term% cat index.txt BITFILE(9.5) BITFILE(9.5)
NAME
bitfile - format of bitmap file
DESCRIPTION
Binary files produced by blitblt(9.1), twid(9.6) and other bitmap-gen‐
erating programs are formatted as follows:
Byte no. Description
0, 1: Zero.
2, 3: X-coordinate of the rectangle origin (low-order byte, high-
order byte).
4, 5: Y-coordinate of the rectangle origin (low-order byte, high-
order byte).
6, 7: X-coordinate of the rectangle corner (low-order byte, high-
order byte).
8, 9: Y-coordinate of the rectangle corner (low-order byte, high-
order byte).
remainder: Compressed raster data. Each raster is exclusive-or'd with
the previous one, and zero-extended (if necessary) to a
16-bit boundary. It is then encoded into byte sequences,
each of which consists of a control byte followed by two or
more data bytes:
Control Data
n (< 127) 2*n bytes of raster data, running from left to right.
0x80 + n 2 bytes of raster data, to be replicated from left to right
n times.
There are also two ASCII formats in current use. Textures and 16×16
icons, typically created by icon(9.1), are encoded as a Texture decla‐
ration with initializer, to be copied unchanged into C program source;
see types(9.5). Faces and other large icons are without any surround‐
ing C syntax. In either case, each scan line of the bitmap is a comma-
separated list of C-style short hexadecimal constants; scan lines are
separated by newlines.
SEE ALSO
blitblt(9.1), icon(9.1), twid(9.1), types(9.5), sysmon(9.1), can(1)
BITFILE(9.5)