Wgpu

- Naga is used by default to translate shaders, SPIRV-Cross is optional behind `cross` feature
- Features:
- buffers are zero-initialized
- downlevel limits for DX11/OpenGL support
- conservative rasterization (native-only)
- buffer resource indexing (native-only)
- API adjustments to the spec:
- Renamed `RenderPassColorAttachmentDescriptor` to `RenderPassColorAttachment`:
- Renamed the `attachment` member to `view`
- Renamed `RenderPassDepthStencilAttachmentDescriptor` to `RenderPassDepthStencilAttachment`:
- Renamed the `attachment` member to `view`
- Renamed `VertexFormat` values
- Examples: `Float3` -> `Float32x3`, `Ushort2` -> `Uint16x2`
- Renamed the `depth` value of `Extent3d` to `depth_or_array_layers`
- Updated blending options in `ColorTargetState`:
- Renamed `BlendState` to `BlendComponent`
- Added `BlendState` struct to hold color and alpha blend state
- Moved `color_blend` and `alpha_blend` members into `blend` member
- Moved `clamp_depth` from `RastizerState` to `PrimitiveState`
- Updated `PrimitiveState`:
- Added `conservative` member for enabling conservative rasterization
- Updated copy view structs:
- Renamed `TextureCopyView` to `ImageCopyTexture`
- Renamed `TextureDataLayout` to `ImageDataLayout`
- Changed `bytes_per_row` and `rows_per_image` members of `ImageDataLayout` from `u32` to `Option<NonZeroU32>` <!-- wgpu-rs only -->
- Changed `BindingResource::Binding` from containing fields directly to containing a `BufferBinding`
- Added `BindingResource::BufferArray`
- Infrastructure:
- switch from `tracing` to `profiling`
- more concrete and detailed errors
- API traces include the command that crashed/panicked
- Vulkan Portability support is removed from Apple platforms
- Validation:
- texture bindings
- filtering of textures by samplers
- interpolation qualifiers
- allow vertex components to be underspecified

wgpu-core-0.7.1 (2021-02-25)

- expose `wgc::device::queue` sub-module in public
- fix the indexed buffer check
- fix command allocator race condition

Changed:

* Now targeting wgpu-native 0.12.0.1.
* Updated API to the latest WebGPU spec.
* Better error logging using the new callbacks in wgpu-native.
* All destructors (drop methods) are now working as they should.

To update, you need to adjust to the following API changes:

* The encoder's `end_pass()` are renamed to `end()`.
* The compute encoder's `dispatch()` is renamed `dispatch_workgroups`, and `dispatch_indirect` to `dispatch_workgroups_indirect`.
* The `load_value` is replaced with `clear_value` and `load_op`.
* Same for `depth_load_value` and `stencil_load_value`.
* The `device.create_sampler()` method for mipmap filtering now uses the `MipmapFilterMode` enum instead of the `FilterMode` enum. Since the fields of these enums are the same, you probably don't need to change anything.


To update, your shaders need the following changes:

* The decorators have changed from `[[...]]` to `...`.
* E.g. change `[[location(0)]]` to `location(0)`.
* E.g. change `[[group(0), binding(0)]]` to `group(0) binding(0)`.
* Structs now use `,` to separate fields instead of `;`.
* The `elseif` keyword is now `else if`.
* Buffers bound as arrays don't need to be defined via a struct anymore.

Fixed:

* Fixed that event handlers could not be added while in an event handler.
* Prevent swap chain errors when minimizing a window.

Added:

* The `QWgpuWidget` now also supports the autogui events.
* Our CI now tests the examples (including image comparisons).

Changed:

* Pointer move and wheel events are now rate-limited, leading to better performance if e.g. picking is done at each event.

Added:

* Added `wgpu.gui.base.log_exception`, a context-manager to catch and log exceptions, e.g. in event callbacks.

Fixed:

* Mouse down events were not emitted during double clicks in the Qt canvas.
* Mouse move events were not emitted no button is pressed in the Qt canvas.

Fixed:

* Position of glfw pointer events on MacOS.