From c2bef232b6e15144ec5ca33a9736105539f86856 Mon Sep 17 00:00:00 2001
From: Balint-H <bkh16@ic.ac.uk>
Date: Thu, 14 Mar 2024 12:38:56 +0000
Subject: [PATCH] Handle the implicit auto value for limits now written by the
 compiler to the xml

---
 .../Components/Joints/MjJointSettings.cs      |  9 +-------
 unity/Runtime/Components/MjActuator.cs        | 11 ++++------
 unity/Runtime/Tools/XmlElementExtensions.cs   | 22 +++++++++++++++++++
 3 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/unity/Runtime/Components/Joints/MjJointSettings.cs b/unity/Runtime/Components/Joints/MjJointSettings.cs
index 322d6568..46da927c 100644
--- a/unity/Runtime/Components/Joints/MjJointSettings.cs
+++ b/unity/Runtime/Components/Joints/MjJointSettings.cs
@@ -165,14 +165,7 @@ namespace Mujoco {
       ImpFriction.FromMjcf(mjcf, "solimpfriction");
       FrictionLoss = mjcf.GetFloatAttribute("frictionloss", 0.0f);
 
-      bool defaultLimited = false;
-      if ((mjcf.OwnerDocument.GetElementsByTagName("compiler")[0]?["compiler"])
-              ?.GetBoolAttribute("autolimits", true) ??
-          true) {
-        defaultLimited = mjcf.HasAttribute("range");
-      }
-
-      Limited = mjcf.GetBoolAttribute("limited", defaultLimited);
+      Limited = mjcf.GetLimitedAttribute("limited", mjcf.HasAttribute("range"));
       Margin = mjcf.GetFloatAttribute("margin", defaultValue: 0.0f);
     }
   }
diff --git a/unity/Runtime/Components/MjActuator.cs b/unity/Runtime/Components/MjActuator.cs
index 9aacf2bf..e44b8579 100644
--- a/unity/Runtime/Components/MjActuator.cs
+++ b/unity/Runtime/Components/MjActuator.cs
@@ -82,13 +82,10 @@ public class MjActuator : MjComponent {
       LengthRange = mjcf.GetVector2Attribute("lengthrange", defaultValue: Vector2.zero);
       Gear = mjcf.GetFloatArrayAttribute("gear", defaultValue: new float[] { 1.0f }).ToList();
 
-      bool autolimits = (mjcf.OwnerDocument.GetElementsByTagName("compiler")[0]?["compiler"])
-                            ?.GetBoolAttribute("autolimits", true) ??
-                        false;
-      CtrlLimited = mjcf.GetBoolAttribute("ctrllimited",
-          defaultValue: autolimits ? CtrlRange != Vector2.zero : false);
-      ForceLimited = mjcf.GetBoolAttribute("forcelimited",
-          defaultValue: autolimits ? ForceRange != Vector2.zero : false);
+      CtrlLimited = mjcf.GetLimitedAttribute("ctrllimited",
+          rangeDefined: mjcf.HasAttribute("ctrlrange"));
+      ForceLimited = mjcf.GetLimitedAttribute("forcelimited",
+          rangeDefined: mjcf.HasAttribute("forcerange"));
     }
   }
 
diff --git a/unity/Runtime/Tools/XmlElementExtensions.cs b/unity/Runtime/Tools/XmlElementExtensions.cs
index 246f3d34..9dd8996a 100644
--- a/unity/Runtime/Tools/XmlElementExtensions.cs
+++ b/unity/Runtime/Tools/XmlElementExtensions.cs
@@ -37,6 +37,28 @@ public static class XmlElementExtensions {
     }
   }
 
+  public static bool GetLimitedAttribute(
+      this XmlElement element, string name, bool rangeDefined) {
+    var strValue = element.GetStringAttribute(name, "auto");
+    if (strValue == "auto" && rangeDefined && element.GetAutolimitsEnabled()) return true;
+    if (strValue == "auto") return false;
+
+    bool parsedValue;
+    if (bool.TryParse(strValue, out parsedValue)) {
+      return parsedValue;
+    } else {
+      throw new ArgumentException($"'{strValue}' is not a bool.");
+    }
+  }
+
+  public static bool GetAutolimitsEnabled(
+      this XmlElement element) {
+    bool autolimits = (element.OwnerDocument?.GetElementsByTagName("compiler")[0]?["compiler"])
+                      ?.GetBoolAttribute("autolimits", true) ??
+                      true;
+    return autolimits;
+  }
+
   public static float GetFloatAttribute(
       this XmlElement element, string name, float defaultValue = 0.0f) {
     if (!element.HasAttribute(name)) {