Re: OpenGL plot canvas
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rathmann
From: David S. <David_Stranz@MassSpec.com> - 2012-03-26 14:15:18
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Hi Uwe, This is very interesting, and I thank you for the work. I have no OpenGL experience, unfortunately, so I can't help much there. I have a question, though - since any QWidget can be used as the canvas, what about QGraphicsView? I spent quite a bit of time over the last year implementing some of the features of QwtPlot into a customized QGraphicsScene / View combination, mainly because I wanted to take advantage of the object identification and picking built into the GV system. It was hard work, especially all of the "decorations" around the canvas - axes, titles, etc. and doesn't have anything close to the feature set of QwtPlot. I could have implemented those features in QwtPlot, but I considered it to be a 50-50 proposition - equally difficult no matter which way I chose. Now, I would be happy to throw it way and go back to QwtPlot if I could have the best of it all. Do you think that I could use a QGraphicsView as the canvas? Regards, David _______________________________________________________________ David Stranz, Ph.D. david_stranz@MassSpec.com Sierra Analytics, Inc. 5815 Stoddard Road, Suite 601 Modesto, CA 95356 Tel: (209) 545-8508 http://www.massspec.com _______________________________________________________________ On 3/26/2012 12:42 AM, Uwe Rathmann wrote: > Hi all, > > This weekend I have decoupled QwtPlot and QwtPlotCanvas, so that QwtPlot > accepts any type of QWidget as canvas. > This step opens QwtPlot for using OpenGL and so to hardware accelerated > rendering on platforms, where Qt uses a software renderer ( f.e Windows > or Qt/Embedded ). > > I played a bit myself with a QGLWidget as canvas what was not faster > than X11 ( no surprise as it is also hardware accelerated on my box ) > but significantly faster than the raster paint engine - especially for > stuff like long polygons with a pen width> 0. > > Now it's time to make something useful - and I would like to have the > following: > > 1) A mode for QwtPlotCanvas, where the items are rendered to a > QGLFramebufferObject/QGLPixelBuffer first and the result is then > translated to a QImage/QPixmap. > 2) A QwtPlotGLCanvas ( derived from QGLWidget ) with an optional > internal backing store ( QGLFramebufferObject/QGLPixelBuffer ). > > Unfortunately my OpenGL experiences are limited and I'm looking for > support from someone with a more solid background ? > > Uwe > > ------------------------------------------------------------------------------ > This SF email is sponsosred by: > Try Windows Azure free for 90 days Click Here > http://p.sf.net/sfu/sfd2d-msazure > _______________________________________________ > qwt-interest mailing list > qwt...@li... > https://lists.sourceforge.net/lists/listinfo/qwt-interest > > |