Made context destruction more consistent and safe against duplicate slot freeing

FSR3UnityPlugin.cpp

@@ -144,14 +144,14 @@ extern "C" bool UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API AMDUP_InitApi()
 
 extern "C" void UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API AMDUP_ShutdownApi()
 {
-    for (auto& feature : s_Features)
+    for (uint32_t slot = 0; slot < s_Features.size(); ++slot)
     {
+        auto& feature = s_Features[slot];
         if (feature.upscalingContext != nullptr)
         {
             ffx::DestroyContext(feature.upscalingContext);
+            FreeFeatureSlot(slot);
         }
-
-        memset(&feature, 0, sizeof(FSR3Feature));
     }
     
     s_BackendDesc.device = nullptr;
@@ -226,9 +226,11 @@ static void UNITY_INTERFACE_API OnRenderEventAndData(int eventID, void* data)
             return;
 
         auto& feature = s_Features[featureSlot];
+        if (feature.upscalingContext != nullptr)
+        {
             ffx::DestroyContext(feature.upscalingContext);
-
             FreeFeatureSlot(featureSlot);
+        }
         break;
     }
     case BaseEventId + FSR3PluginEvent::eExecute:
@@ -316,6 +318,7 @@ static void UNITY_INTERFACE_API OnSetTextureEvent(int eventID, void* data)
 
     auto* params = (UnityRenderingExtTextureUpdateParamsV2*)data;
 
+    // userData = (featureId & (int) ushort.MaxValue) << 16 | (textureSlot & (int) short.MaxValue) << 1 | (clearTextureTable ? 1 : 0);
     uint32_t featureSlot = (params->userData >> 16) & 0xFFFF;
     uint32_t textureSlot = (params->userData >> 1) & 0x7FFF;
     uint32_t clearTextureTable = params->userData & 0x1;