csdvrx's work

README.md

@@ -0,0 +1,180 @@
+> sixel-tmux : a terminal multiplexer that properly display graphics because it does not eat escape sequences
+
+### What is sixel-tmux
+
+sixel-tmux is a fork of tmux, with just one goal: having the most reliable support of graphics.
+
+In a console, this means:
+ 1. ANSI blocks and box-drawing characters <https://en.wikipedia.org/wiki/Box-drawing_character> to display ASCII and ANSI art <https://en.wikipedia.org/wiki/ANSI_art>
+ 2. ANSI escape codes, with a focus on SGR parameters <https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_parameters> to render text attributes
+ 3. and the best of all: sixel graphics <https://en.wikipedia.org/wiki/Sixel> to display graphs <https://github.com/csdvrx/sixel-gnuplot>
+
+This seems very simple requirements, yet a regular tmux fails on all 3:
+ 1. ANSI art is corrupted,
+ 2. some SGR parameters are supported, but the more exotic features like overline do not work, and some sequences may be intercepted and improperly changed
+ 3. sixels are not supported.
+
+For a proper support of all these features, sixel-tmux is necessary but
+not sufficient: the terminal must be able to decode and render the sequences
+passed by sixel-tmux.
+
+Therefore, a separate test suite <https://github.com/csdvrx/sixel-testsuite>
+is provided to first check if a terminal can achieve these goals.
+
+If you are dissatisfied by your current terminal, please consider mlterm
+<http://mlterm.sourceforge.net/> or mintty <https://mintty.github.io/> that are
+tested and known to work well.
+
+Microsoft Window Terminal is very promising, but does not support sixels yet.
+Please upvote the feature request <https://github.com/microsoft/Terminal/issues/448>
+
+You can find a longer list of alternative terminals and terminal multiplexers through
+related works such as <https://github.com/gizak/termui/pull/233>
+
+## Usage
+
+First, use to test-suite to see what your terminal supports:
+
+For the colors:
+1. start by 16-colors.sh
+2. then try 256-colors.pl
+3. see if you are lucky and can use a 24 bits palette with 24-bit-color.sh
+4. if it works, try to switch the 16 colors palette between Solarized dark and light with toggle-solarized-dark.sh and toggle-solarized-light.sh
+
+In the final test, after displaying the 4 continous color lines without bands
+or sudden breaks, your screen should switch to a black background then back to
+a clear yellowish background.
+
+For the fonts:
+1. start with `cat font-ansi-blocks.txt` to see block drawing characters and a test bear
+2. run `font-vt100.sh` to see the basic box drawing characters
+2. `cat font-ansi-box.txt` to see the full set of box drawing characters
+3. `cat font-dec.txt` to check DEC VT220 extra characters
+4. `cat font-test-all.txt` to check unicode support and overall support of the drawing characters
+
+In the final test, boxes should be properly aligned, and lines should intersect cleanly.
+
+If the font test fails, you may need to change your font as it may not support every character.
+
+Alternatively, when using mlterm you can tell it to extend your preferred font with one or more other fonts, for example:
+        ISO8859_1 = Iosevka SS04 18
+        ISO8859_15 = Iosevka SS04 18
+        ISO10646_UCS2_1 =Iosevka SS04 18
+        ISO10646_UCS2_1_BOLD = Iosevka SS04 18
+        U+2500-25ff=Segoe UI Symbol
+        U+25C6 = Tera Special # Diamond                  ◆
+        U+2409 = Tera Special # Horizontal tab           ␉
+        U+240C = Tera Special # Form feed                ␌
+        U+240D = Tera Special # Carrier return           ␍
+        U+240A = Tera Special # Linefeed                 ␊
+        U+2424 = Tera Special # Newline                  ␤
+        U+240B = Tera Special # Vertical tab             ␋
+        U+23BA = Tera Special # Horizontal line 1        ⎺
+        U+23BB = Tera Special # Horizontal line  3       ⎻
+        U+2500 = Tera Special # Horizontal line  5       ─
+        U+23BC = Tera Special # Horizontal line  7       ⎼
+        U+23BD = Tera Special # Horizontal line  9       ⎽
+
+When everything works to your satisfaction, install libevent2 and ncurses, then
+compile with: `./configure && make && make -j8 install`
+
+Then:
+1. install sixel-tmux.terminfo: `tic sixel-tmux.terminfo; tic -o ~/.terminfo sixel-tmux.terminfo`
+2. start sixel-tmux: `sixel-tmux`
+3. select sixel-tmux: `export TERM=sixel-tmux`
+4. verify sixel-tmux is used: `tput smglr|base64` should return GzcbWz82OWgbWyVpJXAxJWQ7JXAyJWRzGzg=
+
+You can then run the test-suite <https://github.com/csdvrx/sixel-testsuite> to check if what was working in your terminal before sixel-tmux is still working.
