pick(3G)

NAME
     pick - puts the system in picking mode

FORTRAN 77 SPECIFICATION
     subroutine pick(buffer, numnam)
     integer*2 buffer(*)
     integer*4 numnam

PARAMETERS
     buffer     expects the array to use for storing names.

     numnam     expects the maximum number of names to store. This must not
                exceed the number of elements in buffer.

DESCRIPTION
     pick facilitates the cursor as a pointing object.  When you draw an image
     in picking mode, nothing is drawn.  It places a special viewing matrix on
     the stack, which discards everything in the image that does not intersect
     a small region around the cursor origin.

     The graphical items that intersect the picking region are hits and store
     the contents of the name stack in buffer. Picking does not work if you
     issue a new viewport in picking  mode.

SEE ALSO
     endpic, endsel, gselec, picksi, pushna, popnam, loadna

NOTE
     This routine is available only in immediate mode.

     In order to pick a large point or a wide line in picking mode, the
     selecting region must intersect the displayed point center or the
     displayed line center respectively.  The displayed point center is the
     imaginary point of size 1 specified by the same vertex as the displayed
     point.  The displayed line center is the imaginary line of width 1
     specified by the same vertices as the displayed line.  In case of a very
     large point or very wide line, you may want to consider drawing a filled
     circle or a filled rectangle respectively instead.