Hi Guanluca, I've only used librsvg from the Ubunutu/debian repositories and haven't come across problems before. Perhaps there is a version issue, or perhaps an issue with librsvg handling the .svg you are passing on. As you are working under Windows I think it may well be simply down to the libs and the OSG being built with different options, this is a very common issue for Windows programmers and comes with the territory am I afraid, it's another one of the reasons that I haven't touched windows development for a decade.
As for rendering svg using the scene graph/OpenGL rather than rendering to a CPU based image then texturing this, we'll it's possible but a for more complex issue than just relying upon a 3rd party lib to the handle all the specifics of vector graphics. NVidia do have a library that does vector graphics ontop of OpenGL so this is probably the way one would tackle it. Robert. On 13 December 2012 12:11, Gianluca Natale <[email protected]> wrote: > Hi all,**** > > I have a couple of issues/questions about the osg plugin for svg file > format.**** > > ** ** > > 1.**** > > I got win32 prebuilt versions of the library librsvg, and all required > dependencies (glib, gdk-pixbuf, cairo, libcroco, fontconfig, libpng, > freetype, gettext-runtime, libxml2, expat, pango), from this website:**** > > http://ftp.acc.umu.se/pub/gnome/binaries/win32.**** > > And rebuilt the osgdb_svg.dll plugin (in OSG 3.0.1).**** > > When I try to read an svg image in my application, I have a crash in the > yellow line in following function inside ReaderWriterSVG.cpp:**** > > ** ** > > osg::Image* createImage(RsvgHandle *handle, unsigned int width, > unsigned int height) const**** > > {**** > > RsvgDimensionData dimensionData;**** > > rsvg_handle_get_dimensions( handle, &dimensionData);**** > > // If image resollution < 128, cairo produces some > artifacts.**** > > // I don't know why, but we check the size...**** > > if (width < 128) width = 128;**** > > if (height < 128) height = 128;**** > > width = osg::Image::computeNearestPowerOfTwo(width);**** > > height = osg::Image::computeNearestPowerOfTwo(height);**** > > osg::Image *image = new osg::Image();**** > > image->allocateImage(width, height, 1, GL_RGBA, > GL_UNSIGNED_BYTE);**** > > image->setPixelFormat(GL_BGRA);**** > > ** ** > > cairo_surface_t *cairo_surface = > cairo_image_surface_create_for_data(image->data(),**** > > CAIRO_FORMAT_ARGB32, width, > height, image->getRowSizeInBytes());**** > > cairo_t *cr = cairo_create(cairo_surface);**** > > cairo_scale(cr,((float)width)/dimensionData.width, ((float > )height)/dimensionData.height);**** > > rsvg_handle_render_cairo(handle, cr);**** > > **** > > cairo_destroy(cr);**** > > free(cairo_surface);**** > > ** ** > > image->flipVertical();**** > > return image;**** > > }**** > > ** ** > > It looks like a memory corruption. Any idea about what might be wrong?**** > > Could anyone of you build and use the svg plugin successfully? If yes, > where did you get the librsvg library? What version? What versions for > required dependencies?**** > > ** ** > > 2.**** > > I looked into ReaderWriterSVG.cpp, and saw that the plugin can read an svg > as an image. Since the svg is a vector file format, isn’t there a way in > OSG to directly construct a scene graph from that file, returning for > example the root node of that scene graph? Also, I saw that there is no > ‘writeImage’ implementation. Is there any way to write an svg file, > starting from a scene graph (i.e. passing the root node of such a graph)? > Or can it only manage the svg files as raster images?**** > > ** ** > > Thanks**** > > Gianluca**** > > ** ** > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > >
_______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
