FT_PAL_ADJUST
ENDIF
tax
lda FT_CH2_PITCH_OFF
tay
adc _FT2NoteTableLSB,x
sta FT_MR_PULSE2_L
tya
ora #$7f
bmi .ch2sign
lda #0
.ch2sign:
adc _FT2NoteTableMSB,x
IFNCONST FT_SFX_ENABLE
cmp FT_PULSE2_PREV
beq .ch2prev
sta FT_PULSE2_PREV
ENDIF
sta FT_MR_PULSE2_H
.ch2prev:
lda FT_CH2_VOLUME
.ch2cut:
ora FT_CH2_DUTY
sta FT_MR_PULSE2_V
lda FT_CH3_NOTE
beq .ch3cut
clc
adc FT_CH3_NOTE_OFF
IFCONST FT_PITCH_FIX
ora FT_PAL_ADJUST
ENDIF
tax
lda FT_CH3_PITCH_OFF
tay
adc _FT2NoteTableLSB,x
sta FT_MR_TRI_L
tya
ora #$7f
bmi .ch3sign
lda #0
.ch3sign:
adc _FT2NoteTableMSB,x
sta FT_MR_TRI_H
lda FT_CH3_VOLUME
.ch3cut:
ora #$80
sta FT_MR_TRI_V
lda FT_CH4_NOTE
beq .ch4cut
clc
adc FT_CH4_NOTE_OFF
and #$0f
eor #$0f
sta <FT_TEMP_VAR1
lda FT_CH4_DUTY
asl
and #$80
ora <FT_TEMP_VAR1
sta FT_MR_NOISE_F
lda FT_CH4_VOLUME
.ch4cut:
ora #$f0
sta FT_MR_NOISE_V
IFCONST FT_SFX_ENABLE
;process all sound effect streams
.if FT_SFX_STREAMS>0
ldx #FT_SFX_CH0
jsr _FT2SfxUpdate
ENDIF
.if FT_SFX_STREAMS>1
ldx #FT_SFX_CH1
jsr _FT2SfxUpdate
ENDIF
.if FT_SFX_STREAMS>2
ldx #FT_SFX_CH2
jsr _FT2SfxUpdate
ENDIF
.if FT_SFX_STREAMS>3
ldx #FT_SFX_CH3
jsr _FT2SfxUpdate
ENDIF
;send data from the output buffer to the APU
lda FT_OUT_BUF ;pulse 1 volume
sta APU_PL1_VOL
lda FT_OUT_BUF+1 ;pulse 1 period LSB
sta APU_PL1_LO
lda FT_OUT_BUF+2 ;pulse 1 period MSB, only applied when changed
cmp FT_PULSE1_PREV
beq .no_pulse1_upd
sta FT_PULSE1_PREV
sta APU_PL1_HI
.no_pulse1_upd:
lda FT_OUT_BUF+3 ;pulse 2 volume
sta APU_PL2_VOL
lda FT_OUT_BUF+4 ;pulse 2 period LSB
sta APU_PL2_LO
lda FT_OUT_BUF+5 ;pulse 2 period MSB, only applied when changed
cmp FT_PULSE2_PREV
beq .no_pulse2_upd
sta FT_PULSE2_PREV
sta APU_PL2_HI
.no_pulse2_upd:
lda FT_OUT_BUF+6 ;triangle volume (plays or not)
sta APU_TRI_LINEAR
lda FT_OUT_BUF+7 ;triangle period LSB
sta APU_TRI_LO
lda FT_OUT_BUF+8 ;triangle period MSB
sta APU_TRI_HI
lda FT_OUT_BUF+9 ;noise volume
sta APU_NOISE_VOL
lda FT_OUT_BUF+10 ;noise period
sta APU_NOISE_LO
ENDIF
IFCONST FT_THREAD
pla
sta FT_TEMP_PTR_H
pla
sta FT_TEMP_PTR_L
ENDIF
rts
;internal routine, sets up envelopes of a channel according to current instrument
;in X envelope group offset, A instrument number
_FT2SetInstrument: subroutine
asl ;instrument number is pre multiplied by 4
tay
lda FT_INSTRUMENT_H
adc #0 ;use carry to extend range for 64 instruments
sta <FT_TEMP_PTR_H
lda FT_INSTRUMENT_L
sta <FT_TEMP_PTR_L
lda (FT_TEMP_PTR),y ;duty cycle
sta <FT_TEMP_VAR1
iny
lda (FT_TEMP_PTR),y ;instrument pointer LSB
sta FT_ENV_ADR_L,x
iny
lda (FT_TEMP_PTR),y ;instrument pointer MSB
iny
sta FT_ENV_ADR_H,x
inx ;next envelope
lda (FT_TEMP_PTR),y ;instrument pointer LSB
sta FT_ENV_ADR_L,x
iny
lda (FT_TEMP_PTR),y ;instrument pointer MSB
sta FT_ENV_ADR_H,x
lda #0
sta FT_ENV_REPEAT-1,x ;reset env1 repeat counter
sta FT_ENV_PTR-1,x ;reset env1 pointer
sta FT_ENV_REPEAT,x ;reset env2 repeat counter
sta FT_ENV_PTR,x ;reset env2 pointer
cpx #<(FT_CH4_ENVS) ;noise channel has only two envelopes
bcs .no_pitch
inx ;next envelope
iny
sta FT_ENV_REPEAT,x ;reset env3 repeat counter
sta FT_ENV_PTR,x ;reset env3 pointer
lda (FT_TEMP_PTR),y ;instrument pointer LSB
