[Interest] Qt and OpenCL crash course

[Gunnar Sletta]

On 12 Mar 2014, at 21:28, Thiago Macieira <thiago.macieira at intel.com> wrote:

> Em qua 12 mar 2014, às 13:14:08, Jason H escreveu:
>> I was hoping someone would say:
>> QPainter is OpenCL enabled by default (or enabled with a switch), all the
>> operations happen automatically because the kernel programs for applicable
>> painter operations are already written. 
> 
> QPainter is raster based only and that cannot change. All painter operations 
> are implemented in the CPU only and that is the way it will be.

I need to correct this, because it is plain wrong :) 

QPainter is a 2D vector graphics API, software/hardware agnostic. It can run on top of hardware (such as OpenGL) and software alike. However, procedural graphics API's fit badly with modern graphics hardware, at least when render commands get structured they way they do in the QWidget / QGraphicsView stack. So we have choosen raster as the default. This is done both to guarantee precision, to integrate well with native styling APIs, and because raster copes with the massive amount of graphics pipeline state changes in this stack quite well. OpenGL does not :)

> If you want some hardware accelerated painting, there's a standard API for it 
> by the Khronos Group already. It's called OpenGL... :-)
> -- 
> Thiago Macieira - thiago.macieira (AT) intel.com
>  Software Architect - Intel Open Source Technology Center
> 
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