bitmap(6) [plan9 man page]

BITMAP(6)							   Games Manual 							 BITMAP(6)

NAME

       bitmap - external format for bitmaps

SYNOPSIS

       #include <libg.h>

DESCRIPTION

       Bitmaps are described in graphics(2).  Fonts and bitmaps are stored in external files in machine-independent formats.

       Bitmap  files  are  read  and  written  using  rdbitmapfile and wrbitmapfile (see balloc(2)).  A bitmap file starts with 5 decimal strings:
       ldepth, r.min.x, r.min.y, r.max.x, and r.max.y.	Each number is right-justified and blank padded in 11 characters,  followed  by  a  blank.
       The  rest  of  the  file contains the r.max.y-r.min.y rows of bitmap data.  A row consists of the byte containing pixel r.min.x and all the
       bytes up to and including the byte containing pixel r.max.x-1.  A pixel with x-coordinate = x in a bitmap with ldepth = ld will appear as w
       =  2^ld	contiguous  bits in a byte, with the pixel's high order bit starting at the byte's bit number w*(x mod (8/w)), where bits within a
       byte are numbered 0 to 7 from the high order to the low order bit.  If w is greater than 8, it is a multiple of 8, so pixel values take	up
       an integral number of bytes.  Rows contain integral number of bytes, so there may be some unused pixels at either end of a row.

       The rdbitmap and wrbitmap functions described in balloc(2) also deal with rows in this format, stored in user memory.

       Some small images, in particular 48x48 face files as used by seemail (see mail(1)) and 16x16 cursors, can be stored textually, suitable for
       inclusion in C source.  Each line of text represents one scan line as a comma-separated sequence of hexadecimal bytes, shorts, or words	in
       C  format.   For cursors, each line defines a pair of bytes.  (It takes two images to define a cursor; each must be stored separately to be
       processed by programs such as tweak(1).)  Face files of one bit per pixel are stored as a sequence of shorts, those of larger  pixel  sizes
       as  a  sequence	of  longs.   Software that reads these files must deduce the image size from the input; there is no header.  These formats
       reflect history rather than design.

SEE ALSO

       tweak(1), graphics(2), bitblt(2), balloc(2), face(6), font(6)

																	 BITMAP(6)

FACE(6) 							   Games Manual 							   FACE(6)

NAME

       face - face files

DESCRIPTION

       The  directory  /lib/face  contains a hierarchy of images of people.  In that directory are subdirectories named by the sizes of the corre-
       sponding image files: 48x48x1 (48 by 48 pixels, one bit per pixel); 48x48x2 (48 by 48 pixels, two bits per pixel); 512x512x8  (512  by  512
       pixels,	eight  bits  per  pixel);  512x512x24 (512 by 512 pixels, twenty-four bits per pixel (3 times 8 bits per color)).  The large files
       serve no special purpose; they are stored either as bitmaps (see bitmap(6)) or as picture files (see picfile(9.6).  The small files are the
       `icons'	displayed by seemail (see mail(1)); their format is special.

       Icons  are stored as text, one line of the file to one scan line of display.  Each line is divided into 8-bit, 16-bit, or 32-bit big-endian
       words, stored as a list of comma-separated hexadecimal C constants, such as:

	      0x9200, 0x1bb0, 0x003e,

       This odd format is historical and the programs that read it are somewhat forgiving about blanks and the need for commas.

       The files /lib/face/*/.dict hold a correspondence between users at machines and face files.  The format is

	      machine/user directory/file.ver

       The machine is the domain name of the machine sending the message, and user the name of the user sending it, as recorded in  /sys/log/mail.
       The  directory  is  a further subdirectory of (say) /lib/face/48x48x1, named by a single letter corresponding to the first character of the
       user names.  The file is the name of the file, typically but not always the user name, and ver is a number to distinguish different images,
       for example to distinguish the image for Bill Gates from the image for Bill Joy, both of which might otherwise be called b/bill.  For exam-
       ple, Bill Gates might be represented by the line

	      microsoft.com/bill b/bill.1

       If multiple entries exist for a user in the various .dict files, seemail chooses the highest pixel size less than or equal to that  of  the
       display on which it is running.

       Finally,  or  rather firstly, the file /lib/face/.machinelist contains a list of machine/domain pairs, one per line, to map any of a set of
       machines to a single domain name to be looked up in the .dict files.  The machine name may be a regular	expression,  so  for  example  the
       entry

	      .*research.att.com    astro

       maps any of the machines in AT&T Research into the shorthand name astro, which then appears as a domain name in the .dict files.

SEE ALSO

       mail(1), tweak(1), bitmap(6)

																	   FACE(6)