[Interest] Console output on OS X

Till Oliver Knoll till.oliver.knoll at gmail.com
Fri May 11 16:07:27 CEST 2012

Am 11.05.2012 um 13:41 schrieb Sherif Ghali <sherif.ghali.1 at gmail.com>:

> The message
>   QPainterPath::lineTo: Adding point where x or y is NaN or Inf, ignoring call
> is not printed in the Terminal. How to make it appear?

Then this can only mean one thing: the message is simply never issued ;)

Apparently you are expecting the Qt Paint Engine to issue this warning (you could simply write your own debug statement with qDebug in main() and check its output in the Terminal).

But simply because the paint engine complains on one platform with a given parameter doesn't necessarily mean it complains on another platform in the same way.

And even more so: you have the choice between *different* Qt Paint Engines! And depending on the platform the one or the other might be the default one.

There's the Raster Engine (Qt's own implementation of most basic painting operations) which on Windows and Linux is default (IIRC), then there is the Native Paint Engine (which was for a long time still the default one on Qt Mac - not sure whether the Raster Engine is now the default one in Qt 4.8). In theory there's also an OpenGL Paint Engine, but that one can give you quite some surprises ;)

See: QApplication::setGraphicsSystem

(which can also be set with the argument -graphicssystem: "native", "raster", "opengl"


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