sta FT_ENV_ADR_L,x
iny
lda (FT_TEMP_PTR),y ;instrument pointer MSB
sta FT_ENV_ADR_H,x
.no_pitch:
lda <FT_TEMP_VAR1
rts
;internal routine, parses channel note data
_FT2ChannelUpdate: subroutine
lda FT_CHN_REPEAT,x ;check repeat counter
beq .no_repeat
dec FT_CHN_REPEAT,x ;decrease repeat counter
clc ;no new note
rts
.no_repeat:
lda FT_CHN_PTR_L,x ;load channel pointer into temp
sta <FT_TEMP_PTR_L
lda FT_CHN_PTR_H,x
sta <FT_TEMP_PTR_H
.no_repeat_r:
ldy #0
.read_byte:
lda (FT_TEMP_PTR),y ;read byte of the channel
inc <FT_TEMP_PTR_L ;advance pointer
bne .no_inc_ptr1
inc <FT_TEMP_PTR_H
.no_inc_ptr1:
ora #0
bmi .special_code ;bit 7 0=note 1=special code
lsr ;bit 0 set means the note is followed by an empty row
bcc .no_empty_row
inc FT_CHN_REPEAT,x ;set repeat counter to 1
.no_empty_row:
sta FT_CHN_NOTE,x ;store note code
sec ;new note flag is set
bcs .done ;bra
.special_code:
and #$7f
lsr
bcs .set_empty_rows
asl
asl
sta FT_CHN_INSTRUMENT,x ;store instrument number*4
bcc .read_byte ;bra
.set_empty_rows:
cmp #$3d
bcc .set_repeat
beq .set_speed
cmp #$3e
beq .set_loop
.set_reference:
clc ;remember return address+3
lda <FT_TEMP_PTR_L
adc #3
sta FT_CHN_RETURN_L,x
lda <FT_TEMP_PTR_H
adc #0
sta FT_CHN_RETURN_H,x
lda (FT_TEMP_PTR),y ;read length of the reference (how many rows)
sta FT_CHN_REF_LEN,x
iny
lda (FT_TEMP_PTR),y ;read 16-bit absolute address of the reference
sta <FT_TEMP_VAR1 ;remember in temp
iny
lda (FT_TEMP_PTR),y
sta <FT_TEMP_PTR_H
lda <FT_TEMP_VAR1
sta <FT_TEMP_PTR_L
ldy #0
jmp .read_byte
.set_speed:
lda (FT_TEMP_PTR),y
sta FT_SONG_SPEED
inc <FT_TEMP_PTR_L ;advance pointer after reading the speed value
bne .read_byte
inc <FT_TEMP_PTR_H
bne .read_byte ;bra
.set_loop:
lda (FT_TEMP_PTR),y
sta <FT_TEMP_VAR1
iny
lda (FT_TEMP_PTR),y
sta <FT_TEMP_PTR_H
lda <FT_TEMP_VAR1
sta <FT_TEMP_PTR_L
dey
jmp .read_byte
.set_repeat:
sta FT_CHN_REPEAT,x ;set up repeat counter, carry is clear, no new note
.done:
lda FT_CHN_REF_LEN,x ;check reference row counter
beq .no_ref ;if it is zero, there is no reference
dec FT_CHN_REF_LEN,x ;decrease row counter
bne .no_ref
lda FT_CHN_RETURN_L,x ;end of a reference, return to previous pointer
sta FT_CHN_PTR_L,x
lda FT_CHN_RETURN_H,x
sta FT_CHN_PTR_H,x
rts
.no_ref:
lda <FT_TEMP_PTR_L
sta FT_CHN_PTR_L,x
lda <FT_TEMP_PTR_H
sta FT_CHN_PTR_H,x
rts
;------------------------------------------------------------------------------
; stop DPCM sample if it plays
;------------------------------------------------------------------------------
FamiToneSampleStop: subroutine
lda #%00001111
sta APU_SND_CHN
rts
IFCONST FT_DPCM_ENABLE
;------------------------------------------------------------------------------
; play DPCM sample, used by music player, could be used externally
; in: A is number of a sample, 1..63
;------------------------------------------------------------------------------
FamiToneSamplePlayM: subroutine ;for music (low priority)
ldx FT_DPCM_EFFECT
beq _FT2SamplePlay
tax
lda APU_SND_CHN
and #16
beq .not_busy
rts
.not_busy:
sta FT_DPCM_EFFECT
txa
jmp _FT2SamplePlay
;------------------------------------------------------------------------------
