Panic with DX12 VirtualGpu

[parasyte]

OS: Windows 10
GPU: Intel HD Graphics 2500

An assertion was added in #348 to ensure the device supports the requested number of bind groups. Unfortunately, this doesn't seem good in practice. I have a really old Intel integrated GPU and the DX12 backend reports that the device supports 0 max_bound_descriptor_sets.

Here I have printed the values of both variables being asserted (desc.limits.max_bind_groups is from wgpu::DeviceDescriptor::default()):

[2019-10-24T03:34:03Z INFO  wgpu_native::instance] Adapter Dx12 AdapterInfo { name: "Microsoft Basic Render Driver", vendor: 5140, device: 140, device_type: VirtualGpu }
[C:\Users\jay\projects\wgpu\wgpu-native\src\instance.rs:465] u32::from(limits.max_bound_descriptor_sets) = 0
[C:\Users\jay\projects\wgpu\wgpu-native\src\instance.rs:465] desc.limits.max_bind_groups = 4
thread 'main' panicked at 'Adapter does not support the requested max_bind_groups', C:\Users\jay\projects\wgpu\wgpu-native\src\instance.rs:466:9

Commenting out this assertion allows my simple game to run just fine (it uses a single bind group):

wgpu/wgpu-native/src/instance.rs

Lines 469 to 472 in a04a4b1

	assert!(
	u32::from(limits.max_bound_descriptor_sets) >= desc.limits.max_bind_groups,
	"Adapter does not support the requested max_bind_groups"
	);

Also, an aside, this page claims that Vulkan is supported, but gfx-backend-vulkan returns no supported devices.

[parasyte]

Some research shows that Vulkan 1.0 is only supported in the Linux driver for this GPU. :)