Is it possible to make it work in Unity 2019?

[AgrYpn1a]

Hey, I am having trouble using this in Unity 2019, there is an error in the Unity Collections dependency package, something about ReadOnly missing from the NativeArray.

[psydack]

Hello there.

I think the error you're saying happens because the original it uses a NativeArray to do some render stuff, like this:

// RendererMesh.cs or RendererProcedual.cs
// ... line160
// TODO: Convert NativeArray to C# array or list (remove collections).
NativeArray<ImDrawVert> vtxArray = NativeArrayUnsafeUtility.ConvertExistingDataToNativeArray<ImDrawVert>(
	(void*)drawList.VtxBuffer.Data, drawList.VtxBuffer.Size, Allocator.None);
NativeArray<ushort> idxArray = NativeArrayUnsafeUtility.ConvertExistingDataToNativeArray<ushort>(
	(void*)drawList.IdxBuffer.Data, drawList.IdxBuffer.Size, Allocator.None);

There is no workaround yet but If you rewrite those lines I'll be glad to merge with the main. =)

Thanks.

[AgrYpn1a]

okay, I've cloned your project directly into the Assets [this way it didn't pull the dependencies] of an empty Unity 2019 Project and it didn't complain about collections, rather it complained about the SetSubMeshes, as it didn't exist, so I had to set the meshes one by one in the loop above:

             // [RenderMesh.cs]
	      for (int i = 0, iMax = drawList.CmdBuffer.Size; i < iMax; ++i)
	      {
		      ImDrawCmdPtr cmd = drawList.CmdBuffer[i];
		      SubMeshDescriptor descriptor = new SubMeshDescriptor
		      {
			      topology = MeshTopology.Triangles,
			      indexStart = idxOf + (int)cmd.IdxOffset,
			      indexCount = (int)cmd.ElemCount,
			      baseVertex = vtxOf + (int)cmd.VtxOffset,
		      };
		      descriptors.Add(descriptor);
                      // This line HERE *********
		      _mesh.SetSubMesh(i, descriptor, NoMeshChecks);
	      }
      
	      vtxOf += vtxArray.Length;
	      idxOf += idxArray.Length;
      }
  }
  
  _mesh.UploadMeshData(false);

Now, I am not sure, but it appears that collections used are there by default in Unity 2019, maybe they separated it into a package later to make Unity lighter, so I am thinking maybe we could just modify this part of the code, and add a conditional package dependency based on Unity version, not sure if that's possible?

[AgrYpn1a]

Alright, I got it working without the NativeArrays.. I do not think it's the best way as it possibly affects performance but I can't tell how much.. plus I don't think there's another way.

[NOTE] Not sure if it's something local, but I first went and just removed the Collections package and it worked in 2019 after modifying what I wrote in a comment above, then I run the same project and upgraded it to 2020 and it was still working without the package. Are you sure you need that dependency?

Here's a screenshot of everything working with FPS, I'll do a pull request and then decide whether or not you want to use it, meanwhile I'll for the repo because I need this asap.

[psydack]

Wow, nice!

I'll test this into a different branch.

[edit]
You're right, we don't need the collections package. ;)

Thank you for your effort.

[AgrYpn1a]

So to sum up...

I did some more testing, there are some more issues, for example while the code I wrote there fixes the compile error and it seems to be working, some parts of imgui features do not work as expected.. not sure if I can further investigate, however this concerns only the Mesh rendering type, you can go fine with Procedural.

About the NativeArray issues, I believe you can freely get rid of the dependency, test it out with your version of Unity to be sure, but here it works fine without it, because it's a built-in feature of Unity.

And that's pretty much it, in the end we just gotta fix that compile error and get rid of the dependency.

[psydack]

The original goal doesn't include the 2019 support, so I think the best way is to rip off render mesh for < 2020.

Thanks again!

[AgrYpn1a]

Sure, that will be quite enough! :) and np, doing this because I also need it hehe, might hear from me again :)