gammaramp(3g) — 4D1 2.0



     gammaramp(3G)                                       gammaramp(3G)



     NAME

          gammaramp - defines a color map ramp for gamma correction


     SPECIFICATION

          C         gammaramp(r,g,b)

                    short r[256],g[256],b[256]




          FORTRAN   subroutine gammar(r,g,b)

                    integer*2 r(256), g(256), b(256)


     DESCRIPTION

          gammaramp supplies a level of indirection for all color map

          and RGB values.  You can use it to provide gamma correction,

          to equalize monitors with different color characteristics,

          or to modify the color warmth of the monitor.  The default

          setting has r[i]=g[i]=b[i]=i.


          When RGBcolor (red, green, blue) is called and objects are

          drawn on the screen, (red, green, blue) are stored in the

          bitplanes, but they are displayed as (r[red], g[green],

          b[blue]) where r,g,b are the arrays last specified by

          gammaramp. Similarly, if color i is mapped to (red, green,

          blue) in color map mode, objects written in color i are

          displayed as (red[red], g[green], blue [blue]).


     SEE ALSO

          mapcolor, RGBcolor, color, cmode


          Programming Guide, Section 6.2, Color Map Mode


     NOTE

          This routine is available only in immediate mode.






















     Page 1                                          (printed 8/20/87)
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