[Interest] Qt and OpenCL crash course

[Sean Harmer]

On Thursday 13 March 2014 07:32:36 Jason H wrote:
> Thanks everyone. 
> 
> Sean, can you elaborate on "Qt has good support for OpenGL so using this
> approach should be pretty simple for you."  Is this just referring to GL
> Widgets?

For basic OpenGL usage you have the choice of QGLWidget or QWindow (or 
QOffscreenSurface) + QOpenGLContext.

For using compute shaders (and all other shader types) see 
QOpenGLShaderProgram.

For textures take a look at QOpenGLTexture.

For framebuffer objects either QOpenGLFramebufferObject or call raw GL (depends 
upon how much control you need over the FBO).

Cheers,

Sean


> 
> Thanks again.
> 
> 
> ________________________________
> From: Sean Harmer <sean.harmer at kdab.com>
> To: interest at qt-project.org; Jason H <scorp1us at yahoo.com>
> Sent: Thursday, March 13, 2014 5:40 AM
> Subject: Re: [Interest] Qt and OpenCL crash course
> 
> On Wednesday 12 March 2014 12:08:53 Jason H wrote:
> > I need to do some elementary graphics operations on QPixmap or QImage. I
> > can do these in Qt to some extent already. But for this latest project I
> > will be processing 4k resolution images. My operations are:
> > Translate off origin
> > Rotate by an acute angle (around a point sometimes not in the image)
> > Pixel value normailzation
> > 
> > To what extent does Qt support these operations in a hardware accelerated
> > manner? Or how hard is it for me to use the hardware to produce those
> > functions to inter-operate with Qt?
> > 
> > Many thanks!
> 
> Have you considered using OpenGL? Two options:
> 
> 1) If you have OpenGL 4.3 capable hw use a compute shader plus a texture or
> shader storage buffer
> 
> 2) If you don't have OpenGL 4.3 capable hw use a framebuffer object and a
> texture.
> 
> Qt has good support for OpenGL so using this approach should be pretty
> simple for you.
> 
> Cheers,
> 
> Sean
> --
> Dr Sean Harmer | sean.harmer at kdab.com | Managing Director UK
> Klarälvdalens Datakonsult AB, a KDAB Group company
> Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322)
> KDAB - Qt Experts - Platform-independent software solutions
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--
Dr Sean Harmer | sean.harmer at kdab.com | Managing Director UK
Klarälvdalens Datakonsult AB, a KDAB Group company
Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322)
KDAB - Qt Experts - Platform-independent software solutions