From c65410a92d22758245bd5fca451e1b137619ee83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A1lint=20Hodossy?= <bkh16@ic.ac.uk>
Date: Sun, 18 Feb 2024 14:45:54 +0000
Subject: [PATCH] Preliminary support for plugins. Load all plugins in plugin
 folder.

---
 unity/Editor/Importer/MjImporterWithAssets.cs |  1 +
 unity/Runtime/Importer/MjcfImporter.cs        |  5 +++++
 unity/Runtime/Plugins.meta                    |  8 ++++++++
 unity/Runtime/Tools/MjEngineTool.cs           | 10 ++++++++++
 4 files changed, 24 insertions(+)
 create mode 100644 unity/Runtime/Plugins.meta

diff --git a/unity/Editor/Importer/MjImporterWithAssets.cs b/unity/Editor/Importer/MjImporterWithAssets.cs
index 6f3f8c61..4713a9f8 100644
--- a/unity/Editor/Importer/MjImporterWithAssets.cs
+++ b/unity/Editor/Importer/MjImporterWithAssets.cs
@@ -50,6 +50,7 @@ public class MjImporterWithAssets : MjcfImporter {
     // mjcfString.
     var name = Path.GetFileNameWithoutExtension(filePath) + $"{UnityEngine.Random.Range(0,999)}";
     string newPath = Path.Combine(Application.temporaryCachePath, $"{name}.xml");
+    MjEngineTool.LoadPlugins();
     _mjModel = MjEngineTool.LoadModelFromFile(filePath);
     MjEngineTool.SaveModelToFile(newPath, _mjModel);
     Debug.Log($"Imported MJCF loaded, saved to {newPath}");
diff --git a/unity/Runtime/Importer/MjcfImporter.cs b/unity/Runtime/Importer/MjcfImporter.cs
index 3442de0b..72181007 100644
--- a/unity/Runtime/Importer/MjcfImporter.cs
+++ b/unity/Runtime/Importer/MjcfImporter.cs
@@ -284,6 +284,11 @@ public class MjcfImporter {
         CreateGameObjectWithCamera(parentObject, child);
         break;
       }
+      case "plugin": {
+        Debug.Log($"Plugin elements are only partially supported.");
+        break;
+      }
+
       default: {
         Debug.Log($"The importer does not yet support tags <{child.Name}>.");
         break;
diff --git a/unity/Runtime/Plugins.meta b/unity/Runtime/Plugins.meta
new file mode 100644
index 00000000..5b2808be
--- /dev/null
+++ b/unity/Runtime/Plugins.meta
@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: 1135ed488170c0444b32c18cc61fb9ef
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/unity/Runtime/Tools/MjEngineTool.cs b/unity/Runtime/Tools/MjEngineTool.cs
index bc07258e..1cac32e6 100644
--- a/unity/Runtime/Tools/MjEngineTool.cs
+++ b/unity/Runtime/Tools/MjEngineTool.cs
@@ -368,6 +368,16 @@ public static class MjEngineTool {
       }
     }
   }
+
+  public static void LoadPlugins() {
+    if(!Directory.Exists("Packages/org.mujoco/Runtime/Plugins/")) return;
+
+    foreach (string pluginPath in Directory.GetFiles("Packages/org.mujoco/Runtime/Plugins/")) {
+      MujocoLib.mj_loadPluginLibrary(pluginPath);
+    }
+    
+  }
+
 }
 
 public static class MjSceneImportSettings {