box_image.F90

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!! Copyright (C) 2002-2006 M. Marques, A. Castro, A. Rubio, G. Bertsch
!! Copyright (C) 2021 M. Oliveira, K. Lively, A. Obzhirov, I. Albar
!!
!! This program is free software; you can redistribute it and/or modify
!! it under the terms of the GNU General Public License as published by
!! the Free Software Foundation; either version 2, or (at your option)
!! any later version.
!!
!! This program is distributed in the hope that it will be useful,
!! but WITHOUT ANY WARRANTY; without even the implied warranty of
!! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
!! GNU General Public License for more details.
!!
!! You should have received a copy of the GNU General Public License
!! along with this program; if not, write to the Free Software
!! Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
!! 02110-1301, USA.
!!
 
#include "global.h"
 
module box_image_oct_m
  use box_oct_m
  use box_shape_oct_m
  use debug_oct_m
  use iso_c_binding
  use global_oct_m
  use math_oct_m
  use messages_oct_m
  use namespace_oct_m
  use profiling_oct_m
  use unit_oct_m
 
  implicit none
 
  public :: box_image_t
 
  type, extends(box_shape_t) :: box_image_t
    private
    integer                       :: image_size(2)
    real(real64), public                 :: pixel_size(2)
    type(c_ptr)                   :: image
    character(len=:), allocatable :: filename
  contains
    procedure :: shape_contains_points => box_image_shape_contains_points
    procedure :: write_info => box_image_write_info
    procedure :: short_info => box_image_short_info
    final     :: box_image_finalize
  end type box_image_t
 
  interface box_image_t
    procedure box_image_constructor
  end interface box_image_t
 
contains
 
  !--------------------------------------------------------------
  function box_image_constructor(center, axes, lsize, filename, periodic_dim, namespace) result(box)
    real(real64),      intent(in) :: center(2)
    real(real64),      intent(in) :: axes(2, 2)
    real(real64),      intent(in) :: lsize(2)
    character(len=*),  intent(in) :: filename
    integer,           intent(in) :: periodic_dim
    type(namespace_t), intent(in) :: namespace
    class(box_image_t), pointer :: box
 
    logical :: found
    integer :: idir, box_npts
    real(real64) :: lsize_adjusted(2)
 
    push_sub(box_image_constructor)
 
    ! Allocate memory
    safe_allocate(box)
 
    ! Initialize box
    box%filename = trim(filename)
    inquire(file=trim(box%filename), exist=found)
    if (.not. found) then
      deallocate(box%filename)
      box%filename = trim(conf%share) // '/' // trim(filename)
      inquire(file=trim(box%filename), exist=found)
 
      if (.not. found) then
        message(1) = "Could not find file '" // trim(filename) // "' for BoxShape = box_image."
        call messages_fatal(1, namespace=namespace)
      end if
    end if
 
    if (.not. c_associated(box%image)) then
      message(1) = "Could not open file '" // trim(box%filename) // "' for BoxShape = box_image."
      call messages_fatal(1, namespace=namespace)
    end if
 
    ! If necessary, adjust the bounding box to ensure that we always have a
    ! pixel at the origin and that the edges always fall between two pixels.
    do idir = 1, 2
      box_npts = box%image_size(idir)
      if ((idir >  periodic_dim .and. even(box%image_size(idir))) .or. &
        (idir <= periodic_dim .and.  odd(box%image_size(idir)))) then
        box_npts = box_npts + 1
        lsize_adjusted(idir) = lsize(idir) * box_npts / box%image_size(idir)
      else
        lsize_adjusted(idir) = lsize(idir)
      end if
    end do
 
    ! Calculate the size of a pixel. To have one grid point = one pixel the
    ! spacing must be the same as the pixel size.
    box%pixel_size(1:2) = m_two*lsize_adjusted(1:2)/box%image_size(1:2)
 
    call box_shape_init(box, namespace, 2, center, bounding_box_min=-lsize_adjusted, bounding_box_max=lsize_adjusted, axes=axes)
 
    box%bounding_box_l = lsize_adjusted + abs(center)
 
    pop_sub(box_image_constructor)
  end function box_image_constructor
 
  !--------------------------------------------------------------
  subroutine box_image_finalize(this)
    type(box_image_t), intent(inout) :: this
 
    push_sub(box_image_finalize)
 
    call box_shape_end(this)
    if (allocated(this%filename)) then
      deallocate(this%filename)
    end if
 
    pop_sub(box_image_finalize)
  end subroutine box_image_finalize
 
  !--------------------------------------------------------------
  function box_image_shape_contains_points(this, nn, xx, tol) result(contained)
    class(box_image_t), intent(in)  :: this
    integer,            intent(in)  :: nn
    real(real64), contiguous,  intent(in)  :: xx(:,:)
    real(real64), optional,    intent(in)  :: tol
    logical :: contained(1:nn)
 
    integer :: ip
    integer :: red, green, blue, ix, iy
 
    do ip = 1, nn
      ! Transform our cartesian coordinates into pixel coordinates.
      ! Why the minus sign for y? Explanation: http://biolinx.bios.niu.edu/bios546/gd_mod.htm
      ! For reasons that probably made sense to someone at some time, computer graphic coordinates are not the same
      ! as in standard graphing. ... The top left corner of the screen is (0,0).
      ix =   nint((xx(ip, 1) - this%center(1))/this%pixel_size(1)) + (this%image_size(1) - 1)/2
      iy = - nint((xx(ip, 2) - this%center(2))/this%pixel_size(2)) + (this%image_size(2) - 1)/2
      contained(ip) = (red == 255 .and. green == 255 .and. blue == 255) .neqv. this%is_inside_out()
    end do
 
  end function box_image_shape_contains_points
 
  !--------------------------------------------------------------
  subroutine box_image_write_info(this, iunit, namespace)
    class(box_image_t),          intent(in) :: this
    integer,           optional, intent(in) :: iunit
    type(namespace_t), optional, intent(in) :: namespace
 
    push_sub(box_image_write_info)
 
    write(message(1),'(2x,3a,i6,a,i6)') 'Type = defined by image "', trim(this%filename), '"', this%image_size(1), ' x ', &
      this%image_size(2)
    call messages_info(1, iunit=iunit, namespace=namespace)
 
    pop_sub(box_image_write_info)
  end subroutine box_image_write_info
 
  !--------------------------------------------------------------
  character(len=BOX_INFO_LEN) function box_image_short_info(this, unit_length) result(info)
    class(box_image_t), intent(in) :: this
    type(unit_t),       intent(in) :: unit_length
 
    push_sub(box_image_short_info)
 
    write(info, '(2a)') 'BoxShape = box_image; BoxShapeImage = ', trim(this%filename)
 
    pop_sub(box_image_short_info)
  end function box_image_short_info
 
end module box_image_oct_m
 
!! Local Variables:
!! mode: f90
!! coding: utf-8
!! End: