On Fri, 2008-01-25 at 10:17 -0500, Jean-Sebastien Guay wrote: > Hi Jeremy, > > > Here are some screenshots, > > Wow, very nice! The potential for this is endless! How is performance compared > to just a normal texture that you would map onto a quad?
Well, the way it current works is that the image (osgCairo::SurfaceImage, which is derived from both osg::Image and the Cairo "surface" type) renders to a memory buffer (which is provided by osg::Image, so wherever it actually stores the data...?) and then you call ->dirty() on the image and apply it to a quad. You can do this as often as you like to update the texture. In terms of performance, Cairo itself makes every attempt to be as fast as possible, and provides multiple surfaces "types" for us to use. I use the "memory buffer" surface, since it maps so well to the memory osg::Image provides, but there are also PDF, PS, and SVG surfaces. There is also an OpenGL accelerated surface type called Glitz, but it's CVS hasn't been updated in a year and I have the hardest time getting it to play nice with other OpenGL apps. Thus, I opted to go with the software Cairo rendering surface, but as long as you aren't redrawing a surface every frame, you should be fine. In fact, my intentions really are to make it so that all images are generated once at load time, so that they are only ever drawn once in the lifetime of the program. Conceptually it would be no different than actually loading the images from files, save that you could define various criteria that control at what resolution the images are rendered for maximum awesomeness. :) > I hope to be able to test this on Windows soon and give you some feedback on > that front. > > J-S > -- > ______________________________________________________ > Jean-Sebastien Guay [EMAIL PROTECTED] > http://whitestar02.webhop.org/ > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
