Another question is how do you enabled efficient erasing? How is the line segments stored so they can be efficiently looked up for erasing?
Thanks, Shuhao On 10/01/2014 05:00 PM, Denis Auroux wrote: > On 10/01/2014 05:20 PM, Shuhao Wu wrote: >> I'm also impressed by the fact that the anti aliasing looks very good. I >> assume this is handled by gnome > > Yes -- by libgnomecanvas specifically (with the help of libart_lgpl > again). Xournal doesn't do any antialiasing of its own. > > Libgnomecanvas has some annoying issues (no longer well-maintained, a > few bugs, not compatible with gtk3, ...) but it does have > some unique features like the high display quality (the other one you > might not notice is performance -- xournal isn't always as fast as one > would like, but with a less optimized display library it would be worse. > Apparently the GTK3 canvas widgets that Daniel tried to use for his gtk3 > port of xournal are much slower. A xournal document typically has > hundreds of thousands of line segments and, while that's nothing > compared to modern video games and other 3d stuff, it's enough to choke > to death libraries that were written with business software in mind -- > display refresh needs to think carefully about what exactly needs to be > redrawn.) > >> and the fact that the line segment is so small? (0.3px?) > > In real life if you write quickly the line segments are not that short > -- my tablet reports motions quickly and if the pen is moved slowly the > line segments end up indeed being very short, but when drawing longer > lines quickly the successive points can be 5-10 pixels apart (but what > helps is that each point has a fractional position which is much more > accurate than having just integer pixel coordinates). > >> Furthermore is pressure sensitivity data recorded per line segment? > > Yes, when pressure sensitivity is on, each line segment has its own > pressure value and hence its own thickness. > > Denis > ------------------------------------------------------------------------------ Meet PCI DSS 3.0 Compliance Requirements with EventLog Analyzer Achieve PCI DSS 3.0 Compliant Status with Out-of-the-box PCI DSS Reports Are you Audit-Ready for PCI DSS 3.0 Compliance? Download White paper Comply to PCI DSS 3.0 Requirement 10 and 11.5 with EventLog Analyzer http://pubads.g.doubleclick.net/gampad/clk?id=154622311&iu=/4140/ostg.clktrk _______________________________________________ Xournal-devel mailing list Xournal-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xournal-devel
