mirror of
https://github.com/cc65/cc65.git
synced 2025-01-12 02:30:44 +00:00
b5fef66f37
Cleaning, and replace tab to spaces Converting hex lowercase value into uppercase char. Changing := and = when it was needed
627 lines
9.4 KiB
ArmAsm
627 lines
9.4 KiB
ArmAsm
.export _Mym_MusicStart
|
|
.importzp sp,tmp2,tmp3,tmp1,ptr1
|
|
|
|
.include "telestrat.inc"
|
|
|
|
; To check: AYC
|
|
; http://cpcwiki.eu/index.php/AYC
|
|
|
|
|
|
|
|
|
|
_DecodedByte :=$D0 ; Byte being currently decoded from the MYM stream
|
|
_DecodeBitCounter :=$D2 ; Number of bits we can read in the current byte
|
|
_DecodedResult :=$D3 ; What is returned by the 'read bits' function
|
|
_CurrentAYRegister :=$D4 ; Contains the number of the register being decoded
|
|
_RegisterBufferHigh :=$D5 ; Points to the high byte of the decoded register buffer, increment to move to the next register
|
|
_BufferFrameOffset :=$D6 ; From 0 to 127, used when filling the decoded register buffer
|
|
_MusicResetCounter :=$D7 ; 2 bytes Contains the number of rows to play before reseting
|
|
_CurrentFrame :=$D9 ; From 0 to 255 and then cycles... the index of the frame to play this vbl
|
|
_PlayerVbl :=$DA
|
|
_FrameLoadBalancer :=$DB ; We depack a new frame every 9 VBLs, this way the 14 registers are evenly depacked over 128 frames
|
|
|
|
|
|
VIA_1 := $30f
|
|
VIA_2 := $30c
|
|
|
|
_MusicData := $c000
|
|
|
|
; mym(char *buf)
|
|
|
|
|
|
|
|
|
|
;
|
|
; Current PSG values during unpacking
|
|
;
|
|
|
|
|
|
.proc _Mym_MusicStart
|
|
|
|
; The two first bytes of the MYM music is the number of rows in the music
|
|
; We decrement that at each frame, and when we reach zero, time to start again.
|
|
sta ptr1
|
|
stx ptr1+1
|
|
|
|
ldy #0
|
|
lda (ptr1),y
|
|
sta _MusicResetCounter+0
|
|
iny
|
|
lda (ptr1),y
|
|
tax
|
|
inx
|
|
stx _MusicResetCounter+1
|
|
|
|
;ldx _MusicData+0
|
|
;stx _MusicResetCounter+0
|
|
;ldx _MusicData+1
|
|
;inx
|
|
;stx _MusicResetCounter+1
|
|
|
|
|
|
; Initialize the read bit counter
|
|
ldy #2 ; should be useless because we can do iny which earn 1 byte
|
|
|
|
lda ptr1
|
|
clc
|
|
adc #2
|
|
bcc next20
|
|
inc ptr1+1
|
|
lda ptr1+1
|
|
sta __auto_music_ptr+2
|
|
next20:
|
|
sta ptr1
|
|
sta __auto_music_ptr+1
|
|
|
|
|
|
|
|
;lda #<(_MusicData+2)
|
|
;sta __auto_music_ptr+1
|
|
;lda #>(_MusicData+2)
|
|
;sta __auto_music_ptr+2
|
|
|
|
lda #1
|
|
sta _DecodeBitCounter
|
|
|
|
; Clear all data
|
|
lda #0
|
|
sta _DecodedResult
|
|
sta _DecodedByte
|
|
sta _PlayerVbl
|
|
sta _PlayerRegCurrentValue
|
|
sta _BufferFrameOffset
|
|
sta _PlayerCount
|
|
sta _CurrentAYRegister
|
|
sta _CurrentFrame
|
|
|
|
ldx #14
|
|
loop_init:
|
|
dex
|
|
sta _PlayerRegValues,x
|
|
bne loop_init
|
|
|
|
|
|
;
|
|
; Unpack the 128 first register frames
|
|
;
|
|
|
|
lda #>_PlayerBuffer
|
|
sta _RegisterBufferHigh
|
|
|
|
ldx #0
|
|
unpack_block_loop:
|
|
stx _CurrentAYRegister
|
|
|
|
; Unpack that register
|
|
jsr _PlayerUnpackRegister2
|
|
|
|
; Next register
|
|
ldx _CurrentAYRegister
|
|
inx
|
|
cpx #14
|
|
bne unpack_block_loop
|
|
|
|
|
|
lda #128
|
|
sta _PlayerVbl+0
|
|
|
|
lda #0
|
|
sta _PlayerCount
|
|
sta _CurrentAYRegister
|
|