; play DPCM sample with higher priority, for sound effects
; in: A is number of a sample, 1..63
;------------------------------------------------------------------------------
FamiToneSamplePlay: subroutine
ldx #1
stx FT_DPCM_EFFECT
_FT2SamplePlay:
sta <FT_TEMP ;sample number*3, offset in the sample table
asl
clc
adc <FT_TEMP
adc FT_DPCM_LIST_L
sta <FT_TEMP_PTR_L
lda #0
adc FT_DPCM_LIST_H
sta <FT_TEMP_PTR_H
lda #%00001111 ;stop DPCM
sta APU_SND_CHN
ldy #0
lda (FT_TEMP_PTR),y ;sample offset
sta APU_DMC_START
iny
lda (FT_TEMP_PTR),y ;sample length
sta APU_DMC_LEN
iny
lda (FT_TEMP_PTR),y ;pitch and loop
sta APU_DMC_FREQ
lda #32 ;reset DAC counter
sta APU_DMC_RAW
lda #%00011111 ;start DMC
sta APU_SND_CHN
rts
ENDIF
IFCONST FT_SFX_ENABLE
;------------------------------------------------------------------------------
; init sound effects player, set pointer to data
; in: X,Y is address of sound effects data
;------------------------------------------------------------------------------
FamiToneSfxInit: subroutine
stx <FT_TEMP_PTR_L
sty <FT_TEMP_PTR_H
ldy #0
IFCONST FT_PITCH_FIX
lda FT_PAL_ADJUST ;add 2 to the sound list pointer for PAL
bne .ntsc
iny
iny
.ntsc:
ENDIF
lda (FT_TEMP_PTR),y ;read and store pointer to the effects list
sta FT_SFX_ADR_L
iny
lda (FT_TEMP_PTR),y
sta FT_SFX_ADR_H
ldx #FT_SFX_CH0 ;init all the streams
.set_channels:
jsr _FT2SfxClearChannel
txa
clc
adc #FT_SFX_STRUCT_SIZE
tax
cpx #FT_SFX_STRUCT_SIZE*FT_SFX_STREAMS
bne .set_channels
rts
;internal routine, clears output buffer of a sound effect
;in: A is 0
; X is offset of sound effect stream
_FT2SfxClearChannel: subroutine
lda #0
sta FT_SFX_PTR_H,x ;this stops the effect
sta FT_SFX_REPEAT,x
sta FT_SFX_OFF,x
sta FT_SFX_BUF+6,x ;mute triangle
lda #$30
sta FT_SFX_BUF+0,x ;mute pulse1
sta FT_SFX_BUF+3,x ;mute pulse2
sta FT_SFX_BUF+9,x ;mute noise
rts
;------------------------------------------------------------------------------
; play sound effect
; in: A is a number of the sound effect 0..127
; X is offset of sound effect channel, should be FT_SFX_CH0..FT_SFX_CH3
;------------------------------------------------------------------------------
FamiToneSfxPlay: subroutine
asl ;get offset in the effects list
tay
jsr _FT2SfxClearChannel ;stops the effect if it plays
lda FT_SFX_ADR_L
sta <FT_TEMP_PTR_L
lda FT_SFX_ADR_H
sta <FT_TEMP_PTR_H
lda (FT_TEMP_PTR),y ;read effect pointer from the table
sta FT_SFX_PTR_L,x ;store it
iny
lda (FT_TEMP_PTR),y
sta FT_SFX_PTR_H,x ;this write enables the effect
rts
;internal routine, update one sound effect stream
;in: X is offset of sound effect stream
_FT2SfxUpdate: subroutine
lda FT_SFX_REPEAT,x ;check if repeat counter is not zero
beq .no_repeat
dec FT_SFX_REPEAT,x ;decrement and return
bne .update_buf ;just mix with output buffer
.no_repeat:
lda FT_SFX_PTR_H,x ;check if MSB of the pointer is not zero
bne .sfx_active
rts ;return otherwise, no active effect
.sfx_active:
sta <FT_TEMP_PTR_H ;load effect pointer into temp
lda FT_SFX_PTR_L,x
sta <FT_TEMP_PTR_L
ldy FT_SFX_OFF,x
clc
.read_byte:
lda (FT_TEMP_PTR),y ;read byte of effect
