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Move logic outside loop for performance reasons.

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Same as earlier commit but for line_down_inv.s, line_up.s
Comment: Should do the same for line_up_inv.s
This commit is contained in:
hugova 2025-03-02 18:29:58 +01:00
parent ee69828ec7
commit f3712eca9f
4 changed files with 58 additions and 59 deletions
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2
wip-hugo/routines/memory/line_down.s
View file

@ -14,7 +14,7 @@
Y_pos = $FB
dx = $0c
dy_2 = $0607
V = $0809 ;Lets reuse dx register ($08)
V = $0809
D = $0a0b
;example values ~~~~~ SHOULD BE PRECOMPILED

50
wip-hugo/routines/memory/line_down_inv.s
View file

@ -12,14 +12,11 @@
Y_end = $05
X_pos = $FC
Y_pos = $FB
dy = $0c
dx_2 = $0607
dy = $08
V = $0809
D = $0a0b
;;Set values
LDA #$00
STA $FD ; for pixel_draw
;example values ~~~~~ SHOULD BE PRECOMPILED
LDA #$00
STA X_pos
@ -31,23 +28,33 @@
STA Y_end
;;~~~~~~~~~~
;;2*dx = 2*(X_end -X_pos)
;;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_end - Y_start, dx = X_end - X_start
LDA X_end
SEC
SBC X_pos
STA >dx_2
LDA #$00
STA <dx_2
mult_16 >dx_2, <dx_2
;;dy = (Y_end -Y_pos)
STA >V
STA >dx_2; >dx_2 = dx. Needed for dx_2 (not for V)
LDA Y_end
SEC
SBC Y_pos
STA dy
SEC
SBC >V
STA >V; <V = dy - dx
mult_16 >V, <V; V = 2*(dy -dx)
;;D = 2*dx - dy + 2*255. 0 <=D <= 4*255
;;Our D is bigger then wikipedia to not use negative numbers
;dx_2 = dx*2
mult_16 >dx_2, <dx_2
;;D = 2*dy - dx + 2*255
;;Our D is bigger then wikipedia because D is unsigned.
LDA >dx_2
STA >D
LDA <dx_2
@ -55,13 +62,6 @@
Add_16 >D, <D, #$00, #$01
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:
jsr pixel_draw
;;Increment Y until Y_pos = Y_end and X_pos = X_end
@ -76,12 +76,10 @@ for_y:
BEQ case_2
case_1:
INC X_pos
;; D = D - 2*dx
Sub_16 >D, <D, >dy_2, <dy_2
Sub_16 >D, <D, >V, <V; D = D - V
JMP for_y
case_2:
;;D = D + 2*dy
Add_16 >D, <D, >dx_2, <dx_2
last:
Add_16 >D, <D, >dx_2, <dx_2;D = D + 2*dx
JMP for_y
end:
.endproc

45
wip-hugo/routines/memory/line_up.s
View file

@ -14,13 +14,10 @@
X_pos = $FC
Y_pos = $FB
dy_2 = $0607
dx = $08
dx = $0c
V = $0809
D = $0a0b
;;Set values
LDA #$00
STA $FD ; for pixel_draw
;example values ~~~~~ SHOULD BE PRECOMPILED
LDA #$90
STA X_pos
@ -32,23 +29,33 @@
STA Y_end
;;~~~~~~~~~~
;;2*dy = 2*(Y_pos-Y_end)
;;We need to clear this memory
LDA #$00
STA <V
STA <dy_2
STA $FD ; for pixel_draw
;; V = 2*(dx -dy)
;; where: dy = Y_pos - Y_end, dx = X_end - X_start
LDA Y_pos
SEC
SBC Y_end
STA >dy_2
LDA #$00
STA <dy_2
mult_16 >dy_2, <dy_2
;;dx = (X_end -X_pos)
STA >V
STA >dy_2; >dy_2 = dy. Needed for dy_2 (not for V)
LDA X_end
SEC
SBC X_pos
STA dx
SEC
SBC >V
STA >V; <V = dx - dy
mult_16 >V, <V; V = 2*(dx -dy)
;;D = 2*dy - dx + 2*255. 0 <=D <= 4*255
;;Our D is bigger then wikipedia to not use negative numbers
;dy_2 = dy*2
mult_16 >dy_2, <dy_2
;;D = 2*dy - dx + 2*255
;;Our D is bigger then wikipedia because D is unsigned.
LDA >dy_2
STA >D
LDA <dy_2
@ -56,12 +63,6 @@
Add_16 >D, <D, #$00, #$01
Sub_16 >D, <D, dx, #$00
;;We wont use dx, only 2*dx from now on
dx_2 = $0809 ;Lets reuse dx register ($08)
LDA #$00
STA <dx_2
mult_16 >dx_2, <dx_2
for_x:
jsr pixel_draw
;;Increment X until X_pos = X_end and Y_pos = Y_end
@ -76,10 +77,10 @@ for_x:
BEQ case_2
case_1:
DEC Y_pos
Sub_16 >D, <D, >dx_2, <dx_2; D = D -2*dx
Sub_16 >D, <D, >V, <V; D = D - V
JMP for_x
case_2:
Add_16 >D, <D, >dy_2, <dy_2;D = D + 2*dy
last:
JMP for_x
end:
.endproc

2
wip-hugo/source.s
View file

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