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.
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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
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C submitting the module and files associated with said module BE LIABLE TO
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C WITHOUT LIMITATION, DAMAGES RESULTING FROM LOST DATA OR LOST PROFITS, OR ANY
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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	AVS MODULE RIVER BED
C	by Terry Myerson
C	   International AVS Center
C	   North Carolina Supercomputing Center
C
C   This module is used to construct the outline of a river
C   bed. The length parameter specifies the length of the
C   river in grid cells and cooridinates.  The river starts
C   at y coordinate 0 and extends downward to y coordinate
C   length at y index length.  The river is constructed in the
C   xy plane.  Width specifies the width of the river in the
C   x direction in grid cells.  Width has nothing to do with
C   the shape of the river.  The outline of the river is assumed
C   to be a sinusoidal function of the form A * Sin (wt) + O
C   A - Amplitude w - Omega t - Length O - Offset
C   The data set that is constructed is filled with 0's
C   This module subroutine is meant to hook up to the
C   river fill coroutine to create a simulation of river
C   contaminants.
 
      subroutine AVSinit_modules
C   IAC CODE CHANGE :       include '/usr/avs/include/avs.inc'
	INCLUDE '/usr/avs/include/avs.inc'
      external river_compute
      integer iparm
      
      call AVSset_module_name('river bed', 'data')

      call AVSset_module_flags( single_arg_data )

      oport = AVScreate_output_port('field',
     *     'field 3D scalar real 3-space')

      call AVSautofree_output(oport)

      iparm = AVSadd_parameter('depth','integer',1,1,100)
      iparm = AVSadd_parameter('length','integer',30,1,100)
      iparm = AVSadd_parameter('width','integer',7,1,10)
      iparm = AVSadd_parameter('omega','real',2.5,0.0,5.0)
      iparm = AVSadd_parameter('amplitude','real',1.0,0.0,10.0)
      iparm = AVSadd_parameter('offset','integer',5,0,100)

      call AVSset_compute_proc(river_compute)
      
      return
      end
      
      integer function river_compute(output_field,
     *     depth,length,width,omega,amplitude,offset )

C   IAC CODE CHANGE :       include '/usr/avs/include/avs.inc'
	INCLUDE '/usr/avs/include/avs.inc'

      integer output_field, length,width,offset,depth
      real omega,amplitude

      external river_field
      integer dims, coordflag, iresult, river_field
      integer ofield, ocoords, pfield, pcoords
      real field_data, coords
      dimension field_data(1), coords(1), dims(3)

      dims(1) = width
      dims(2) = length
      dims(3) = depth

	print *,depth

      output_field = AVSdata_alloc(
     &   'field 3D irregular scalar real 3-space', dims)

      if (output_field .eq. 0) then 
         write(6,90) field_descriptor
 90      format('Error allocating field ',A)
         river_compute=0
         return
      endif

      iresult = AVSfield_data_offset(output_field, field_data, ofield)
      iresult = AVSfield_points_offset(output_field, coords, ocoords)

      iresult=river_field(field_data(ofield+1),depth,
     *     length,width,coords(ocoords+1),omega,amplitude,offset )

      river_compute = iresult
      return

      end

C *******************************************************************
      integer function river_field(field_data,
     *     depth,length,width,coords,omega,amplitude,offset )
      
C   IAC CODE CHANGE :       include '/usr/avs/include/avs.inc'
	INCLUDE '/usr/avs/include/avs.inc'

      integer depth,length,width,offset
      real field_data(width,length,depth),coords(width,length,depth,3)
      real omega,amplitude
      real func,frac

      do 10 k=1,depth
      do 10 j=1,length
         func = amplitude*sin(omega*j)+offset
         do 10 i=1,width
            frac = 2*func/width*i
            field_data(i,j,k) = 0.0
            coords(i,j,k,1)   = -1*func+frac
            coords(i,j,k,2)   = -1.0*float(j)
            coords(i,j,k,3)   = k
 10   continue
      
      river_field=1

      return
      end