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ppmdraw(1) |
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ppmdraw
Updated: 22 June 2005
Table Of Contents
NAME
ppmdraw - draw lines, text, etc on a PPM image
SYNOPSIS
ppmdraw { -script=script | -scriptfile=filename } [-verbose] [ppmfile]
All options can be abbreviated
to their shortest unique prefix. You may use
two hyphens instead of one to designate an option. You may
use either white
space or an equals sign between an option name and its
value.
DESCRIPTION
This program is part of Netpbm.
ppmdraw draws lines, shapes,
text, etc. on a PPM image. It is essentially an
easy-to-program front end to libnetpbm’s
"ppmd" subroutines. It lets you
create a human-friendly script to describe the drawing
rather than write a C
program.
You supply drawing instructions
with a script, which you supply either in a
file named by a -scriptfile option or as the value of a
-script option. Here
is an example script:
setpos 50 50; text_here 10 30 "hello"; setcolor black; text_here 10 0 "there"; line_here 5 20;
This example starts at Column
50, Row 50 of the input image and writes the
word "hello" there in 10 pixel high white letters
at a 30 degree angle up
from horizontal. Then, from where that leaves off, the
script writes "there"
in 10 pixel high black letters horizontally. Finally, it
draws a black line
to a point 5 pixels over and 20 pixels down from the end of
"there."
If you don’t specify
ppmfile, ppmdraw reads its input PPM image from
Standard Input.
The output image goes to Standard Output.
ppmdraw works on multi-image
streams. It executes the same script on each
input image and produces an output stream with one image for
each input
image. But before Netpbm 10.32 (February 2006), ppmdraw
ignored every image
after the first.
If you just want to add a single
line of text to an image, ppmlabel may be
more what you want.
OPTIONS
-script=script
This option gives the script. See Script.
You may not specify both -script and -scriptfile.
-scriptfile=filename
This option names a file that contains the script. - means
Standard
Input.
You may not specify both -script and -scriptfile.
You may not specify - (Standard Input) for both -scriptfile
and the
input image file.
SCRIPT
The heart of ppmdraw function is
its script. The script is a character
stream. The stream consists of commands. Commands are
separated by
semicolons. White space is regarded just like in C: Any
contiguous stretch
of unquoted white space is equivalent to a single space
character. Note that
this means newlines have no particular significance.
A command is composed of tokens,
separated from each other by white space.
To write a token that contains white space, enclose it in
double quotes.
Everything between two matched quotation marks is one
token.
The first token of a command is
the verb, which determines the basic
function of the command. The rest of the tokens of the
command are
arguments, the meaning of which depends upon the verb. The
following list
gives all the valid verbs, and for each its meaning and its
arguments.
setpos
Set the "current position" in the image. This
affects where
subsequent commands draw things. The 2 arguments are the
column and
row number.
At the start of the script, the current position is (0,0).
setlinetype
The 1 argument is "normal" or "nodiag.".
This effects a
ppmd_setlinetype() call. Further details are not yet
documented.
setlineclip
This effects a ppmd_setlineclip() call. Not yet
documented.
setcolor
This sets the "current color", which determines
the color in which
subsequent drawing commands draw. Before the first setcolor,
the
current color is white.
setfont
This sets the "current font", which determines the
font in which
subsequent text drawing commands draw. Before the first
setfont, the
current color is a built in font called
"standard."
The argument of this command is
a file name. It is the name of a
Netpbm PPMD font file.
A Netpbm PPMD font file
typically has a name that ends in ".ppmdfont"
and its first 8 bytes are the ASCII encoding of
"ppmdfont".
There is only one of these fonts
as far as we know. It is distributed
with Netpbm as the file standard.ppmdfont, but you
don’t need to use
that file because the same font is built into the Netpbm
library and
is the default. If you want to make a new font, you can find
the
format of a ppmdfont file in the Netpbm interface header
file
ppmdfont.h, but you’ll have to make your own tools to
build it.
line
This draws a one pixel wide line in the current color. The 4
arguments are: starting column, starting row, ending column,
ending
row.
This command does not affect the current position.
line_here
This is like line, except it works in a more relative
way.
The line starts at the current
point. The two arguments are the
rightward and downard displacement from there of the
terminal point.
The command moves the current position to the terminal point
after
drawing.
spline3
This draws a spline in the current color through 3 points.
The 6
arguments are the starting column, starting row, middle
column,
middle row, ending column, and ending row.
This command does not affect the current position.
circle
This command draws a circle in the current color. The three
arguments
are the column number and row number of the center of the
circle and
the radius of the circle in pixels.
filledrectangle
This command draws a rectangle filled with the current
color. The 4
arguments are the column and row numbers of the upper left
corner of
the rectangle, the width of the rectangle, and the height of
the
rectangle.
text
This command draws text in the current color in the built-in
font.
The 5 arguments are:
1. column number of starting
point of baseline
2. row number of starting point of baseline
3. height of characters, in pixels
4. angle of baseline in degrees elevated from the horizontal
5. text
Note that if your text contains
white space, you’ll have to use
double quotes to cause it to be a single token.
text_here
This is like text, except that the baseline starts at the
current
position and the command updates the current position to the
other
end of the baseline after it draws.
Bear in mind that a script
starts with the current position in the
top line, so if you leave it there, only the bottom line of
your text
will be within the image!
HISTORY
ppmdraw was new in Netpbm 10.29 (August 2005).
SEE ALSO
ppmlabel, ppm
_________________________________________________________________
Table Of Contents
* SYNOPSIS
* DESCRIPTION
* OPTIONS
* SCRIPT
* SEE ALSO
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ppmdraw(1) | ![]() |