On Fri, 20 Apr 2012 10:39:11 +0200 Brandon Invergo <bran...@invergo.net> wrote:
>Hi, >As some background, I've been using st on an Arm device (Genesi Efika >MX) which has relatively low specs compared to your average x86/amd64 >computer. st should be ideal because of how small it is compared to >xterm or rxvt but the reality is that its rendering is quite a bit >slower. Under heavy processor load, such as building a package, I can >literally watch the terminal window refreshing (ie I can see a line >traveling down the window, above which the window is refreshed and >below which the window is dirty...."tearing"). > >I've changed the code to use the X Double Buffer Extension (Xdbe). >Instead of rendering to a Pixbuf and then copying that Pixbuf to the >window, which is a relatively slow operation, it now renders to an >XdbeBackBuffer and then simply swaps buffers with the window. The >result is tear-free and apparently faster rendering even on an 800mhz >Arm cpu. > >A side effect is that the code is a bit shorter as a result too. For >example, xresize() does almost nothing now, since the XdbeBackBuffer is >automatically resized with the window (see the DBE manpage), so several >Xlib calls can be removed from that function. > >The provided diff is against the default branch, however I also got it >working for the xft branch. I can provide a diff for that too if you >want but the only extra difference is that any Xft draw-related calls >should work on xw.buf rather than xw.win (including the one in >xresize()). > >LIBS in config.mk should have -lXext appended. I forgot to include that >in the patch. > >A few caveats: 1) my C skills are a bit rusty, 2) I'm unfamiliar with >Mercurial, 3) I'm completely new to Xlib. So, while it Works For Me >(tm), you might want to test it a bit and let me know if I messed up >something. > >I'm going to keep hacking on it to try to improve further the speed if >I can. > >Cheers, >Brandon Invergo > Thanks for your work. I'll try st with your patch later this week. With regards, Hadrian Węgrzynowski.
