[Interest] Drawing slow.

[Allan Sandfeld Jensen]

On Samstag, 18. August 2018 17:03:43 CEST william.crocker at analog.com wrote:
> On 08/17/2018 02:36 PM, Bill Crocker wrote:
> > Hello:
> > 
> > My newer, Qt based drawing program takes orders of magnitude longer to
> > draw lines than my good old plain X-Windows based drawing program.
> > 
> > The Qt call stack, as revealed by VTune, is:
> > 
> > QPainterPath::draw
> > QPaintEngineEx::draw
> > QRasterPaintEngine::stroke
> > QPaintEngineEx::stroke
> > QRasterPaintEngine::fill
> > QRasterizer::rasterize
> > QScanConverter::end
> 
>  From some experimentation it appears that the CPU time required by the
> QPainterPath system is quite non-linear in the number of control points.
> So, if I break my one long path up into a number of shorter paths, it
> draws MUCH faster.
> 
Is that the case with both antialiasing on and off? (They use different 
rasterization backends)

'Allan