This is an introduction to the draw widget and some of the pixes
that can be drawn in it.  Drag on the scrollbar of the text widget
to scroll through the text.

The first draw contains a number of shape pixes, demonstrating
different drawmodes.

The second draw contains assorted pixes

Each draw widget can display its contents in several draw modes. These
can be selected by the following keystrokes on the draw widget:
x - looking down from the x axis, so that z is up and y is to the right
y - looking down from the y axis, so that z is up and x is to the right
z - looking down from the z axis, so that y is up and x is to the right
o - Orthographic projection. Looking from any point in space, but without
	perspective.
X - like x, but with perspective.
Y - like y, but with perspective.
Z - like z, but with perspective.
p - like o, but with perspective.


Draws can zoom in and out using the < and > keys.

Draws can move left, right, up and down using the arrow keys.

In the o and p modes, draws can rotate in 3 d using shift-arrow keys.
	q and a also rotate up and down.

In the perpective modes, the square brackets set the position of the viewer.
	The further in, the more extreme the perspective.

Note that not all the features of perspective such as occluding bodies and
vanishing objects when they are behind the viewer, have been implemented.

The first draw demonstrates how one can implement drag-and-drop using
shapes. You can click on objects and move them around in the draw.

The second draw demonstrates a number of other pixes. If you click runit,
you will see the var pix changing shape, and the plot pix plotting a
graph. There is also an axis pix. In the graph widget, the axis and
plot pixes are automatically placed appropriately, but if you want do
put them in an ordinary draw widget you need to specify a lot of parameters.