sta _CurrentFrame
|
|
|
|
lda #9
|
|
sta _FrameLoadBalancer
|
|
|
|
lda #1
|
|
sta _MusicPlaying
|
|
|
|
;
|
|
; Install the IRQ
|
|
;
|
|
php
|
|
sei
|
|
lda #<_Mym_PlayFrame
|
|
sta _InterruptCallBack_3+1
|
|
lda #>_Mym_PlayFrame
|
|
sta _InterruptCallBack_3+2
|
|
plp
|
|
|
|
rts
|
|
|
|
|
|
_Mym_MusicStop:
|
|
|
|
; Indicate the main code that the music is finished
|
|
lda #0
|
|
sta _MusicPlaying
|
|
|
|
; Disable the IRQ so it does not conflict or cause weird things
|
|
php
|
|
sei
|
|
lda #<_DoNothing
|
|
sta _InterruptCallBack_3+1
|
|
lda #>_DoNothing
|
|
sta _InterruptCallBack_3+2
|
|
plp
|
|
|
|
; Cut the sound so it does not sounds like a dying cat
|
|
|
|
; y=register number
|
|
; x=value to write
|
|
ldy #7 ; Control register
|
|
ldx #$FF
|
|
jsr _PsgPlayRegister
|
|
|
|
ldy #8 ; Volume A
|
|
ldx #0
|
|
jsr _PsgPlayRegister
|
|
|
|
ldy #9 ; Volume B
|
|
ldx #0
|
|
jsr _PsgPlayRegister
|
|
|
|
ldy #10 ; Volume C
|
|
ldx #0
|
|
jsr _PsgPlayRegister
|
|
rts
|
|
|
|
|
|
_Mym_PlayFrame:
|
|
|
|
;
|
|
; Check for end of music
|
|
; CountZero: $81,$0d
|
|
dec _MusicResetCounter+0
|
|
bne music_contines
|
|
dec _MusicResetCounter+1
|
|
bne music_contines
|
|
|
|
music_resets:
|
|
jmp _Mym_MusicStop
|
|
|
|
music_contines:
|
|
|
|
;
|
|
; Play a frame of 14 registers
|
|
;
|
|
|
|
lda _CurrentFrame
|
|
sta _auto_psg_play_read+1
|
|
lda #>_PlayerBuffer
|
|
sta _auto_psg_play_read+2
|
|
|
|
ldy #0
|
|
register_loop:
|
|
|
|
_auto_psg_play_read:
|
|
ldx _PlayerBuffer
|
|
|
|
; y=register number
|
|
; x=value to write
|
|
jsr _PsgPlayRegister
|
|
|
|
inc _auto_psg_play_read+2
|
|
iny
|
|
cpy #14
|
|
bne register_loop
|
|
|
|
|
|
|
|
inc _CurrentFrame
|
|
inc _PlayerCount
|
|
|
|
lda _CurrentAYRegister
|
|
cmp #14
|
|
bcs end_reg
|
|
|
|
|
|
dec _FrameLoadBalancer
|
|
bne end
|
|
|
|
jsr _PlayerUnpackRegister
|
|
inc _CurrentAYRegister
|
|
lda #9
|
|
sta _FrameLoadBalancer
|
|
end:
|
|
rts
|
|
|
|
|
|
end_reg:
|
|
|
|
lda _PlayerCount
|
|
cmp #128
|
|
bcc skip2
|
|
|
|
lda #0
|
|
sta _CurrentAYRegister
|
|
sta _PlayerCount
|
|
lda #9
|
|
sta _FrameLoadBalancer
|
|
|
|
clc
|
|
lda _PlayerVbl+0
|
|
adc #128
|
|
sta _PlayerVbl+0
|
|
skip2:
|
|
|
|
|
|
rts
|
|
|
|
|
|
|
|
; y=register number
|
|
; x=value to write
|
|
_PsgPlayRegister:
|
|
|
|
sty VIA_1
|
|
txa
|
|
|
|
pha
|
|
lda VIA_2
|
|
ora #$EE ; $EE 238 11101110
|
|
sta VIA_2
|
|
|
|
and #$11 ; $11 17 00010001
|
|
ora #$CC ; $CC 204 11001100
|
|
sta VIA_2
|
|
|
|
tax
|
|
pla
|
|
sta VIA_1
|
|
txa
|
|
ora #$EC ; $EC 236 11101100
|
|
sta VIA_2
|
|
|
|
and #$11 ; $11 17 00010001
|
|
ora #$CC ; $CC 204 11001100
|
|
sta VIA_2
|
|
|
|
rts
|
|
|
|
|
|
|
|
|
|
;
|
|
; Initialise X with the number of bits to read
|
|
; Y is not modifier
|
|
;
|
|
_ReadBits:
|
|
|
|
lda #0
|
|
sta _DecodedResult
|
|
|
|
; Will iterate X times (number of bits to read)
|
|
loop_read_bits:
|
|
|
|
dec _DecodeBitCounter
|
|
beq get_next_byte
|
|
|
|
shift_bit:
|
|
asl _DecodedByte
|
|
rol _DecodedResult
|
|
|
|
dex
|
|
bne loop_read_bits
|
|
rts
|
|
|
|
get_next_byte:
|
|
; reset mask
|
|
lda #8
|
|
sta _DecodeBitCounter
|
|
|
|
; fetch a new byte, and increment the adress.
