Apple-2gs-SW/iigs-game-engine
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Remove a CLC from the inner dispatch. Saves 2 cycles per block per sprite at the cost of 2 cycles per sprite

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This commit is contained in:
Lucas Scharenbroich 2022-07-26 00:11:47 -05:00
parent d332783c85
commit 68b8ca5856
2 changed files with 10 additions and 9 deletions
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1
src/Sprite2.s
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@ -186,6 +186,7 @@ _CalcDirtySprite
eor #$FFFF ; A = -X - 1
sec ; C = 1
adc _Sprites+SPRITE_DISP,y ; A = SPRITE_DISP + (-X - 1) + 1 = SPRITE_DISP - X
dec ; [!! INTERLOCK !!] pre-decrement to save clc in core blitter. See dobit macros in src/Tiles.s
sta _Sprites+TS_VBUFF_BASE,y
; Create an offset value for loading the calculated VBUFF addresses within the core renderer by

18
src/Tiles.s
View File

@ -571,14 +571,14 @@ dobit mac
bcc next_bit
beq last_bit
tax
lda (SPRITE_VBUFF_PTR+{]1*2}),y
clc
adc _Sprites+TS_VBUFF_BASE+{]1*2}
lda (SPRITE_VBUFF_PTR+{]1*2}),y ; The carry is always set
; clc
adc _Sprites+TS_VBUFF_BASE+{]1*2} ; [!! INTERLOCK !!] The table is pre-decremented in Sprite2.s
sta sprite_ptr0+{]2*4}
txa
jmp ]3
last_bit lda (SPRITE_VBUFF_PTR+{]1*2}),y
clc ; pre-adjust these later
; clc ; pre-adjust these later
adc _Sprites+TS_VBUFF_BASE+{]1*2}
sta sprite_ptr0+{]2*4}
jmp ]4
@ -593,13 +593,13 @@ dobit1 mac
beq last_bit
tax
lda (SPRITE_VBUFF_PTR+{]1*2}),y
clc
; clc
adc _Sprites+TS_VBUFF_BASE+{]1*2}
sta sprite_ptr0+{]2*4}
txa
jmp ]3
last_bit lda (SPRITE_VBUFF_PTR+{]1*2}),y
clc ; pre-adjust these later
; clc ; pre-adjust these later
adc _Sprites+TS_VBUFF_BASE+{]1*2}
sta sprite_ptr0+{]2*4}
tyx
@ -612,7 +612,7 @@ stpbit mac
lsr
bcc next_bit
lda (SPRITE_VBUFF_PTR+{]1*2}),y
clc ; pre-adjust these later
; clc ; pre-adjust these later
adc _Sprites+TS_VBUFF_BASE+{]1*2}
sta sprite_ptr0+{]2*4}
jmp ]3
@ -622,7 +622,7 @@ next_bit
; Last bit test which *must* be set
endbit mac
lda (SPRITE_VBUFF_PTR+{]1*2}),y
clc ; pre-adjust these later
; clc ; pre-adjust these later
adc _Sprites+TS_VBUFF_BASE+{]1*2}
sta sprite_ptr0+{]2*4}
jmp ]3
@ -630,7 +630,7 @@ endbit mac
endbit1 mac
lda (SPRITE_VBUFF_PTR+{]1*2}),y
clc ; pre-adjust these later
; clc ; pre-adjust these later
adc _Sprites+TS_VBUFF_BASE+{]1*2}
sta sprite_ptr0+{]2*4}
tyx