On Tuesday 13 Sep 2011 01:10:55 Tom Breton (Tehom) wrote: > > On Monday, September 12, 2011, D. Michael McIntyre wrote: > [...] > > > m_segmentsDrawBuffer is a QPixmap. QPixmap::resize() no longer exists. > > The > > API docs say to replace > > > > pixmap.resize(width, height) > > > > with > > > > pixmap = pixmap.copy(0, 0, width, height) > > > > According to the docs, this was the way the conversion was supposed to be > > done. I've looked at these lines several times, and I don't see any > > parameters out of order, type changes, or other things that might explain > > why > > what is supposed to be equivalent code is clearly not doing an equivalent > > job. > > Just to throw my $0.02 in, are "width" and "height" always larger than the > originals? And do we know what QPixmap::copy does in that case? > > I ask because http://www.greyc.ensicaen.fr/ensicaen/Docs/Qt4/qpixmap.html > says that copy "Returns a deep copy of the subset of the pixmap that is > specified by the given rectangle. " > > So what does it do when the rectangle is too big? I don't know and it > doesn't say, but if what it does is copy nothing or make a blank pixmap, > that might explain what you are seeing.
Of course, in C++ you can pass references implicitly, so it is quite possible that pixmap.copy actually modifies width and height in the calling context... I expect you thought about that about 50ms after seeing the bug, but I remember spending a v long time indeed sorting out something which eventually came down to that. I'll shut up now :) Nick/. > > Or I could be totally wrong, since I'm just learning Qt. > > Tom Breton (Tehom) > > > > --------------------------------------------------------------------------- > --- BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA > Learn about the latest advances in developing for the > BlackBerry® mobile platform with sessions, labs & more. > See new tools and technologies. Register for BlackBerry® DevCon today! > http://p.sf.net/sfu/rim-devcon-copy1 > _______________________________________________ > Rosegarden-devel mailing list > Rosegarden-devel@lists.sourceforge.net - use the link below to unsubscribe > https://lists.sourceforge.net/lists/listinfo/rosegarden-devel -- Dr Nicholas Bailey http://www.n-ism.org/People/nick.php Science and Music Research Group, School of Engineering, The University of Glasgow Find out about our Music Informatics MSc: http://www.n-ism.org/SPECTRUM Signal Processing, Electronics and Computing Techniques for Researching and Understanding Music ------------------------------------------------------------------------------ BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA Learn about the latest advances in developing for the BlackBerry® mobile platform with sessions, labs & more. See new tools and technologies. Register for BlackBerry® DevCon today! http://p.sf.net/sfu/rim-devcon-copy1 _______________________________________________ Rosegarden-devel mailing list Rosegarden-devel@lists.sourceforge.net - use the link below to unsubscribe https://lists.sourceforge.net/lists/listinfo/rosegarden-devel