|
|
__auto_music_ptr:
|
|
lda _MusicData+2
|
|
sta _DecodedByte
|
|
|
|
inc __auto_music_ptr+1
|
|
bne shift_bit
|
|
inc __auto_music_ptr+2
|
|
jmp shift_bit
|
|
|
|
|
|
|
|
|
|
|
|
_PlayerUnpackRegister:
|
|
lda #>_PlayerBuffer
|
|
clc
|
|
adc _CurrentAYRegister
|
|
sta _RegisterBufferHigh
|
|
_PlayerUnpackRegister2:
|
|
;
|
|
; Init register bit count and current value
|
|
;
|
|
ldx _CurrentAYRegister
|
|
lda _PlayerRegValues,x
|
|
sta _PlayerRegCurrentValue
|
|
|
|
|
|
;
|
|
; Check if it's packed or not
|
|
; and call adequate routine...
|
|
;
|
|
ldx #1
|
|
jsr _ReadBits
|
|
ldx _DecodedResult
|
|
bne DecompressFragment
|
|
|
|
|
|
UnchangedFragment:
|
|
|
|
;
|
|
; No change at all, just repeat '_PlayerRegCurrentValue' 128 times
|
|
;
|
|
lda _RegisterBufferHigh ; highpart of buffer adress + register number
|
|
sta __auto_copy_unchanged_write+2
|
|
|
|
ldx #128 ; 128 iterations
|
|
lda _PlayerRegCurrentValue ; Value to write
|
|
|
|
ldy _PlayerVbl
|
|
|
|
repeat_loop:
|
|
__auto_copy_unchanged_write:
|
|
sta _PlayerBuffer,y
|
|
iny
|
|
dex
|
|
bne repeat_loop
|
|
|
|
|
|
jmp player_main_return
|
|
|
|
|
|
player_main_return:
|
|
; Write back register current value
|
|
ldx _CurrentAYRegister
|
|
lda _PlayerRegCurrentValue
|
|
sta _PlayerRegValues,x
|
|
|
|
; Move to the next register buffer
|
|
inc _RegisterBufferHigh
|
|
rts
|
|
|
|
|
|
|
|
|
|
DecompressFragment:
|
|
lda _PlayerVbl ; Either 0 or 128 at this point else we have a problem...
|
|
sta _BufferFrameOffset
|
|
|
|
decompressFragmentLoop:
|
|
|
|
player_copy_packed_loop:
|
|
; Check packing method
|
|
ldx #1
|
|
jsr _ReadBits
|
|
|
|
ldx _DecodedResult
|
|
bne PlayerNotCopyLast
|
|
|
|
UnchangedRegister:
|
|
|
|
; We just copy the current value 128 times
|
|
lda _RegisterBufferHigh ; highpart of buffer adress + register number
|
|
sta __auto_player_copy_last+2
|
|
|
|
ldx _BufferFrameOffset ; Value between 00 and 7f
|
|
lda _PlayerRegCurrentValue ; Value to copy
|
|
__auto_player_copy_last:
|
|
sta _PlayerBuffer,x
|
|
|
|
inc _BufferFrameOffset
|
|
|
|
|
|
|
|
player_return:
|
|
|
|
; Check end of loop
|
|
lda _BufferFrameOffset
|
|
and #127
|
|
bne decompressFragmentLoop
|
|
|
|
jmp player_main_return
|
|
|
|
|
|
PlayerNotCopyLast:
|
|
; Check packing method
|
|
ldx #1
|
|
jsr _ReadBits
|
|
|
|
ldx _DecodedResult
|
|
beq DecompressWithOffset
|
|
|
|
ReadNewRegisterValue:
|
|
; Read new register value (variable bit count)
|
|
ldx _CurrentAYRegister
|
|
lda _PlayerRegBits,x
|
|
tax
|
|
jsr _ReadBits
|
|
ldx _DecodedResult
|
|
stx _PlayerRegCurrentValue
|
|
|
|
; Copy to stream
|
|
lda _RegisterBufferHigh ; highpart of buffer adress + register number
|
|
sta __auto_player_read_new+2
|
|
|
|
ldx _BufferFrameOffset ; Value between 00 and 7f
|
|
lda _PlayerRegCurrentValue ; New value to write
|
|
__auto_player_read_new:
|
|
sta _PlayerBuffer,x
|
|
|
|
inc _BufferFrameOffset
|
|
jmp player_return
|
|
|
|
|
|
|
|
|
|
DecompressWithOffset:
|
|
|
|
; Read Offset (0 to 127)
|
|
ldx #7
|
|
jsr _ReadBits
|
|
|
|
lda _RegisterBufferHigh ; highpart of buffer adress + register number
|
|
sta __auto_write+2 ; Write adress
|
|
sta __auto_read+2 ; Read adress
|
|
|
|
; Compute wrap around offset...
