chrisly42/PretrackerRaspberryCasket
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 2 Wiki Activity

Optimized track delay code further.

Browse Source
This commit is contained in:
Chris Hodges 2022-12-28 11:58:03 +01:00
parent 2a1d9e9bc1
commit b177277d40
2 changed files with 30 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
README.md
View File

@ -119,7 +119,8 @@ solve this problem.
- Store instrument number * 4 on loading to avoid using two adds every frame
- Optimized speed/shuffle code. Idea of using xor turned out to make things too complicated for pattern breaks/jumps.
- Rearranged code for more short branches.
- Drop-in replacement code size: 6324 bytes.
- Optimized track delay code further.
- Drop-in replacement code size: 6304 bytes.
### V1.0 (26-Dec-22)

60
src/raspberry_casket.asm
View File

@ -3872,31 +3872,34 @@ pre_PlayerTick:
; ----------------------------------------
; track delay handling
move.b pcd_track_delay_steps_b(a5),d0
beq .incrementchannel ; no track delay
move.b pcd_track_delay_steps_b(a5),d3
beq .incrementchannel ; no track delay
cmp.b #NUM_CHANNELS-1,pcd_channel_num_b(a5) ; last channel processed?
beq .updatechannels ; no track delay for last channel
beq .updatechannels ; no track delay for last channel
moveq.l #MAX_TRACK_DELAY-1,d0 ; load from last buffer
; handle track delay
cmpi.b #$FF,d0
cmpi.b #$FF,d3
beq.s .clear_track_delay
; advance and wrap offset
move.b pcd_SIZEOF+pcd_track_delay_offset_b(a5),d1
addq.b #1,d1
andi.w #$1F,d1
and.w d0,d1
move.b d1,pcd_SIZEOF+pcd_track_delay_offset_b(a5)
move.w d1,d2
lea pcd_SIZEOF(a5),a3
lsl.w #4,d2
lea (a5,d2.w),a1
lea pcd_SIZEOF+pcd_track_delay_buffer(a1),a3
move.l pcd_out_base+0(a5),(a3)+ ; ocd_sam_ptr
move.l pcd_out_base+4(a5),(a3)+ ; ocd_length/ocd_loop_offset
move.l pcd_out_base+8(a5),(a3)+ ; ocd_period/ocd_volume/ocd_trigger
;move.l pcd_out_base+12(a5),(a3)+ ; this is never used
lea pcd_track_delay_buffer(a3,d2.w),a3
lea pcd_out_base(a5),a1
move.l (a1)+,(a3)+ ; ocd_sam_ptr
move.l (a1)+,(a3)+ ; ocd_length/ocd_loop_offset
move.l (a1)+,(a3)+ ; ocd_period/ocd_volume/ocd_trigger
;move.l (a1)+,(a3)+ ; this is never used
move.b -(a3),d2
add.b d2,d2 ; increment channel
bne.s .copy_trigger_for_delayed_channel
@ -3913,26 +3916,22 @@ pre_PlayerTick:
move.w (sp)+,d4
clr.b d4
add.w d4,d4
move.b -(a3),d4 ; ocd_volume
move.b -(a3),d4 ; ocd_volume
move.b (a1,d4.w),(a3)+
ELSE
moveq.l #0,d4
move.b -(a3),d4 ; ocd_volume
move.b -(a3),d4 ; ocd_volume
move.b pcd_track_delay_vol16_b(a5),d2
ext.w d2
mulu d4,d2 ; apply track delay volume
mulu d4,d2 ; apply track delay volume
lsr.w #4,d2
move.b d2,(a3)+ ; fix volume
move.b d2,(a3)+ ; fix volume
ENDC
move.b d0,pcd_SIZEOF+pcd_track_delay_steps_b(a5)
move.b d3,pcd_SIZEOF+pcd_track_delay_steps_b(a5)
sub.b d0,d1
bpl.s .no_wrap_trd_pos
addi.b #$20,d1
.no_wrap_trd_pos
move.b d1,d0
ext.w d0
sub.b d3,d1
and.w d1,d0
IFNE PRETRACKER_DUBIOUS_PITCH_SHIFT_FOR_DELAYED_TRACK
moveq.l #7,d4
@ -3950,20 +3949,17 @@ pre_PlayerTick:
move.b d1,pcd_SIZEOF+pcd_track_delay_steps_b(a5)
st pcd_SIZEOF+pcd_track_delay_offset_b(a5)
moveq.l #$1f,d0 ; load from last buffer
.load_track_data_from_buffer
lea pcd_SIZEOF(a5),a5 ; skip the channel we applied track delay to
lea pcd_SIZEOF(a5),a5 ; skip the channel we applied track delay to
lsl.w #4,d0
lea (a5,d0.w),a0
lea pcd_track_delay_buffer(a5,d0.w),a1
lea pcd_out_base(a5),a3
lea pcd_track_delay_buffer(a0),a1
move.l (a1)+,(a3)+
move.l (a1)+,(a3)+
move.l (a1)+,(a3)+
move.l (a1)+,(a3)+ ; ocd_sam_ptr
move.l (a1)+,(a3)+ ; ocd_length/ocd_loop_offset
move.l (a1)+,(a3)+ ; ocd_period/ocd_volume/ocd_trigger
;move.l (a1)+,(a3)+ ; this is never used
clr.b pcd_track_delay_buffer+ocd_volume(a0)
;clr.b ocd_volume-ocd_unused(a1) ; does not seem to bother
IFNE PRETRACKER_DUBIOUS_PITCH_SHIFT_FOR_DELAYED_TRACK
; FIXME this seems odd! Why modulate the period by the distance?