RALCGM(1) User Command (Local) RALCGM(1)
NAME
ralcgm - translate, view or print Computer Graphics
Metafiles.
ORIGIN
Rutherford Appleton Laboratory
SYNOPSIS
ralcgm [ -btcnpixfev ] [ -d driver name ] [ -g gdp types ]
[ -l profile name ] [ -o driver options ]
[ -a terminal string ]
[ infilename ] [ outfilename ] [ errfilename ]
AVAILABILITY
This is RALCGM release 3.0 (man version 2.7). The source
code of this program together with information on how to
install it is available from the University of Kent.
DESCRIPTION
ralcgm is a program for:
- translation between CGM encodings;
- viewing CGM files on X Windows.
- hardcopy output of CGM files on PostScript printers.
- viewing CGM files on Silicon Graphics Iris 3130 or 4D
workstation.
- viewing a CGM file on a Tektronix 4200 series
Terminal.
- translating a CGM file to a Tektronix 4200 file.
- converting a CGM file to a HPGL file.
- viewing on an IBM PC or compatible with a VGA screen.
On the translation side, four encoding methods exist in
ralcgm:
- binary
- character
- clear text
- native character output (non-ASCII machines only)
Any input CGM file can be translated to one of the above
encodings by specifying options -b, -c, -t, -n respectively.
Binary, character, and clear text encodings are as described
in ISO 8632(1987) document. The native character encoding
is a variant of the character encoding with input and output
being treated according to the host machine's native
character set, i.e. EBCDIC for the IBM machines.
The encoding method of the input CGM is automatically
detected on entry. If an output encoding is specified, the
input file is translated accordingly. If no output encoding
option is specified, a system dependent default (determined
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by the installer at the compilation time or by setting an
environment variable) is chosen. For instance, where X-
windows has been selected as the system default, the CGM
file will be viewed in an X window. The normal default is
clear text encoding to standard output.
All of the filename arguments are optional, and they have to
appear on the command line in the order described in the
synopsis. If none of the filename arguments is present,
ralcgm reads from standard input and writes to standard
output, or sends the picture to the screen, depending on
whether translation or viewing is required. On some non-
unix systems (VMS and CMS) piping from stdin is not allowed.
All diagnostics and error messages are sent to the standard
error stream.
If a number of filename arguments are given, the first
argument will be taken to represent the input file name,
second the output file name, and the third the error file
name. An extension of cgm is assumed if no file extension
is specified.
To view a CGM file in a X Windows environment, GL Window or
on a terminal, invoke ralcgm by selecting the option -d
driver , where driver is the name of the output device as
specified below.
ARGUMENTS
infilename - optional input file name.
outfilename - optional output file name.
errorfilename - optional error file name.
OPTIONS
Options may appear anywhere on the command line and single
character options may be grouped together, as long as each
set of options starts with a '-'. If an option has an extra
data string this must follow the option, with or without a
seperating space, and must terminate the group. All single
character options may be either upper or lower case.
-b translate input CGM into binary encoding.
-c translate input CGM into character encoding.
-n produce native character set version of input CGM's
character encoding.
-t translate input CGM into clear text encoding.
-p convert input CGM to PostScript. The PostScript output
can be directed to standard output or a named file, and
subsequently printed out on a PostScript printer.
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(This option has been replaced by the -d ps option, but
is retained for compatability.)
-i display input CGM using the Iris Graphics Library
(applicable to the Silicon Graphics Iris Workstations
only). (This option has been replaced by the -d igl
option, but is retained for compatability.)
-x display input CGM using X-windows (applicable to the
X-windows environment only). (This option has been
replaced by the -d xw option, but is retained for
compatability.)
-a terminal string
(Applicable to the X Windows environment only). This
option will pass the terminal string specifing the host
and the default display device for the X Window
environment. Note that the terminal string is case
dependent.
-e ignore error count limit (16 by default).
-f sends diagnostic and error messages to a file. If no
error filename is given the default is to send to a
file with the root of the input file and a suffix of
.err.
-v use verbose mode. This causes diagnostic messages to
appear on the standard error stream.
-g gdp types
Generalized Drawing Primitive Identifiers may be non-
negative or negative. Non-negative values are reserved
for ISO registration and future use, and negative
values are available for private use. No GDP
identifiers have been registered yet, hence non-
negative GDP identifiers are illegal. A number of
packages generate negative GDPs. At present ralcgm can
only interpret those that have been generated by RAL-
GKS. Specifying -g RAL or -g ral will turn this
feature on. By default, negative GDPs are treated as
errors.
-l profile name
This flag is used to define a profile.
At present the only profile supported is oldbin , which
allows ralcgm to read Binary CGMs produced by RAL-CGM
version 2.00 and earlier. These CGMs have wrongly
coded negative integers. Only use this flag if there
are problems reading a CGM as not many CGMs contain
negative integers.