|
|
lda _BufferFrameOffset ; between 0 and 255
|
|
clc
|
|
adc _DecodedResult ; + Offset Between 00 and 7f
|
|
sec
|
|
sbc #128 ; -128
|
|
tay
|
|
|
|
; Read count (7 bits)
|
|
ldx #7
|
|
jsr _ReadBits
|
|
|
|
inc _DecodedResult ; 1 to 129
|
|
|
|
|
|
ldx _BufferFrameOffset
|
|
|
|
player_copy_offset_loop:
|
|
|
|
__auto_read:
|
|
lda _PlayerBuffer,y ; Y for reading
|
|
iny
|
|
|
|
__auto_write:
|
|
sta _PlayerBuffer,x ; X for writing
|
|
|
|
inx
|
|
dec _DecodedResult
|
|
bne player_copy_offset_loop
|
|
|
|
stx _BufferFrameOffset
|
|
sta _PlayerRegCurrentValue
|
|
|
|
jmp player_return
|
|
|
|
|
|
|
|
|
|
;
|
|
; Size in bits of each PSG register
|
|
;
|
|
_PlayerRegBits:
|
|
; Chanel A Frequency
|
|
.byt 8
|
|
.byt 4
|
|
|
|
; Chanel B Frequency
|
|
.byt 8
|
|
.byt 4
|
|
|
|
; Chanel C Frequency
|
|
.byt 8
|
|
.byt 4
|
|
|
|
; Chanel sound generator
|
|
.byt 5
|
|
|
|
; select
|
|
.byt 8
|
|
|
|
; Volume A,B,C
|
|
.byt 5
|
|
.byt 5
|
|
.byt 5
|
|
|
|
; Wave period
|
|
.byt 8
|
|
.byt 8
|
|
|
|
; Wave form
|
|
.byt 8
|
|
|
|
_PlayerCount:
|
|
.res 1,0 ; must be equal to 0
|
|
_MusicPlaying:
|
|
.res 1,0 ; must be equal to 0
|
|
|
|
|
|
_PlayerRegValues:
|
|
_RegisterChanAFrequency:
|
|
; Chanel A Frequency
|
|
.res 1,8
|
|
.res 1,4
|
|
|
|
_RegisterChanBFrequency:
|
|
; Chanel B Frequency
|
|
.res 1,8
|
|
.res 1,4
|
|
|
|
_RegisterChanCFrequency:
|
|
; Chanel C Frequency
|
|
.res 1,8
|
|
.res 1,4
|
|
|
|
_RegisterChanNoiseFrequency:
|
|
; Chanel sound generator
|
|
.res 1,5
|
|
|
|
; select
|
|
.res 1,8
|
|
|
|
; Volume A,B,C
|
|
_RegisterChanAVolume:
|
|
.res 1,5
|
|
_RegisterChanBVolume:
|
|
.res 1,5
|
|
_RegisterChanCVolume:
|
|
.res 1,5
|
|
|
|
; Wave period
|
|
.res 1,8
|
|
.res 1,8
|
|
|
|
; Wave form
|
|
.res 1,8
|
|
|
|
_PlayerRegCurrentValue:
|
|
.res 1,0
|
|
_DoNothing:
|
|
rts
|
|
|
|
_InterruptCallBack_3: ; Used by the music player
|
|
jsr _DoNothing ; Transformed to "jsr _Mym_PlayFrame" -> 12 cycles
|
|
|
|
; jsr MiniScrollLoading ; -> 338 cycles
|
|
|
|
pla
|
|
tay
|
|
pla
|
|
tax
|
|
pla
|
|
|
|
rti
|
|
_PlayerBuffer:
|
|
.res 256*14 ; About 3.5 kilobytes somewhere in memory, we put the music file in overlay memory
|
|
|
|
.endproc
|
|
|