This is a tiny program that displays the content of text files as an overlay on your desktop.
Its goal is simplicity, a non-distracting visualization and especially it should not interfere with user interactions targeting the underlying content.

It is designed as a front-end tool to show alarms or the health status of any system. To do so, just write your custom script that generates and updates a text file with the information you want to be displayed. Use this file as input for x11-overlay and that's it. But of course, it's absolutely not limited to alarming dashboards. Be creative!

• Simple and easy to use text input files (WYSIWYG)
• Don't disturb (not in taskbar nor in task-switcher)
• Don't interfere UI (delegate all user interactions to underlying elements)
• Screen selection for multi-monitor setup
• Colorized text with Ansi Escape Sequences.
  Supported are the well known color formats for 3-4bit, 8bit and 24bit (see SGR).

debian/ubuntu:

$> apt install libx11-dev libxfixes-dev libxrandr-dev libxft-dev libfreetype-dev

arc/manjaro:

$> pacman -S libx11 libxfixes libxrandr libxft freetype2

$> make && ./bin/run_tests

usage: overlay [OPTIONS] <INPUT_FILE>

  -c, --config=FILE      file path to read configuration from
  -h, --help             prints this help text
  -v, --verbose          be verbose and print some debug output
  -V, --version          print version number and quit

Positioning:
  -e PIXEL               screen edge spacing in pixels; defaults to '0'
  -l PIXEL               line spacing in pixels; defaults to '0'
  -m INDEX               monitor to use; defaults to '0'
  -o ORIENTATION         orientation to align window and lines; defaults to 'NW'
                         possible values are N, NE, E, SE, S, SW, W, NW and CENTER

Font:
  -f, --font-name=FONT   font name; defaults to 'NotoSansMono'
  -s, --font-size=SIZE   font size; defaults to '12'

Colors:
  -p, --profile=PROFILE  profile for ansi colors; values are VGA or XP
      --fg-color=COLOR   foreground color; defaults to '[97m' (equals '[38;2;255;255;255m')
      --fg-alpha=ALPHA   foreground alpha; defaults to '200'
      --bg-color=COLOR   background color; defaults to '[40m' (equals '[48;2;0;0;0')
      --bg-alpha=ALPHA   background alpha; defaults to '100'

Behavior:
  -d, --dim=PERCENT      dim the text on mouse over; defaults to '75'%
  -D PERCENT             dim the text in general; defaults to '0'%
  -t PIXEL               pixel tolerance for mouse over dimming; defaults to '0'

The overlay tool uses the FreeType font rasterizer to render fonts. Therefore all available fonts on your system can be listed using the fontconfig tools (e.g. fc-list).

So here is an example how to display the project's ansi logo as an overlay:

• install a nice looking mono space font that supports charset CP437 (e.g. a classic IBM font from int10h.org)
• find out the correct name of the (new) installed font
  $> fc-list | grep -i "IBM"
/usr/local/share/fonts/m/Mx437_IBM_VGA_8x16.ttf: Mx437 IBM VGA 8x16:style=Regular
• start overlay using specific font
  $> ./bin/overlay -f "Mx437 IBM VGA 8x16" docs/logo.utf8.ans

The default foreground text color and the default background color can be set as regular ansi color code (see SGR). For convenience the heading ESC control character can be omitted for option parameters or in the configuration file. The transparency of colors has to be set separately.