UI with pixels

[teevik]

Hey, I'm pretty new to graphics programming and wgpu. I was wondering how you'd go about adding UI while using pixels?

Would a library like Iced work, since it has wgpu support?

Is this where you'd use render passes?

[parasyte]

There is no need for a render pass to draw a GUI. iced has a mode of operation allowing it to integrate with any wgpu-based application (instead of taking over the event loop and windowing system, as the normal App-based examples do.)

I haven't tried this yet, but I will see about getting an example written. It will just be based on the "integration" example from the iced repo: https://github.com/hecrj/iced/tree/master/examples/integration

[SpyrosRoum]

I'll to make it work myself but in the meantime I'd also love to see an example like that from as it will probably be better haha
Thanks for all the work as well :D

[JMS55]

I'm using imgui, imgui-wgpu, and imgui-winit-support along with Pixels::render_with() for my UI and it works great. The only gotcha is that you have to modify Pixels::render_with() to take &Device, and make Pixels's device and queue fields pub, so that you can pass them both to imgui_wgpu::Renderer::new().

[parasyte]

For anyone else following the conversation, there is an experimental branch which makes those changes, providing a struct with many of the necessary references:

pixels/src/lib.rs

Lines 49 to 63 in 00d1255

	#[derive(Debug)]
	pub struct PixelsContext {
	// WGPU state
	pub device: wgpu::Device,
	pub queue: wgpu::Queue,
	swap_chain: wgpu::SwapChain,
	// Texture state for the source
	pub texture: wgpu::Texture,
	pub texture_extent: wgpu::Extent3d,
	pub texture_format_size: u32,
	// A default renderer to scale the input texture to the screen size
	pub scaling_renderer: ScalingRenderer,
	}

[JMS55]

There's currently no way to get a PixelContext outside of render_with(), which is needed to setup imgui-wgpu (need to borrow &Device and &mut Queue at the same time).

[parasyte]

That's why these were originally stored as Rc<Device>, and Rc<RefCell<Queue>> (to provide shared ownership with interior mutability). I think a slightly more intricate design can provide access to these without runtime overhead, as discussed in #107

[teevik]

Is UI with pixels now possible since #112 got merged?

[parasyte]

@teevik I added an example that incorporates imgui. #116 Have a look and provide any feedback on that PR! I also want to do an example for iced. Just haven't gotten around to it.

[teevik]

Thanks so much for this, I'll try it out! I'm planning on making some sort of 2d shooter with pixel simulation, really hyped for trying this out now 😄