Refactor period limit subroutine

Fixes #276.
Dn-Programming-Core-Management · Jul 20, 2024 · 4ce047d · 4ce047d
1 parent bdf33eb
commit 4ce047d
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Showing 12 changed files with 3,004 additions and 3,006 deletions.
diff --git a/Source/drivers/asm/driver.s b/Source/drivers/asm/driver.s
@@ -647,6 +647,39 @@ bit_mask:		;;; ;; ; general-purpose bit mask
 	.include "vibrato.s"
 .endif
 
+LIMIT_PERIOD_2A03 = $7FF
+LIMIT_PERIOD_VRC6 = $FFF
+; VRC7: period is between 0 to (1 << (VRC7_PITCH_RESOLUTION + 9)) - 1 or $7FF
+LIMIT_PERIOD_VRC7 = LIMIT_PERIOD_2A03
+LIMIT_PERIOD_N163 = $FFFF
+LIMIT_PERIOD_LINEAR = (95<<5)
+
+ft_limit_freq_lo:
+	.byte >LIMIT_PERIOD_2A03		; 2A03
+	.byte >LIMIT_PERIOD_2A03		; 2A03
+	.byte >0						; 2A03 noise
+	.byte >0						; 2A03 dpcm
+	.byte >LIMIT_PERIOD_VRC6		; VRC6
+	.byte >LIMIT_PERIOD_VRC6		; VRC6
+	.byte >LIMIT_PERIOD_2A03		; VRC7
+	.byte >LIMIT_PERIOD_VRC6		; FDS
+	.byte >LIMIT_PERIOD_2A03		; MMC5
+	.byte >LIMIT_PERIOD_N163		; N163
+	.byte >LIMIT_PERIOD_VRC6		; S5B
+ft_limit_freq_hi:
+	.byte <LIMIT_PERIOD_2A03		; 2A03
+	.byte <LIMIT_PERIOD_2A03		; 2A03
+	.byte <0						; 2A03 noise
+	.byte <0						; 2A03 dpcm
+	.byte <LIMIT_PERIOD_VRC6		; VRC6
+	.byte <LIMIT_PERIOD_VRC6		; VRC6
+	.byte <LIMIT_PERIOD_2A03		; VRC7
+	.byte <LIMIT_PERIOD_VRC6		; FDS
+	.byte <LIMIT_PERIOD_2A03		; MMC5
+	.byte <LIMIT_PERIOD_N163		; N163
+	.byte <LIMIT_PERIOD_VRC6		; S5B
+
+
 ;
 ; An example of including music follows
 ;

diff --git a/Source/drivers/asm/effects.s b/Source/drivers/asm/effects.s
@@ -316,6 +316,7 @@ ft_calc_period:
 	sta var_ch_PeriodCalcHi, x
 @Skip:
 
+	; apply vibrato and tremolo
 	jsr ft_vibrato
 	jsr ft_tremolo
 
@@ -330,35 +331,57 @@ ft_calc_period:
 	beq :+
 	cmp #CHAN_DPCM
 	beq :+
+	; TODO: implement VRC7 linear pitch?
+.if .defined(USE_VRC7)
+	cmp #CHAN_VRC7
+	beq :+
+.endif
 	jsr ft_load_freq_table
 	jsr ft_linear_fetch_pitch
 :
 .endif								; ;; ;;;
 
 	; apply frequency multiplication
+.if .defined(USE_FDS)
+	lda ft_channel_type, x
+	cmp #CHAN_FDS
+	bne :+
+	; copy unmultiplied period to FDS carrier
+	jsr @CopyPeriodToCarrier
+:
+.endif
+
 	lda var_ch_Harmonic, x
-	beq @MaxPeriod									; K00 results in lowest possible frequency
+
+	; K00 results in lowest possible frequency
+	beq @MaxPeriod
+
+	; skip calculation if it's not affecting pitch
 	cmp #$01
-	beq @SkipHarmonic								; skip calculation if it's not affecting pitch
+	beq @EndHarmonic
 
 	lda ft_channel_type, x
+	; noise does not use this
 	cmp #CHAN_NOI
-	beq @SkipHarmonic
+	beq @EndHarmonic
 
