Fix #303

- Completely review the way of how the preview icon is releasing the
resources.
- Never ever release resources from the finalizer! Unity will just
crash, it won't politely report the mistake.

CHANGELOG.md

@@ -3,6 +3,7 @@
 * [Fix #301] "volumeOverride" is not working .
 * [Fix #297] IMC-15K has wrong part volume.
 * [Fix #302] Structurel panel has wrong nodes.
+* [Fix #303] Game's crashing on the new parts.
 
 # 1.17 (January 28th, 2019):
 * KSP 1.6 support. This mod's version is not compatible with the prior versions of KSP!

Source/KIS_IconViewer.cs

@@ -1,25 +1,27 @@
 using KISAPIv1;
+using KSPDev.LogUtils;
 using KSPDev.PartUtils;
 using System;
 using System.Linq;
 using UnityEngine;
 
 namespace KIS {
 
-public sealed class KIS_IconViewer : IDisposable {
+  public sealed class KIS_IconViewer {
   const float IconPosY = 0;
   const int CameraLayer = 22;
   const float LightIntensity = 0.4f;
   const float CameraZoom = 0.75f;
   const float RotationsPerSecond = 0.20f;  // Full round in 5 seconds.
 
   Camera camera;
-  int cameraShift;
+  float cameraShift;
   GameObject iconPrefab;
+  bool disposed;
 
   static Light iconLight;
-  static int cameraGlobalShift;
   static int iconCount;
+  static float globalCameraShift;
 
   public Texture texture { get; private set; }
 
@@ -29,39 +31,45 @@ public sealed class KIS_IconViewer : IDisposable {
     } else {
       MakePartIcon(part.partInfo, resolution, VariantsUtils.GetCurrentPartVariant(part));
     }
-    iconCount += 1;
   }
 
   public KIS_IconViewer(AvailablePart avPart, int resolution, PartVariant variant) {
     MakePartIcon(avPart, resolution, variant);
-    iconCount += 1;
   }
 
+  /// <summary>Warns if the icon is not disposed properly.</summary>
+  /// <remarks>
+  /// This method cannot release the Unity resources since teh access to them is only allowed from
+  /// the Unity main thread. The best thing this method can do is spamming log errors.
+  /// </remarks>
   ~KIS_IconViewer() {
-    if (camera != null) {
-      Dispose();
+    if (!disposed) {
+      DebugEx.Error("RESOURCES LEAK! The IconViewer was not disposed: camera={0}, iconPrefab={1}",
+                    camera, iconPrefab);
     }
   }
+
+  /// <summary>Releases all the used resources.</summary>
+  /// <remarks>
+  /// This method <i>must</i> be called if an icon becomes unusable. Otherwise, all the cached Unity
+  /// objects will live and take memory till the scene is reloaded. Some of the internal counters
+  /// will also not get updated as expected. Simply put, jut call it!
+  /// <para>It's safe to call this method multiple times.</para>
+  /// </remarks>
+  public void Dispose() {
+    if (!disposed) {
+      if (camera != null) {
+        UnityEngine.Object.Destroy(camera.gameObject);
+      }
+      if (iconPrefab != null) {
+        UnityEngine.Object.Destroy(iconPrefab);
+      }
+      ReleaseCameraSpot();
 
-  // The Dispose() method MUST be called instead of garbage-collecting icon instances
-  // because we can only access the cam.gameObject member from the main thread.
-  public void Dispose()
-  {
-    if (camera != null) {
-      UnityEngine.Object.DestroyImmediate(camera.gameObject);
       camera = null;
-    }
-    if (iconPrefab != null) {
-      UnityEngine.Object.DestroyImmediate(iconPrefab);
       iconPrefab = null;
-    }
-    if (texture != null) {
-      (texture as RenderTexture).Release();
       texture = null;
-    }
-    iconCount -= 1;
-    if (iconCount == 0) {
-      cameraGlobalShift = 0;
+      disposed = true;
     }
   }
 
@@ -78,10 +86,6 @@ public void Dispose()
     camera.Render();  // Update snapshot.
   }
 
-  static void ResetCamIndex() {
-    cameraGlobalShift = 0;
-  }
-
   #region Local utility methods
   void SetLayerRecursively(GameObject obj, int newLayer) {
     if (null == obj) {
@@ -98,7 +102,8 @@ public void Dispose()
 
   void MakeKerbalAvatar(Part ownerPart, int resolution) {
     // Icon Camera
-    GameObject camGo = new GameObject("KASCamItem" + cameraGlobalShift);
+    cameraShift = ReserveCameraSpot();
+    GameObject camGo = new GameObject("KASCamItem" + cameraShift);
     camGo.transform.parent = ownerPart.transform;
     camGo.transform.localPosition = Vector3.zero + new Vector3(0, 0.35f, 0.7f);
     camGo.transform.localRotation = Quaternion.identity;
@@ -134,8 +139,9 @@ public void Dispose()
     }
 
     // Icon Camera
-    GameObject camGo = new GameObject("KASCamItem" + cameraGlobalShift);
-    camGo.transform.position = new Vector3(cameraGlobalShift, IconPosY, 0);
+    cameraShift = ReserveCameraSpot();
+    GameObject camGo = new GameObject("KASCamItem" + cameraShift);
+    camGo.transform.position = new Vector3(cameraShift, IconPosY, 0);
     camGo.transform.rotation = Quaternion.identity;
     camera = camGo.AddComponent<Camera>();
     camera.orthographic = true;
@@ -146,6 +152,25 @@ public void Dispose()
     RenderTexture tex = new RenderTexture(resolution, resolution, 8);
     texture = tex;
 
+    // Layer
+    camera.cullingMask = 1 << CameraLayer;
+    SetLayerRecursively(iconPrefab, CameraLayer);
+
+    // Texture
+    camera.targetTexture = tex;
+    camera.ResetAspect();
+
+    ResetPos();
+  }
+
+  void ReleaseCameraSpot() {
+    if (--iconCount == 0) {
+      globalCameraShift = 0;
+      DebugEx.Fine("Icon camera global shift is reset to zero");
+    }
+  }
+
+  float ReserveCameraSpot() {
     //light
     if (iconLight == null && HighLogic.LoadedSceneIsFlight) {
       GameObject lightGo = new GameObject("KASLight");
@@ -157,18 +182,10 @@ public void Dispose()
       iconLight.renderMode = LightRenderMode.ForcePixel;
     }
 
-    // Layer
-    camera.cullingMask = 1 << CameraLayer;
-    SetLayerRecursively(iconPrefab, CameraLayer);
-
-    // Texture
-    camera.targetTexture = tex;
-    camera.ResetAspect();
-
-    // Cam index
-    cameraShift = cameraGlobalShift;
-    cameraGlobalShift += 2;
-    ResetPos();
+    iconCount++;
+    globalCameraShift += 2.0f;
+
+    return globalCameraShift;
   }
   #endregion
 }

Source/ModuleKISInventory.cs

@@ -868,6 +868,7 @@ public enum InventoryType {
     GameEvents.OnHelmetChanged.Remove(OnHelmetChanged);
     GameEvents.onPartActionUICreate.Remove(OnPartActionMenuCreate);
     GameEvents.onEditorVariantApplied.Remove(OnPartVariandChanged);
+    DisableIcon();  // Release the resources!
   }
   #endregion