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RALCGM(1) User Command (Local) RALCGM(1)-d driver name
To allow for a larger range of drivers than are allowed
by single character codes, drivers may be specified by
name. The following names are recognised where capital
letters indicate the minimum abbreviation:
CHaracter
Character encoding
Native
Character encoding (native)
CLear Text or TEXt
Clear Text encoding
Binary
Binary encoding
Postscript or PS
PostScript
Xwindows or X11
X-Windows (release 11.4)
Igl or IRIS
Iris Graphics Library (GL2)
Hpgl HPGL
TEKtronix
Tektronix 4200 series (including EMU-TEK)
Vga PC VGA screen
-o driver options
This option allows driver dependent options to be
specified as as single string which is interpreted by
the output driver. Options may be case dependent for
some drivers. Currently the following options are
recognised:
Applicable to PostScript driver only.
-o[BFCMENIVPLQ]
where any combination of single characters (case
independent) can be specified, from each of the
following pairs of mutually exclusive options:
B Ignore Background Colour setting. This is
needed when a black background is put in the
CGM for screen output and the foreground
colour is not set, which would normally
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result in the output consisting of a Black
square with all drawing done in black.
F Respect Background Colour setting (default).
C Colour PostScript.
M Monochrome PostScript (default).
E EPSF (Encapsulated PostScript).
N Normal PostScript (default).
V Add Picture border.
I Do not print Border (default).
P Portrait mode (default).
L Landscape mode.
Q Output for extended A4 on a QMS plotter.
This gives a larger plotting area than the
default.
Applicable to Iris Graphics Library only
-o[DSBMCFTVP]
where any combination of single characters (case
independent) can be specified.
D Use double buffer mode for graphics display.
This means that the process of updating the
graphic screen is done off-screen and will
only become visible when a picture is
complete.
S Use single buffer mode for graphics display
(default). Also stop after each frame.
M Movie mode. Do not pause between frames and
use double buffered mode.
C Continuous mode. Do not pause between
frames, but do not use current buffered mode,
unless D is also set.
B Single Buffer mode. Same as S option, but
does not disable movie mode.
F Full screen mode. In full screen mode no
textport is displayed. This prevents
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diagnostic messages appearing on the screen.
T Textport on. In full screen mode the
textport is displayed to the right of the
screen.
V Virtual 24-bit Colour mode for Iris Indigo
(Default for direct colour)
P Pseudocolour mode for direct colours, rather
than Virtual 24-bit mode.
Applicable to HPGL only
-o[34PLCN]
where any combination of single characters (case
independent) can be specified.
3 Use A3 paper
4 Use A4 paper (default)
P Portrait mode (default)
L Landscape mode
C Output printer initialisation controls
(default)
N Do not output printer initialisation controls
Applicable to Tektronix 4200 Terminal only
-o[NC]
where any combination of single characters (case
independent) can be specified.
N Use 16 colours ie 4 bit-planes (default)
C Use 256 colours rather than default of 16.
This only applies to terminals with more than
4 bit-planes.
Applicable to PC (VGA) only
-o[HL]
where a single characters (case independent) can
be specified.
H Use High Resolution mode (default) - 760x480
pixels with 16 colors
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L Use Low Resolution mode - 480x360 pixels with
256 colors
ENVIRONMENT
Ralcgm recognises various environment variables to override
default options. The following Environment variables are
recognised:
CGMDATA pathname
A directory name to overridew the default data
directory pathname (specified at installation time).
Note that the name must include the trailing delimiter
('/' on Unix systems).
CGMMENUFONT font (X-Windows only)
Override default font used by X-Window menus.
CGMOUTPUT driver name
A text string specifying the Output driver as listed in
the '-D' option above, plus the 'CHaracter', 'Native',
'CLeartext', 'Text' or 'Binary' for translators.
CGMERRCOUNT num
A number to indicate the number of errors before RALCGM
aborts processing. Setting CGMERRCOUNT to 0 will
prevent aborting.
CGMPSOPT option list
PostScript options. See '-O' option above.
CGMIGLOPT option list
Iris Graphics Library options. See '-O' option above.
CGMHPGLOPT option list
HPGL driver options. See '-O' option above.
CGMTEKOPT option list
Tektronix 4200 driver options. See '-O' option above.
CGMVGAOPT option list
VGA Screen driver options. See '-O' option above.
CGMGDP gdptype
A text string to set a default GDP type. See option
'-G' above.
CGMVERBOSE on | off
See option '-V' above.
CGMHPGLn + 4 floating point numbers
where n is a pen number. HPGL Pen description (red,
green, blue values in range 0.0 to 1.0 plus pen width
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in mm).
CGMPROFILE profile type
specify a Profile type. see option '-L' above.
X WINDOWS VIEWER COMMANDS
To display a CGM file in an X window, invoke the ralcgm
program (with X running) selecting the appropriate option
and passing the CGM file name as the first argument, e.g.
ralcgm-d xw map.cgm
This displays the picture in a window with the current frame
number and title printed in the title window (the invoking X
terminal acts as a console for ralcgm interpreter messages).
