LENS(1)                                                   LENS(1)

     NAME
          lens - interactive screen magnifier

     SYNOPSIS
          lens

     DESCRIPTION
          Lens presents a magnified view in its window of an arbitrary
          area on the screen.  The default magnification is 4 (showing
          each pixel as a 4×4 pixel block in lens's window). This may
          be changed by typing a digit on the keyboard (with 0 stand-
          ing for 10), or by using the + and - keys to increase or
          decrease the magnification by one unit.  The lower limit is
          ×1; the upper ×16.

          The interface to indicate what area to magnify is dictated
          by the mouse multiplexing rules of rio(1). Start by pressing
          mouse button 1 in the lens window and dragging, with the
          button pressed, to the center of the area to magnify.  Lens
          will update the display as the mouse moves.  Releasing the
          button freezes the lens display.  The magnified view is
          static-a snapshot, not a movie-but typing a space or . key
          in the lens window will refresh the display, as will chang-
          ing the magnification.

          To make counting pixels easier, typing a g toggles whether a
          checkerboard grid is imposed on the magnified area.

          Button 3 brings up a menu of actions.

     SOURCE
          /sys/src/cmd/lens.c

     BUGS
          There should be an easier way to indicate what to magnify.