+
+If it isn't, oops: it means sixel-tmux broke something. Patches are welcome!
+
+### Current status and tests failed
+
+Sixels fully work, but images are not redrawn when returning from another buffer (snake.six)
+
+Overlines are not working yet (ansi-vte52.sh)
+
+Ansi blocks are separated until you move to another buffer and back (font-ansi-blocks.txt)
+
+24-bit mode is not supported (24-bit-color.sh)
+
+dynamic switching of the 16 colors palette is not working (toggle-solarized-dark.sh/toggle-solarized-light.sh)
+
+vertical split does not plays well with ansi and sixel
+
+### Example inside mintty
+
+Here is what my terminal looks like while I am editing this file in VIM
+
+![mintty running tmux split window and displaying sixels inside](https://raw.githubusercontent.com/csdvrx/sixel-tmux/master/sixel-tmux.jpg)
+
+### Why a fork
+
+To support slow terminal with little bandwith, tmux started implementing
+some controversial features after version 2.3. For example, when a lot of text
+arrives, tmux start silently discarding the output until a redraw can be done.
+
+Bug reports <https://github.com/tmux/tmux/issues/1019#issuecomment-318284445>
+<https://github.com/tmux/tmux/issues/1502#issuecomment-429710887> mention
+serious issues, such as being unable to cat a long text file without some parts
+being cut off, so this questionable feature for slow terminals impacts many usecases. 
+
+Among other things, it breaks sixel support. Even when not using sixels, it
+seems very wrong for tmux to be taking the initiative of silently discarding
+parts of the outputs, without providing any command line flags to override that
+"feature".
+
+As it can't be disabled, this anti-feature is not just a questionable default,
+but a perverse feature: I believe breaking the integrity of the output of
+whatever command was run, with no recourse, is not acceptable for a terminal multiplexer.
+
+Also, refusing to even provide a command-line toggle to opt-out is not
+respectful of the end user freedom: no one should have to track patches to
+allow basic functionality like properly displaying long text files!
+
+The maintainer explicitely said several times that even if a patch was provided
+to support sixels, the functionality would never be added to tmux, and it would
+have to be a fork
+<https://github.com/tmux/tmux/issues/44#issuecomment-119755304>
+
+By becoming a permanent fork of tmux, sixel-tmux will do just what was asked.
+
+sixel-tmux is not just made for sixels but for all graphical things that can no
+longer be properly displayed inside tmux, including long text files.
+
+Unfortunately, a permanent fork seems necessary as the problem seems to be more
+general, and spreading: tmux intercept and improperly rewrites various escapes
+codes, breaking other things
+<https://github.com/tmux/tmux/issues/1391#issuecomment-403267557>
+
+At this point, it is very unlikely that tmux will be fixed: all these
+questionable choices start piling up, and make the correct display of what is
+not just simple plain text inside tmux harder and harder.
+
+This is a sad situation as tmux was one of the best terminal multiplexer, and
+supported what GNU screen couldn't when too many questionable choices had been
+accumulated and frozen in over 32 years of spaghetti code.
+
+Therefore, all patches adding functionality to sixel-tmux are welcome-
+including cleanups, and ports of tmux features. Even the features that may affect the
+proper display of graphics and text are welcome, as long as they are off by
+default since obscure usecases like limited bandwidth are now as rare as
+serial ports.
+
+### History
+
+Hayaki Saito <https://github.com/saitoha/tmux-SIXEL> wrote a patch and released
+a tmux-sixel fork in 2015.  As tmux keep adding features, Chris Steinbach
+<https://github.com/ChrisSteinbach/tmux-sixel> tried to integrate them in
+tmux-sixel.  Patches were released by others to add to the version of tmux
+officialy packaged by distributions to have tmux-sixel features, like Mehdi
+Abaakouk <https://gist.github.com/sileht/8759089d5620da763bb456a0ae82e4d0>
+
+Yatao Li <https://github.com/yatli/tmux> had a branch that was the closet to upstream
+tmux, but the most recent changes dated from 2017 and some sixel isues remained.
+
+When I tried them, none had full support for ANSI SGR parameters. In 2019, as
+there was no recent activity on any of these, I forked the most recent branch,
+fixed the remaining issues to have good sixel support at least in the current
+buffer, added the missing SGR parameters I needed, and fixed issues brough by
+the inclusion of unavoidable anti-features in mainline tmux.

