mapcolor(3g) — 4D1 2.0



     mapcolor(3G)                                         mapcolor(3G)



     NAME

          mapcolor - changes a color map entry


     SPECIFICATION

          C         mapcolor(i, red, green, blue)

                    Colorindex i;

                    short red, green, blue;




          FORTRAN   subroutine mapcol(i, red, green, blue

                    integer*4 i, red, green, blue


     DESCRIPTION

          mapcolor changes a single color map entry for the current

          drawing mode to a specified RGB value. i loads the color map

          entry that corresponds with the RGB triple; its range is 0

          to 3 for CURSORDRAW, OVERDRAW, UNDERDRAW, and PUPDRAW modes.

          For NORMALDRAW, the range is 0 to 4095.  (See drawmode for

          descriptions of the drawing modes.)  red, green, blue

          specify a color map index (i) and 8 bits each of red, green,

          and blue intensities.  Pixels written with i display the

          specified RGB intensities.


          Note:  There are 4096 entries in the color map.  mapcolor

          can alter all the entries for most applications, although in

          some applications, the top 256 colors (3840 through 4095)

          should not be altered when running under the window manager,

          because the system uses them in specific ways for the

          cursor, overlay bitplanes, and RGB mode.  If those entries

          are mapped, some features on the screen can appear in

          strange colors.


          In multimap mode, only the current color map can be updated

          with mapcolor.  The system ignores invalid indices.


     SEE ALSO

          drawmode, multimap, onemap, setmap


          Programming Guide, Section 6.2, Color Map Mode


     NOTE

          This routine is available only in immediate mode.













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