From af122e258fe45d5081213dc1ac55f782c3dd8b9f Mon Sep 17 00:00:00 2001
From: "B. Watson" <urchlay@slackware.uk>
Date: Tue, 8 Nov 2022 01:31:41 -0500
Subject: Optimize the new drunkwalk...

---
 drunkwalk.s | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drunkwalk.s b/drunkwalk.s
index ca80475..6156e4a 100644
--- a/drunkwalk.s
+++ b/drunkwalk.s
@@ -13,12 +13,12 @@ drunkwalk:
  ldy part_x           ; 3
  ldx part_y           ; 3
 
- ; do we need this now?
  lda lineaddrs_l,x    ; 5
  sta pixptr           ; 3
  lda lineaddrs_h,x    ; 5
  sta pixptr+1         ; 3
 
+move_pixel:
  bit RANDOM     ; 4 ; use top 2 bits (probably more random, definitely faster)
  bmi lr         ; 2/3
  bvc down       ; 2/3
@@ -79,9 +79,14 @@ check_ud:
  sta pixptr2+1
  lda (pixptr2),y
  bne stick
- jmp drunkwalk
+ jmp move_pixel
 
 check_lru:
+ lda lineaddrs_l,x    ; 5
+ sta pixptr           ; 3
+ lda lineaddrs_h,x    ; 5
+ sta pixptr+1         ; 3
+
  ; check left neighbor
  dey
  lda (pixptr),y
@@ -99,9 +104,14 @@ check_lru:
  sta pixptr2+1
  lda (pixptr2),y
  bne stick
- jmp drunkwalk
+ jmp move_pixel
 
 check_lrd:
+ lda lineaddrs_l,x    ; 5
+ sta pixptr           ; 3
+ lda lineaddrs_h,x    ; 5
+ sta pixptr+1         ; 3
+
  ; check left neighbor
  dey
  lda (pixptr),y
@@ -119,7 +129,7 @@ check_lrd:
  sta pixptr2+1
  lda (pixptr2),y
  bne stick
- jmp drunkwalk
+ jmp move_pixel
 
 stick:
  rts
-- 
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