(interest (COMMAND [args]))Allows you to express interest in a command. When geomview executes
that command in the future it will echo it to the communication pool
from which the interest command came. COMMAND can be any command.
Args specify restrictions on the values of the arguments; if args are
present in the interest command, geomview will only echo calls to the
command in which the arguments match those given in the interest
command. Two special argument values may appear in the argument list.
* matches any value. nil matches any value but supresses
the reporting of that value; its value is reported as nil.
The purpose of the interest command is to allow external
modules to find out about things happening inside geomview.
For example, a module interested in knowing when a geom called
foo is deleted could say (interest (delete foo)) and would
receive the string (delete foo) when foo is deleted.
Picking is a special case of this. For most modules interested in pick
events the command (interest (pick world)) is sufficient. This
causes geomview to send a string of the form (pick world …)
every time a pick event (right mouse double click). See the (pick …) command for details.