/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSimulator Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using OpenSim.Region.Framework.Interfaces;

namespace OpenSim.Region.CoreModules.World.Terrain.PaintBrushes
{
    public class LowerSphere : ITerrainPaintableEffect
    {
        #region ITerrainPaintableEffect Members

        public void PaintEffect(ITerrainChannel map, bool[,] mask, double rx, double ry, double rz, double strength, double duration)
        {
            int s = (int) (Math.Pow(2, strength) + 0.5);

            int x;
            int xFrom = (int)(rx-s+0.5);
            int xTo   = (int)(rx+s+0.5) + 1;
            int yFrom = (int)(ry-s+0.5);
            int yTo   = (int)(ry+s+0.5) + 1;

            if (xFrom < 0)
                xFrom = 0;

            if (yFrom < 0)
                yFrom = 0;

            if (xTo > map.Width)
                xTo = map.Width;

            if (yTo > map.Width)
                yTo = map.Width;

            for (x = xFrom; x < xTo; x++)
            {
                int y;
                for (y = yFrom; y < yTo; y++)
                {
                    if (!mask[x,y])
                        continue;

                    // Calculate a cos-sphere and add it to the heighmap
                    double r = Math.Sqrt((x-rx) * (x-rx) + ((y-ry) * (y-ry)));
                    double z = Math.Cos(r * Math.PI / (s * 2));
                    if (z > 0.0)
                    {
                        double newz = map[x, y] - z * duration;
                        if (newz < 0.0)
                            map[x, y] = 0.0;
                        else
                            map[x, y] = newz;
                    } 
                }
            }

        }
        #endregion
    }
}
