Function:     GDI_DEFIMG

Purpose:      Defines the sizes and scaling of a display image.

Category:     DISPLAY

File:         gdilib.c

Author:       K.G. Begeman

Use:          INTEGER GDI_DEFIMG( GDI_ID ,     Input     INTEGER
                                  GLO ,        Input     INTEGER ARRAY
                                  GHI ,        Input     INETEGR ARRAY
                                  BSCALE ,     Input     REAL
                                  BZERO )      Input     REAL

              GDI_DEFIMG     Returns zero on succes, negative on error.
              GDI_ID         Display identifier.
              GLO            Array containing the lower grid units
                             (first X, then Y) of image on display.
              GHI            Array containing the upper grid units
                             (fitst X, then Y) of image on display.
              BSCALE         Scaling factor from display data to
                             real data:
                             real = BSCALE * display + BZERO
              BZERO          See above.

Notes:        GDI_DEFIMG must be called prior to GDI_IMWRITE.

Updates:      Dec 18, 1990: KGB Document created.