aevaMar 9, 2025
if you think about it, vulkan logical device implies the existence of vulkan illogical device
Show threadaevaMar 9, 2025

I'm slowly working through the vulkan spec writing a compute-only vulkan program from scratch that doesn't render anything, and it's going pretty well because the spec is really well written and I already know more or less exactly what I want to do anyway, but I just want to say just how silly (fun) it feels to write a program like this because you get to just skip over large swaths of the API.

Like, I'm working from the spec because the tutorials all make it more complicated.

Show threadaevaMar 9, 2025
also the tutorials I reviewed all did the annoying thing where the tutorial squirrels away the stuff you're trying to learn or reference into abstractions that only serve the needs of the tutorial writer, which given my goal is very specifically to *not draw anything*, there's really not much of a point to any of them lol. I'm really not the intended audience here though :3
Show threadaevaMar 10, 2025

I think it's cute that practically every vulkan command has one or more optional args to let you enter Hard Mode

(sorry for the double post, I added this to the wrong thread)

Show threadaevaMar 10, 2025
ok even with just the compute-only subset vulkan is a slog D:
Show threadaevaMar 10, 2025

I wonder how many people have actually managed to knuckle down and write a complete, useful vulkan program from scratch (no copy pasting from tutorials and stack overflow, no offloading significant parts to 3rd party libraries like VMA)

To think if I power through and get this thing working I could potentially be like the 20th person to bother

Show threadJosh SimmonsMar 10, 2025
@aeva hmm how useful is "useful" :') but to be honest I think the hardest part of vulkan is actually the same as opengl, it's knowing which set of extensions you're supposed to use because they make things much easier, and which extensions you're not supposed to use because they're pointless or not practical on the hardware you care about.
Show threadJosh SimmonsMar 10, 2025
@aeva e.g. you can skip pretty much all the shitty binding APIs in vulkan if you want, which makes things better in many ways (but still complex)
Show threadaevaMar 10, 2025
@dotstdy what would you say are the good extensions? (keep in mind I'm not rendering anything, just doing compute)
Show threadJosh SimmonsMar 10, 2025
@aeva buffer device address for starters
Show threadJosh Simmons

@aeva So for example, here's passing some buffers into a compute shader with my thing.

Shader:
https://github.com/jsimmons/narcissus/blob/main/title/shark-shaders/shaders/radix_sort_0_upsweep.comp#L32-L39

Associated struct definition:
https://github.com/jsimmons/narcissus/blob/main/title/shark-shaders/src/pipelines.rs#L238-L246

Dispatch:
https://github.com/jsimmons/narcissus/blob/main/title/shark/src/draw.rs#L940-L956

Mar 10, 2025 at 8:19amPhanpy
Show threadaevaMar 10, 2025
@dotstdy what's the extension name
Show threadJosh SimmonsMar 10, 2025
@aeva https://registry.khronos.org/vulkan/specs/latest/man/html/VK_EXT_buffer_device_address.html (it's actually standard in Vulkan 1.2, and mandatory for Vulkan 1.3, but that's more or less the same problem as extensions at least until everyone is on board with the new hotness)
VK_EXT_buffer_device_address(3)

Show threadaevaMar 10, 2025
@dotstdy gotcha. maybe I should read through everything that got added to core between 1.1 and 1.4 (which is what my laptop supports)...
Show threadJosh SimmonsMar 10, 2025
@aeva yeah, the other big one that comes to mind is https://github.com/KhronosGroup/Vulkan-Docs/blob/main/proposals/VK_KHR_dynamic_rendering.adoc but that's not relevant for compute. it just means less pointless boilerplate (okay, technically the boilerplate has a point if you're trying to soup up a mobile renderer, but i'm not) on doing graphics.
Vulkan-Docs/proposals/VK_KHR_dynamic_rendering.adoc at main · KhronosGroup/Vulkan-Docs

The Vulkan API Specification and related tools. Contribute to KhronosGroup/Vulkan-Docs development by creating an account on GitHub.

GitHub
Show threadaevaMar 13, 2025
@dotstdy this was a huge help :) ty for the tip