From a0c603ee7aabcf30d4290f74f879f4b714068616 Mon Sep 17 00:00:00 2001
From: Hugo H <hugo@haaxman.co.uk>
Date: Thu, 25 Dec 2025 19:50:13 +0000
Subject: [PATCH] Fixed CENTERX and CENTERY variables

---
 editor.html |  3 ++-
 screen.js   | 38 ++++++++++++++++++++++++++------------
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/editor.html b/editor.html
index fe24d32..ee0a527 100644
--- a/editor.html
+++ b/editor.html
@@ -267,8 +267,9 @@
 
         function builtinRead(x) {
             if (x === 'screen' || x === './screen.js') {
+                const url = new URL('screen.js', window.location.href).href;
                 const xhr = new XMLHttpRequest();
-                xhr.open("GET", document.location.href + "screen.js", false);
+                xhr.open("GET", url, false);
                 xhr.send();
                 if (xhr.status === 200) return xhr.responseText;
                 else throw "Could not load screen.js";
diff --git a/screen.js b/screen.js
index 81d8e1a..071fb98 100644
--- a/screen.js
+++ b/screen.js
@@ -162,29 +162,43 @@ var $builtinmodule = function (name) {
         };
     }
 
-    Object.defineProperty(mod, 'T', { get: function () { return toPy(typeof T !== 'undefined' ? T : 0); } });
-    Object.defineProperty(mod, 'W', { get: function () { return toPy(typeof W !== 'undefined' ? W : 0); } });
-    Object.defineProperty(mod, 'H', { get: function () { return toPy(typeof H !== 'undefined' ? H : 0); } });
+    Object.defineProperty(mod, 'T', { get: function () { return toPy(lc_instance ? lc_instance.T : (window.T || 0)); } });
+    Object.defineProperty(mod, 'W', { get: function () { return toPy(lc_instance ? lc_instance.W : (window.W || 0)); } });
+    Object.defineProperty(mod, 'H', { get: function () { return toPy(lc_instance ? lc_instance.H : (window.H || 0)); } });
     Object.defineProperty(mod, 'MX', {
         get: function () {
-            if (typeof MX === 'undefined') return toPy(-1);
+            let mx = lc_instance ? lc_instance.MX : (window.MX || -1);
             const el = document.getElementById('canvas');
-            if (!el) return toPy(MX);
+            if (!el || mx === -1) return toPy(mx);
             const r = el.getBoundingClientRect();
-            return toPy((MX - r.left) * (el.width / r.width));
+            return toPy((mx - r.left) * (el.width / r.width));
         }
     });
     Object.defineProperty(mod, 'MY', {
         get: function () {
-            if (typeof MY === 'undefined') return toPy(-1);
+            let my = lc_instance ? lc_instance.MY : (window.MY || -1);
             const el = document.getElementById('canvas');
-            if (!el) return toPy(MY);
+            if (!el || my === -1) return toPy(my);
             const r = el.getBoundingClientRect();
-            return toPy((MY - r.top) * (el.height / r.height));
+            return toPy((my - r.top) * (el.height / r.height));
+        }
+    });
+    Object.defineProperty(mod, 'CENTERX', {
+        get: function () {
+            if (lc_instance && lc_instance.CENTERX !== undefined) return toPy(lc_instance.CENTERX);
+            if (window.CENTERX !== undefined) return toPy(window.CENTERX);
+            let w = lc_instance ? lc_instance.W : (window.W || 0);
+            return toPy(w / 2);
+        }
+    });
+    Object.defineProperty(mod, 'CENTERY', {
+        get: function () {
+            if (lc_instance && lc_instance.CENTERY !== undefined) return toPy(lc_instance.CENTERY);
+            if (window.CENTERY !== undefined) return toPy(window.CENTERY);
+            let h = lc_instance ? lc_instance.H : (window.H || 0);
+            return toPy(h / 2);
         }
     });
-    Object.defineProperty(mod, 'CENTERX', { get: function () { return toPy(typeof CENTERX !== 'undefined' ? CENTERX : 0); } });
-    Object.defineProperty(mod, 'CENTERY', { get: function () { return toPy(typeof CENTERY !== 'undefined' ? CENTERY : 0); } });
 
     mod.PI = toPy(Math.PI);
     mod.TWO_PI = toPy(Math.PI * 2);
@@ -223,4 +237,4 @@ var $builtinmodule = function (name) {
     mod.resume = new Sk.builtin.func(() => { resume(); return Sk.builtin.none.none$; });
 
     return mod;
-};
\ No newline at end of file
+};