dos33fsprogs/interlace_demo/pt3_lib_init.s

; pt3_lib_init.s

; Initialize a song

; this is done before song starts playing so it is not
; as performance / timing critical

	;====================================
	; pt3_init_song
	;====================================
	;
pt3_init_song:

	lda	#$0
	sta	DONE_SONG						; 3
	ldx	#(end_vars-begin_vars)
zero_song_structs_loop:
	dex
	sta	note_a,X
	bne	zero_song_structs_loop

	sta	pt3_noise_period_smc+1					; 4
	sta	pt3_noise_add_smc+1					; 4

	sta	pt3_envelope_period_l_smc+1				; 4
	sta	pt3_envelope_period_h_smc+1				; 4
	sta	pt3_envelope_slide_l_smc+1				; 4
	sta	pt3_envelope_slide_h_smc+1				; 4
	sta	pt3_envelope_slide_add_l_smc+1				; 4
	sta	pt3_envelope_slide_add_h_smc+1				; 4
	sta	pt3_envelope_add_smc+1					; 4
	sta	pt3_envelope_type_smc+1					; 4
	sta	pt3_envelope_type_old_smc+1				; 4
	sta	pt3_envelope_delay_smc+1				; 4
	sta	pt3_envelope_delay_orig_smc+1				; 4

	sta	PT3_MIXER_VAL						; 3

	sta	current_pattern_smc+1					; 4
	sta	current_line_smc+1					; 4
	sta	current_subframe_smc+1					; 4

	lda	#$f							; 2
	sta	note_a+NOTE_VOLUME					; 4
	sta	note_b+NOTE_VOLUME					; 4
	sta	note_c+NOTE_VOLUME					; 4

	; default ornament/sample in A
	; 	X is zero coming in here
	;ldx	#(NOTE_STRUCT_SIZE*0)					; 2
	jsr	load_ornament0_sample1					; 6+93

	; default ornament/sample in B
	ldx	#(NOTE_STRUCT_SIZE*1)					; 2
	jsr	load_ornament0_sample1					; 6+93

	; default ornament/sample in C
	ldx	#(NOTE_STRUCT_SIZE*2)					; 2
	jsr	load_ornament0_sample1					; 6+93

	;=======================
	; load default speed

	lda	PT3_LOC+PT3_SPEED					; 4
	sta	pt3_speed_smc+1						; 4

	;=======================
	; load loop

	lda	PT3_LOC+PT3_LOOP					; 4
	sta	pt3_loop_smc+1						; 4


	;========================
	;========================
	; set up note/freq table
	; this saves some space and makes things marginally faster longrun
	;========================
	;========================
	; note (heh) that there are separate tables if version 3.3
	; but we are going to assume we are only going to be playing
	; newer 3.4+ version files so only need the newer tables

	ldx	PT3_LOC+PT3_HEADER_FREQUENCY				; 4
	beq	use_freq_table_0
	dex
	beq	use_freq_table_1
	dex
	beq	use_freq_table_2
	; fallthrough (freq table 3)

use_freq_table_3:
	;=================================================
	;  Create Table #3, v4+, "PT3NoteTable_REAL_34_35"
	;=================================================

	ldy	#11			; !2
freq_table_3_copy_loop:
	; note, high lookup almost same as 2v4, just need to adjust one value

	lda	base2_v4_high,Y		; !3
	sta	NoteTable_high,Y	; !3
	lda	base3_low,Y		; !3
	sta	NoteTable_low,Y		; !3
	dey				; !1
	bpl	freq_table_3_copy_loop	; !2

	dec	NoteTable_high			; adjust to right value

	jsr	NoteTablePropogate	; !3

	lda	#<table3_v4_adjust
	sta	note_table_adjust_smc+1
	lda	#>table3_v4_adjust
	sta	note_table_adjust_smc+2

	jsr	NoteTableAdjust

	jmp	done_set_freq_table



use_freq_table_2:
	;=================================================
	;  Create Table #2, v4+, "PT3NoteTable_ASM_34_35"
	;=================================================

