/*
 *  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
 *
 *  Copyright(c) 2004 Jordi Martin Perez
*/

package org.piratis.j2me.core.game;

import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;

import org.piratis.j2me.core.BBox2D;
import org.piratis.j2me.core.QuickList;

/**
 * A type of Layer composed of a grid of 
 * cells which can contain a reduced set of predefined images. 
 * This class allows large virtual layers to be created 
 * without the need for an extremely large Image. It is
 * commonly used to creat very large scrolling backgrounds.
 * 
 * @author		Jordi Mart韓
 * @copyright	Copyright (c) 2004
 * @created 	30-jun-2004
 * @version		$Id: TiledLayer.java,v 1.5 2004/07/29 20:13:06 piratis Exp $
 */

public class TiledLayer 
	extends Layer 
{
    /**
     * Tile's columns
     */
    private int columns;
    /**
     * Tile's rows
     */
    private int rows;
    /**
     * Height of one tile
     */
    private int tileHeight;
    /**
     * Width of one tile
     */
    private int tileWidth;
    /**
     * Grid
     */
    private int[][] grid;
    /**
     * Where common tiles will be stored
     */
    private QuickList commonTiles;
    /**
     * The image containing the tiles
     */
    private Image tiles;
    private int nTilesRow;
    
    /**
     * Creates a new TiledLayer.<br>
     * <br>
     * TODO:
     * @param columns
     * @param rows
     * @param image
     * @param tileWidth
     * @param tileHeight
     */
    public TiledLayer (int columns, int rows, Image image,
            int tileWidth, int tileHeight)
    {
        this.columns = columns;
        this.rows = rows;
        this.grid = new int	[columns][rows];
        this.tiles = image;
        this.nTilesRow = image.getWidth() / tileWidth;

        // void initialization
        this.fillCells(0, 0, columns, rows, 0);
        
        // layer values
        this.tileWidth = tileWidth;
        this.tileHeight = tileHeight;
        this.bbox.width = columns * tileWidth;
        this.bbox.height = rows * tileHeight;
        
        // animated tiles
        this.commonTiles = new QuickList();
    }
    
	/**
	 * Sets the given tileIndex in a given region.
     * @param col top-left region column
     * @param row top-left region row
     * @param colNumber region col number
     * @param rowNumber region row number
     * @param tileIndex tile index to set
     */
    public void fillCells(int col, int row, 
            int colNumber, int rowNumber, int tileIndex)
    {
        int i, j;
        for (i = col + colNumber - 1; i >= col; i--)
            for (j = row + rowNumber - 1; j >= row; j--)
                this.grid[i][j] = tileIndex;
    }
   
    /**
     * Sets the contents of a cell.
     * @param col column from the grid
     * @param row row from the grid
     * @param tileIndex the index of the tile
     */
    public void setCell(int col, int row, int tileIndex)
    {
        this.grid[col][row] = tileIndex;
    }

    /**
     * Gets cell's contents
     * @param col column from the grid
     * @param row row from the grid
     * @return the index of the tile in the cell
     */
    public int getCell(int col, int row)
    {
        return this.grid[col][row];
    }

    /**
     * Cretates a new common tile returning the index referring to this new
     * common tile. It is initially assigned with the provided tileIndex.
     * @param tileIndex
     * @return
     */
    public int createCommonTile(int tileIndex)
    {
		this.commonTiles.add(new Integer(tileIndex));
		return -this.commonTiles.length();
    }
    

    /**
     * Gets the tile referenced by the given common tile. 
     * @param commonTileIndex the index of the common tile.
     * @return the tile index currently associated with the common tile.
     */
    public int getCommonTile(int commonTileIndex)
    {
        return ((Integer) this.commonTiles.elementAt((-commonTileIndex)-1)).intValue();
    }
    
    /**
     * Changes the tile associated to this common tile.
     * @param commonTileIndex
     * @param tileIndex
     */
    public void setCommonTile(int commonTileIndex, int tileIndex)
    {
        this.commonTiles.setElementAt(new Integer(tileIndex),
                (-commonTileIndex)-1);
    }

    /**
	 * @see org.piratis.j2me.core.game.Layer#paint(javax.microedition.lcdui.Graphics)
	 */
	public void paint(Graphics g) 
	{
	    // get clipping
	    int clipX, clipY, clipW, clipH;
	    clipX = g.getClipX(); clipY = g.getClipY();
	    clipW = g.getClipWidth(); clipH = g.getClipWidth();
	    // check inside clipping
	    if (!this.bbox.collide(clipX, clipY, clipW, clipH)) return;
	    // where to begin
	    int startCol = (clipX - this.bbox.x) / this.tileWidth;
	    int startRow = (clipY - this.bbox.y) / this.tileHeight;
	    // where to end
	    int endCol = Math.min(startCol + (clipW / this.tileWidth) + 1, 
	            this.columns - 1);
	    int endRow = Math.min(startRow + (clipH / this.tileHeight) + 1,
	            this.rows - 1);
	    // go, go, go!
	    int i, j, transX, transY, oldTransX, oldTransY, tileNum, auxTrans;
	    // store previous translation values
	    oldTransX = g.getTranslateX();
	    oldTransY = g.getTranslateY();
	    // start moving translation through the drawn tiles
        g.translate(this.bbox.x + (endCol * this.tileWidth), 
        	this.bbox.y + (endRow * this.tileHeight));
	    for (i = endCol; i >= startCol; i--)
	    {
	        for (j = endRow; j >= startRow; j--)
	        {
	    	    tileNum = this.grid[i][j];
	    	    // check if 'common' (i.e. animated) tile
	    	    if (tileNum < 0)
	    	        tileNum = this.getCommonTile(tileNum);
	    	    if (tileNum > 0)
	    	    {
		            // store clipping
		    	    clipX = g.getClipX(); clipY = g.getClipY();
		    	    clipW = g.getClipWidth(); clipH = g.getClipWidth();
		    	    // set new clipping -> drawing at '0,0' because of translation!
		    	    g.clipRect(0, 0, this.tileWidth, this.tileHeight);
		    	    // calc image to draw
		    	    tileNum--; // easier to calc image location 
		    	    transX = (tileNum % this.nTilesRow) * this.tileWidth;  // tileNum % nTilesRow = col
		    	    transY = (tileNum / this.nTilesRow) * this.tileHeight; // tileNum / nTilesRow = row
		    	    // draw there
		    	    g.drawImage(this.tiles, -transX, -transY, Layer.TOP_LEFT);
		    	    // restore clipping
		    	    g.setClip(clipX, clipY, clipW, clipH);
	    	    }
	    	    // move clipping
	    	    g.translate(0, -this.tileHeight);
	        }
	        // move clipping
	        g.translate(-this.tileWidth, this.tileHeight*(endRow-startRow+1));
	    }
	    // restore clipping
	    g.translate(oldTransX - g.getTranslateX(), 
	            oldTransY - g.getTranslateY());
	}
	
	/**
	 * Check colliding but checking cells.
	 * @param l Layer to check
	 * @return whether colliding exists
	 */
	public boolean cellCollides(Layer l)
	{
	    // where to begin
	    BBox2D layerBox = l.bbox;
	    int startCol = Math.max(0, (layerBox.x - this.bbox.x) / this.tileWidth);
	    int startRow = Math.max(0, (layerBox.y - this.bbox.y) / this.tileHeight);
	    // where to end
	    int endCol = Math.min(startCol + (layerBox.width / this.tileWidth) + 1, 
	            this.columns - 1);
	    int endRow = Math.min(startRow + (layerBox.height / this.tileHeight) + 1,
	            this.rows - 1);
	    // go, go, go!!
	    int i, j, boxX, boxY;
	    // limits will be calculated incrementaly (boxX and boxY) -> more efficient
	    boxX = this.bbox.x + endCol*this.tileWidth;
	    for (i = endCol; i >= startCol; i--)
	    {
	        boxY = this.bbox.y + endRow*this.tileHeight;
	        for (j = endRow; j >= startRow; j--)
	        {
	            if (this.grid[i][j] != 0)
	            {
	                if (layerBox.collide(boxX, boxY, tileWidth, tileHeight))
	                {
	                    return true;
	                }
	            }
	            boxY -= tileHeight;
	        }
	        boxX -= tileWidth;  
	    }
	    return false;
	}
}