 .if .defined(USE_VRC7)
 	; VRC7 not yet implemented
 	cmp #CHAN_VRC7
-	beq @SkipHarmonic
+	beq @EndHarmonic
 .endif
+
 ; FDS and N163 use angular frequency
 .if .defined(USE_FDS)
 	cmp #CHAN_FDS
-	beq @HarmonicMultiplyFDS
+	beq @HarmonicMultiply
 .endif
+
 .if .defined(USE_N163)
 	cmp #CHAN_N163
 	beq @HarmonicMultiply
 .endif
+
 @HarmonicDivide:
 	lda var_ch_PeriodCalcLo, x
 	sta ACC
@@ -369,11 +392,7 @@ ft_calc_period:
 	lda #$00
 	sta AUX + 1
 	jsr DIV
-	jmp @HarmonicEnd
-.if .defined(USE_FDS)
-@HarmonicMultiplyFDS:
-	jsr @CopyPeriodToCarrier
-.endif
+	jmp @HarmonicEpilogue
 @HarmonicMultiply:
 	lda var_ch_PeriodCalcLo, x
 	sta var_Temp16
@@ -388,30 +407,21 @@ ft_calc_period:
 	lda var_ch_Harmonic, x
 	sta var_Temp
 	jsr MUL
-@HarmonicEnd:
+@HarmonicEpilogue:
 	lda ACC
 	sta var_ch_PeriodCalcLo, x
 	lda ACC + 1
 	sta var_ch_PeriodCalcHi, x
-	jmp @JumpHarmonicEnd
-@SkipHarmonic:
-.if .defined(USE_FDS)
-	lda ft_channel_type, x
-	cmp #CHAN_FDS
-	bne @JumpHarmonicEnd
-	jsr @CopyPeriodToCarrier
-.endif
-@JumpHarmonicEnd:
-	rts
+	jmp @EndHarmonic
 
 @MaxPeriod:
 	; no limits for noise
 	lda ft_channel_type, x
 	cmp #CHAN_NOI
-	beq @EndCalcPeriod
+	beq @EndHarmonic
 .if .defined(USE_VRC7)
 	cmp #CHAN_VRC7
-	beq @EndCalcPeriod
+	beq @EndHarmonic
 .endif
 .if .defined(USE_N163)
 	cmp #CHAN_N163
@@ -421,19 +431,25 @@ ft_calc_period:
 	cmp #CHAN_FDS
 	beq @InvertedPeriod
 .endif
-	; 12-bit/11-bit period
-	; will be handled in their respective chip handlers
 	lda #$FF
-	sta var_ch_PeriodCalcHi, x
-	lda #$0F
 	sta var_ch_PeriodCalcLo, x
-	jmp @EndCalcPeriod
+	lda #$0F
+	sta var_ch_PeriodCalcHi, x
+	jmp @EndHarmonic
 @InvertedPeriod:
 	lda #$00
 	sta var_ch_PeriodCalcHi, x
 	sta var_ch_PeriodCalcLo, x
-@EndCalcPeriod:
-	rts
+@EndHarmonic:
+
+
+	; CChannelHandler::LimitRawPeriod()
+	jmp ft_limit_final_freq_raw
+	; we're done here
+	; in the case of CChannelHandlerVRC7::CalculatePeriod() and
+	; CChannelHandlerN163::CalculatePeriod(), the freq bitshifts will be applied
+	; in their respective chip handlers (see n163.s, vrc7.s)
+;	rts
 
 .if .defined(USE_FDS)
 @CopyPeriodToCarrier:

diff --git a/Source/drivers/asm/instrument.s b/Source/drivers/asm/instrument.s
@@ -621,179 +621,3 @@ ft_load_instrument_vrc7:
 