	ldy	#11
freq_table_2_copy_loop:
	lda	base2_v4_high,Y
	sta	NoteTable_high,Y
	lda	base2_v4_low,Y
	sta	NoteTable_low,Y
	dey
	bpl	freq_table_2_copy_loop

	jsr	NoteTablePropogate	; !3

	lda	#<table2_v4_adjust
	sta	note_table_adjust_smc+1
	lda	#>table2_v4_adjust
	sta	note_table_adjust_smc+2

	jsr	NoteTableAdjust

	jmp	done_set_freq_table

use_freq_table_1:
	;=================================================
	;  Create Table #1, "PT3NoteTable_ST"
	;=================================================

	ldy	#11
freq_table_1_copy_loop:
	lda	base1_high,Y
	sta	NoteTable_high,Y
	lda	base1_low,Y
	sta	NoteTable_low,Y
	dey
	bpl	freq_table_1_copy_loop

	jsr	NoteTablePropogate	; !3

	; last adjustments
	lda	#$FD				; Tone[23]=$3FD
	sta	NoteTable_low+23
	dec	NoteTable_low+46		; Tone[46]-=1;


	jmp	done_set_freq_table


use_freq_table_0:
	;=================================================
	;  Create Table #0, "PT3NoteTable_PT_34_35"
	;=================================================

	ldy	#11
freq_table_0_copy_loop:
	lda	base0_v4_high,Y
	sta	NoteTable_high,Y
	lda	base0_v4_low,Y
	sta	NoteTable_low,Y
	dey
	bpl	freq_table_0_copy_loop

	jsr	NoteTablePropogate	; !3

	lda	#<table0_v4_adjust
	sta	note_table_adjust_smc+1
	lda	#>table0_v4_adjust
	sta	note_table_adjust_smc+2

	jsr	NoteTableAdjust


done_set_freq_table:


	;======================
	; calculate version
	ldx	#6							; 2
	lda	PT3_LOC+PT3_VERSION					; 4
	sec								; 2
	sbc	#'0'							; 2
	cmp	#9							; 2
	bcs	not_ascii_number	; bge				; 2/3
	tax								; 2

not_ascii_number:

	; adjust version<6 SMC code in the slide code

	; FIXME: I am sure there's a more clever way to do this

	lda	#$2C		; BIT					; 2
	cpx	#$6							; 2
	bcs	version_greater_than_or_equal_6	; bgt			; 3
	; less than 6, jump
	; also carry is known to be clear
	adc	#$20		; BIT->JMP  2C->4C			; 2
version_greater_than_or_equal_6:
	sta	version_smc						; 4

pick_volume_table:

	;=======================
	; Pick which volume number, based on version

	; if (PlParams.PT3.PT3_Version <= 4)

	cpx	#5							; 2

	; carry clear = 3.3/3.4 table
	; carry set = 3.5 table

	;==========================
	; VolTableCreator
	;==========================
	; Creates the appropriate volume table
	; based on z80 code by Ivan Roshin ZXAYHOBETA/VTII10bG.asm
	;

	; Called with carry==0 for 3.3/3.4 table
	; Called with carry==1 for 3.5 table

	; 177f-1932 = 435 bytes, not that much better than 512 of lookup


VolTableCreator:

	; Init initial variables
	lda	#$0
	sta	z80_d_smc+1
	ldy	#$11

	; Set up self modify

	ldx	#$2A		; ROL for self-modify
	bcs	vol_type_35

vol_type_33:

	; For older table, we set initial conditions a bit
	; different

	dey
	tya

	ldx	#$ea		; NOP for self modify

vol_type_35:
	sty	z80_l_smc+1	; l=16 or 17
	sta	z80_e_smc+1	; e=16 or 0
	stx	vol_smc		; set the self-modify code

	ldy	#16		; skip first row, all zeros
	ldx	#16		; c=16
vol_outer:
	clc			; add HL,DE
z80_l_smc:
	lda	#$d1
z80_e_smc:
	adc	#$d1
	sta	z80_e_smc+1
	lda	#0
z80_d_smc:
	adc	#$d1
	sta	z80_d_smc+1	; carry is important

