tools: describe the various debug-gui features in the man page

There are too many things now to make it immediately obvious, let's describe
all this accordingly.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

diff --git a/tools/libinput-debug-gui.man b/tools/libinput-debug-gui.man
index c02aaeb..3a1b295 100644 (file)
--- a/tools/libinput-debug-gui.man
+++ b/tools/libinput-debug-gui.man
@@ -43,6 +43,54 @@ The default behavior is equivalent to \-\-udev "seat0".
 Use verbose output
 .PP
 For libinput configuration options, see libinput-debug-events(1)
+.SH FEATURES
+.PP
+.TP 8
+.B Cursor movement
+The cursor is displayed as black triangle. Various markers are displayed in
+light grey to help debug cusor positioning. The cursor movement is
+the one as seen by libinput and may not match the cursor movement of the
+display server.
+.TP 8
+.B Button testing
+Four oblongs are displayed at the bottom. The top three are left, middle,
+right, the bottom one is for any other button and displays the button name
+on press.
+.TP 8
+.B Scrolling
+The green oblongs show the scrolling in continuous space, the smaller red
+oblongs the scroll steps in discrete steps.
+.TP 8
+.B Gestures
+A set of four horizontal black rings show swipe gestures, with the number of
+detected fingers filled in. A set of two black rings show pinch gestures,
+filled when events are detected.
+.TP 8
+.B Touch and absolute mouse events
+Touch and absolute mouse events are displayed as red and blue circles,
+respectively, at the touch point or absolute position.
+.TP 8
+.B Tablet tools
+Events from tablet tools show a cyan square at the proximity-in and
+proximity-out positions. The tool position is shown as circle and increases
+in radius with increasing pressure or distance. Where tilt is available, the
+circle changes to an ellipsis to indicate the tilt angle. Relative events
+from the tablet tool are displayed as a yellow snake, always starting from
+the center of the window on proximity in. Button events are displayed in the
+bottom-most button oblong, with the name of the button displayed on press.
+.TP 8
+.B Tablet pads
+Button events are displayed in the bottom-most button oblong, with the name
+of the button displayed on press. Ring and strip events are displayed in the
+yellow 'IO' symbol, with the position and the number of the ring/strip
+filled in when events are available.
+.TP 8
+.B Kernel events
+Left of the center is a blue ring to debug kernel relative events (REL_X and
+REL_Y). Each unit is displayed as one arrow in the respective direction.
+Right of the center is a blue oblong representing the most recently-used
+touch device. Touch events are displayed as they are read from the kernel.
+
 .SH NOTES
 .PP
 Events shown by this tool may not correspond to the events seen by a