outflow.ca

/*

Copyright (c) 2013 Centre for Water Systems,
                   University of Exeter

This file is part of cafloodpro.

cafloodpro 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 3 of the License, 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, see <http://www.gnu.org/licenses/>
*/

// Update the water depth by removing the water
// that infiltrate into the ground.
// ATTENTION, This version add the volume extracted into a buffer
CA_FUNCTION outflow(CA_GRID grid, CA_CELLBUFF_REAL_IO WD, CA_CELLBUFF_STATE_I MASK, CA_CELLBUFF_REAL_IO VOL, CA_REAL tol)
{
    // Initialise the grid
    CA_GRID_INIT(grid);

    // Read Mask.
    CA_STATE mask  = caReadCellBuffState(grid,MASK,0);

    // Read bit 31 (true if the main cell is nodata and at least one
    // neighbour has data)
    CA_STATE bit31  = caReadBitsState(mask,31,32);

    // If bit 31 is false do nothing.
    if(bit31 == 0)
        return;

    // Retrieve the current value of the water depth.
    CA_REAL  wd  = caReadCellBuffReal(grid,WD,0);
    //if (wd < tol)
    //    return;

    // Update the water depth value with the removed amount.
    caWriteCellBuffReal(grid,VOL,wd);
}