From 6681593cb2db39b6ab35d5b44066212e9d68b979 Mon Sep 17 00:00:00 2001
From: Kaalleen <36401965+kaalleen@users.noreply.github.com>
Date: Sun, 13 Apr 2025 21:41:46 +0200
Subject: Fix simulator scale for small elements (#3658)

Co-authored-by: CapellanCitizen <>
---
 lib/gui/simulator/drawing_panel.py | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/lib/gui/simulator/drawing_panel.py b/lib/gui/simulator/drawing_panel.py
index d343ea5d..abe6fa0f 100644
--- a/lib/gui/simulator/drawing_panel.py
+++ b/lib/gui/simulator/drawing_panel.py
@@ -3,7 +3,7 @@
 # Copyright (c) 2024 Authors
 # Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
 import time
-from sys import platform
+import math
 
 import wx
 from numpy import split
@@ -217,15 +217,24 @@ class DrawingPanel(wx.Panel):
 
         one_mm = PIXELS_PER_MM * self.zoom
         scale_width = one_mm
+        scale_width_mm = 1
         max_width = min(canvas_width * 0.5, 300)
-
-        while scale_width > max_width:
-            scale_width /= 2.0
-
-        while scale_width < 50:
-            scale_width += one_mm
-
-        scale_width_mm = int(scale_width / self.zoom / PIXELS_PER_MM)
+        min_width = 50
+
+        if scale_width > max_width:
+            # max_width = one_mm * 2 ^ x
+            # x = log2(max_width/one_mm)
+            exponent = math.floor(math.log2(max_width/one_mm))
+            if exponent < -6:
+                canvas.EndLayer()
+                return
+
+            scale_width = one_mm * 2 ** exponent
+            scale_width_mm = round(2 ** exponent, 2)
+
+        if scale_width < min_width:
+            scale_width_mm = int(min_width / one_mm)
+            scale_width = one_mm * scale_width_mm
 
         # The scale bar looks like this:
         #
-- 
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