[iOS] Metal-Prerelease: Map Snapshotter fails on simulator

[hactar]

Describe the bug
When using the metal prerelease, for example ios-v6.0.0-pre8820165ccafb4f3db109b0b4ae91739d577d7ece you cannot use MLNMapSnapshotter on the iOS simulator, for example an iPhone Pro 15 (17.2) simulator. The code builds and runs fine, but during snapshotting, the app crashes with the following message:

-[MTLTextureDescriptorInternal validateWithDevice:]:1357: failed assertion `Texture Descriptor Validation
MTLTextureDescriptor: Depth, Stencil, DepthStencil textures cannot be allocated with MTLStorageModeShared on this device.

On real devices, for example my iPhone 12 Pro Max running iOS 17.1 the snapshotter works fine.

To Reproduce

• Build and run the attached project on the simulator.
• Hit the "Generate Map Snapshot"

Expected behavior
A UIImage of the map should be generated. Instead the app crashes as described above.

Screenshots
On device, this works, the final result being this:

Platform information (please complete the following information):

• iOS 17.2 Simulator
• Version ios-v6.0.0-pre8820165ccafb4f3db109b0b4ae91739d577d7ece

Example App
MapLibreSnapshotterExample.zip

[louwers]

Thanks for the report! This is expected. The Snapshotter still needs to be implemented for Metal. #1862

[louwers]

I updated the pre-release overview thread. #1609

Please let us know if you come across anything else!