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optimize note calculation

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This commit is contained in:
Peter Ferrie 2019-06-01 00:26:29 -04:00 committed by Vince Weaver
parent dca5cb2e95
commit 6f56cfc254
1 changed files with 10 additions and 18 deletions
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28
pt3_player/pt3_lib.s
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@ -542,44 +542,36 @@ note_enabled:
; a->tone = pt3->data[a->sample_pointer + a->sample_position*4+2];
; a->tone+=(pt3->data[a->sample_pointer + a->sample_position*4+3])<<8;
; a->tone += a->tone_accumulator;
iny ; 2
clc ; 2
lda (SAMPLE_L),Y ; 5+
adc note_a+NOTE_TONE_ACCUMULATOR_L,X ; 4+
sta note_a+NOTE_TONE_L,X ; 4
iny ; 2
lda (SAMPLE_L),Y ; 5+
sta note_a+NOTE_TONE_H,X ; 4
; a->tone += a->tone_accumulator;
clc ; 2
lda note_a+NOTE_TONE_L,X ; 4+
adc note_a+NOTE_TONE_ACCUMULATOR_L,X ; 4+
sta note_a+NOTE_TONE_L,X ; 4+
lda note_a+NOTE_TONE_H,X ; 4+
adc note_a+NOTE_TONE_ACCUMULATOR_H,X ; 4+
sta note_a+NOTE_TONE_H,X ; 4+
sta note_a+NOTE_TONE_H,X ; 4
;=============================
; Accumulate tone if set
; (if sample_b1 & $40)
lda #$40 ; if (b1&0x40)
bit sample_b1
beq no_accum ; (so, if b1&0x40 is zero, skip it)
bvc no_accum ; (so, if b1&0x40 is zero, skip it)
sta note_a+NOTE_TONE_ACCUMULATOR_H,X
lda note_a+NOTE_TONE_L,X ; tone_accumulator=tone
sta note_a+NOTE_TONE_ACCUMULATOR_L,X
lda note_a+NOTE_TONE_H,X
sta note_a+NOTE_TONE_ACCUMULATOR_H,X
no_accum:
;============================
; Calculate tone
; j = a->note + (pt3->data[a->ornament_pointer + a->ornament_position]
clc
lda note_a+NOTE_ORNAMENT_POSITION,X
tay
clc ;;can be removed if ADC ACCUMULATOR_H cannot overflow
ldy note_a+NOTE_ORNAMENT_POSITION,X
lda (ORNAMENT_L),Y
adc note_a+NOTE_NOTE,X
@ -610,7 +602,7 @@ note_not_too_high:
adc note_a+NOTE_TONE_SLIDING_H,X
sta note_a+NOTE_TONE_H,X
clc
clc ;;can be removed if ADC SLIDING_H cannot overflow
lda note_a+NOTE_TONE_L,X
adc freq_l
sta note_a+NOTE_TONE_L,X
@ -631,7 +623,7 @@ note_not_too_high:
; a->tone_sliding+=a->tone_slide_step
clc
clc ;;can be removed if ADC freq_h cannot overflow
lda note_a+NOTE_TONE_SLIDING_L,X
adc note_a+NOTE_TONE_SLIDE_STEP_L,X
sta note_a+NOTE_TONE_SLIDING_L,X