[Interest] Drawing slow.

[william.crocker at analog.com]

>
> Il 17/08/2018 20:36, Bill Crocker ha scritto:
>> 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
>>
>> Am I using some fancy, expensive feature
>> that I should turn off.
>
> How are you measuring the time / framerate / CPU usage for the XWindows-based
> one? Note that when using X11 some rendering may happen "server side", therefore
> it's not accounted for in your application's CPU time.
>

In the end, I was just sitting there
waiting for the screen to refresh, like my users.

> It would also be great if you had testcases.

At this point I am not going to invest any more time.
My problem is mitigated (not solved) by breaking my
large element count paths up in to a larger number
of small element count paths (as noted in my subsequent
email).

Thanks.

Bill

>
> HTH,
>
>
>
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