!*==sbdirini.spg  processed by SPAG 6.70Rc at 15:33 on 10 Dec 2012
!*------------------   SPAG Configuration Options   --------------------
!*--0323,76 000101,-1 000000102011332010100002000000210211210,136 10 --
!*--1100000011112111000000000000,10,10,10,10,10,10,900,100 200000000 --
!*--000000010000000000000,72,72 73,42,38,33 00011112110000100000000  --
!*----------------------------------------------------------------------
!$Author: joelevin $
!$Date: 2011-03-24 11:33:26 -0500 (Thu, 24 Mar 2011) $
!$Revision: 11724 $
!$HeadURL: https://eweru-dev1.eweru.ksu.edu/svn/code/weps1/branches/WEPS_F90_update/weps.src/src/lib_erosion/sbdirini.for $
!**********************************************************************
!     subroutine sbdirini - initializes grid/wind direction relationships
!**********************************************************************
 
      subroutine sbdirini(wind_dir,prev_dir)
      use i_p1werm
      use i_m1geo
      use i_m1subr
      use i_s1sgeo
      use i_w1wind
      use i_m2geo
      use i_e3grid
      use i_s2sgeo
      implicit none
!*--SBDIRINI25
!
!*** Start of declarations rewritten by SPAG
!
! PARAMETER definitions
!
      real,parameter :: pid180 = 3.14159/180.
!
! Dummy arguments
!
      real :: prev_dir,wind_dir
      intent (in) wind_dir
      intent (inout) prev_dir
!
! Local variables
!
      integer :: ke
!
!*** End of declarations rewritten by SPAG
!
 
!     +++ purpose +++
!     Calc. wind angle on the sim. region
!     Calc. sweep sequence for update of grid cells
!     calc. ridge spacing parallel the wind
!
!     +++ ARGUMENT DECLARATIONS +++
!
!     +++ ARGUMENT DEFINITIONS +++
!     wind_dir - direction of the wind in degrees from north
!     prev_dir - previously computed direction of the wind
!
!     +++ PARAMETER +++
!
!     + + + GLOBAL COMMON BLOCKS + + +
 
!
!     + + +  LOCAL COMMON BLOCKS + + +
!
!     + + + LOCAL VARIABLES + + +
 
!
!     + + + LOCAL VARIABLE DEFINITIONS + + +
!     icsr  = index of current subregion
!
!     + + + SUBROUTINES CALLED + + +
!     sbsfdi
!
!     + + + END SPECIFICATION + + +
!
!     check and do not calculate if done on last entry
      if (wind_dir==prev_dir) return
      prev_dir = wind_dir
 
 
!
!     calc wind angle relative to the field Y-axis (+, - 45 deg. range)
      awa = wind_dir - amasim
      if (awa<0.0) awa = awa + 360.0
      if (awa>360.0) awa = awa - 360.0
 
      sin_awa = sin(awa*pid180)
      cos_awa = cos(awa*pid180)
      tan_awa = tan(awa*pid180)
!
!     find wind quadrant relative to sim region & select sweep sequence
!
      if (awa>=0.0.AND.awa<90.0) then
         i1 = imax - 1
         i2 = 1
         i3 = -1
         i4 = jmax - 1
         i5 = 1
         i6 = -1
         ke = 1
!
      else if (awa>=90.0.AND.awa<180.0) then
         i1 = imax - 1
         i2 = 1
         i3 = -1
         i4 = 1
         i5 = jmax - 1
         i6 = 1
         ke = 1
!
      else if (awa>=180.0.AND.awa<270.0) then
         i1 = 1
         i2 = imax - 1
         i3 = 1
         i4 = 1
         i5 = jmax - 1
         i6 = 1
         ke = 1
!
 
      else
         i1 = 1
         i2 = imax - 1
         i3 = 1
         i4 = jmax - 1
         i5 = 1
         i6 = -1
         ke = 1
      end if
!
!     determine barrier influence direction index (kbr)
!
      if (wind_dir>=337.5.OR.wind_dir<22.5) then
         kbr = 1
      else if (wind_dir<67.5) then
         kbr = 2
      else if (wind_dir<112.5) then
         kbr = 3
      else if (wind_dir<157.5) then
         kbr = 4
      else if (wind_dir<202.5) then
         kbr = 5
      else if (wind_dir<247.5) then
         kbr = 6
      else if (wind_dir<292.5) then
         kbr = 7
      else
         kbr = 8
      end if
!
      end subroutine sbdirini