Function:     GgiPlotMapColors

Purpose:      Map plotfield colors to colors from the master table

Category:     USER-INTERFACE, GRAPHICS

File:         ggi.src

Author:       J.P. Terlouw

Use:
              #include "ggi.h"
              ident plotter;

              GgiPlotMapColors(plotter, ...);

                 plotter -  the plotfield element.
                  ...    -  any number of pairs ci, nc :
                            int ci -  color index in master color table.
                                      -1 indicates end of arguments.
                            int nc -  number of colors to be used.


Description:  GgiPlotMapColors() builds a plotfield-specific color table
              from one or more spans from the master color table.
              This mechanism can be used to either separate or share
              colors in different plotfields.
              Initially color indices 0..15 in the master color table have been
              assigned a set of standard color representations. Indices
              16 and above are initially undefined and must be defined by
              calling PGSCR.

Example:      GgiPlotMapColors(p1, 0, 16, 16 16, -1);
              GgiPlotMapColors(p2, 0, 16, 32 16, -1);

              After this call, plotfields p1 and p2 share cells 0..15 from
              the master color table, and color indices 16..31 are different
              for p1 and p2.
              So if color index 3 is modified by calling PGSCR for
              plotfield p1, this change will also be visible in plotfield p2.
              But if color index 20 is modified, only p1 is affected.

Related doc.: GgiPlotColors.dc2

Updates:      Sep  6, 1999: JPT, Document created.