Hi All, On Fri, May 13, 2011 at 5:45 PM, Robert Osfield <[email protected]> wrote: > I still haven't tracked down the bugs > I'm seeing on rendering using txf with the osgtext example, so there is > chance that you might see problems later with more intensive use. I'm > still hunting this bug down so fingers crossed I'll nail it soon.
After a rather exhusting and perplexing debug session I finally conerned the bug to the way that the src/osgText/Font.cpp was caching seperate sets of osgText::Glyph for different font resolutions. This is correct behviour for formats like FreeType or QFont, but for fonts like the osgText::DefaultFont and the TXF fonts it's not appropriate as these only support a fixed resolution size, so if you request a different font resolution you don't actually get a different glyph, so it's inappropriate to cache it multiple times. It's this sharing of single Glyph between multiple apparent font resolutions that caused the problem with rendering of osgtext when using with Helvertica.txf. I have now changed osgText::Font::FontImplementation so it can automatically tell osgText::Font that it's inappropriate to use the font resolution requested as guide, and to just use a single glyph cache for this fixed size. I had to update the freetype, DefaultFont, osgQt::QFontImplementation and txf plugin all to provide the correct setting, and this is all now checked in. Curiously this particular bug will have been in the OSG for a very long time, almost as long as osgText, but was just never detected or characterised. I also spotted and fixed a bug in handling of the Object::resizeGLObjectLists request that may have meant that opening new contexts whilst using fonts would have resulted in the texturing of the text quads going astray. All these changes are now checked into svn/trunk. Cheers, Robert. _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