README.tmux

@@ -0,0 +1,83 @@
+Note on tmux-sixel
+
+This fork has been created to make it a little easier to keep the sixel support
+patch provided by Hayaki Saito working (see https://github.com/saitoha).
+
+-----------
+
+Welcome to tmux!
+
+tmux is a "terminal multiplexer", it enables a number of terminals (or windows)
+to be accessed and controlled from a single terminal. tmux is intended to be a
+simple, modern, BSD-licensed alternative to programs such as GNU screen.
+
+This release runs on OpenBSD, FreeBSD, NetBSD, Linux, OS X and Solaris.
+
+tmux depends on libevent 2.x. Download it from:
+
+	http://libevent.org
+
+It also depends on ncurses, available from:
+
+	http://invisible-island.net/ncurses/
+
+To build and install tmux from a release tarball, use:
+
+	$ ./configure && make
+	$ sudo make install
+
+tmux can use the utempter library to update utmp(5), if it is installed - run
+configure with --enable-utempter to enable this.
+
+To get and build the latest from version control:
+
+	$ git clone https://github.com/tmux/tmux.git
+	$ cd tmux
+	$ sh autogen.sh
+	$ ./configure && make
+
+(Note that this requires at least a working C compiler, make, autoconf,
+automake, pkg-config as well as libevent and ncurses libraries and headers.)
+
+For more information see http://git-scm.com. Patches should be sent by email to
+the mailing list at tmux-users@googlegroups.com or submitted through GitHub at
+https://github.com/tmux/tmux/issues.
+
+For documentation on using tmux, see the tmux.1 manpage. It can be viewed from
+the source tree with:
+
+	$ nroff -mdoc tmux.1|less
+
+A small example configuration in example_tmux.conf.
+
+A vim(1) syntax file is available at:
+
+	https://github.com/ericpruitt/tmux.vim
+	https://raw.githubusercontent.com/ericpruitt/tmux.vim/master/vim/syntax/tmux.vim
+
+And a bash(1) completion file at:
+
+	https://github.com/imomaliev/tmux-bash-completion
+
+For debugging, running tmux with -v or -vv will generate server and client log
+files in the current directory.
+
+tmux mailing lists are available. For general discussion and bug reports:
+
+	https://groups.google.com/forum/#!forum/tmux-users
+
+And for Git commit emails:
+
+	https://groups.google.com/forum/#!forum/tmux-git
+
+Subscribe by sending an email to <tmux-users+subscribe@googlegroups.com>.
+
+Bug reports, feature suggestions and especially code contributions are most
+welcome. Please send by email to:
+
+	tmux-users@googlegroups.com
+
+This file and the CHANGES, FAQ, SYNCING and TODO files are licensed under the
+ISC license. All other files have a license and copyright notice at their start.
+
+-- Nicholas Marriott <nicholas.marriott@gmail.com>

attributes.c

@@ -25,21 +25,25 @@
 const char *
 attributes_tostring(int attr)
 {
-	static char	buf[128];
+	static char	buf[512];
 	size_t		len;
 
 	if (attr == 0)
 		return ("none");
 
-	len = xsnprintf(buf, sizeof buf, "%s%s%s%s%s%s%s%s",
+	len = xsnprintf(buf, sizeof buf, "%s%s%s%s%s%s%s%s%s%s%s%s",
 	    (attr & GRID_ATTR_BRIGHT) ? "bright," : "",
 	    (attr & GRID_ATTR_DIM) ? "dim," : "",
 	    (attr & GRID_ATTR_UNDERSCORE) ? "underscore," : "",
 	    (attr & GRID_ATTR_BLINK)? "blink," : "",
 	    (attr & GRID_ATTR_REVERSE) ? "reverse," : "",
 	    (attr & GRID_ATTR_HIDDEN) ? "hidden," : "",
 	    (attr & GRID_ATTR_ITALICS) ? "italics," : "",
-	    (attr & GRID_ATTR_STRIKETHROUGH) ? "strikethrough," : "");
+	    (attr & GRID_ATTR_STRIKETHROUGH) ? "strikethrough," : "",
+	    (attr & GRID_ATTR_UNDERSCORE_2) ? "double-underscore," : "",
+	    (attr & GRID_ATTR_UNDERSCORE_3) ? "curly-underscore," : "",
+	    (attr & GRID_ATTR_UNDERSCORE_4) ? "dotted-underscore," : "",
+	    (attr & GRID_ATTR_UNDERSCORE_5) ? "dashed-underscore," : "");
 	if (len > 0)
 		buf[len - 1] = '\0';
 
