/**
 * @(#) $RCSfile: GroundLookup.as,v $ $Revision: 1.1 $ $Date: 2003/04/20 13:13:18 $
 *
 * Copyright 2003 Orgdot AS. All Rights Reserved.
 * http://dev.swfit.com
 *
 * 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
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

/**
 * Lookup script for the ground generator. We should input a x-value inside a clip
 * that we want to compare to the ground. Both the ground clip and this clip should
 * reside in the same movie clip.
 *
 * @author      Olaf Havnes
 * @version     $Revision: 1.1 $ $Date: 2003/04/20 13:13:18 $
 * @since       SWFIT1.0
 */

// Adjust for offset
find_point_x = _x + val_x + 1;

// Find the left-most block of the landscape
which_left = _parent.ground.clip_counter + 1;
if (which_left == _parent.ground.NUM_CLIPS) which_left = 0;
left_point = _parent.ground._x + getProperty ("../ground/clip_" add which_left, _x);

// Find the difference
diff = find_point_x - left_point;
block0 = int (diff / _parent.ground.STEP) + which_left;
block1 = block0 + 1;

// Make sure we don't loop over the top
if (block0 >= _parent.ground.NUM_CLIPS) block0 -= _parent.ground.NUM_CLIPS;
if (block1 >= _parent.ground.NUM_CLIPS) block1 -= _parent.ground.NUM_CLIPS;

// Measure the x values
dp0 = find_point_x - _parent.ground._x - getProperty ("../ground/clip_" add block0, _x);
dp1 = _parent.ground._x + getProperty ("../ground/clip_" add block1, _x) - find_point_x;

// Measure the y values
val_y =
_parent.ground._y - _y + 
(
    dp1 * getProperty ("../ground/clip_" add block0, _y) +
    dp0 * getProperty ("../ground/clip_" add block1, _y)
) / _parent.ground.STEP;