4va(1)4va(1)NAME
4va, ctorus, cutctorus, 4vdmake - 4D object tumbler for X-Windows and
object generation programs
SYNOPSIS4va [{ -xy -xz -yz -xw -yw -zw } <angle> ] [-np] [-ns] [-nt] [-cw] [
-zd <dist> ] [ -wd <dist> ] [ -lc <color> ] [ -bc <color> ] [ -lw
<width> ] [ -d <display> ] [ -s <scale> ] [ -h | -? ] <object-file>
ctorus <x-increments> <y-increments>
cutctorus <x-increments> <y-increments>
4vdmake <x-grid-size> <y-grid-size>
DESCRIPTION4va is a fourth dimensional visualization program for X-Windows. It
takes as input a file describing an object in up to 4 dimensions and
tumbles it in a window according to rotation values given on the com‐
mand line.
Options
-xy, -xz, -yz, -xw, -yw, -zw <angle>
Specify the amount of rotation each cycle in each of the 6
planes (x-y, x-z, and so on). The angle is given in degrees and
appended directly to the option, as in -xw4.5. If any of these
options are set on the command line, the defaults are cleared.
The defaults are -xz0.6, -xw0.6, and -yw0.45.
-np Tell 4va not to do perspective. Normally perspective is done on
both the z and w axes.
-ns Don't rescale the object in the window if the window is resized.
Normally, if the window is resized, the object is rescaled in
proportion to the new window size. Specifying -ns turns this
off.
-nt Don't set a name for the title bar. On some window managers,
this will suppress a title bar even being displayed on the win‐
dow.
-cw Tell 4va to clear the window each cycle with a call to XClear‐
Window() instead of drawing over the old object in the back‐
ground color. Using -cw is nice for larger objects, but for
smaller objects letting 4va draw over the lines is faster and
doesn't flicker.
-zd <dist>, -wd <dist>
Specify the viewer's distance, in pixels, along the z and w axes
for perspective purposes. Naturally this doesn't have much mean‐
ing if -np is specified. The default is 430.0. Place the number
directly after the switch, as in -zd400.0.
-lc <color>, -bc <color>
Specify the names of the foreground (line) and background col‐
ors, as in -lc LightGreen. The defaults are black background
with red lines.
-lw <width>
Specify the width of the object's lines, in pixels. The default
is a width of 0, which is the hardware-defined fastest line.
Example is -lw5.
-d <display>
Specify the display name. 4va first checks the -d switch, then
the DISPLAY environment variable, then then defaults to the dis‐
play unix:0.
-s <scale>
Specify the scaling factor for all four dimensions, as in
-s150.0. The default is 200.0.
-h, -? Get a listing of 4va's options.
Ctorus, cutctorus, and 4vdmake options
These three programs are object file generators for 4va. Ctorus gener‐
ates a Clifford Torus with the densities named. For example, ctorus 20
20 will generate a Clifford Torus file with 20 increments around each
of the two sets of circles defining the torus (the x-y set and the z-w
set).
Cutctorus is the same as ctorus, except that all of the circles in one
direction are invisible, making the torus easier to see.
4vdmake is a "customizable" object generation program that produces
objects in three dimensions. The program generates a grid of points and
lines on the x and y plane and applies to them a function (defined in
the code) for the z value of each coordinate. This is a quick hack to
let 4va display 3D functions. It can easily be modified to generate 4D
functions. 4vdmake fits the grid (with the density on the x and y axes
given on the command line) into a -1 to 1 square on the x and y axes.
Object files
Object files (usually with the extension .4vd) have the following for‐
mat:
p={ number-of-points }
<points...>
l={ number-of-lines }
<lines...>
n=name-of-object
For example, a simple object file for a single line might look like
p={2}
1.0 1.0 1.0 1.0
-1.0 -1.0 -1.0 -1.0
l={1}
0 1
n=StupidLine
If the number-of-points and number-of-lines do not match the number of
points and lines in their sections, 4va will read the incorrect amount
of data from the object file and will get confused. As you can see,
each point specifies the x, y, z, and w coordinates as floating-point
numbers. If you're only creating a 3D object, for example, you can set
all the w values to 0.0. Each line specifies the points between which
the line extends. In the above example, we have one line between point
0 and point 1 (notice that numbering starts with 0).
NOTES4va allocates memory for objects dynamically. If 4va runs out of memory
it will exit with a return code of -1 and print a "malloc" error mes‐
sage.
4va does not check that the object file that it's reading is well-
behaved. If your object file is corrupt, 4va may hang.
4va has worked on every system I've tried it on; it's basic enough that
it should port to your machine. If you have problems, let me know.
AUTHOR
Matt Welsh (welsh@odin.ncssm.edu). Please send me any questions, bugs,
or suggestions.
X11R4 4va(1)