@@ -52,6 +56,25 @@ attributes_fromstring(const char *str)
 	const char	delimiters[] = " ,|";
 	int		attr;
 	size_t		end;
+	u_int		i;
+	struct {
+		const char*	name;
+		int		attr;
+	} table[] = {
+		{ "bright", GRID_ATTR_BRIGHT },
+		{ "bold", GRID_ATTR_BRIGHT },
+		{ "dim", GRID_ATTR_DIM },
+		{ "underscore", GRID_ATTR_UNDERSCORE },
+		{ "blink", GRID_ATTR_BLINK },
+		{ "reverse", GRID_ATTR_REVERSE },
+		{ "hidden", GRID_ATTR_HIDDEN },
+		{ "italics", GRID_ATTR_ITALICS },
+		{ "strikethrough", GRID_ATTR_STRIKETHROUGH },
+		{ "double-underscore", GRID_ATTR_UNDERSCORE_2 },
+		{ "curly-underscore", GRID_ATTR_UNDERSCORE_3 },
+		{ "dotted-underscore", GRID_ATTR_UNDERSCORE_4 },
+		{ "dashed-underscore", GRID_ATTR_UNDERSCORE_5 }
+	};
 
 	if (*str == '\0' || strcspn(str, delimiters) == 0)
 		return (-1);
@@ -64,24 +87,15 @@ attributes_fromstring(const char *str)
 	attr = 0;
 	do {
 		end = strcspn(str, delimiters);
-		if ((end == 6 && strncasecmp(str, "bright", end) == 0) ||
-		    (end == 4 && strncasecmp(str, "bold", end) == 0))
-			attr |= GRID_ATTR_BRIGHT;
-		else if (end == 3 && strncasecmp(str, "dim", end) == 0)
-			attr |= GRID_ATTR_DIM;
-		else if (end == 10 && strncasecmp(str, "underscore", end) == 0)
-			attr |= GRID_ATTR_UNDERSCORE;
-		else if (end == 5 && strncasecmp(str, "blink", end) == 0)
-			attr |= GRID_ATTR_BLINK;
-		else if (end == 7 && strncasecmp(str, "reverse", end) == 0)
-			attr |= GRID_ATTR_REVERSE;
-		else if (end == 6 && strncasecmp(str, "hidden", end) == 0)
-			attr |= GRID_ATTR_HIDDEN;
-		else if (end == 7 && strncasecmp(str, "italics", end) == 0)
-			attr |= GRID_ATTR_ITALICS;
-		else if (end == 13 && strncasecmp(str, "strikethrough", end) == 0)
-			attr |= GRID_ATTR_STRIKETHROUGH;
-		else
+		for (i = 0; i < nitems(table); i++) {
+			if (end != strlen(table[i].name))
+				continue;
+			if (strncasecmp(str, table[i].name, end) == 0) {
+				attr |= table[i].attr;
+				break;
+			}
+		}
+		if (i == nitems(table))
 			return (-1);
 		str += end + strspn(str + end, delimiters);
 	} while (*str != '\0');

grid.c

@@ -753,7 +753,11 @@ grid_string_cells_code(const struct grid_cell *lastgc,
 		{ GRID_ATTR_BLINK, 5 },
 		{ GRID_ATTR_REVERSE, 7 },
 		{ GRID_ATTR_HIDDEN, 8 },
-		{ GRID_ATTR_STRIKETHROUGH, 9 }
+		{ GRID_ATTR_STRIKETHROUGH, 9 },
+		{ GRID_ATTR_UNDERSCORE_2, 42 },
+		{ GRID_ATTR_UNDERSCORE_3, 43 },
+		{ GRID_ATTR_UNDERSCORE_4, 44 },
+		{ GRID_ATTR_UNDERSCORE_5, 45 },
 	};
 	n = 0;
 
@@ -779,11 +783,15 @@ grid_string_cells_code(const struct grid_cell *lastgc,
 		else
 			strlcat(buf, "\033[", len);
 		for (i = 0; i < n; i++) {
-			if (i + 1 < n)
-				xsnprintf(tmp, sizeof tmp, "%d;", s[i]);
-			else
+			if (s[i] < 10)
 				xsnprintf(tmp, sizeof tmp, "%d", s[i]);
+			else {
+				xsnprintf(tmp, sizeof tmp, "%d:%d", s[i] / 10,
+				    s[i] % 10);
+			}
 			strlcat(buf, tmp, len);
+			if (i + 1 < n)
+				strlcat(buf, ";", len);
 		}
 		strlcat(buf, "m", len);
 	}