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Fix circle-code (wip) Now the test renders the forth quarter of a circle!

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hugova 2025-06-28 21:05:25 +02:00
parent 50a17ad691
commit 363e3907ff
2 changed files with 13 additions and 12 deletions
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23
wip-hugo/routines/circle/circle.s
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@ -6,22 +6,23 @@
;; https://schwarzers.com/algorithms/ ;; https://schwarzers.com/algorithms/
;; X_pos = X_pos + r (hack, should fix later ( xpos == ypos is not always true)) ;; X_pos is changed (fix this later)
CLC LDA radius
LDA X_pos
ADC radius
STA X_pos STA X_pos
LDA #$00
STA Y_pos
;; t1 = radius >> 4 ;; t1 = radius >> 4
LDA radius LDA radius
LSR A LSR
LSR A LSR
LSR A LSR
LSR A LSR
STA t1 STA t1
while_x_bigger_then_y: while_x_bigger_then_y:
jsr pixel_draw JSR pixel_draw
INC Y_pos ; y++ INC Y_pos ; y++
@ -32,7 +33,7 @@ while_x_bigger_then_y:
STA t1 STA t1
;; t2 = t1 - x ;; t2 = t1 - x
SEC SEC
LDA t2 LDA t1
SBC X_pos SBC X_pos
STA t2 STA t2
;; if t2 < 0 then skip to endif ;; if t2 < 0 then skip to endif
@ -47,6 +48,6 @@ endif:
LDA X_pos LDA X_pos
CMP Y_pos CMP Y_pos
BNE while_x_bigger_then_y BCS while_x_bigger_then_y
RTS RTS
.endproc .endproc

2
wip-hugo/routines/circle/circle_test.s
View file

@ -3,7 +3,7 @@
LDA #$50 LDA #$50
STA X_pos STA X_pos
STA Y_pos STA Y_pos
LDA #$08 LDA #$55
STA radius STA radius
JSR circle JSR circle
.endscope .endscope