! Copyright (c) 2015 Jiaxing Qi <jiaxing.qi@uni-siegen.de>
! Copyright (c) 2016 Tobias Schneider <tobias1.schneider@student.uni-siegen.de>
! Copyright (c) 2020 Peter Vitt <peter.vitt2@uni-siegen.de>
!
! Redistribution and use in source and binary forms, with or without
! modification, are permitted provided that the following conditions are met:
!
! 1. Redistributions of source code must retain the above copyright notice,
! this list of conditions and the following disclaimer.
!
! 2. Redistributions in binary form must reproduce the above copyright notice,
! this list of conditions and the following disclaimer in the documentation
! and/or other materials provided with the distribution.
!
! THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY OF SIEGEN “AS IS” AND ANY EXPRESS
! OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
! OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
! IN NO EVENT SHALL UNIVERSITY OF SIEGEN OR CONTRIBUTORS BE LIABLE FOR ANY
! DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
! (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
! LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
! ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
! (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
! SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

??!------------------------------------------------------------------------------
??! This macro is still in here because there are two siblings for q19 and q27
??! stencils that are more complex than this one.
??! real, intent(out) :: u_x, u_y
??! real, intent(in)  :: f(9), inv_rho
?? text :: vel_d2q9( u_x, u_y, f, inv_rho )
  ?u_x? = ?f?(3) + ?f?(7) + ?f?(8) - ?f?(1) - ?f?(5) - ?f?(6)
  ?u_y? = ?f?(4) + ?f?(6) + ?f?(8) - ?f?(2) - ?f?(5) - ?f?(7)

  ?u_x? = ?u_x? * ?inv_rho?
  ?u_y? = ?u_y? * ?inv_rho?
?? end text vel_d2q9
??!------------------------------------------------------------------------------
