C                  INTERNATIONAL AVS CENTER
C        (This disclaimer must remain at the top of all files)
C
C WARRANTY DISCLAIMER
C
C This module and the files associated with it are distributed free of charge.
C It is placed in the public domain and permission is granted for anyone to use,
C duplicate, modify, and redistribute it unless otherwise noted.  Some modules
C may be copyrighted.  You agree to abide by the conditions also included in
C the AVS Licensing Agreement, version 1.0, located in the main module
C directory located at the International AVS Center ftp site and to include
C the AVS Licensing Agreement when you distribute any files downloaded from
C that site.
C
C The International AVS Center, MCNC, the AVS Consortium and the individual
C submitting the module and files associated with said module provide absolutely
C NO WARRANTY OF ANY KIND with respect to this software.  The entire risk as to
C the quality and performance of this software is with the user.  IN NO EVENT
C WILL The International AVS Center, MCNC, the AVS Consortium and the individual
C submitting the module and files associated with said module BE LIABLE TO
C ANYONE FOR ANY DAMAGES ARISING FROM THE USE OF THIS SOFTWARE, INCLUDING,
C WITHOUT LIMITATION, DAMAGES RESULTING FROM LOST DATA OR LOST PROFITS, OR ANY
C SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
C
C This AVS module and associated files are public domain software unless
C otherwise noted.  Permission is hereby granted to do whatever you like with
C it, subject to the conditions that may exist in copyrighted materials. Should
C you wish to make a contribution toward the improvement, modification, or
C general performance of this module, please send us your comments:  why you
C liked or disliked it, how you use it, and most important, how it helps your
C work. We will receive your comments at avs@ncsc.org.
C
C Please send AVS module bug reports to avs@ncsc.org.
C
C  NOTE:  THIS MODULE AND SOURCE CODE IS FOR USE 
C  WITH THE AVS SOFTWARE ENVIRONMENT ONLY 
      subroutine hsva_to_rgb(ht,s,v,r,g,b)

      real f, p, q, t
      real r, g, b
      real ht, s, v
      real h
      integer i

C Make sure not to trash the input colormap
      h = ht

      if(v.eq.0) then
         r=0
         g=0
         b=0
         goto 100
      elseif(s.eq.0) then
	 r = v
	 g = v
	 b = v
         goto 100
      else
         h = h * 6.0
         if(h.ge.6.0) then
	    h = 0.0
	 endif
      
         i = h
         f = h - i
         p = v*(1.0-s)
         q = v*(1.0-s*f)
         t = v*(1.0-s*(1.0-f))
      endif
      
      if(i.eq.0) then
	  r = v
	  g = t
	  b = p
      elseif(i.eq.1) then 
	 r = q
	 g = v
	 b = p
      elseif(i.eq.2) then
	 r = p
	 g = v
	 b = t
      elseif(i.eq.3) then
	 r = p
	 g = q
	 b = v
      elseif(i.eq.4) then
	 r = t
	 g = p
	 b = v
      elseif(i.eq.5) then
	 r = v
	 g = p
	 b = q
      endif

 100  return
      end