Simplifying Vulkan One Subsystem at a Time
khronos.org120 points by amazari 4 hours ago
120 points by amazari 4 hours ago
The main problem with Vulkan isn't the programming model or the lack of features. These are tackled by Khronos. The problem is with coverage and update distribution. It's all over the place! If you develop general purpose software (like Zed), you can't assume that even the basic things like dynamic rendering are supported uniformly. There are always weird systems with old drivers (looking at Ubuntu 22 LTS), hardware vendors abandoning and forcefully deprecating the working hardware, and of course driver bugs... So, by the time I'm going to be able to rely on the new shiny descriptor heap/buffer features, I'll have more gray hair and other things on the horizon.
> Ubuntu LTS
This is why I try to encourage new Linux users away from Ubuntu: it's a laggard with, often important, functionality. It is now an enterprise OS (where durability is more important than functionality), it's not really suitable for a power user (like someone who would use Zed).
Which one would you recommend for regular users and power users?
Debian/testing, with stable pinned on at low priority.
It slows down for a couple months around release, but generally provides pretty reliable & up to date experience with a very good OS.
Dance dance the red spiral.
Tbh, we should more readily abandon GPU vendors that refuse to go with the times. If we cater to them for too long, they have no reason to adapt.
> we should more readily abandon GPU vendors
This was so much more practical before the market coalesced to just 3 players. Matrox, it's time for your comeback arc! and maybe a desktop pcie packaging for mali?
I had a relatively recent graphics card (5 years old perhaps?). I don't care about 3D or games, or whatever.
So I was sad not to be able to run a text editor (let's be honest, Zed is nice but it's just displaying text). And somehow the non-accelerated version is eating 24 cores. Just for text.
https://github.com/zed-industries/zed/discussions/23623
I ended up buying a new graphics card in the end.
I just wish everyone could get along somehow.
No. I remember a phone app ( Whatsapp?) doggedly supporting every godforsaken phone, even the nokias with the zillion incompatible Java versions. A developer should go where the customers are.
What does help is an industry accepted benchmark, easily ran by everyone. I remember browser css being all over the place, until that whatsitsname benchmark (with the smiley face) demonstrated which emperors had no clothes. Everyone could surf to the test and check how well their favorite browser did. Scores went up quickly, and today, css is in a lot better shape.
At least they are making an effort to correct the extension spaghetti, already worse than OpenGL.
Addiitionally most of these fixes aren't coming into Android, now getting WebGPU for Java/Kotlin[0] after so many refused to move away from OpenGL ES, and naturally any card not lucky to get new driver releases.
Still, better now than never.
[0] - https://developer.android.com/jetpack/androidx/releases/webg...
I'm really enjoying these changes. Going from render passes to dynamic rendering really simplified my code. I wonder how this new feature compares to existing bindless rendering.
From the linked video, "Feature parity with OpenCL" is the thing I'm most looking forward to.
You can use descriptor heaps with existing bindless shaders if you configure the optional "root signature".
However it looks like it's simpler to change your shaders (if you can) to use the new GLSL/SPIR-V functionality (or Slang) and don't specify the root signature at all (it's complex and verbose).
Descriptor heaps really reduce the amount of setup code needed, with pipeline layouts gone you can drop like third of the code needed to get started.
Similar in magnitude to dynamic rendering.
Having quite recently written a (still experimental) Vulkan backend for sokol_gfx.h, my impression is that starting with `VK_EXT_descriptor_buffer` (soon-ish to be replaced with `VK_EXT_descriptor_heap`), the "core API" is in pretty good shape now (with the remaining problem that all the outdated and depreciated sediment layers are still part of the core API, this should really be kicked out - e.g. when I explicitly request a specific API version like 1.4 I don't care about any features that have been deprecated in versions up to 1.4 and I don't care about any extensions that have been incorporated into the core API up until 1.4, so I'd really like to have them at least not show up in the Vulkan header so that code completion cannot sneak in outdated code (like EXT/KHR postfixes for things that have been moved into core).
