FAQ: add some details about the w3m img hack

... and an example patch to switch from double-buffering to a single buffer.
This commit is contained in:
Hiltjo Posthuma 2020-05-30 21:50:54 +02:00
parent e6e2c6199f
commit 0f8b40652b

59
FAQ
View file

@ -2,12 +2,14 @@
Use the excellent tool of [utmp](https://git.suckless.org/utmp/) for this task. Use the excellent tool of [utmp](https://git.suckless.org/utmp/) for this task.
## Some _random program_ complains that st is unknown/not recognised/unsupported/whatever! ## Some _random program_ complains that st is unknown/not recognised/unsupported/whatever!
It means that st doesnt have any terminfo entry on your system. Chances are It means that st doesnt have any terminfo entry on your system. Chances are
you did not `make install`. If you just want to test it without installing it, you did not `make install`. If you just want to test it without installing it,
you can manually run `tic -sx st.info`. you can manually run `tic -sx st.info`.
## Nothing works, and nothing is said about an unknown terminal! ## Nothing works, and nothing is said about an unknown terminal!
* Some programs just assume theyre running in xterm i.e. they dont rely on * Some programs just assume theyre running in xterm i.e. they dont rely on
@ -15,6 +17,7 @@ you can manually run `tic -sx st.info`.
* Some programs dont complain about the lacking st description and default to * Some programs dont complain about the lacking st description and default to
another terminal. In that case see the question about terminfo. another terminal. In that case see the question about terminfo.
## How do I scroll back up? ## How do I scroll back up?
* Using a terminal multiplexer. * Using a terminal multiplexer.
@ -23,11 +26,13 @@ you can manually run `tic -sx st.info`.
* Using the excellent tool of [scroll](https://git.suckless.org/scroll/). * Using the excellent tool of [scroll](https://git.suckless.org/scroll/).
* Using the scrollback [patch](https://st.suckless.org/patches/scrollback/). * Using the scrollback [patch](https://st.suckless.org/patches/scrollback/).
## I would like to have utmp and/or scroll functionality by default ## I would like to have utmp and/or scroll functionality by default
You can add the absolute patch of both programs in your config.h You can add the absolute patch of both programs in your config.h
file. You only have to modify the value of utmp and scroll variables. file. You only have to modify the value of utmp and scroll variables.
## Why doesn't the Del key work in some programs? ## Why doesn't the Del key work in some programs?
Taken from the terminfo manpage: Taken from the terminfo manpage:
@ -83,12 +88,14 @@ If you are using zsh, then read the zsh FAQ
Putting these lines into your .zshrc will fix the problems. Putting these lines into your .zshrc will fix the problems.
## How can I use meta in 8bit mode? ## How can I use meta in 8bit mode?
St supports meta in 8bit mode, but the default terminfo entry doesn't St supports meta in 8bit mode, but the default terminfo entry doesn't
use this capability. If you want it, you have to use the 'st-meta' value use this capability. If you want it, you have to use the 'st-meta' value
in TERM. in TERM.
## I cannot compile st in OpenBSD ## I cannot compile st in OpenBSD
OpenBSD lacks librt, despite it being mandatory in POSIX OpenBSD lacks librt, despite it being mandatory in POSIX
@ -97,6 +104,7 @@ If you want to compile st for OpenBSD you have to remove -lrt from config.mk, an
st will compile without any loss of functionality, because all the functions are st will compile without any loss of functionality, because all the functions are
included in libc on this platform. included in libc on this platform.
## The Backspace Case ## The Backspace Case
St is emulating the Linux way of handling backspace being delete and delete being St is emulating the Linux way of handling backspace being delete and delete being
@ -158,19 +166,60 @@ terminal users wants its backspace to be how he feels it:
[1] http://www.ibb.net/~anne/keyboard.html [1] http://www.ibb.net/~anne/keyboard.html
[2] http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-5.html [2] http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-5.html
## But I really want the old grumpy behaviour of my terminal ## But I really want the old grumpy behaviour of my terminal
Apply [1]. Apply [1].
[1] https://st.suckless.org/patches/delkey [1] https://st.suckless.org/patches/delkey
## Why do images not work in st (in programs such as w3m)?
This is a terrible hack that overdraws an image on top of the terminal emulator ## Why do images not work in st using the w3m image hack?
window. It also relies on a very specific way the terminal draws it's contents.
w3mimg uses a hack that draws an image on top of the terminal emulator Drawable
window. The hack relies on the terminal to use a single buffer to draw its
contents directly.
st uses double-buffered drawing so the image is quickly replaced and may show a
short flicker effect.
Below is a patch example to change st double-buffering to a single Drawable
buffer.
diff --git a/x.c b/x.c
--- a/x.c
+++ b/x.c
@@ -561,10 +561,6 @@ xresize(int col, int row)
win.tw = MAX(1, col * win.cw);
win.th = MAX(1, row * win.ch);
- XFreePixmap(xw.dpy, xw.buf);
- xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
- DefaultDepth(xw.dpy, xw.scr));
- XftDrawChange(xw.draw, xw.buf);
xclear(0, 0, win.w, win.h);
}
@@ -921,8 +917,7 @@ xinit(void)
gcvalues.graphics_exposures = False;
dc.gc = XCreateGC(xw.dpy, parent, GCGraphicsExposures,
&gcvalues);
- xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
- DefaultDepth(xw.dpy, xw.scr));
+ xw.buf = xw.win;
XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
@@ -1386,8 +1381,6 @@ void
draw(void)
{
drawregion(0, 0, term.col, term.row);
- XCopyArea(xw.dpy, xw.buf, xw.win, dc.gc, 0, 0, win.w,
- win.h, 0, 0);
XSetForeground(xw.dpy, dc.gc,
dc.col[IS_SET(MODE_REVERSE)?
defaultfg : defaultbg].pixel);
A more proper (but limited way) would be using sixels. Which st doesn't
support.
## BadLength X error in Xft when trying to render emoji ## BadLength X error in Xft when trying to render emoji