The `imgui_wgpu` and `wgpu_glyph` crates have been updated to `wgpu` 0.8 so I was able to fixed the demos! They both still use GLSL, and I don't think I'll be changing that for now. I may switch them over to `naga` at some point.
Originally I wanted to wait until the WGSL spec fully stabilized, but due to some issues with the GLSL code, I've decided to switch over the code now. While GLSL is supported by WebGPU, it's currently secondary to WGSL. I'll keep an example of how to use GLSL (and maybe add HLSL and Metal as well), but I'm going to use WGSL from now on.
I've been thinking about doing this for a while now. Because shaderc is a c library, it often has to be redownloaded during builds. This has been slowing down my ability to add new content and maintain old content. I had been considering switching to naga earlier, but some of my shaders (notably the lighting ones) weren't compiling with naga as I was using features not available for compatibility reasons (`inverse` is not available in all languages targeting spirv).
Since I needed to make a bunch of changes to the code base to make the glsl, and because I wanted to switch the tutorial to WGSL anyways, I decided to bite the bullet and recode everything in WGSL and remove shaderc from the tutorials.
### Some of the showcase examples are broken
The `wgpu_glyph`, and `imgui-wgpu` crates currently depend on `wgpu` 0.7, which is causing the `pong` and `imgui-demo` to not compile. I decided to excluded them from the workspace until the underlying crates update to using `wgpu` 0.8. (Feel free to submit a issue or even PR when that happens!)
There were a lot of changes particularly to the `RenderPipelineDescriptor`. Most other things have not changed. You can check out the [0.9 PR](https://github.com/sotrh/learn-wgpu/pull/140) for the full details.
## November 2020 Cleanup, Content Freeze, and Patreon
School is starting to ramp up, so I haven't had as much time to work on the site as I would like to. Because of that there were some issues piling up. I decided to tackle a bunch of them in one go. Here's a snapshot of what I did:
* The tutorial now handles `SwapChainError` properly
* I'm now using bytemuck's derive feature on all buffer data structs.
Now in the headline I mentioned a "Content Freeze". Wgpu is still a moving target. The migration from `0.4` to `0.5` was lot of work. The same goes for `0.5` to `0.6`. I'm expected the next migration to be just as much work. As such, I won't be added much content until the API becomes a bit more stable. That being said, I still plan on resolving any issues with the content.
One more thing. This is actually quite awkward for me (especially since I'll be slowing down development), but I've started a [patreon](https://www.patreon.com/sotrh). My job doesn't give me a ton of hours, so things are a bit tight. You are by no means obligated to donate, but I would appreciate it.
This took me way too long. The changes weren't difficult, but I had to do a lot of copy pasting. The main changes are using `queue.write_buffer()` and `queue.write_texture()` everywhere. I won't get into the nitty gritty, but you can checkout the [pull request](https://github.com/sotrh/learn-wgpu/pull/90) if you're interested.
Too many things changed to make note of them here. Check out [the 0.5 pull request](https://github.com/sotrh/learn-wgpu/pull/29) if you're curious about specifics. That being said, 2 things are worth mentioning directly: the y-axis now points up like with DirectX and Metal, and requesting an adapter and creating a device now use `Future`s. The tutorials have been updated as well as the code.
Up to this point, we created textures manually everytime. I've pulled out the texture creation code into a new `texture.rs` file and included it every tutorial from the [textures tutorial](/beginner/tutorial5-textures/#cleaning-things-up) onward.
## Fixed panics do to not specifying the correct `usage`
Wgpu has become more strict about what `BufferUsage`s and `TextureUsage`s are required when performing certain operations. For example int the [Wgpu without a window example](/intermediate/windowless/), the `texture_desc` only specified the usage to by `COPY_SRC`. This caused a crash when the `texture` was used as a render target. Adding `OUTPUT_ATTACHMENT` fixed the issue.
## Updating Winit from 0.20.0-alpha5 to 0.20
There were a lot of small changes to how the dpi stuff works. You can see all the changes [in the changelog](https://github.com/rust-windowing/winit/blob/master/CHANGELOG.md). That means that some of the tutorials had to change.
* I've removed `hidpi_factor` from `State` entirely. They removed the `hidpi_factor()` method from `winit::window::Window`, and changed `inner_size()` to return `PhysicalSize` instead of `LogicalSize`, so we don't need to store the `hidpi_factor` anymore.
*`update_hidpi_and_resize` is no more. Since `ScaleFactorChanged` passes in the windows new `PhysicalSize`, we can simply use `resize()`.
*`State::size` is now `PhysicalSize<u32>` instead of the pre 0.20 `LogicalSize`.
*`EventsCleared` is now `MainEventsCleared`.
I may have missed a change, but I made sure that all the examples compile an run, so if you have trouble with your code you can use them as a reference.
## Changed tutorial examples to use a src directory
I wasn't using the traditional cargo binary folder setup. I've changed it to the standardized form now.
1. The use of `Instance` has been removed. Creating a `Surface` and requesting an `Adapter` are done as follows.
```rust
let surface = wgpu::Surface::create(window);
let adapter = wgpu::Adapter::request(&wgpu::RequestAdapterOptions {
..Default::default()
}).unwrap(); // needs to be unwrapped
```
2. The `request_device` method now returns a `(Device, Queue)` tuple. This means that you can borrow the `Queue` mutably while using the `Device` immutably. Because of this change, submitting `CommandBuffer`s to the queue uses the `submit` method on the `Queue` directly.
```rust
self.queue.submit(&[
encoder.finish()
]);
```
3. The `create` method on `Surface` takes in any struct that implements the `HasRawWindow` trait, instead of a `RawWindowHandle`. This means that the `raw-window-handle = "0.3"` line in `Cargo.toml` is no longer needed.
I don't know if this is a change from 0.4, but you use `wgpu = "0.4"` line in dependencies instead of the `[dependencies.wgpu]` as wgpu will determine the best back end for you.
