Hi Ian,
>> thanks for your answer. >> I am writing to you directly, >Best not - I very seldom reply to off-list posts... Sorry, will post to the list. > OK: Then you need to composite the bar graph on top of the image. > Fltk does not provide support for transparent widgets (yet) as it is a hard > thing to do in a consistent cross-platform way, so the best bet may be for > you to just blit the image into the box, then render the bar on top of it. > This is easy and cheap to do, if you are rendering the graph on top of an > image your app "owns". > If you want to render the graph transparently on top of (for example) the > desktop then you are on your own out there, since fltk can't really do that > without a lot of platform specific code...! > Hope that made sense! > FWIW, I think Greg's cheat pages have examples of doing some of this, so it > would be worth a look... > http://www.seriss.com/people/erco/fltk/ I need a bit of thinking. I am writing an app for creating supervision screens on an embedded platform. All is ruled by a configuration text file : it is parsed from my program which then creates all the pages, the buttons for page jumps, the graphics objects and so on. In general I do not know what there will be under my bargraph : maybe a picture, maybe a filled background. The situation is more similar to the desktop you mentioned. For now the simplest solution I can imagine is to redraw the whole parent of my object. Thanks a lot for your observations, regards Lucio _______________________________________________ fltk mailing list fltk@easysw.com http://lists.easysw.com/mailman/listinfo/fltk