			; sbc hl,hl
	lda	#0
	adc	#$ff
	eor	#$ff

vol_write:
	sta	z80_h_smc+1
	pha

vol_inner:
	pla
	pha

vol_smc:
	nop			; nop or ROL depending

z80_h_smc:
	lda	#$d1

	adc	#$0		; a=a+carry;

	sta	VolumeTable,Y
	iny

	pla			; add HL,DE
	adc	z80_e_smc+1
	pha
	lda	z80_h_smc+1
	adc	z80_d_smc+1
	sta	z80_h_smc+1

	inx		; inc C
	txa		; a=c
	and	#$f
	bne	vol_inner


	pla

	lda	z80_e_smc+1	; a=e
	cmp	#$77
	bne	vol_m3

	inc	z80_e_smc+1

vol_m3:
	txa			; a=c
	bne	vol_outer

vol_done:
	rts


	;=========================================
	; copy note table seed to proper location
	;=========================================

; faster inlined

;NoteTableCopy:

;	ldy	#11			; !2
;note_table_copy_loop:
;ntc_smc1:
;	lda	base1_high,Y		; !3
;	sta	NoteTable_high,Y	; !3
;ntc_smc2:
;	lda	base1_low,Y		; !3
;	sta	NoteTable_low,Y		; !3
;	dey				; !1
;	bpl	note_table_copy_loop	; !2
;	rts				; !1


	;==========================================
	; propogate the freq down, dividing by two
	;==========================================
NoteTablePropogate:

	ldy	#0
note_table_propogate_loop:
	clc
	lda	NoteTable_high,Y
	ror
	sta	NoteTable_high+12,Y

	lda	NoteTable_low,Y
	ror
	sta	NoteTable_low+12,Y

	iny
	cpy	#84
	bne	note_table_propogate_loop

	rts


	;================================================
	; propogation isn't enough, various values
	; are ofte off by one, so adjust using a bitmask
	;================================================
NoteTableAdjust:

	ldx	#0
note_table_adjust_outer:

note_table_adjust_smc:
	lda	table0_v4_adjust,X
	sta	PT3_TEMP

	; reset smc
	lda	#<NoteTable_low
	sta	ntl_smc+1
	lda	#>NoteTable_low
	sta	ntl_smc+2


	ldy	#7
note_table_adjust_inner:
	ror	PT3_TEMP
	bcc	note_table_skip_adjust

ntl_smc:
	inc	NoteTable_low,X

note_table_skip_adjust:
	clc
	lda	#12
	adc	ntl_smc+1
	sta	ntl_smc+1
	lda	#0
	adc	ntl_smc+2	; unnecessary if aligned
	sta	ntl_smc+2

skip_adjust_done:
	dey
	bpl	note_table_adjust_inner

	inx
	cpx	#12
	bne	note_table_adjust_outer

	rts


;base0_v3_high:
;.byte	$0C,$0B,$0A,$0A,$09,$09,$08,$08,$07,$07,$06,$06
;base0_v3_low:
;.byte	$21,$73,$CE,$33,$A0,$16,$93,$18,$A4,$36,$CE,$6D

; note: same as base0_v3_high
base0_v4_high:
.byte	$0C,$0B,$0A,$0A,$09,$09,$08,$08,$07,$07,$06,$06
base0_v4_low:
.byte	$22,$73,$CF,$33,$A1,$17,$94,$19,$A4,$37,$CF,$6D

base1_high:
.byte	$0E,$0E,$0D,$0C,$0B,$0B,$0A,$09,$09,$08,$08,$07
base1_low:
.byte	$F8,$10,$60,$80,$D8,$28,$88,$F0,$60,$E0,$58,$E0

;base2_v3_high:
;.byte	$0D,$0C,$0B,$0B,$0A,$09,$09,$08,$08,$07,$07,$07
;base2_v3_low:
;.byte	$3E,$80,$CC,$22,$82,$EC,$5C,$D6,$58,$E0,$6E,$04

