NAME

ged − graphical editor

SYNOPSIS

ged [−euRrn] [GPS file ...]

DESCRIPTION

Ged is an interactive graphical editor used to display, construct, and edit GPS files on Tektronix 4010 series display terminals.  If GPS file(s) are given, ged reads them into an internal display buffer and displays the buffer.  The GPS in the buffer can then be edited.  If − is given as a file name, ged reads a GPS from the standard input. 

Ged accepts the following command line options:

e Do not erase the screen before the initial display. 

rn Display region number n. 

u Display the entire GPS universe. 

R Restricted shell invoked on use of !. 

A GPS file is composed of instances of three graphical objects:  lines, arc, and text.  Arc and lines objects have a start point, or object-handle, followed by zero or more points, or point-handles.  Text has only an object-handle.  The objects are positioned within a Cartesian plane, or universe, having 64K (−32K to +32K) points, or universe-units, on each axis.  The universe is divided into 25 equal sized areas called regions.  Regions are arranged in five rows of five squares each, numbered 1 to 25 from the lower left of the universe to the upper right. 

Ged maps rectangular areas, called windows, from the universe onto the display screen.  Windows allow the user to view pictures from different locations and at different magnifications.  The universe-window is the window with minimum magnification, i.e. the window that views the entire universe.  The home-window is the window that completely displays the contents of the display buffer. 

COMMANDS

Ged commands are entered in stages. Typically each stage ends with a <cr> (return).  Prior to the final <cr> the command may be aborted by typing rubout.  The input of a stage may be edited during the stage using the erase and kill characters of the calling shell.  The prompt ∗ indicates that ged is waiting at stage 1.  Each command consists of a subset of the following stages:

1.  Command line
A command line consists of a command name followed by argument(s) followed by a <cr>.  A command name is a single character.  Command arguments are either option(s) or a file-name.  Options are indicated by a leading −. 

2.   Text Text is a sequence of characters terminated by an unescaped <cr>.  (120 lines of text maximum.) 

3.   Points Points is a sequence of one or more screen locations (maximum of 30) indicated either by the terminal crosshairs or by name.  The prompt for entering points is the appearance of the crosshairs.  When the crosshairs are visible, typing:

sp (space) enters the current location as a point.  The point is identified with a number. 

$n enters the previous point numbered n. 

>x labels the last point entered with the upper case letter x. 

$x enters the point labeled x. 

. establishes the previous points as the current points.  At the start of a command the previous points are those locations given with the previous command. 

= echoes the current points. 

$.n enters the point numbered n from the previous points. 

# erases the last point entered. 

@ erases all of the points entered. 

4.   Pivot The pivot is a single location, entered by typing <cr> or by using the $ operator, and indicated with a ∗. 

5.   Destination
The destination is a single location entered by typing <cr> or by using $. 

COMMAND SUMMARY

In the summary, characters typed by the user are printed in bold.  Command stages are printed in italics.  Arguments surrounded by brackets “[]” are optional.  Parentheses “()” surrounding arguments separated by “or” means that exactly one of the arguments must be given. 

Construct commands:

Arc [−echo,style,weight] points

Box [−echo,style,weight] points

Circle [−echo,style,weight] points

Hardware [−echo] text points

Lines [−echo,style,weight] points

Text [−angle,echo,height,mid-point,right-point,text,weight] text points

Edit commands:

Delete ( − (universe or view) or points )

Edit [−angle,echo,height,style,weight] ( − (universe or view) or points )

Kopy [−echo,points,x] points pivot destination

Move [−echo,points,x] points pivot destination

Rotate [−angle,echo,kopy,x] points pivot destination

Scale [−echo,factor,kopy,x] points pivot destination

View commands:

coordinates points

erase

new-display

object-handles ( − (universe or view) or points )

point-handles ( − (labelled-points or universe or view) or points )

view ( − (home or universe or region) or [−x] pivot destination )

x [−view] points

zoom [−out]  points

Other commands:

quit or Quit

read [−angle,echo,height,mid-point,right-point,text,weight] file-name [destination]

set [−angle,echo,factor,height,kopy,mid-point,points, right-point,style,text,weight,x]

write file-name

!command

?

