From 44fec2c72906c03a4337b21af55d40d7f1e70804 Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Fri, 6 Sep 2024 15:56:41 +0200
Subject: [PATCH] some additional last minute optimization to life example

---
 examples/cx16/life.p8 | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/examples/cx16/life.p8 b/examples/cx16/life.p8
index d7c96ce14..79b21a95a 100644
--- a/examples/cx16/life.p8
+++ b/examples/cx16/life.p8
@@ -89,14 +89,15 @@ main {
     sub next_gen() {
         const ubyte DXOFFSET = 0
         const ubyte DYOFFSET = 2
-        uword voffset = STRIDE+1-DXOFFSET
-        uword @zp offset
         ubyte[2] cell_chars = [sc:' ', sc:'●']
 
         uword @requirezp new_world = world1
         if active_world == world1
             new_world = world2
 
+        uword @requirezp new_world_ptr = new_world + STRIDE+1-DXOFFSET
+        uword @requirezp active_world_ptr = active_world + STRIDE+1-DXOFFSET
+
         ubyte x
         ubyte y
         for y in DYOFFSET to HEIGHT+DYOFFSET-1 {
@@ -104,11 +105,9 @@ main {
             cx16.vaddr_autoincr(1, $b000 + 256*y, 0, 2)     ;  allows us to use simple Vera data byte assigns later instead of setchr() calls
 
             for x in DXOFFSET to WIDTH+DXOFFSET-1 {
-                offset = voffset + x
-
                 ; count the living neighbors
-                ubyte cell = active_world[offset]
-                uword @requirezp ptr = active_world + offset - STRIDE - 1
+                ubyte cell = @(active_world_ptr + x)
+                uword @requirezp ptr = active_world_ptr + x - STRIDE - 1
                 ubyte neighbors = @(ptr) + @(ptr+1) + @(ptr+2) +
                                   @(ptr+STRIDE) + cell + @(ptr+STRIDE+2) +
                                   @(ptr+STRIDE*2) + @(ptr+STRIDE*2+1) + @(ptr+STRIDE*2+2)
@@ -118,13 +117,14 @@ main {
                     cell=1
                 else if neighbors!=4
                     cell=0
-                new_world[offset] = cell
+                @(new_world_ptr + x) = cell
 
                 ; draw new cell
                 ; txt.setchr(x,y,cell_chars[cell])
                 cx16.VERA_DATA0 = cell_chars[cell]
             }
-            voffset += STRIDE
+            active_world_ptr += STRIDE
+            new_world_ptr += STRIDE
         }
 
         active_world = new_world