; note almost same as above
base2_v4_high:
.byte	$0D,$0C,$0B,$0A,$0A,$09,$09,$08,$08,$07,$07,$06
base2_v4_low:
.byte	$10,$55,$A4,$FC,$5F,$CA,$3D,$B8,$3B,$C5,$55,$EC

; note almost same as above
;base3_high:
;.byte	$0C,$0C,$0B,$0A,$0A,$09,$09,$08,$08,$07,$07,$06
base3_low:
.byte	$DA,$22,$73,$CF,$33,$A1,$17,$94,$19,$A4,$37,$CF


; Adjustment factors
table0_v4_adjust:
.byte	$40,$e6,$9c,$66,$40,$2c,$20,$30,$48,$6c,$1c,$5a

table2_v4_adjust:
.byte	$20,$a8,$40,$f8,$bc,$90,$78,$70,$74,$08,$2a,$50

table3_v4_adjust:
.byte	$B4,$40,$e6,$9c,$66,$40,$2c,$20,$30,$48,$6c,$1c


; Table #1 of Pro Tracker 3.3x - 3.5x
;PT3NoteTable_ST_high:
;.byte $0E,$0E,$0D,$0C,$0B,$0B,$0A,$09
;.byte $09,$08,$08,$07,$07,$07,$06,$06
;.byte $05,$05,$05,$04,$04,$04,$04,$03
;.byte $03,$03,$03,$03,$02,$02,$02,$02
;.byte $02,$02,$02,$01,$01,$01,$01,$01
;.byte $01,$01,$01,$01,$01,$01,$01,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00

;PT3NoteTable_ST_low:
;.byte $F8,$10,$60,$80,$D8,$28,$88,$F0
;.byte $60,$E0,$58,$E0,$7C,$08,$B0,$40
;.byte $EC,$94,$44,$F8,$B0,$70,$2C,$FD
;.byte $BE,$84,$58,$20,$F6,$CA,$A2,$7C
;.byte $58,$38,$16,$F8,$DF,$C2,$AC,$90
;.byte $7B,$65,$51,$3E,$2C,$1C,$0A,$FC
;.byte $EF,$E1,$D6,$C8,$BD,$B2,$A8,$9F
;.byte $96,$8E,$85,$7E,$77,$70,$6B,$64
;.byte $5E,$59,$54,$4F,$4B,$47,$42,$3F
;.byte $3B,$38,$35,$32,$2F,$2C,$2A,$27
;.byte $25,$23,$21,$1F,$1D,$1C,$1A,$19
;.byte $17,$16,$15,$13,$12,$11,$10,$0F


; Table #2 of Pro Tracker 3.4x - 3.5x
;PT3NoteTable_ASM_34_35_high:
;.byte $0D,$0C,$0B,$0A,$0A,$09,$09,$08
;.byte $08,$07,$07,$06,$06,$06,$05,$05
;.byte $05,$04,$04,$04,$04,$03,$03,$03
;.byte $03,$03,$02,$02,$02,$02,$02,$02
;.byte $02,$01,$01,$01,$01,$01,$01,$01
;.byte $01,$01,$01,$01,$01,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00
;.byte $00,$00,$00,$00,$00,$00,$00,$00

;PT3NoteTable_ASM_34_35_low:
;.byte $10,$55,$A4,$FC,$5F,$CA,$3D,$B8
;.byte $3B,$C5,$55,$EC,$88,$2A,$D2,$7E
;.byte $2F,$E5,$9E,$5C,$1D,$E2,$AB,$76
;.byte $44,$15,$E9,$BF,$98,$72,$4F,$2E
;.byte $0F,$F1,$D5,$BB,$A2,$8B,$74,$60
;.byte $4C,$39,$28,$17,$07,$F9,$EB,$DD
;.byte $D1,$C5,$BA,$B0,$A6,$9D,$94,$8C
;.byte $84,$7C,$75,$6F,$69,$63,$5D,$58
;.byte $53,$4E,$4A,$46,$42,$3E,$3B,$37
;.byte $34,$31,$2F,$2C,$29,$27,$25,$23
;.byte $21,$1F,$1D,$1C,$1A,$19,$17,$16
;.byte $15,$14,$12,$11,$10,$0F,$0E,$0D


