mag(6D)

NAME
     mag - pixel replication and magnification in a window

SYNOPSIS
     /usr/sbin/mag [integer]

DESCRIPTION
     Mag copies and enlarges areas of the screen. The mag program demonstrates
     pixel reading and writing on the IRIS.  The area of the screen copied is
     chosen by the user with the mouse.  The power of magnification is an
     integer value which must be entered into the command line.  If no integer
     is specified, the default value of the power of magnification is 2.

     Operator control of this demo is strictly with the mouse.

          Mouse buttons   Function

          left            pick area on screen under cursor
          right           mag pop-up menu

     It is important to note that the program needs to maintain input focus
     when selecting a region under the cursor.  This can be achieved by
     positioning the cursor in the mag window and then depressing
     either the Shift or Ctrl key.  While continuing to hold the key, move
     the cursor to the desired location on the screen and click the Left
     mouse button.

COMMENTS
     Values of magnification greater than 2 significantly degrade the
     magnified image.

     Trying to magnify the mag window causes some inexplicable results.

     Sometimes, when the window manager is in double buffer mode, the area
     magnified appears in the wrong color.  The mag program works best in
     single buffer mode.

BUGS
     In release 4.0, there is a known problem with mag on VGX machines
     relating to the use of subpixel.  The symptom is the initial appearance
     of a grid inside the mag window even when the popup menu item "grid off"
     is selected.  The workaround for this is to change the line in the source
     for mag, located at /usr/people/4Dgifts/iristools/tools/mag.c that reads

          subpixel(1);

     to read

          subpixel(0);

     This is not the best solution but it will work.  The problem here centers
     on old-style drawing commands like rectfi and point sampled polygons
     which are turned on with subpixel(1).  This program will be revamped to
     not use rectfi and the math will consequently be "changed by one" as
     well.