From 363e3907ff2f0d3784b5c5b5c55b13050503c278 Mon Sep 17 00:00:00 2001
From: hugova <hugova@kth.se>
Date: Sat, 28 Jun 2025 21:05:25 +0200
Subject: [PATCH] Fix circle-code (wip) Now the test renders the forth quarter
 of a circle!

---
 wip-hugo/routines/circle/circle.s      | 23 ++++++++++++-----------
 wip-hugo/routines/circle/circle_test.s |  2 +-
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/wip-hugo/routines/circle/circle.s b/wip-hugo/routines/circle/circle.s
index b272ee3..b11f683 100644
--- a/wip-hugo/routines/circle/circle.s
+++ b/wip-hugo/routines/circle/circle.s
@@ -6,22 +6,23 @@
         ;; https://schwarzers.com/algorithms/
 
 
-        ;; X_pos = X_pos + r (hack, should fix later ( xpos == ypos is not always true))
-        CLC
-        LDA X_pos
-        ADC radius
+        ;; X_pos is changed (fix this later)
+        LDA radius
         STA X_pos
 
+        LDA #$00
+        STA Y_pos
+
         ;; t1 = radius >> 4
         LDA radius
-        LSR A
-        LSR A
-        LSR A
-        LSR A
+        LSR
+        LSR
+        LSR
+        LSR
         STA t1
 while_x_bigger_then_y:
 
-        jsr pixel_draw
+        JSR pixel_draw
 
         INC Y_pos ; y++
 
@@ -32,7 +33,7 @@ while_x_bigger_then_y:
         STA t1
         ;; t2 = t1 - x
         SEC
-        LDA t2
+        LDA t1
         SBC X_pos
         STA t2
         ;; if t2 < 0 then skip to endif
@@ -47,6 +48,6 @@ endif:
         LDA X_pos
         CMP Y_pos
 
-        BNE while_x_bigger_then_y
+        BCS while_x_bigger_then_y
         RTS
 .endproc
diff --git a/wip-hugo/routines/circle/circle_test.s b/wip-hugo/routines/circle/circle_test.s
index de42b01..bfe18aa 100644
--- a/wip-hugo/routines/circle/circle_test.s
+++ b/wip-hugo/routines/circle/circle_test.s
@@ -3,7 +3,7 @@
         LDA #$50
         STA X_pos
         STA Y_pos
-        LDA #$08
+        LDA #$55
         STA radius
         JSR circle
 .endscope