;PT3VolumeTable_33_34:
;.byte $0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0
;.byte $0,$0,$0,$0,$0,$0,$0,$0,$1,$1,$1,$1,$1,$1,$1,$1
;.byte $0,$0,$0,$0,$0,$0,$1,$1,$1,$1,$1,$2,$2,$2,$2,$2
;.byte $0,$0,$0,$0,$1,$1,$1,$1,$2,$2,$2,$2,$3,$3,$3,$3
;.byte $0,$0,$0,$0,$1,$1,$1,$2,$2,$2,$3,$3,$3,$4,$4,$4
;.byte $0,$0,$0,$1,$1,$1,$2,$2,$3,$3,$3,$4,$4,$4,$5,$5
;.byte $0,$0,$0,$1,$1,$2,$2,$3,$3,$3,$4,$4,$5,$5,$6,$6
;.byte $0,$0,$1,$1,$2,$2,$3,$3,$4,$4,$5,$5,$6,$6,$7,$7
;.byte $0,$0,$1,$1,$2,$2,$3,$3,$4,$5,$5,$6,$6,$7,$7,$8
;.byte $0,$0,$1,$1,$2,$3,$3,$4,$5,$5,$6,$6,$7,$8,$8,$9
;.byte $0,$0,$1,$2,$2,$3,$4,$4,$5,$6,$6,$7,$8,$8,$9,$A
;.byte $0,$0,$1,$2,$3,$3,$4,$5,$6,$6,$7,$8,$9,$9,$A,$B
;.byte $0,$0,$1,$2,$3,$4,$4,$5,$6,$7,$8,$8,$9,$A,$B,$C
;.byte $0,$0,$1,$2,$3,$4,$5,$6,$7,$7,$8,$9,$A,$B,$C,$D
;.byte $0,$0,$1,$2,$3,$4,$5,$6,$7,$8,$9,$A,$B,$C,$D,$E
;.byte $0,$1,$2,$3,$4,$5,$6,$7,$8,$9,$A,$B,$C,$D,$E,$F

;PT3VolumeTable_35:
;.byte $0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0,$0
;.byte $0,$0,$0,$0,$0,$0,$0,$0,$1,$1,$1,$1,$1,$1,$1,$1
;.byte $0,$0,$0,$0,$1,$1,$1,$1,$1,$1,$1,$1,$2,$2,$2,$2
;.byte $0,$0,$0,$1,$1,$1,$1,$1,$2,$2,$2,$2,$2,$3,$3,$3
;.byte $0,$0,$1,$1,$1,$1,$2,$2,$2,$2,$3,$3,$3,$3,$4,$4
;.byte $0,$0,$1,$1,$1,$2,$2,$2,$3,$3,$3,$4,$4,$4,$5,$5
;.byte $0,$0,$1,$1,$2,$2,$2,$3,$3,$4,$4,$4,$5,$5,$6,$6
;.byte $0,$0,$1,$1,$2,$2,$3,$3,$4,$4,$5,$5,$6,$6,$7,$7
;.byte $0,$1,$1,$2,$2,$3,$3,$4,$4,$5,$5,$6,$6,$7,$7,$8
;.byte $0,$1,$1,$2,$2,$3,$4,$4,$5,$5,$6,$7,$7,$8,$8,$9
;.byte $0,$1,$1,$2,$3,$3,$4,$5,$5,$6,$7,$7,$8,$9,$9,$A
;.byte $0,$1,$1,$2,$3,$4,$4,$5,$6,$7,$7,$8,$9,$A,$A,$B
;.byte $0,$1,$2,$2,$3,$4,$5,$6,$6,$7,$8,$9,$A,$A,$B,$C
;.byte $0,$1,$2,$3,$3,$4,$5,$6,$7,$8,$9,$A,$A,$B,$C,$D
;.byte $0,$1,$2,$3,$4,$5,$6,$7,$7,$8,$9,$A,$B,$C,$D,$E
;.byte $0,$1,$2,$3,$4,$5,$6,$7,$8,$9,$A,$B,$C,$D,$E,$F