From 2ce91ef49c50882cf1d7cff71bc97e9ea0551235 Mon Sep 17 00:00:00 2001
From: Dennis Ranke <dennis.ranke@gmail.com>
Date: Wed, 22 Jun 2022 00:18:20 +0200
Subject: [PATCH] continue TomCat's optimization of the tunnel

---
 examples/wat/tunnel_opt.wat | 74 +++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 examples/wat/tunnel_opt.wat

diff --git a/examples/wat/tunnel_opt.wat b/examples/wat/tunnel_opt.wat
new file mode 100644
index 0000000..9214917
--- /dev/null
+++ b/examples/wat/tunnel_opt.wat
@@ -0,0 +1,74 @@
+(module
+  (import "env" "atan2" (func $atan2 (param f32 f32) (result f32)))
+  (import "env" "time" (func $time (result f32)))
+  (import "env" "memory" (memory 4))
+  (func (export "upd")
+    (local $y i32)
+    (local $i i32) 
+    (local $x i32)
+
+    (loop $pixels
+      i32.const 1
+      local.get $i
+
+      local.get $i
+
+      i32.const 36928
+      f32.convert_i32_s
+      local.get $i
+      i32.const 320
+      i32.rem_s
+      i32.const 160
+      i32.sub
+      local.tee $x
+      local.get $x
+      i32.mul
+      local.get $i
+      i32.const 320
+      i32.div_s
+      i32.const 120
+      i32.sub
+      local.tee $y
+      local.get $y
+      i32.mul
+      i32.add
+      f32.convert_i32_s
+      f32.sqrt
+      f32.div
+      i32.const 163
+      f32.convert_i32_s
+      call $time
+      f32.mul
+      f32.add
+      i32.trunc_sat_f32_s
+
+      i32.const 163
+      f32.convert_i32_s
+      local.get $x
+      f32.convert_i32_s
+      local.get $y
+      f32.convert_i32_s
+      call $atan2
+      f32.mul
+      i32.const 64
+      f32.convert_i32_s
+      call $time
+      f32.mul
+      f32.add
+      i32.trunc_f32_s
+
+      i32.xor
+      i32.const 4
+      i32.shr_s
+      i32.const 15
+      i32.and
+      i32.store8 offset=120
+
+      i32.add
+      local.tee $i
+      i32.const 76800
+      i32.rem_s
+      br_if $pixels
+  )
+ )
+)