There are four title window buttons for controlling the
display sequence, a pop-up button box to manipulate scaling
and translation of any part of the picture within the
window, and a pop-up keypad to display a randomly chosen
frame.
The title window buttons are:
nx display next frame
pr display previous frame
cu re-display current frame
ab abort current frame
The buttons set and the keypad are invoked by clicking
different mouse buttons. Here, the mouse button will be
referred to as button 1, button 2 and button 3 for left,
middle and right button respectively. To move through the
CGM file frame by frame, pick appropriate title window
button and click mouse button 1.
To select a random frame, click button 1 on the picture
window to raise the keypad. Select frame number by clicking
on the appropriate digits, and then pick D. Picking D with
no number selected drops the window. Picking C clears the
number selected.
If a frame beyond the end of the file is selected, the last
frame will be displayed. If a frame before the first frame
in the file is selected, the first frame will be displayed.
The set of pop-up buttons is invoked by clicking button 2 in
the picture window. To select any of the items in the set,
click button 1.
The set of items includes:
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copy Creates new display windows showing the same
frame as the present window. New windows can
be used independently in the same way as the
original ones.
bigger Makes the picture bigger. Use the mouse to
define two points at opposite corners of a
rectangle which is then expanded as much as
possible (see note on dragging the mouse
below).
smaller Makes the picture smaller. Use the mouse to
define two points at opposite corners of a
rectangle. The picture will then be
compressed into the defined rectangle.
move Moves the frame in the window. Define two
points - the first is moved to the second.
normal Restore picture to normal size and position.
close Remove this window but leave others.
finish Close all windows and terminate program.
drop Remove the menu with no action.
For bigger, smaller and move you must define two points on
the screen. To do this, depress button 3 at one point, drag
the mouse to the other point and then release the button.
Move is operated in a similar manner, with first point as
the anchor point and the second point as the destination of
the specified anchor point.
Note: There is no rubber banding when dragging the mouse
button, so the user has to estimate the result of the
scaling and moving while dragging the mouse with button 3
depressed.
IGL VIEWER COMMANDS
On the Silicon Graphis Iris 3130, there are two modes of
working, Full screen mode or Window mode (mex). The RAL-CGM
interpreter will work in either mode, but the control is
slightly different. On the Iris 4D only the Window mode is
used.
In both modes the left mouse button is used to pause the
current frame and if the middle mouse button is pressed
while the left button is held down then the frame is
aborted, otherwise a second left button will continue
processing.
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In full screen mode, unless in movie mode, at the end of
each frame a 'beep' will sound and pressing the left button
will advance to the next frame. Pressing the middle button
will prompt for a frame number, unless the left button is
held down at the same time, in which case the program will
be aborted. In movie mode, a left button will interupt the
program, which can then be controlled as above.
In window mode at the end of each frame a pop-up menu will
appear, which is controlled by the right mouse button. This
menu give you the options:
Next next frame
Redraw redraw current frame
Last return to last frame
Find displays a second menu to choose a frame number
Quit exit program
To use the second menu click the right mouse on each digit
until the required number is displayed in the 'Frame' box,
then select the 'Frame' box. Use the 'undo' box to delete
the last digit.
TEKTRONIX VIEWER
The Tektronix has only a very basic control, which issues a
prompt at the end of each picture. The allowable replies
are 'Q' to quit, or anything else to continue.
EXAMPLES
ralcgm ship.bin -t clear
will create a CGM file clear which will contain the
clear text encoding version of the input CGM ship.bin.
ralcgm-d xw ship.clear
will view ship.clear in an X window.
ralcgm-d ps ship laser.ps
will produce a PostScript version of ship.cgm, in file
laser.ps.
DIAGNOSTICS
As soon as the input encoding is recognized, a message to
that effect is sent to standard error if verbose mode is
chosen. Three levels of error severity exist. Fatal errors
abort the program; errors and warnings do not. Messages are
sent to the standard error stream.
BUGS
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Some CGM Metafile Descriptor elements are ignored.
Particularly Polygon Set and Auxillary colour are not
handled on most drivers. Correct Pattern Filling for User
defined patterns is not yet supported.
Complicated Polygon Sets may hit the ceiling of available
memory when processed by the PostScript interpreter.
The Tektronix does not support Hatch fill and HPGL will
currently only Hollow fill.
Convex Polygons are not displayed correctly using the Iris
Graphics Library. Also Direct colours are not support if
less than 24-bit planes are available, except on an Iris
Indigo which uses the Virtual 24-bit system.
AUTHORS
R T Platon ( RAL CCD ) is the original author.
Contributors: C D Osland, A R Mayhook, C D Seelig, K E V
Palmen, N M Hill, W M Lam (all from RAL CCD ); P L Popovic
and W K Lui ( RAL ID ); A H Francis ( Page Description ).
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