Fixed memory corruption issue caused by SHMaterialInstance::SetMaterial()

SHADE_Engine/src/Graphics/MiddleEnd/Interface/SHMaterialInstance.h

@@ -43,9 +43,9 @@ namespace SHADE
     /*-----------------------------------------------------------------------------*/
     struct OverrideData
     {
-      size_t Index;
+      uint32_t Index;
-      size_t DataSize;
+      uint32_t DataSize;
-      size_t StoredDataOffset;
+      uint32_t StoredDataOffset;
     };
 
     /*-----------------------------------------------------------------------------*/

SHADE_Engine/src/Graphics/MiddleEnd/Interface/SHMaterialInstance.hpp

@@ -35,9 +35,20 @@ namespace SHADE
       dataStore.reset(new char[dataStoreSize]);
     }
 
+    // Check if this was stored before
+    const uint32_t VAR_IDX = SHADER_INFO->GetVariableIndex(key);
+    auto existingOverride = std::find_if(overrideData.begin(), overrideData.end(), [&](const OverrideData& od)
+    {
+        return od.Index == VAR_IDX;
+    });
+    
+    // Otherwise, create it
+    if (existingOverride == overrideData.end())
+    {
       OverrideData od;
-    od.Index = SHADER_INFO->GetVariableIndex(key);
+      od.Index = VAR_IDX;
       od.DataSize = sizeof(T);
+
       if (overrideData.empty())
       {
         od.StoredDataOffset = 0;
@@ -48,12 +59,14 @@ namespace SHADE
         od.StoredDataOffset = lastInsertedData.StoredDataOffset + lastInsertedData.DataSize;
       }
 
-    // Get offset and modify the memory directly
-    T* dataPtr = reinterpret_cast<T*>(dataStore.get() + od.StoredDataOffset);
-    *dataPtr = value;
-
       // Save the override data information
       overrideData.emplace_back(std::move(od));
+      existingOverride = overrideData.end() - 1;
+    }
+
+    // Get offset and modify the memory directly
+    T* dataPtr = reinterpret_cast<T*>(dataStore.get() + existingOverride->StoredDataOffset);
+    *dataPtr = value;
     
     // Flag
 	dataWasChanged = true;