Use SetNum EAllowShrinking (UE 5.5 compatibility)

[ericwomer]

* Fixes for deprication warnings with update to 5.5.2 (5.5.1 also?) messages
* Changes bool param for allowing shrinking to enum EAllowShrinking

[jonpas]

Is compatibility with 4.27 checked?

[ericwomer]

Is compatibility with 4.27 checked?

I don't have 4.27 Installed, eventually you will have to have two versions of this plugin one for UE5 and one for UE4, especially when then remove the deprecated features are removed, you could wrap it in #if blocks though.

[jonpas]

I am well aware, for now #if declarations will do, we will split when it will become necessary.

[ericwomer]

Would something like this work for you?

ImGuiContextProxy.cpp

		// Setting Allow Shrinking via bool bAllowShrinking is deprecated in engines 5.5 and higher
		#if  ((ENGINE_MAJOR_VERSION > 4) && (ENGINE_MINOR_VERSION > 4))
			DrawLists.SetNum(DrawData->CmdListsCount, EAllowShrinking::No);
		#else
			DrawLists.SetNum(DrawData->CmdListsCount, false);
		#endif

ImGuiDrawData.cpp

	// Setting Allow Shrinking via bool bAllowShrinking is deprecated in engines 5.5 and higher
	#if ((ENGINE_MAJOR_VERSION > 4) && (ENGINE_MINOR_VERSION > 4))
		// Reset buffer.
		OutIndexBuffer.SetNumUninitialized(NumElements, EAllowShrinking::No);
	#else
		// Reset buffer.
		OutIndexBuffer.SetNumUninitialized(NumElements,  false);
	#endif

**EDIT The engine still threw warning about deprecation even though the code was unreachable so I wrapped it in pre-processor blocks

[jonpas]

Use the following preprocessor macros:

UnrealImGui/Source/ImGui/Private/VersionCompatibility.h

Lines 5 to 6 in 2f81668

	#define BELOW_ENGINE_VERSION(Major, Minor) (ENGINE_MAJOR_VERSION < (Major) || (ENGINE_MAJOR_VERSION == (Major) && ENGINE_MINOR_VERSION < (Minor)))
	#define FROM_ENGINE_VERSION(Major, Minor) !BELOW_ENGINE_VERSION(Major, Minor)

Feel free to even add a definition for this specifically at the end.

[ericwomer]

I made the last push because the deprecation was introduced in January of 2024 but wasn't pushed to release until 5.4.

[kushagra10025]

Hey,
Have tested this PR with 4.27, 5.3, 5.4 and 5.5. Looks good to me. Should be safe to merge :)

Thanks 😄

[jonpas]

Awesome! Thank you very much!