getcmap(9) [plan9 man page]

GETCMAP(9.2)															      GETCMAP(9.2)

NAME

       getcmap - read a color map from a file

SYNOPSIS

       #include <libg.h>

       #include <fb.h>

       int getcmap(char *name, uchar *map)

DESCRIPTION

       Getcmap retrieves the named colormap and stores it in map.  Usually name is the name of a colormap file (see cmap(9.6)) or a picfile with a
       CMAP= attribute.  If the file is not found, it is sought in /lib/fb/cmap.

       If the file cannot be found, and its name has the form gammanumber, a colormap is fabricated with all three channels of its nth	entry  set
       to 255x(n/255)1/number.	If the name is just gamma, number=2.3 is assumed.

       There is no putcmap, because write (in read(2)) can do the job.

SOURCE

       /sys/src/libfb/getcmap.c

SEE ALSO

       cmap(9.6), picfile(9.6) rgbpix(2)

																      GETCMAP(9.2)

CMAP(5)                                                         File Formats Manual                                                        CMAP(5)

NAME

       cmap - format of .cmap files (color maps)

DESCRIPTION

       Color-map  files  define  the mapping between eight-bit color numbers and red, green and blue intensities used for those numbers.  They are
       read by Magic as part of system startup, and also by the :load and :save commands in color-map windows.  Color-map file names usually  have
       the form x.y.z.cmapn, where x is a class of technology files, y is a class of displays, z is a class of monitors, and n is a version number
       (currently 1). The version number will change in the future if the formap of color-map files ever changes.  Normally, x and y correspond to
       the  corresponding parts of a display styles file.  For example, the color map file mos.7bit.std.cmap1 is used today for most nMOS and CMOS
       technology files using displays that support at least seven bits of color per pixel and standard-phosphor monitors.  It corresponds to  the
       display styles file mos.7bit.dstyle5.

       Color-map  files are stored in ASCII form, with each line containing four decimal integers separated by white space.  The first three inte-
       gers are red, green, and blue intensities, and the fourth field is a color number.  For current displays the intensities must  be  integers
       between  0 and 255.  The color numbers must increase from line to line, and the last line must have a color number of 255.  The red, green,
       and blue intensities on the first line are used for all colors from 0 up to and including the color number on that line.  For other  lines,
       the  intensities  on that line are used for all colors starting one color above the color number on the previous line and continuing up and
       through the color number on the current line.  For example, consider the color map below:

       255     0       0       2
       0       0       255     3
       255     255     255     256

       This color map indicates that colors 0, 1, and 2 are to be red, color 3 is to be blue, and all other colors are to be white.

SEE ALSO

       magic(1), dstyle(5)

4th Berkeley Distribution                                                                                                                  CMAP(5)