color(3G)

NAME
     color, colorf - sets the color index in the current draw mode

FORTRAN 77 SPECIFICATION
     subroutine color(c)
     integer*4 c

     subroutine colorf(c)
     real c

PARAMETERS
     c   expects an index into the current color map.

DESCRIPTION
     color sets the color index of the currently active GL framebuffer, one of
     normal, popup, overlay, or underlay (see drawmo).  The current
     framebuffer must be in color map mode (see cmode) for the color command
     to be applicable.  Most drawing commands copy the current color index
     into the color bitplanes of the current framebuffer.  color is retained
     in each draw mode, so when a draw mode is re-entered, color is reset to
     the last value specified in that draw mode.

     color values range from 0 through 2n-1, where n is the number of
     bitplanes available in the current draw mode.  n can be ascertained by
     calling getpla while in the desired draw mode, or by calling getgde at
     any time.  Color indices larger than 2n-1 are clamped to 2n-1; color
     indices less than zero yield undefined results.

     The color displayed by a given color index is determined by the current
     color map (see mapcol.)  Each draw mode has its own color map.

     colorf is similar to color, except that it expects a floating point color
     index.  Before the color is written into display memory, it is rounded to
     the nearest integer value.  When dithering is enabled and the hardware
     supports it, the extra precision is used in the dithering.  Also, when
     drawing with the GOURAU shading model, machines that iterate color
     indices with fractional precision yield more precise shading results
     using colorf than with color.

     It is an error to call color or colorf while the current framebuffer is
     in RGB mode.

     The color indices of all framebuffers in color map mode are set to zero
     when gconfi is called.

SEE ALSO
     drawmo, getcol, mapcol, writem

NOTE
     IRIS-4D B, G, GT, and GTX models do not iterate color with fractional
     precision, nor do early serial numbers of the Personal Iris.  Use
     getgde(GDCIFR) to determine whether fractional color index iteration is
     supported.