/*
 * Copyright (c) 2003, jMonkeyEngine - Mojo Monkey Coding
 * All rights reserved.
 *
 * 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 Mojo Monkey Coding, jME, jMonkey Engine, 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 COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR 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.
 *
 */

package jme.locale.external.data;

import java.util.logging.Level;

import jme.exception.MonkeyRuntimeException;
import jme.utility.LoggingSystem;

/**
 * <code>CombinerHeightMap</code> generates a new height map based on
 * two provided height maps. These had maps can either be added together
 * or substracted from each other. Each heightmap has a weight to 
 * determine how much one will affect the other. By default it is set to
 * 0.5, 0.5 and meaning the two heightmaps are averaged evenly. This
 * value can be adjusted at will, as long as the two factors are equal
 * to 1.0.
 * 
 * @author Mark Powell
 * @version 1
 */
public class CombinerHeightMap extends AbstractHeightMap {
	/**
	 * Constant mode to denote adding the two heightmaps.
	 */
	public static final int ADDITION = 0;
	/**
	 * Constant mode to denote subtracting the two heightmaps.
	 */
	public static final int SUBTRACTION = 1;

	//the two maps.
	private AbstractHeightMap map1;
	private AbstractHeightMap map2;

	//the two factors
	private float factor1 = 0.5f;
	private float factor2 = 0.5f;

	//the combine mode.
	private int mode;

	/**
	 * Constructor combines two given heightmaps by the specified mode.
	 * The heightmaps will be evenly distributed. The heightmaps
	 * must be of the same size.
	 * 
	 * @param map1 the first heightmap to combine.
	 * @param map2 the second heightmap to combine.
	 * @param mode denotes whether to add or subtract the heightmaps, may
	 * 		be either ADDITION or SUBTRACTION.
	 * @throws MonkeyRuntimeException if either map is null, their size
	 * 		do not match or the mode is invalid.
	 */
	public CombinerHeightMap(
		AbstractHeightMap map1,
		AbstractHeightMap map2,
		int mode) {
		
		//insure all parameters are valid.	
		if (null == map1 || null == map2) {
			throw new MonkeyRuntimeException("Height map may not be null");
		}

		if (map1.getSize() != map2.getSize()) {
			throw new MonkeyRuntimeException("The two maps must be of the same size");
		}

		if ((factor1 + factor2) != 1.0f) {
			throw new MonkeyRuntimeException("factor1 and factor2 must add to 1.0");
		}
		
		this.size = map1.getSize();
		this.map1 = map1;
		this.map2 = map2;

		this.mode = mode;

		load();
	}

	/**
	 * Constructor combines two given heightmaps by the specified mode.
	 * The heightmaps will be distributed based on the given factors. 
	 * For example, if factor1 is 0.6 and factor2 is 0.4, then 60% of
	 * map1 will be used with 40% of map2. The two factors must add up
	 * to 1.0. The heightmaps must also be of the same size.
	 * 
	 * @param map1 the first heightmap to combine.
	 * @param factor1 the factor for map1.
	 * @param map2 the second heightmap to combine.
	 * @param factor2 the factor for map2.
	 * @param mode denotes whether to add or subtract the heightmaps, may
	 * 		be either ADDITION or SUBTRACTION.
	 * @throws MonkeyRuntimeException if either map is null, their size
	 * 		do not match, the mode is invalid, or the factors do not add
	 * 		to 1.0. 
	 */
	public CombinerHeightMap(
		AbstractHeightMap map1,
		float factor1,
		AbstractHeightMap map2,
		float factor2,
		int mode) {
			
		//insure all parameters are valid.
		if (null == map1 || null == map2) {
			throw new MonkeyRuntimeException("Height map may not be null");
		}

		if (map1.getSize() != map2.getSize()) {
			throw new MonkeyRuntimeException("The two maps must be of the same size");
		}

		if ((factor1 + factor2) != 1.0f) {
			throw new MonkeyRuntimeException("factor1 and factor2 must add to 1.0");
		}

		if (mode != ADDITION || mode != SUBTRACTION) {
			throw new MonkeyRuntimeException("Invalid mode");
		}

		this.size = map1.getSize();
		this.map1 = map1;
		this.map2 = map2;
		this.factor1 = factor1;
		this.factor2 = factor2;

		this.mode = mode;

		load();
	}

	/**
	 * <code>setFactors</code> sets the distribution of heightmaps. 
	 * For example, if factor1 is 0.6 and factor2 is 0.4, then 60% of
	 * map1 will be used with 40% of map2. The two factors must add up
	 * to 1.0. 
	 * @param factor1 the factor for map1.
	 * @param factor2 the factor for map2.
	 * @throws MonkeyRuntimeException if the factors do not add to 1.0.
	 */
	public void setFactors(float factor1, float factor2) {
		if ((factor1 + factor2) != 1.0f) {
			throw new MonkeyRuntimeException("factor1 and factor2 must add to 1.0");
		}

		this.factor1 = factor1;
		this.factor2 = factor2;
	}

	/**
	 * <code>setHeightMaps</code> sets the height maps to combine. 
	 * The size of the height maps must be the same.
	 * @param map1 the first height map.
	 * @param map2 the second height map.
	 * @throws MonkeyRuntimeException if the either heightmap is null, or their
	 * 		sizes do not match.
	 */
	public void setHeightMaps(AbstractHeightMap map1, AbstractHeightMap map2) {
		if (null == map1 || null == map2) {
			throw new MonkeyRuntimeException("Height map may not be null");
		}
		
		if (map1.getSize() != map2.getSize()) {
			throw new MonkeyRuntimeException("The two maps must be of the same size");
		}

		this.size = map1.getSize();
		this.map1 = map1;
		this.map2 = map2;
	}

	/**
	 * <code>setMode</code> sets the mode of the combiner. This may either
	 * be ADDITION or SUBTRACTION.
	 * @param mode the mode of the combiner.
	 * @throws MonkeyRuntimeException if mode is not ADDITION or SUBTRACTION.
	 */
	public void setMode(int mode) {
		if (mode != ADDITION || mode != SUBTRACTION) {
			throw new MonkeyRuntimeException("Invalid mode");
		}
		this.mode = mode;
	}

	/**
	 * <code>load</code> builds a new heightmap based on the combination of
	 * two other heightmaps. The conditions of the combiner determine the
	 * final outcome of the heightmap.
	 * 
	 * @return boolean if the heightmap was successfully created.
	 */
	public boolean load() {
		if (null != heightData) {
			unloadHeightMap();
		}

		heightData = new int[size][size];

		int[][] temp1 = map1.getHeightMap();
		int[][] temp2 = map2.getHeightMap();

		if (mode == ADDITION) {
			for (int i = 0; i < size; i++) {
				for (int j = 0; j < size; j++) {
					heightData[i][j] =
						(int) (temp1[i][j] * factor1
							+ temp2[i][j] * factor2);
				}
			}
		} else if (mode == SUBTRACTION) {
			for (int i = 0; i < size; i++) {
				for (int j = 0; j < size; j++) {
					heightData[i][j] =
						(int) (temp1[i][j] * factor1
							- temp2[i][j] * factor2);
				}
			}
		}

		LoggingSystem.getLoggingSystem().getLogger().log(
			Level.INFO,
			"Created heightmap using Combiner");

		return true;
	}

}
