It seems I didn't fix this issue before committing teken to the tree. My
initial idea was to somehow add an error mechanism to instruct the video
driver author to increase T_NUMCOL when using very big terminals. It
turns out we have platforms where we have gigantic consoles on systems
like the Apple PowerMac G5, which means we crash there right now.
Just ignore tabstops placed beyond column 160. Just force tabs to be
placed on each 8 columns.
Reported by: nwhitehorn
After I imported libteken into the source tree, I noticed syscons didn't
store the cursor position inside the terminal emulator, but inside the
virtual terminal stat. This is not very useful, because when you
implement more complex forms of line wrapping, you need to keep track of
more state than just the cursor position.
Because the kernel messages didn't share the same terminal emulator as
ttyv0, this caused a lot of strange things, like kernel messages being
misplaced and a missing notification to resize the terminal emulator for
kernel messages never to be resized when using vidcontrol.
This patch just removes kernel_console_ts and adds a special parameter
to te_puts to determine whether messages should be printed using regular
colors or the ones for kernel messages.
Reported by: ache
Tested by: nyan, garga (older version)
Some time ago I tried adding Unicode rendering to the teken demo
application, but I didn't get it working. It seems I forgot to call
setlocale(). Polish this code and make sure it doesn't get lost.
Also a small fix for my previous commit: all Unicode characters in
teken_boxdrawing are below 0x10000, so store them as 16-bit values.
Even though VT100-like devices can display non-ASCII characters, they do
not use an 8-bit character set. Special escape sequences allow the VT100
to switch character maps. The special graphics character set stores the
box drawing characters, starting at 0x60, ending at 0x7e. This means
we now pass the character map tests in vttest, even the save/restore
cursor test, combined with character maps. dialog(1) also works a lot
better now.
This commit also includes some other minor fixes:
- Default to 24 lines in teken_demo when using xterm emulation.
- Make white foreground and background work in teken_demo.
Cons25 doesn't seem to use a straight 1:1 mapping to the ANSI colors,
but uses the same color numbers as at least used by syscons on i386. I
suspect if you change the definitions on a different architecture,
things may break? Not sure.
Add a small array to convert syscons-style color codes to ANSI
equivalents, which are used by libteken internally. I didn't notice this
bug, because I only tested my code with black, white and green, all of
them shared the same numbers.
It turns out I forgot to implement two escape sequences that allows the
user to change the default foreground and background colors. I thought
they were implemented by syscons itself, but vidcontrol just generates
some escape sequences, which get interpreted by the terminal emulator.
Reported by: mgp (forums)
The teken library already supports UTF-8 handling and xterm emulation,
but we have reasons to disable this right now. Because we should make it
easy and interesting for people to experiment with these features, allow
them to be set in kernel configuration files.
Before this commit we had a flag called `TEKEN_CONS25' to enable
cons25-style emulation. I'm calling it the opposite now, `TEKEN_XTERM',
because we want to enable it in kernel configuration files explicitly.
Requested by: kib
- Implement NP (ASCII 12, Form Feed). When used with cons25, it should
clear the screen and place the cursor at the top of the screen. When
used with xterm, it should just simulate a newline.
- When we want to use xterm emulation, make teken_demo set TERM to
xterm.
Spotted by: Paul B. Mahol <onemda@gmail.com>
Because we now have cons25-style linewrapping, we must also use cons25-
style reverse linewrapping. This means that a ^H on column 0 will move
the cursor one line up.
Also fix a small regression: if the user invokes a RIS (Reset to Initial
State), we must show the cursor again.
Spotted by: Paul B. Mahol <onemda gmail com>
With cons25, there are printable characters below 0x1B. This is not the
case with ASCII, UTF-8, etc. but in this case we just have to.
Also don't set LC_CTYPE to UTF-8 when libteken is compiled without UTF-8
in the demo-application.
It turns out I was looking too much at mimicing xterm, that I didn't
take the differences of cons25 into account. There are some differences
between xterm and cons25 that are important. Create a new #define called
TEKEN_CONS25 that can be toggled to switch between cons25 and xterm
mode.
- Don't forget to redraw the cursor after processing a forward/backward
tabulation.
- Implement cons25-style (WYSE?) autowrapping. This form of autowrapping
isn't that nice. It wraps the cursor when printing something on column
80. xterm wraps when printing the first character that doesn't fit.
- In cons25, a \t shouldn't overwrite previous contents, while xterm
does.
Reported by: Garrett Cooper <yanefbsd gmail com>
The cursor is only inside the scrolling region when we are in origin
mode. In that case, it should use originreg instead of scrollreg. It is
completely valid to place the cursor outside the scrolling region.
Some time ago I started working on a library called libteken, which is
terminal emulator. It does not buffer any screen contents, but only
keeps terminal state, such as cursor position, attributes, etc. It
should implement all escape sequences that are implemented by the
cons25 terminal emulator, but also a fair amount of sequences that are
present in VT100 and xterm.
A lot of random notes, which could be of interest to users/developers:
- Even though I'm leaving the terminal type set to `cons25', users can
do experiments with placing `xterm-color' in /etc/ttys. Because we
only implement a subset of features of xterm, this may cause
artifacts. We should consider extending libteken, because in my
opinion xterm is the way to go. Some missing features:
- Keypad application mode (DECKPAM)
- Character sets (SCS)
- libteken is filled with a fair amount of assertions, but unfortunately
we cannot go into the debugger anymore if we fail them. I've done
development of this library almost entirely in userspace. In
sys/dev/syscons/teken there are two applications that can be helpful
when debugging the code:
- teken_demo: a terminal emulator that can be started from a regular
xterm that emulates a terminal using libteken. This application can
be very useful to debug any rendering issues.
- teken_stress: a stress testing application that emulates random
terminal output. libteken has literally survived multiple terabytes
of random input.
- libteken also includes support for UTF-8, but unfortunately our input
layer and font renderer don't support this. If users want to
experiment with UTF-8 support, they can enable `TEKEN_UTF8' in
teken.h. If you recompile your kernel or the teken_demo application,
you can hold some nice experiments.
- I've left PC98 the way it is right now. The PC98 platform has a custom
syscons renderer, which supports some form of localised input. Maybe
we should port PC98 to libteken by the time syscons supports UTF-8?
- I've removed the `dumb' terminal emulator. It has been broken for
years. It hasn't survived the `struct proc' -> `struct thread'
conversion.
- To prevent confusion among people that want to hack on libteken:
unlike syscons, the state machines that parse the escape sequences are
machine generated. This means that if you want to add new escape
sequences, you have to add an entry to the `sequences' file. This will
cause new entries to be added to `teken_state.h'.
- Any rendering artifacts that didn't occur prior to this commit are by
accident. They should be reported to me, so I can fix them.
Discussed on: current@, hackers@
Discussed with: philip (at 25C3)
