On Samstag, 18. August 2018 17:03:43 CEST william.croc...@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 _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
