## 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.
* The [instancing tutorial](/beginner/tutorial7-instancing) now uses vertex buffers instead of storage buffers.
*`build.rs` now updates when individual shaders are changed, not whenever `/src` is changed.
* Had some help from Github user @kanerogers to clean up the [texturing tutorial](/beginner/tutorial5-textures).
* I made a [compute pipeline showcase](/showcase/compute) that computes the tangent and bitangent for each vertex in a model.
* I made a [imgui showcase](/showcase/imgui-demo). It's very basic, but it should be a good starting point.
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.
You can find out more about contributing to this project on the [introduction page](/#contribution-and-support)
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.
