This program is a bitmap font editor running under X11.  You will
need the X11R4 libraries to compile it.  As well as installing the
binary, you must install the resource file `XBfe.ad' somewhere where the
resource manager will find it; for example,
/usr/lib/X11/app-defaults/XBfe.  That file has many comments as to what
you can and cannot change for the program to work properly.  The class
name for this program is, as you might guess, `XBfe'.

The side bearing and kern values you enter are all given in pixels.

At one point I implemented a previewing window, so you could see the
characters from the font in context.  This turned out not be as useful as
I hoped, however, because the characters in the fonts we're developing
are so large.  If you want to try something with it yourself, the code
is in widgets/Fontview*.

By default, xbfe inverts the pixel under the pointer when you click
the right button.  When you drag with the right button, the pixels under
the pointer are all changed to the same color as the result of the
inversion.  That is, supposing you click on a black pixel, the pixel
turns white, and then, as you continue to hold the button down and move
the pointer, black pixels turn white and white pixels remain unchanged.

Left button down starts a selection; you can drag the mouse with the
button down to define the selection.  Releasing the button defines the
selection.

Middle button down starts a paste of the current selection, in the same
or a different character.  Dragging the mouse with the button down moves
the paste point, and releasing the button performs the paste.  By
default, the paste is opaque -- white pixels in the select clear
corresponding black pixels in the bitmap.  To get a transparent paste,
where no black pixels turn white, hold the META (a.k.a. Alt) down when
releasing.

One of the parts of the window is a place where you can type a character
code.  (In fact, wherever you type in the window, the keyboard input is
directed to there.)  I use the Athena Text widget to handle this input.
See the Athena documentation for the key bindings; they resemble the
default Emacs bindings.  When you have finished typing the character
code, you must hit RET to tell xbce you've finished typing!  See
../README for a list of the valid ways you can specify character codes.

The Exit command assumes you know what you're doing, and doesn't ask you
if you ``really want to quit'', even if the font is modified.

The Save command attempts to make sure that the input file doesn't get
overwritten by the output file.  Before making substantive changes, I
suggest making a trivial change, saving the file, and checking the
results with the gftype program in the TeX distribution.  If some bug is
lurking, this will save you from wasting a lot of effort.  And save
*frequently*.  xbfe has no Emacs-like autosaving mechanism.
