Solid FFCs (In-Source Model)

//ffc solidity for canwalk
//chexck this in the canwalk() function that Link uses

//FFCs are part of the current mapscreen, and all of their values are available.
for ( int q = 0; q < 31; ++q )
{
    /*skip all ffs with the solid flag off, to save system overhead*/
    if ( !(Maps.FFCFlags[q]&FFCSOLID) ) continue;

    switch(dir)//Link's dir
    {
        case DIR_UP:
        {
            /*find the bottom of the ffc effectheight
            and is Y
            */

            if ( stepdest_y > bottom_hitbox || stepdest_y < ffc_y )
                /* before its edge, or beyond its other edge*/
                break;

            /*then find out if Link's X is within the X+effectwidth
            of the ffc*/

            /*if not, then we break*/

            /*if it is, then we can't walk, and return false*/

        }
        case DIR_DOWN:
        {
            /*find the top of the ffc effectheight
            and is Y
            */
            if ( stepdest_y < top_hitbox || stepdest_y > ffc_Y )
                /* before its edge, or beyond its other edge*/
                break;
            /*then find out if Link's X is within the X+effectwidth
            of the ffc*/

            /*if not, then we break*/

            /*if it is, then we can't walk, and return false*/
        }
        case DIR_LEFT:
        {
            /* find the right edge of the ffc effectwidth
            and its X*/
            if ( stepdest_x > right_hitbox || stepdest_x < ffc_x )              )
                /* before its edge, or beyond its other edge*/
                break;

            /*then find out if Link's Y is within the Y+effectheight
            of the ffc*/

            /*if not, then we break*/

            /*if it is, then we can't walk, and return false*/

        }

        case DIR_RIGHT:
        {
            /* find the left edge of the ffc effectwidth
            and its X*/
            if ( stepdest_x < right_hitbox || stepdest_x > ffc_x )              )
                /* before its edge, or beyond its other edge*/
                break;

            /*then find out if Link's Y is within the Y+effectheight
            of the ffc*/

            /*if not, then we break*/

            /*if it is, then we can't walk, and return false*/

        }
    }
}