ff-chess.1

.Dd 2024-04-03
.Dt FF-CHESS 1
.Os farbfeld-utils
.Sh NAME
.Nm ff-chess
.Nd creates an empty chess board of arbitrary size
.Sh SYNOPSIS
.Nm
<columns> <rows> <tile size> <colour> <colour>
.Sh DESCRIPTION
.Nm
creates an empty
.Xr farbfeld 5
chess board of arbitrary size and writes the result to stdout.
.Pp
.Nm
does not read any data from stdin.
.Pp
In case of an error
.Nm
writes a diagnostic message to stderr.
.Sh EXIT STATUS
.Bl -tag -width Ds
.It 0
Image processed successfully.
.It 1
An error occurred.
.El
.Sh OPTIONS
The program takes five arguments:
   - the number of columns (files)
   - the number of rows (ranks)
   - tile size (in pixels)
   - first tile colour
   - second tile colour

The colours can have the following patterns:
   rrggbb            three pairs of 8-bit hex values
   rrggbbaa          four pairs of 8-bit hex values
   rrrrggggbbbb      three pairs of 16-bit hex values
   rrrrggggbbbbaaaa  four pairs of 16-bit hex values

A normal chess board has 8 files and 8 ranks, and the first tile colour will
be white (or a light colour).

It is possible to use
.Xr ff-composite 1
and
.Xr ff-text 1
(together with sed) in order to draw the pieces on a chess board, see the example below.
.Sh EXAMPLES
$
.Nm
8 8 64 DDDDDD 222222 > chess.ff
.Pp
$
.Nm
8 8 32 E5E5D7 001000 \\
 | ff-composite <(pngff < pieces.png \\
 | ff-text +PNBRQKpnbrqk 32 32 `sed 's.7.43.g;s.6.33.g;s.5.32.g;s.4.22.g;s.3.21.g;s.2.11.g;s./. .g' < board.fen`) 0,0,0 \\
 | ff-border 0020FF 8
.Sh SEE ALSO
.Xr ff-composite 1 ,
.Xr ff-text 1 ,
.Xr farbfeld 5 ,
.Xr farbfeld-utils 7