On 17 Sep 2013, at 19:47, Rick Armstrong <rick.armstr...@urbanrobotics.net> wrote:
> Indeed, PNG would be ideal! > > - if you have any interested in > > doing this, I can point you at examples since the screenshot code was > > converted to do the same thing recently -it's probably a couple of hours > > hacking at most) > > I'd be happy to take a crack at it. This would be my first foray into the > FlightGear source tree, so a pointer to some sample code would be great. > Okay, various pieces: gui_funcs.cxx has the screenshot dumping code, especially the logic to run things safely via an OSG GraphicsContextOperation. Its run() virtual contains a call to: sg_glDumpWindow which is defined in SimGear and does the actual reading of the frame-buffer and writing via: // dump the screen buffer to a png file, returns true on success bool sg_glDumpWindow(const char *filename, int win_width, int win_height) { osg::ref_ptr<osg::Image> img(new osg::Image); img->readPixels(0,0, win_width, win_height, GL_RGB, GL_UNSIGNED_BYTE); return osgDB::writeImageFile(*img, filename); } The trick will be to interface this with the jpg-httpd infrastructure. There's a problem I can see here - the osgDB API is very file orientated, but I assume you need the image data in memory to send down the HTTP socket. We might need to ask on the OSG mailing list if this can be done, otherwise you'd have to read the file back after writing it. This is little ugly but the file should be in the cache so probably no actual disk access happens. Most of jpgfactory.cxx is irrelevant, I'd ignore it completely since it only deals with the tile-rendering (not needed these days since we can render big GL viewports natively) and the mechanics of running the image compressor. If you can plug the stuff you need into line 227 of jpg-httpd, I think you're good. That's a very rough sketch based on ten minutes reading of course. Note if you want actual good performance from this system, there's much smarter things that could be done, such as grabbing the frame buffer each normal rendering frame, instead of re-rendering the scene each time an HTTP get is received. That would need much more drastic changes to the system however. As ever, any further questions, just ask. Regards, James ------------------------------------------------------------------------------ LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151&iu=/4140/ostg.clktrk _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel