I have just recently started using Krita on macOS (it's amazing BTW) but like many users, I have noticed how OpenGL is lacking in performance and rightfully so as Apple deprecated it over 3 years ago (macOS 10.14 Mojave, released September 2018). The proprietary Metal API succeeded OpenGL on macOS which KDE doesn't want to implement (https://bugs.kde.org/show_bug.cgi?id=399820) because of the aforementioned proprietary-ness and single platform support. Vulkan however solves both those problems as it is open-source and supported on all platforms, including macOS using the official MoltenVK (https://github.com/KhronosGroup/MoltenVK) translation layer.

Thanks

Dear destroyerxyz,

Thx for your interest in Krita.

You have to know that opengl doesn't lack of performances, and lastest versions are pretty capable.

You can see Vulkan like a next version of opengl (and cool new name) , with more convenience for developpers, and closer to the architecture of GPUs, allowing to do kinda more stuffs.

The lack of performance you see in krita doesn't come from opengl, but from the fact that krita does not fully use the full capacity of parallelism of GPUs in the rendering process, and still do lot of the rendering with the CPU.

So it does not come from opengl, plus, using opengl really help to support older GPUs, not supported by Vulkan.

Saru wrote:Dear destroyerxyz,

Thx for your interest in Krita.

You have to know that opengl doesn't lack of performances, and lastest versions are pretty capable.

You can see Vulkan like a next version of opengl (and cool new name) , with more convenience for developpers, and closer to the architecture of GPUs, allowing to do kinda more stuffs.

The lack of performance you see in krita doesn't come from opengl, but from the fact that krita does not fully use the full capacity of parallelism of GPUs in the rendering process, and still do lot of the rendering with the CPU.

So it does not come from opengl, plus, using opengl really help to support older GPUs, not supported by Vulkan.

Hi Saru,

Thnx for the reply.
Its not really about opengl being bad or anything like that. macOS hasn't supported opengl for quite some time and to my understanding doesn't update the API to newer versions, thus not getting new performance enhancements. And it's also about the fact that seeing apple's history, sooner or later they're going to complete remove opengl from macOS, at which point many apps including krita would just suddenly so working.

Thanks

The truth is, it's apple fault.

They could provide a support for opengl, it cost nothing to keep a compatibility layer with opengl, it just a matter of paying one guy on maintaining for new apple GPUs. Apple as always try to push their standards, with no concern, either for their customers, or the IT community (or maybe they just want to impose those as a strategy ? who knows ?)

As for krita, you can run it with opengl turned off and full CPU rendering (thats what i do anyway since the opengl canvas doesnt give so much increase performance), and honestly it's still very good, if you dont work on very high image size with lot of layers / filter layers and big brushes.

If you really want gpu aceleration through opengl you can still install a linux version on your mac for the moment.

The priority for krita is to be used by a majority of persons, regardless of the machine price, so opengl is the best for the moment.

Maybe we will see a Vulkan implementation in the futur with a new rendering process to make it more gpu compatible. Because that's a good thing.

Saru wrote: The truth is, it's apple's fault.

I don't really think Apple is at fault here as OpenGL has been a dying API for quite some time. Its own developer (Khronos Group) is also the developer for Vulkan (which was formerly literally named "glNext" or "Next Generation OpenGL Initiative"). OpenGL lacks many new features like ray tracing and even GPU video rendering. It is completely understandable why Apple would deprecate OpenGL and I would even expect other platforms to do so soon (except Linux of course).

Saru wrote: They could provide a support for opengl, it cost nothing to keep a compatibility layer with opengl, it just a matter of paying one guy on maintaining for new apple GPUs.

I believe you are wrong here, making a compatibility layer between two completely different graphics APIs is a HUGE undertaking (just look at the WIne project) and probably not worth it for Apple.

Saru wrote: The priority for krita is to be used by a majority of persons, regardless of the machine price, so opengl is the best for the moment.

I understand that and Vulkan is supported on virtually every platform, including Apple platforms and Google's Fuschisa, so arguably more than OpenGL.

Anyways, thanks for all the replies.
I do believe Vulkan is the right direction to go for Krita developers but also understand that as of now it may not be worth the high effort.

Saru wrote:
The truth is, it's apple's fault.

I don't really think Apple is at fault here as OpenGL has been a dying API for quite some time. Its own developer (Khronos Group) is also the developer for Vulkan (which was formerly literally named "glNext" or "Next Generation OpenGL Initiative"). OpenGL lacks many new features like ray tracing and even GPU video rendering. It is completely understandable why Apple would deprecate OpenGL and I would even expect other platforms to do so soon (except Linux of course).

=> wrong, "dying api" mean nothing, and there is nothing preventing company to provide a opengl implementation for their drivers even if those api are not evolving, because A LOT os software use opengl.
When you buy an nvidia gpu i.e, and you can use a large set of api: opengl, vulkan, cuda, opencl, directx, etc. and this on multiple platform.
Apple are providing both hardware and OS, and its easier for them to build those implementation since they know what hardware is in a mac.(plus opengl is still easier than vulkan lol)
They just dont care (or its a strategy to push vulkan? in order to compete against cuda ? directx ?), and thus its not unstandable.

OpenGL lacks many new features like ray tracing and even GPU video rendering

Well, you should know ray tracing did exist before it was a buzzword, and can be done using compute shaders on opengl for exemple, it was just too resources consuming to have it in a real time rendering engine (and its still hard), Vulkan allow just to an access to the dedicated part of GPU hardware acceleration for ray tracing in newest GPUs.

I believe you are wrong here, making a compatibility layer between two completely different graphics APIs is a HUGE undertaking (just look at the WIne project) and probably not worth it for Apple.

wrong => first some compatibilty layers exist yet (ANGLE ?) so its doable. But anyway, they could just provide an opengl implementation with their drivers considering the cash they are stealing from their customers? man they dont lack money to hire people.

I understand that and Vulkan is supported on virtually every platform, including Apple platforms and Google's Fuschisa, so arguably more than OpenGL.

wrong => Opengl is still the most compatible graphic API out there, vulkan doesnt works on old GPUs. Man, i even see opengl run on a raspberry. Plus the platform support still depend of the hardware provider and their drivers.

I do believe Vulkan is the right direction to go for Krita developers

I Do believe it too, especially for a new rendering process, vulkan allow really cool things, i am a huge fan as a dev. But vulkan is not for "compatibility" as you make it sound (platform agnotism),but for more controls with newest GPUs and compute parellism.