/* CropImageFilter.java -- Java class for cropping image filter
   Copyright (C) 1999, 2004  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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package java.awt.image;

import java.awt.Rectangle;
import java.util.Hashtable;

/**
 * Currently this filter does almost nothing and needs to be implemented.
 *
 * @author C. Brian Jones (cbj@gnu.org) 
 */
public class CropImageFilter extends ImageFilter
{
    int x;
    int y;
    int width;
    int height;

    /**
     * Construct a new <code>CropImageFilter</code> instance.
     *
     * @param x the x-coordinate location of the top-left of the cropped rectangle
     * @param y the y-coordinate location of the top-left of the cropped rectangle
     * @param width the width of the cropped rectangle
     * @param height the height of the cropped rectangle
     */
    public CropImageFilter(int x, int y, int width, int height) {
	this.x = x;
	this.y = y;
	this.width = width;
	this.height = height;
    }

    /**
     * An <code>ImageProducer</code> indicates the size of the image
     * being produced using this method.  This filter overrides this
     * method in order to set the dimentions to the size of the
     * cropped rectangle instead of the size of the image.
     * 
     * @param width the width of the image
     * @param height the height of the image 
     */
    public void setDimensions(int width, int height)
    {
	consumer.setDimensions(this.width, this.height);
    }

    /**
     * An <code>ImageProducer</code> can set a list of properties
     * associated with this image by using this method.
     * <br>
     * FIXME - What property is set for this class?
     *
     * @param props the list of properties associated with this image 
     */
    public void setProperties(Hashtable props)
    {
  	props.put("filters", "CropImageFilter");
	consumer.setProperties(props);
    }

    /**
     * This function delivers a rectangle of pixels where any
     * pixel(m,n) is stored in the array as a <code>byte</code> at
     * index (n * scansize + m + offset).  
     *
     * @param x the x coordinate of the rectangle
     * @param y the y coordinate of the rectangle
     * @param w the width of the rectangle
     * @param h the height of the rectangle
     * @param model the <code>ColorModel</code> used to translate the pixels
     * @param pixels the array of pixel values
     * @param offset the index of the first pixels in the <code>pixels</code> array
     * @param scansize the width to use in extracting pixels from the <code>pixels</code> array
     */
    public void setPixels(int x, int y, int w, int h, 
	   ColorModel model, byte[] pixels, int offset, int scansize)
    {
	Rectangle filterBounds = new Rectangle(this.x, this.y,
	                                       this.width, this.height);
	Rectangle pixelBounds = new Rectangle(x, y, w, h);

	if (filterBounds.intersects(pixelBounds))
	{
	    Rectangle bounds = filterBounds.intersection(pixelBounds);

	    byte[] cropped = new byte[bounds.width * bounds.height];
	    for (int i = 0; i < bounds.height; i++)
	    {
		int start = (bounds.y - pixelBounds.y + i) * scansize + offset;

		for (int j = 0; j < bounds.width; j++)
		    cropped[i * bounds.width + j] = pixels[start + bounds.x + j];
	    }
	    
	    consumer.setPixels(bounds.x, bounds.y,
	                       bounds.width, bounds.height,
	                       model, cropped, 0, bounds.width);
	}
    }

    /**
     * This function delivers a rectangle of pixels where any
     * pixel(m,n) is stored in the array as an <code>int</code> at
     * index (n * scansize + m + offset).  
     *
     * @param x the x coordinate of the rectangle
     * @param y the y coordinate of the rectangle
     * @param w the width of the rectangle
     * @param h the height of the rectangle
     * @param model the <code>ColorModel</code> used to translate the pixels
     * @param pixels the array of pixel values
     * @param offset the index of the first pixels in the <code>pixels</code> array
     * @param scansize the width to use in extracting pixels from the <code>pixels</code> array
     */
    public void setPixels(int x, int y, int w, int h, 
           ColorModel model, int[] pixels, int offset, int scansize)
    {
	Rectangle filterBounds = new Rectangle(this.x, this.y,
	                                       this.width, this.height);
	Rectangle pixelBounds = new Rectangle(x, y, w, h);

	if (filterBounds.intersects(pixelBounds))
	{
	    Rectangle bounds = filterBounds.intersection(pixelBounds);

	    int[] cropped = new int[bounds.width * bounds.height];
	    for (int i = 0; i < bounds.height; i++)
	    {
		int start = (bounds.y - pixelBounds.y + i) * scansize + offset;

		for (int j = 0; j < bounds.width; j++)
		    cropped[i * bounds.width + j] = pixels[start + bounds.x + j];
	    }
	    
	    consumer.setPixels(bounds.x, bounds.y,
	                       bounds.width, bounds.height,
	                       model, cropped, 0, bounds.width);
	}
    }

}