bmi .get_data ;if bit 7 is set, it is a register write
beq .eof
iny
sta FT_SFX_REPEAT,x ;if bit 7 is reset, it is number of repeats
tya
sta FT_SFX_OFF,x
jmp .update_buf
.get_data:
iny
stx <FT_TEMP_VAR1 ;it is a register write
adc <FT_TEMP_VAR1 ;get offset in the effect output buffer
tax
lda (FT_TEMP_PTR),y ;read value
iny
sta FT_SFX_BUF-128,x ;store into output buffer
ldx <FT_TEMP_VAR1
jmp .read_byte ;and read next byte
.eof:
sta FT_SFX_PTR_H,x ;mark channel as inactive
.update_buf:
lda FT_OUT_BUF ;compare effect output buffer with main output buffer
and #$0f ;if volume of pulse 1 of effect is higher than that of the
sta <FT_TEMP_VAR1 ;main buffer, overwrite the main buffer value with the new one
lda FT_SFX_BUF+0,x
and #$0f
cmp <FT_TEMP_VAR1
bcc .no_pulse1
lda FT_SFX_BUF+0,x
sta FT_OUT_BUF+0
lda FT_SFX_BUF+1,x
sta FT_OUT_BUF+1
lda FT_SFX_BUF+2,x
sta FT_OUT_BUF+2
.no_pulse1:
lda FT_OUT_BUF+3 ;same for pulse 2
and #$0f
sta <FT_TEMP_VAR1
lda FT_SFX_BUF+3,x
and #$0f
cmp <FT_TEMP_VAR1
bcc .no_pulse2
lda FT_SFX_BUF+3,x
sta FT_OUT_BUF+3
lda FT_SFX_BUF+4,x
sta FT_OUT_BUF+4
lda FT_SFX_BUF+5,x
sta FT_OUT_BUF+5
.no_pulse2:
lda FT_SFX_BUF+6,x ;overwrite triangle of main output buffer if it is active
beq .no_triangle
sta FT_OUT_BUF+6
lda FT_SFX_BUF+7,x
sta FT_OUT_BUF+7
lda FT_SFX_BUF+8,x
sta FT_OUT_BUF+8
.no_triangle:
lda FT_OUT_BUF+9 ;same as for pulse 1 and 2, but for noise
and #$0f
sta <FT_TEMP_VAR1
lda FT_SFX_BUF+9,x
and #$0f
cmp <FT_TEMP_VAR1
bcc .no_noise
lda FT_SFX_BUF+9,x
sta FT_OUT_BUF+9
lda FT_SFX_BUF+10,x
sta FT_OUT_BUF+10
.no_noise:
rts
ENDIF
;dummy envelope used to initialize all channels with silence
_FT2DummyEnvelope:
.byte $c0,$00,$00
;PAL and NTSC, 11-bit dividers
;rest note, then octaves 1-5, then three zeroes
;first 64 bytes are PAL, next 64 bytes are NTSC
_FT2NoteTableLSB:
IFCONST FT_PAL_SUPPORT
.byte $00,$33,$da,$86,$36,$eb,$a5,$62,$23,$e7,$af,$7a,$48,$19,$ec,$c2
.byte $9a,$75,$52,$30,$11,$f3,$d7,$bc,$a3,$8c,$75,$60,$4c,$3a,$28,$17
.byte $08,$f9,$eb,$dd,$d1,$c5,$ba,$af,$a5,$9c,$93,$8b,$83,$7c,$75,$6e
.byte $68,$62,$5c,$57,$52,$4d,$49,$45,$41,$3d,$3a,$36,$33,$30,$2d,$2b
ENDIF
IFCONST FT_NTSC_SUPPORT
.byte $00,$ad,$4d,$f2,$9d,$4c,$00,$b8,$74,$34,$f7,$be,$88,$56,$26,$f8
.byte $ce,$a5,$7f,$5b,$39,$19,$fb,$de,$c3,$aa,$92,$7b,$66,$52,$3f,$2d
.byte $1c,$0c,$fd,$ee,$e1,$d4,$c8,$bd,$b2,$a8,$9f,$96,$8d,$85,$7e,$76
.byte $70,$69,$63,$5e,$58,$53,$4f,$4a,$46,$42,$3e,$3a,$37,$34,$31,$2e
ENDIF
_FT2NoteTableMSB:
IFCONST FT_PAL_SUPPORT
.byte $00,$06,$05,$05,$05,$04,$04,$04,$04,$03,$03,$03,$03,$03,$02,$02
.byte $02,$02,$02,$02,$02,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01
.byte $01,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
.byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
ENDIF
IFCONST FT_NTSC_SUPPORT
.byte $00,$06,$06,$05,$05,$05,$05,$04,$04,$04,$03,$03,$03,$03,$03,$02
.byte $02,$02,$02,$02,$02,$02,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01
.byte $01,$01,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
.byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
ENDIF
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