From 3ce76c02a8825d1ca081e9225beb284d0e58c6d7 Mon Sep 17 00:00:00 2001
From: hugova <hugova@kth.se>
Date: Mon, 24 Mar 2025 18:00:17 +0100
Subject: [PATCH] Rewrote 4 branch instructions to 2. 2% performance increase

---
 .gitignore                         | 1 +
 wip-hugo/routines/line/line_down.s | 9 +++------
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/.gitignore b/.gitignore
index 448c5a2..07ddc1e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 *.prg
 *.o
 *.list
+*.note
diff --git a/wip-hugo/routines/line/line_down.s b/wip-hugo/routines/line/line_down.s
index c45e3b6..cc0d657 100644
--- a/wip-hugo/routines/line/line_down.s
+++ b/wip-hugo/routines/line/line_down.s
@@ -50,8 +50,8 @@
         Add_16 >D, <D, #$ff, #$01, !
         Sub_16 >D, <D, dx, #$00
 
-        LDY #$00
         jsr pixel_draw ;;only used first pixel. after this relative position is abused
+        LDY #$00
 for_x:
         ;; Paints A to address i btp_mem_pos* + Y
         ;; Y is our Y-pos-chunk-offset.
@@ -59,10 +59,8 @@ for_x:
         ORA (>btp_mem_pos), Y
         STA (>btp_mem_pos), Y
 increment_pixel_x:
-        ;CLC
         LSR byte_to_paint
-        BCS move_8px_left
-        JMP increment_pixel_x_end
+        BCC increment_pixel_x_end
 move_8px_left:
         ;; add +8 to btp_mem_pos. Find more of why in pixel_draw
         Add_16 >btp_mem_pos, <btp_mem_pos, #$08, #$00
@@ -83,8 +81,7 @@ increment_y_pos:
         ;Add_16 >btp_mem_pos, <btp_mem_pos, #$01, #$00
         INY
         CPY #$08 ;
-        BEQ move_8px_down
-        jmp for_x
+        BNE for_x
 move_8px_down: ; Z=1 --> C=1
         ;; +320-8 bytes
         LDY #$00