The current OpenGL-like sediment-layer-model (e.g. never remove old stuff) is extremely confusing when not following Vulkan development very closely since 2016, since there's often 5 ways to do the same thing, 3 of which are deprecated - but finding out whether a feature is deprecated is its own sidequest.
What I actually wrestled with most was getting the outer frame-loop right without validation layer errors. I feel like this should be the next thing which the "Eye of Khronos" should focus on.
All official tutorial/example code I've tried doesn't run without swapchain-sync-related validation errors on one or another configuration. Even this 'best practices' example code which demonstrates how to do the frame-loop scaffolding correctly produces valiation layer errors, so it's also quite useless:
https://docs.vulkan.org/guide/latest/swapchain_semaphore_reu...
What's worse: different hardware/driver combos produce different validation layer errors (even in the swapchain-code which really shouldn't have different implementations across GPU vendors - e.g. shouldn't Khronos provide common reference code for those GPU-independent parts of drivers?). I wonder if there is actually any Vulkan code out there which is completely validation-layer-clean across all possible configs (I seriously doubt it).
Also the VK_[EXT/KHR]_swapchain_maintenance1 extension which is supposed to fix all those little warts has such a low coverage that it's not worth supporting (but it should really be part of the core API by now - the extension is from 2019).
Anyway... baby steps into the right direction, only a shame that it took a decade ;)
Vulkan is by far the most powerful and the most pain in the ass API I've ever worked with. I agree on every point you just made.
Isn't the idea that 99% of people use a toolkit atop of Vulkan?
Like, these days game devs just use Unreal Engine, which abstracts away having to work with the PS5 / PS4, DirectX 12, and Vulkan APIs.
I imagine unless it's either for A. edification or B. very bespoke purpose code, you're not touching Vulkan.
Many people need something in-between heavy frameworks and engines or oppinionated wrappers with questionable support on top of Vulkan; and Vulkan itself. OpenGL served that purpose perfectly, but it's unfortunately abandoned.
Are there any good Vulkan tutorials that are continuously updated to reflect these advancement and ease of use improvements?
It's a similar challenge to the many different historical strata of C++ resources.
https://howtovulkan.com is a recent one which targets the modern flavour of Vulkan that everything supports today.
Well, all desktop hardware and drivers at least. God help you if you want to ship on Android.
The one on Vulkan.org recently got updated to use dynamic rendering and a bunch of the newest features (plus modern C++, Slang instead of glsl, etc...).
https://docs.vulkan.org/tutorial/latest/00_Introduction.html
Finding the optimal sub-language is about API coupling with client code, making a moving sweet spot for where bread & butter techniques live.
I would like to / am "supposed to" use Vulkan but it's a massive pain coming from OpenCL, with all kinds of issues that need safe handling which simply don't come from OpenCL workloads.
Everyone keeps telling me OpenCL is deprecated (which is true, although it's also true that it continues to work superbly in 2026) but there isn't a good / official OpenCL to Vulkan wrapper out there to justify it for what I do.
I personally just switched to using push descriptors everywhere. On desktops, the real world limits are high enough that it end up working out fine and you get a nice immediate mode API like OpenGL.
That's the right way to go for simple use cases and especially getting started on a new project.
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I suspect we are only 5-10 years away until Vulkan is finaly usable. There are so many completely needlessly complex things, or things that should have an easy-path for the common case.
BDA, dynamic rendering and shader objects almost make Vulkan bearable. What's still sorely missing is a single-line device malloc, a default queue that can be used without ever touching the queue family API, and an entirely descriptor-free code path. The latter would involve making the NV bindless extension the standard which simply gives you handles to textures, without making you manage descriptor buffers/sets/heaps. Maybe also put an easy-path for synchronization on that list and making the explicit API optional.
Until then I'll keep enjoying OpenGL 4.6, which already had BDA with c-style pointer syntax in glsl shaders since 2010 (NV_shader_buffer_load), and which allows hassle-free buffer allocation and descriptor-set-free bindless textures.