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more pritty circle bugs

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hugova 2025-06-26 22:38:11 +02:00
parent 8b955a5007
commit d691d692b9
1 changed files with 13 additions and 23 deletions
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32
wip-hugo/routines/circle/circle.s
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@ -4,15 +4,14 @@
.include "circle.inc" .include "circle.inc"
;; We use the algorithm jerkos method ;; We use the algorithm jerkos method
;; https://schwarzers.com/algorithms/ ;; https://schwarzers.com/algorithms/
LDY Y_pos
LDX X_pos
;; X_pos = X_pos + r (hack, should fix later ( xpos == ypos is not always true)) ;; X_pos = X_pos + r (hack, should fix later ( xpos == ypos is not always true))
CLC CLC
LDA X_pos LDA X_pos
ADC radius ADC radius
STA X_pos STA X_pos
;; t1 = radius >> 4 ;; t1 = radius >> 4
LDA radius LDA radius
LSR LSR
@ -22,39 +21,30 @@
STA t1 STA t1
while_x_bigger_then_y: while_x_bigger_then_y:
STY Y_pos
STX X_pos
STA temp
jsr pixel_draw jsr pixel_draw
LDY Y_pos
LDX X_pos
LDA temp
INC Y_pos ; y++
INY ; y++
;;t1 += y ;;t1 += y
CLC CLC
LDA t1 LDA t1
STY temp ADC Y_pos
ADC temp
STA t1 STA t1
;; t2 = t1 - x ;; t2 = t1 - x
SEC SEC
STX temp LDA t2
SBC temp SBC X_pos
STA t2
;; if t2 < 0 then skip to endif ;; if t2 < 0 then skip to endif
CMP #$00 CMP #$00
BMI endif BMI endif
if: if:
DEX; x-- DEC X_pos ; x--
STA t1 ; t1 = t2 STA t1 ; t1 = t2
endif: endif:
;; repeat if X > Y ;; repeat if X > Y
STX temp LDA X_pos
TYA CMP Y_pos
CMP temp
JMP while_x_bigger_then_y JMP while_x_bigger_then_y
BEQ while_x_bigger_then_y ;BNE while_x_bigger_then_y
.endproc .endproc