c(3G)

NAME
     c3f, c3i, c3s, c4f, c4i, c4s - sets the RGB (or RGBA) values for the
     current color vector

FORTRAN 77 SPECIFICATION
     subroutine c3s(cv)
     integer*2 cv(3)

     subroutine c3i(cv)
     integer*4 cv(3)

     subroutine c3f(cv)
     real cv(3)

     subroutine c4s(cv)
     integer*2 cv(4)

     subroutine c4i(cv)
     integer*4 cv(4)

     subroutine c4f(cv)
     real cv(4)

     The subroutines above are functionally the same but declare their
     parameters differently.

PARAMETER
     cv   For the c4 routines, this parameter expects a four element array
          containing RGBA (red, green, blue, and alpha) values.  If you use
          the c3 routines, this parameter expects a three element array
          containing RGB values.

          Array components 1, 2, 3, and 4 are red, green, blue, and alpha,
          respectively. Floating point RGBA values range from 0.0 through 1.0.
          Integer RGBA values range from 0 through 255.  Values that exceed
          the upper limit are clamped to it.  Values that exceed the lower
          limit are not clamped, and therefore result in unpredictable
          operation.

DESCRIPTION
     c4 sets the red, green, blue, and alpha color components of the currently
     active GL framebuffer, one of normal, popup, overlay, or underlay (see
     drawmo).  c3 sets red, green, and blue to the specified values, and sets
     alpha to the maximum value.  The current framebuffer must be in RGB mode
     (see RGBmod) for the c command to be applicable.  Most drawing commands
     copy the current RGBA color components into the color bitplanes of the
     current framebuffer.  Color components are retained in each draw mode, so
     when a draw mode is re-entered, red, green, blue, and alpha are reset to
     the last values specified in that draw mode.
     Integer color component values range from 0, specifying no intensity,
     through 255, specifying maximum intensity.  Floating point color
     component values range from 0.0, specifying no intensity, through 1.0,
     specifying maximum intensity.

     It is an error to call c while the current framebuffer is in color map
     mode.

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

SEE ALSO
     cpack, drawmo, lmcolo, gRGBco

NOTE
     These routines can also be used to modify the current material while
     lighting is active (see lmcolo).  Note that clamping to 1.0 is disabled
     in this case.

     Because only the normal framebuffer currently supports RGB mode, c should
     be called only while draw mode is NORMAL.  Use getgde to determine
     whether RGB mode is available in draw mode NORMAL.

BUGS
     On the IRIS-4D/120GTX and IRIS-4D/140GTX, there is problem with the
     graphics DMA hardware that can cause data to be sent to the hardware
     after the subroutine call has returned.  If the data is modified
     immediately after the subroutine call, the modified data may get sent
     down.  To avoid this, don't modify the data until after another n, v, or
     c call has been made.

     This is an example of the bug: