Document: Themes


This document describes the format for piece sets and sounds
and how eboard searches for them.

Felipe Bergo 

1. File format
2. Location
3. Sound Files


1. File format

Each piece set is a graphic file in the PNG format.
I Recommend indexed PNG images without alpha channel,
which will provide good, lossless compression. (RGB-color
can be used instead on indexed, but will often produce
larger files)

The file must have an aspect ratio of exactly 7:2
(the width must be a multiple of 7, the height
must be a multiple of 2, and the resulting aspect
must be 7:2 -- other arrangements _may_ work or not,
and will not be officially supported).

The graphic is logically divided in 14 squares of
same size, which contain the pieces and squares
in the following order:

First Row, left to right:
White Rook, White Knight, White Bishop, White Queen,
White King, White Pawn, Light Square.

Second Row, left to right:
Black Rook, Black Knight, Black Bishop, Black Queen,
Black King, Black Pawn, Dark Square.

The color of pixel (0,0) (the topmost, leftmost pixel in the
image file) is taken to be the transparent color for the
pieces. Any format-dependent alpha information is not
considered (thus using PNGs with alpha channel only wastes
memory and disk usage).

Transparent color information is not considered for the
board squares, which are taken to be fully opaque.

2. Location

Theme configuration is read on startup from one or more
files called eboard_themes.conf, these file are
looked for in the following directories (in this order):

. (current directory)

(prefix is configured with --prefix in the configure script,
the default is /usr/local)

next, any files named themeconf.* (where * can be anything)
in the datadir directory are loaded (usually
/share/eboard , to check what your datadir is type
'eboard-config --datadir' after ebaord is installed).

The eboard_themes.conf should contain one theme per line,
lines started by '#' are considered comments. Lines
started with '+' are considered sound files, sound files
are described later in this document. Example:

# eboard themes

basic_y.png,Simple Pieces on Wood 1
basic_w.png,Simple Pieces on Wood 2
basic_g.png,Simple Pieces on Metal
rock.png,Stone Cold
+Move.wav,whatever follows the comma is discarded

The first field in the line is the filename of the graphics
file, the second field is the name that will be shown in the
Settings -> Bitmapped Piece Sets menu. The fields are
separated by a comma.

The contents of all eboard_theme.conf files are merged and
this becomes the set of available themes. If two files
with same name are listed in different .conf files with
different descriptions, the first seen is used (according to
the order listed above).

Each graphic file must be in one of the directories
listed above, not necessarily the same directory
eboard_themes.conf or the other themes are.

There's a script to help adding themes, eboard-addtheme,
but it's syntax is still subject to changes and we do
not encourage anyone to use this script in any package
until we decide on a stable syntax for it.

3. Sound Files

Lines starting with a '+' can be used to list
sound files. The syntax is


whatever follows the comma (which must be present) is

The sound files listed will be available in the eboard's
sound configuration interface. We strongly advise the
use of the following suffixes:

.wav          --> WAV audio file
.mid or .midi --> MIDI sequencer files

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