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A optimisation of line_up_inv.s by moving some logic out of loop

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hugova 2025-03-02 23:14:51 +01:00
parent f3712eca9f
commit 1524c837ca
4 changed files with 32 additions and 35 deletions
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1
wip-hugo/routines/memory/line_down.s
View file

@ -28,7 +28,6 @@
STA Y_end STA Y_end
;;~~~~~~~~~~ ;;~~~~~~~~~~
;;We need to clear this memory ;;We need to clear this memory
LDA #$00 LDA #$00
STA <V STA <V

1
wip-hugo/routines/memory/line_up.s
View file

@ -62,7 +62,6 @@
STA <D STA <D
Add_16 >D, <D, #$00, #$01 Add_16 >D, <D, #$00, #$01
Sub_16 >D, <D, dx, #$00 Sub_16 >D, <D, dx, #$00
for_x: for_x:
jsr pixel_draw jsr pixel_draw
;;Increment X until X_pos = X_end and Y_pos = Y_end ;;Increment X until X_pos = X_end and Y_pos = Y_end

47
wip-hugo/routines/memory/line_up_inv.s
View file

@ -13,13 +13,10 @@
X_pos = $FC X_pos = $FC
Y_pos = $FB Y_pos = $FB
dx_2 = $0607 dx_2 = $0607
dy = $08 dy = $0c
V = $0809
D = $0a0b D = $0a0b
;;Set values
LDA #$00
STA $FD ; for pixel_draw
;example values ~~~~~ SHOULD BE PRECOMPILED ;example values ~~~~~ SHOULD BE PRECOMPILED
LDA #$60 LDA #$60
STA X_pos STA X_pos
@ -31,37 +28,39 @@
STA Y_end STA Y_end
;;~~~~~~~~~~ ;;~~~~~~~~~~
;;2*dx = 2*(X_pos - X_end) ;We need to clear this memory
LDA #$00
STA <V
STA <dx_2
STA $FD ; for pixel_draw
;; V = 2*(dy -dx)
;; where: dy = Y_pos - Y_end, dx = X_end - X_start
LDA X_pos LDA X_pos
SEC SEC
SBC X_end SBC X_end
STA >dx_2 STA >V
LDA #$00 STA >dx_2; >dy_2 = dy. Needed for dy_2 (not for V)
STA <dx_2
mult_16 >dx_2, <dx_2
;;dy = (Y_end -Y_pos)
LDA Y_end LDA Y_end
SEC SEC
SBC Y_pos SBC Y_pos
STA dy STA dy
SEC
SBC >V
STA >V; <V = dx - dy
mult_16 >V, <V; V = 2*(dx -dy)
;;D = 2*dx - dy + 2*255. 0 <=D <= 4*255 ;dy_2 = dy*2
;;Our D is bigger then wikipedia to not use negative numbers mult_16 >dx_2, <dx_2
;;D = 2*dx - dy + 2*255
;;Our D is bigger then wikipedia because D is unsigned.
LDA >dx_2 LDA >dx_2
STA >D STA >D
LDA <dx_2 LDA <dx_2
STA <D STA <D
Add_16 >D, <D, #$00, #$01 Add_16 >D, <D, #$00, #$01
Sub_16 >D, <D, dy, #$00 Sub_16 >D, <D, dy, #$00
;;We wont use dy, only 2*dy from now on
dy_2 = $0809 ;Lets reuse dy register ($08)
LDA #$00
STA <dy_2
mult_16 >dy_2, <dy_2
for_y: for_y:
jsr pixel_draw jsr pixel_draw
;;Increment Y until Y_pos = Y_end and X_pos = X_end ;;Increment Y until Y_pos = Y_end and X_pos = X_end
@ -76,10 +75,10 @@ for_y:
BEQ case_2 BEQ case_2
case_1: case_1:
DEC X_pos DEC X_pos
Sub_16 >D, <D, >dy_2, <dy_2; D = D - 2*dx Sub_16 >D, <D, >V, <V; D = D - V
JMP for_y
case_2: case_2:
Add_16 >D, <D, >dx_2, <dx_2;D = D + 2*dy Add_16 >D, <D, >dx_2, <dx_2;D = D + 2*dy
last:
JMP for_y JMP for_y
end: end:
.endproc .endproc

2
wip-hugo/source.s
View file

@ -1,6 +1,6 @@
.include "STARTUP.s" .include "STARTUP.s"
.include "macros/16aritmatic.s" .include "macros/16aritmatic.s"
.include "routines/memory/line_up.s" .include "routines/memory/line_up_inv.s"
loop_: loop_:
jmp loop_ jmp loop_