 	ldy var_Temp		;;; ;; ;
 	rts
-
-; Make sure the period doesn't exceed max or min
-ft_limit_freq:
-
-.if .defined(USE_LINEARPITCH)
-	; linear pitch mode has different bounds check
-	lda var_SongFlags
-	and #FLAG_LINEARPITCH
-	beq :+
-	lda ft_channel_type, x
-	asl
-	tay
-	lda ft_limit_linear_pointers, y
-	sta var_Temp16
-	iny
-	lda ft_limit_linear_pointers, y
-	sta var_Temp16 + 1
-	ldy #$00
-	jmp (var_Temp16)
-:
-.endif
-
-	; Jump to the instrument setup routine
-	lda ft_channel_type, x
-	asl		;;; ;; ;
-	tay
-	lda ft_limit_pointers, y
-	sta var_Temp16
-	iny
-	lda ft_limit_pointers, y
-	sta var_Temp16 + 1
-	ldy #$00
-	jmp (var_Temp16)
-
-
-ft_limit_pointers:			;;; ;; ; 0CC: optimize this
-	.word ft_limit_period_2a03		; 2A03
-	.word ft_limit_period_2a03		; 2A03
-	.word ft_limit_period_no		; 2A03 noise
-	.word ft_limit_period_no		; 2A03 dpcm
-	.word ft_limit_period_vrc6		; VRC6
-	.word ft_limit_period_vrc6		; VRC6
-	.word ft_limit_period_no		; VRC7
-	.word ft_limit_period_vrc6		; FDS
-	.word ft_limit_period_2a03		; MMC5
-	.word ft_limit_period_no		; N163
-	.word ft_limit_period_vrc6		;;; ;; ; S5B
-
-ft_limit_period_no:
-ft_limit_linear_period_no:
-	rts
-
-; 2A03: period is between 0 to $7FF
-ft_limit_period_2a03:
-	lda var_ch_TimerPeriodHi, x
-	bmi @LimitMin
-	cmp #$08
-	bcc @NoLimit
-	lda #$07
-	sta var_ch_TimerPeriodHi, x
-	lda #$FF
-	sta var_ch_TimerPeriodLo, x
-@NoLimit:
-	rts
-@LimitMin:
-	lda #$00
-	sta var_ch_TimerPeriodLo, x
-	sta var_ch_TimerPeriodHi, x
-	rts
-
-; VRC6: period is between 0 to $FFF
-ft_limit_period_vrc6:
-	lda var_ch_TimerPeriodHi, x
-	bmi @LimitMin
-	cmp #$10
-	bcc @NoLimit
-	lda #$0F
-	sta var_ch_TimerPeriodHi, x
-	lda #$FF
-	sta var_ch_TimerPeriodLo, x
-@NoLimit:
-	rts
-@LimitMin:
-	lda #$00
-	sta var_ch_TimerPeriodLo, x
-	sta var_ch_TimerPeriodHi, x
-	rts
-
-ft_limit_linear_pointers:			;;; ;; ; 0CC: optimize this
-	.word ft_limit_linear_period_2a03		; 2A03
-	.word ft_limit_linear_period_2a03		; 2A03
-	.word ft_limit_linear_period_no		; 2A03 noise
-	.word ft_limit_linear_period_no		; 2A03 dpcm
-	.word ft_limit_linear_period_vrc6		; VRC6
-	.word ft_limit_linear_period_vrc6		; VRC6
-	.word ft_limit_linear_period_no		; VRC7
-	.word ft_limit_linear_period_vrc6		; FDS
-	.word ft_limit_linear_period_2a03		; MMC5
-	.word ft_limit_linear_period_no		; N163
-	.word ft_limit_linear_period_vrc6		;;; ;; ; S5B
-
-; std::min(std::max(Period, 0), (NOTE_COUNT - 1) << LINEAR_PITCH_AMOUNT);
-; even though this is a virtual function,
-; nothing seems to override this in linear pitch mode
-ft_limit_linear_period_2a03:
-ft_limit_linear_period_vrc6:
-	lda var_ch_TimerPeriodHi, x
-	bmi @LimitMin
-	sec
-	lda var_ch_TimerPeriodLo, x
-	sbc #<(95<<5)
-	lda var_ch_TimerPeriodHi, x
-	sbc #>(95<<5)
-	bcc @NoLimit
-	lda #>(95<<5)
-	sta var_ch_TimerPeriodHi, x
-	lda #<(95<<5)
-	sta var_ch_TimerPeriodLo, x
-@NoLimit:
-	rts
-@LimitMin:
-	lda #$00
-	sta var_ch_TimerPeriodLo, x
-	sta var_ch_TimerPeriodHi, x
-	rts
-
-.if 0
-
-	lda var_ch_TimerPeriodHi, x
-	bmi @LimitMin						; period < 0
-.if .defined(USE_VRC6)
-	pha									;;; ;; ;
-	lda ft_channel_type, x
-	cmp #CHAN_VRC6
-	beq :+
-	cmp #CHAN_SAW
-	beq :+
-	pla
-	bpl :++ ; always
-:	pla									; ;; ;;;
-	cmp #$10							; period > $FFF
-	bcc @NoLimit
-	lda #$0F
-	sta var_ch_TimerPeriodHi, x
-	lda #$FF
-	sta var_ch_TimerPeriodLo, x
-	rts
-:
-.endif
-.if .defined(USE_FDS)
-	cpx #FDS_OFFSET
-	bne :+
-	cmp #$11							; period > $1000?
-	bcc @NoLimit
-	lda #$10
-	sta var_ch_TimerPeriodHi, x
-	lda #$FF
-	sta var_ch_TimerPeriodLo, x
-	rts
-:
-.endif
-	cmp #$08							; period > $7FF
-	bcc @NoLimit
-	lda #$07
-	sta var_ch_TimerPeriodHi, x
-	lda #$FF
-	sta var_ch_TimerPeriodLo, x
-@NoLimit:
-	rts
-@LimitMin:
-	lda #$00
-	sta var_ch_TimerPeriodLo, x
-	sta var_ch_TimerPeriodHi, x
-	rts
-
-.endif