WebGPU backend incorrectly assumes WGPUTextureView pointers will never be reused about imgui HOT 8 OPEN

I don't really know/understand WebGPU yet but I would assume we could call wgpuDeviceCreateBindGroup() one time per frame with a list of all unique WGPUTextureView, and then call wgpuRenderPassEncoderSetBindGroup() with the right index?

So we remove bd->ImageBindGroups[] as a persistent storage, instead we use it as temporary storage during the frame:

• iterate all draw cmd to create a list of unique WGPUTextureView, with each a unique integer.
• create the bind group
• iterate all draw cmd to perform render, call wgpuRenderPassEncoderSetBindGroup() with the right index pulled from that map?

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Hello,

Do you have a suggested solution as to how to decently solve this?

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I'm not sure WebGPU exposes any kind of truly unique identifier for resources.

The only decent solution I can think of is to remove the cache, use WGPUBindGroup as ImTextureID, and provide a helper function for the user to create bind groups from texture views. It would unfortunately require the user to manually manage those bind groups, which kind of feels like it goes against the spirit of IMGUI.

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That sounds like a reasonable solution. I'm new to WebGPU as well, so that didn't even occur to me.

It might be worth supporting multiple bind groups for "chunks", since WGPULimits::maxBindingsPerBindGroup could be as low as 640.

Edit: Actually, I think such a solution would require the proposed binding_array feature, which isn't in the spec yet.

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Let's start with a single bind group and we can easily change it to multiple of them based on runtime limits.

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I don't have test code for loading a texture in the WebGPU example so one would be helpful but otherwise I'll work toward one eventually.

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Hello @dkaste, could you share your workaround solution? I'm facing the same issue and a temporary work around would help. Thanks!

Edit: never mind, was able to figure it out. Just called bd->renderResources.ImageBindGroups.Clear(); at the beginning of ImGui_ImplWGPU_RenderDrawData

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As mentioned, I would likely be able to tackle the issue if I had an example of loading textures with WebGPU, e.g a WebGPU version of the tutorial here: https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples

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