[Development] Vulkan

[Sean Harmer]

On Saturday 09 April 2016 01:57:24 Tom Kulaga wrote:
> Hi All,
> 
> Is anyone actively working on vulkan integration? Or even a QVulkanWidget?
> I saw that d3d12 had a preview widget so thought it was reasonable to ask.
> 
> If anyone isn't I'm keen to have a crack. In terms of implementation, is it
> as naively simple as creating a new widget similar to the QOpenGLWidget
> one, just to get a drawable canvas up and running? I believe that on Linux
> a xcb_window_t is used for vulkan samples and deep in the QPA I saw it too.
> 
> I was wondering if for a novice like me this would be feasible to actually
> do?
> 
> Does the whole rendering stack need to transfer over to vulkan?

It all depends what level of integration you are after. Using a QWindow and 
using Vulkan with it doesn't require much. Making something equivalent to 
QOpenGLWidget is much more work as you have to worry about compositing 
QPainter content into the window too.

Making a Vulkan backend for Qt Quick 2 is also more work, considerably more 
work than much of the other low hanging fruits that could be used to improve 
performance there on the existing OpenGL backend. Although, like the D3D12 
backend it might give better results on windows (for Vulkan capable hardware).

Putting a Vulkan backend on Qt 3D is a very real possibility and one where 
Vulkan could potentially make a big impact. This is something I want to 
investigate later after we have done a stable release or two of Qt 3D. The 
good thing is that Qt 3D's architecture maps very well to Vulkan (by design).

Some IHV's provide drivers that have OpenGL/Vulkan interop in that you can use 
both Vulkan and OpenGL on the same surface which would be another interesting 
option if this support becomes widespread.

If you want to have a go, then certainly nobody is going to stop you and you 
may well get some help. We have some early proof of concept stuff we can look 
to tidy up and publish along these lines.

Cheers,

Sean
--
Dr Sean Harmer | sean.harmer at kdab.com | Managing Director UK
Klarälvdalens Datakonsult AB, a KDAB Group company
Tel. UK +44 (0)1625 809908, Sweden (HQ) +46-563-540090
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