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pt3: optimize envelope code

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This commit is contained in:
Peter Ferrie 2019-06-02 23:37:05 -04:00 committed by Vince Weaver
parent 90b8a76a4b
commit 7b447699f8
1 changed files with 31 additions and 36 deletions
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67
pt3_player/pt3_lib.s
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@ -911,35 +911,26 @@ envelope_slide:
; Envelope slide
; If b1 top bits are 10 or 11
lda sample_b0
asl
asl
asl ; b0 bit 5 to carry flag
lda #$20
bit sample_b0
php
bit sample_b1
bpl else_noise_slide ; if ((b1 & 0x80) != 0) {
plp
bit sample_b1 ; b1 bit 7 to sign flag, bit 5 to zero flag
php
;;bug? always falls through
beq envelope_slide_down ; if ((b0 & 0x20) != 0) {
bpl else_noise_slide ; if ((b1 & 0x80) != 0) {
tya
ora #$f0
bcs envelope_slide_down ; if ((b0 & 0x20) == 0) {
; FIXME: this can be optimized
envelope_slide_up:
; j = ((b0>>1)&0xF) + a->envelope_sliding;
and #$0f
clc
envelope_slide_down:
; j = ((b0>>1)|0xF0) + a->envelope_sliding
tya
ora #$f0
clc
adc note_a+NOTE_ENVELOPE_SLIDING,X
sta e_slide_amount ; j
;;+jmp envelope_slide_done?
envelope_slide_up:
; j = ((b0>>1)&0xF) + a->envelope_sliding;
tya
and #$0f
clc
adc note_a+NOTE_ENVELOPE_SLIDING,X
sta e_slide_amount ; j
@ -950,6 +941,7 @@ envelope_slide_done:
; a->envelope_sliding = j;
sta note_a+NOTE_ENVELOPE_SLIDING,X
clc
last_envelope:
@ -973,7 +965,7 @@ else_noise_slide:
sta pt3_noise_add
plp
beq noise_slide_done ; if ((b1 & 0x20) != 0) {
bcc noise_slide_done ; if ((b1 & 0x20) != 0) {
; noise_sliding = pt3_noise_add
sta note_a+NOTE_NOISE_SLIDING,X
@ -1035,7 +1027,7 @@ handle_onoff:
eor #$1 ; toggle
sta note_a+NOTE_ENABLED,X
bne do_offon
.byte $a9 ;mask do_onoff
do_onoff:
dex ; select ONOFF
;lda note_a+NOTE_ONOFF_DELAY,X ; if (a->enabled) a->onoff=a->onoff_delay;
@ -1457,30 +1449,33 @@ effect_2_small: ; FIXME: make smaller
iny
iny
lda (PATTERN_L),Y ; load byte, set as slide_step low
iny
sta note_a+NOTE_TONE_SLIDE_STEP_L,X
lda (PATTERN_L),Y ; load byte, set as slide_step high
sta note_a+NOTE_TONE_SLIDE_STEP_H,X
php
; 16-bit absolute value
bpl slide_step_positive
bpl slide_step_positive1
eor #$ff
slide_step_positive1:
sta note_a+NOTE_TONE_SLIDE_STEP_H,X
lda note_a+NOTE_TONE_SLIDE_STEP_L,X
dey
lda (PATTERN_L),Y ; load byte, set as slide_step low
plp
bpl slide_step_positive2
eor #$ff
adc #$0 ;+carry set by earlier CMP
slide_step_positive2:
sta note_a+NOTE_TONE_SLIDE_STEP_L,X
bcc skip_step_inc1
inc note_a+NOTE_TONE_SLIDE_STEP_H,X
skip_step_inc1:
slide_step_positive:
iny ; moved here as it messed with flags
iny
; a->tone_delta=GetNoteFreq(a->note,pt3)-
@ -1489,18 +1484,18 @@ slide_step_positive:
lda note_a+NOTE_NOTE,X
jsr GetNoteFreq
lda freq_l
sta note_a+NOTE_TONE_DELTA_L,X
sta temp_word_l
lda freq_h
sta note_a+NOTE_TONE_DELTA_H,X
sta temp_word_h
lda prev_note
jsr GetNoteFreq
sec
lda note_a+NOTE_TONE_DELTA_L,X
lda temp_word_l
sbc freq_l
sta note_a+NOTE_TONE_DELTA_L,X
lda note_a+NOTE_TONE_DELTA_H,X
lda temp_word_h
sbc freq_h
sta note_a+NOTE_TONE_DELTA_H,X