Options:

Options specify parameters used to construct, edit, and view graphical objects.  If a parameter used by a command is not specifed as an option, the default value for the parameter will be used (see set below).  The format of command options is

−option[,option]

where option is keyletter[value].  Flags take on the values of true or false indicated by + and − respectively.  If no value is given with a flag, true is assumed.  Object options:

anglen Angle of n degrees. 

echo When true, echo additions to the display buffer. 

factorn Scale factor is n percent. 

heightn Height of text is n universe-units (0≤n<1280).

kopy When true, copy rather than move. 

mid-point When true, mid-point is used to locate text string. 

points When true, operate on points otherwise operate on objects. 

right-point When true, right-point is used to locate text string. 

styletype Line style set to one of following types:
sosolid
dadashed
dddot-dashed
dodotted
ldlong-dashed

text When false, text strings are outlined rather than drawn. 

weighttype Sets line weight to one of following types:
nnarrow
mmedium
bbold

Area options:

home Reference the home-window. 

out Reduce magnification. 

regionn Reference region n. 

universe Reference the universe-window. 

view Reference those objects currently in view. 

x Indicate the center of the referenced area. 

COMMAND DESCRIPTIONS

Construct commands:

Arc and Lines
behave similarly. Each consists of a command line followed by points. The first point entered is the object-handle.  Successive points are point-handles.  Lines connects the handles in numerical order.  Arc fits a curve to the handles (currently a maximum of 3 points will be fit with a circular arc; splines will be added in a later version). 

Box and Circle
are special cases of Lines and Arc, respectively.  Box generates a rectangle with sides parallel to the universe axes.  A diagonal of the rectangle would connect the first point entered with the last point.  The first point is the object-handle.  Point-handles are created at each of the vertices.  Circle generates a circular arc centered about the point numbered zero and passing through the last point.  The circle’s object-handle coincides with the last point.  A point-handle is generated 180 degrees around the circle from the object-handle. 

Text and Hardware
generate text objects.  Each consists of a command line, text and points. Text is a sequence of characters delimited by <cr>.  Multiple lines of text may be entered by preceding a cr with a backslash (i.e. \cr).  The Text command creates software generated characters.  Each line of software text is treated as a separate text object.  The first point entered is the object-handle for the first line of text.  The Hardware command sends the characters in text uninterpreted to the terminal. 

Edit commands:

Edit commands operate on portions of the display buffer called defined-areas.  A defined-area is referenced either with an area option or interactively.  If an area option is not given, the perimeter of the defined-area is indicated by points. If no point is entered, a small defined-area is built around the location of the <cr>.  This is useful to reference a single point.  If only one point is entered, the location of the <cr> is taken in conjunction with the point to indicate a diagonal of a rectangle.  A defined-area referenced by points will be outlined with dotted lines. 

Delete
removes all objects whose object-handle lies within a defined-area.  The universe option removes all objects and erases the screen. 

Edit modifies the parameters of the objects within a defined-area.  Parameters that can be edited are:
angleangle of text
heightheight of text
stylestyle of lines and arc
weightweight of lines, arc, and text. 

Kopy (or Move)
copies (or moves) object- and/or point-handles within a defined-area by the displacement from the pivot to the destination. 

Rotate
rotates objects within a defined-area around the pivot.  If the kopy flag is true then the objects are copied rather than moved. 

Scale
For objects whose object-handles are within a defined-area, point displacements from the pivot are scaled by factor percent.  If the kopy flag is true then the objects are copied rather than moved. 

View commands:

coordinates
prints the location of point(s) in universe- and screen-units. 

erase
clears the screen (but not the display buffer).

new-display
erases the screen then displays the display buffer.

object-handles (or point-handles)
labels object- (and/or point-handles) that lie within the defined-area with O (or P).  point-handles identifies labelled points when the labelled-points flag is true. 

view moves the window so that the universe point corresponding to the pivot coincides with the screen point corresponding to the destination.  Options for home, universe, and region display particular windows in the universe. 

x indicates the center of a defined-area.  Option view indicates the center of the screen. 

zoom
decreases (zoom out) or increases the magnification of the viewing window based on the defined-area.  For increased magnification, the window is set to circumscribe the defined-area.  For a decrease in magnification the current window is inscribed within the defined-area. 

Other commands:

quit or Quit
exit from ged.  quit responds with ? if the display buffer has not been written since the last modification. 

read inputs the contents of a file.  If the file contains a GPS it is read directly.  If the file contains text it is converted into text object(s).  The first line of a text file begins at destination. 

set when given option(s) resets default parameters, otherwise it prints current default values. 

write
outputs the contents of the display buffer to a file.

! escapes ged to execute a UNIX command. 

? lists ged commands. 

SEE ALSO

graphics(1G), gdev(1G), rsh(1), gps(5). 
A Tutorial Introduction to the Graphical Editor by A. R. Feuer. 

May 16, 1980