Thanks Robert, I'll try with different versions of libraries and different .svg test files, to see if the crash disappears.
Gianluca Da: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] Per conto di Robert Osfield Inviato: giovedì 13 dicembre 2012 15:51 A: OpenSceneGraph Users Oggetto: Re: [osg-users] a couple of questions about svg plugin (OSG 3.0.1) 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 <nat...@europe.altair.com<mailto:nat...@europe.altair.com>> 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 osg-users@lists.openscenegraph.org<mailto:osg-users@lists.openscenegraph.org> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
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