From 865510ce332d2f18cf74f7a5da8bf1be8846011f Mon Sep 17 00:00:00 2001
From: Mario Voigt <mario.voigt@stadtfabrikanten.org>
Date: Tue, 2 Jul 2024 21:06:11 +0200
Subject: [PATCH] fix small bugs in isometric projection

---
 .../isometric_projection/dimetric_projection.inx               | 2 +-
 .../isometric_projection/isometric_projection.inx              | 2 +-
 .../isometric_projection/isometric_projection.py               | 3 +++
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/extensions/fablabchemnitz/isometric_projection/dimetric_projection.inx b/extensions/fablabchemnitz/isometric_projection/dimetric_projection.inx
index 4c3497b..e179461 100644
--- a/extensions/fablabchemnitz/isometric_projection/dimetric_projection.inx
+++ b/extensions/fablabchemnitz/isometric_projection/dimetric_projection.inx
@@ -8,7 +8,7 @@
         <option value="right">Dimetric right-hand side</option>
     </param>
     <param name="reverse" type="bool" gui-text="Reverse transformation">false</param>
-    <param name="orthoangle" type="float" precision="3" min="0.000" max="90.000" gui-text="Orthographic angle">15.000</param>
+    <param name="orthoangle" type="float" precision="3" min="0.001" max="90.000" gui-text="Orthographic angle">15.000</param>
     <effect>
         <object-type>all</object-type>
         <effects-menu>
diff --git a/extensions/fablabchemnitz/isometric_projection/isometric_projection.inx b/extensions/fablabchemnitz/isometric_projection/isometric_projection.inx
index e18b5f0..0a4338f 100644
--- a/extensions/fablabchemnitz/isometric_projection/isometric_projection.inx
+++ b/extensions/fablabchemnitz/isometric_projection/isometric_projection.inx
@@ -8,7 +8,7 @@
         <option value="right">Isometric right-hand side</option>
     </param>
     <param name="reverse" type="bool" gui-text="Reverse transformation">false</param>
-    <param name="orthoangle" type="float" precision="3" min="0" max="90" gui-text="Orthographic angle">30.000</param>
+    <param name="orthoangle" type="float" precision="3" min="0.001" max="90.000" gui-text="Orthographic angle">30.000</param>
     <effect>
         <object-type>all</object-type>
         <effects-menu>
diff --git a/extensions/fablabchemnitz/isometric_projection/isometric_projection.py b/extensions/fablabchemnitz/isometric_projection/isometric_projection.py
index f23a262..7d633e1 100644
--- a/extensions/fablabchemnitz/isometric_projection/isometric_projection.py
+++ b/extensions/fablabchemnitz/isometric_projection/isometric_projection.py
@@ -67,6 +67,9 @@ class IsometricProjection(inkex.EffectExtension):
         self.arg_parser.add_argument('--orthoangle', type=float, default=15.0, help='Isometric angle in degrees')
 
     def __initConstants(self, angle):
+        if angle == 0:
+            inkex.utils.debug("angle is set to 0°. This is not supported")
+            return
         # Precomputed values for sine, cosine, and tangent of orthoangle.
         self.rad = math.radians(angle)
         self.cos = math.cos(self.rad)