Qwt makes plots just fine on the monitor, but when asked to save to an image file using QwtPlot;;print(QPainter, ...) it fails to rotate the letters in the vertical scale's text.

As a hack to investigate, I added code to write the labels for the tic marks at an angle. Note that for these too, the on-screen rendering is fine but the print( ) version shows the letters untransformed. The screen rendering doesn't use print(). How it does work, I'm not entirely sure, just that it has a completely different path of execution.

The app I'm working on is very complex, with code in hundreds of classes, messy multiple inheritance, too few comments and poor naming non-conventions. Somehow QwtPlot;;print() has a different idea about font angles than whatever normally does the drawing. Even after several months working on this source code, I've never found anyplace where angles are mentioned regarding fonts for vertical (or horizontal) axes.

Could this be a bug in QwtPlot;;print( )? Are there any properties of QwtPlot or some object connected to it that needs to be given some parameter? Advice for nailing this bug?

(note: by ;; I eally mean two colons. This online editor wants to convert double colons to a smileyface. Don't know how to disable this.)

I'm using Qt4.3.4, qwt 5.1.1 on a Red Hat 5 machine running KDE 3.5.4. Several users with different systems see the same bad vertical scale rendering.

As drawn on screen, coming out fine:


As drawn to a .png file using print() (and also, why is it gray? Our app does not say anywhere to change the color):