From 63b0b11510c623b3b847a084cf29fd39fb04b578 Mon Sep 17 00:00:00 2001
From: Scott Richmond <kredati@users.noreply.github.com>
Date: Thu, 2 Jan 2025 16:28:12 -0500
Subject: [PATCH] change turtle color based on background color so it's always
 visible

---
 build/ludus.mjs | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/build/ludus.mjs b/build/ludus.mjs
index bf99997..992ef88 100644
--- a/build/ludus.mjs
+++ b/build/ludus.mjs
@@ -189,15 +189,17 @@ const turtle_radius = 20
 
 const turtle_angle = 0.385
 
-const turtle_color = [255, 255, 255, 150]
+let turtle_color = [255, 255, 255, 150]
 
-const p5_call_root = [
-  ["background", ...resolve_color(background_color)],
-  ["push"],
-  ["rotate", Math.PI],
-  ["scale", -1, 1],
-  ["stroke", ...resolve_color(turtle_init.pencolor)],
-]
+function p5_call_root () {
+  return [
+    ["background", ...resolve_color(background_color)],
+    ["push"],
+    ["rotate", Math.PI],
+    ["scale", -1, 1],
+    ["stroke", ...resolve_color(turtle_init.pencolor)],
+  ]
+}
 
 function rotate (vector, heading) {
   const radians = turn_to_rad(heading)
@@ -293,7 +295,8 @@ export function svg (commands) {
     return accum
     
   }, {maxX: 0, maxY: 0, minX: 0, minY: 0})
-  const [r, g, b, a] = resolve_color(background_color)
+  const [r, g, b, a] = resolve_color(background_color)  
+  if ((r+g+b)/3 > 128) turtle_color = [0, 0, 0, 150]
   const view_width = (maxX - minX) * 1.2
   const view_height = (maxY - minY) * 1.2
   const margin = Math.max(view_width, view_height) * 0.1
@@ -353,7 +356,9 @@ export function p5 (commands) {
     return new_state
   }, turtle_init)
   // console.log(states)
-  const p5_calls = [...p5_call_root]
+  const [r, g, b, _] = resolve_color(background_color)  
+  if ((r + g + b)/3 > 128) turtle_color = [0, 0, 0, 150]
+  const p5_calls = [...p5_call_root()]
   for (let i = 1; i < states.length; ++i) {
     const prev = states[i - 1]
     const curr = states[i]