Ubuntu Manpage: ppmdraw - draw lines, text, etc on a PPM image

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(1).

       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

       In addition to the options common to all programs based on libnetpbm (most notably -quiet,
       see
        Common Options ⟨index.html#commonoptions⟩ ), ppmdraw  recognizes  the  following  command
       line options:

       -script=script
              This option gives the script.  See Script ⟨#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.

Many command have arguments that specify a position on the canvas, which you specify by
row and column. Row 0 is the top row. Column 0 is the leftmost column. You may specify
negative numbers (but such a position would necessarily be off the canvas).

Your drawing instructions may involve positions not on the canvas. But any pixels you
draw there just get discarded.

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.

There is one argument. It specifies the color as described for the argument of the
pnm_parsecolor() library routine ⟨libnetpbm_image.html#colorname⟩ .

setfont
This sets the "current font", which determines the font in which subsequent text
drawing commands draw. Before the first setfont, the current font 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. The program
ppmdmkfont generates standard.ppmdfont, so you can use that as an example.

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
downward displacement from there to the terminal point. The command moves the
current position to the terminal point after drawing.

spline3
This draws a spline in the current color between 2 points, using a third as a
control point. It approximates a cubic spline segment.

The shape of the curve is such that it passes through the specified endpoints, and
lines tangent to the curve at those endpoints intersect at the control point.
Controlling the tangents allows you to connect this curve to other curves generated
the same way without having corners at the connection points.

The 6 arguments are the starting point column, starting point row, control point
column, control point row, ending point column, and ending point 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:

• column number of starting point of baseline

• row number of starting point of baseline

• height of characters, in pixels

• angle of baseline in degrees elevated from the horizontal

• 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).

DOCUMENT SOURCE

       This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The  master
       documentation is at

              http://netpbm.sourceforge.net/doc/ppmdraw.html