Add CreationState to fill in lightdef lookup start.

src/ObjLoading/Game/IW5/LightDef/LightDefAssetCreationStateIW5.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "Asset/IZoneAssetCreationState.h"
+#include "Asset/AssetCreationContext.h"
+#include "Game/IW5/IW5.h"
+
+namespace IW5
+{
+    constexpr auto MAX_LMAP_USAGE = 512;
+
+    class LightDefAssetCreationState : public IZoneAssetCreationState
+    {
+    public:
+        LightDefAssetCreationState();
+
+        void SetLightDefLookupStart(GfxLightDef* lightDef, AssetCreationContext& context);
+
+    private:
+        int m_lmap_pixels_used_for_falloff;
+    };
+} // namespace light_def