bggen(l) UNIX System V bggen(l)
NAME
bggen - generates colored backgrounds on X11 displays
SYNTAX
bggen [-w width] [-s size] [-b bits] r1 g1 b1 [r2 g2 b2 ... rn gn bn]
DESCRIPTION
bggen is a program that generates a width-pixel wide by size-pixels high
vertical stripe. The top of the stripe is in color (r1,g1,b1), and the
bottom of the stripe is in color (rn,gn,bn). Intermediate colors are
interpolated between these colors. If you specify more than 2 colors,
the stripe passes through all the specified colors, in the order
specified.
The '-b' option specifies the number of significant bits in the (output)
color specifications. It must range between 1 and 8, inclusive. Use
values less than 8 (the default) to limit color use by increasing the
color granularity.
Values for 'r', 'g', and 'b' should range between 0 and 255, inclusive.
0 means 'off', and 255 means 'fully on'.
bggen doesn't actually affect your background directly. bggen merely
generates a small PPM (Portable Pixmap Format) datafile that XV can read
and display.
To use bggen, you should pipe its output into an XV command, such as:
"xv -root -quit -slow24"
The default 'size' is 1024 pixels, which should be as tall as your
display. If your display is taller than that, you should specify its
actual height, otherwise you will get a bizarre repeating effect, that
you probably didn't want. Note: If you specify small values of '-s',
you can get some neat effects.
The '-w' argument has been added to improve the performance of various
stippling algorithms (as in XV). More information to work with, and
such. Try using '-w 16' on these command lines to see what is meant.
TRY THESE
Light Blue to Dark Blue
bggen 100 100 255 50 50 150 | xv -ro -q -slow24 -
RGB Rainbow
bggen 0 0 255 0 255 0 255 0 0 | xv -ro -q -slow24 -
Green Cylinders
bggen 0 0 0 0 255 0 0 0 0 -s 128 | xv -ro -q -slow24 -
Blue to Magenta
bggen 0 0 255 200 0 100 | xv -ro -q -slow24 -
Full Rainbow
bggen 0 0 255 0 255 255 0 255 0 255 255 0 255 0 0 | xv -ro -q -slow24 -
Repeating Rainbow
bggen 0 0 255 0 255 255 0 255 0 255 255 0 255 0 0
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bggen(l) UNIX System V bggen(l)
255 0 255 0 0 255 -s 256 | xv -ro -q -slow24 -
It'd probably be nice if the program used some X calls to determine
screen size. It'd also probably be nice if the program could take colors
by 'name', and also by hexadecimal value.
AUTHOR
John Bradley - bradley@cis.upenn.edu
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