/*
       Color_Transformation

       written July 1, 2001
       by Frank Wattenberg

       Version 0.00
 */

import java.awt.*;
import java.awt.image.*;
import java.applet.*;
import java.lang.*;
import java.util.*;

public class Color_Transformation extends Applet
{
	Image    bI, picture;
	Graphics bG;
	String   picture_filename;
	int      width, height;
	double   red_constant, red_from_red, red_from_blue, red_from_green;
	double   blue_constant, blue_from_red, blue_from_blue, blue_from_green;
	double   green_constant, green_from_red, green_from_blue, green_from_green;
	int      picture_array[] = new int[1000000];
	PixelGrabber  get_picture;
	
	public void init()
	{
		double     red, green, blue, work;
		double     new_red, new_green, new_blue;
		int        work_red, work_green, work_blue;
		
		red_constant = java.lang.Double.valueOf(
			                   getParameter("red_constant")).doubleValue();
		red_from_red = java.lang.Double.valueOf(
			                   getParameter("red_from_red")).doubleValue();
		red_from_blue = java.lang.Double.valueOf(
			                   getParameter("red_from_blue")).doubleValue();
		red_from_green = java.lang.Double.valueOf(
			                   getParameter("red_from_green")).doubleValue();

		blue_constant = java.lang.Double.valueOf(
			                   getParameter("blue_constant")).doubleValue();
		blue_from_red = java.lang.Double.valueOf(
			                   getParameter("blue_from_red")).doubleValue();
		blue_from_blue = java.lang.Double.valueOf(
			                   getParameter("blue_from_blue")).doubleValue();
		blue_from_green = java.lang.Double.valueOf(
			                   getParameter("blue_from_green")).doubleValue();

		green_constant = java.lang.Double.valueOf(
			                   getParameter("green_constant")).doubleValue();
		green_from_red = java.lang.Double.valueOf(
			                   getParameter("green_from_red")).doubleValue();
		green_from_blue = java.lang.Double.valueOf(
			                   getParameter("green_from_blue")).doubleValue();
		green_from_green = java.lang.Double.valueOf(
			                   getParameter("green_from_green")).doubleValue();
		
		width = Integer.parseInt(getParameter("width"));
		height = Integer.parseInt(getParameter("height"));
		
		bI = createImage(width, height);
		bG = bI.getGraphics();
		
        picture_filename = getParameter("picture_filename");
		picture = getImage(getCodeBase(), picture_filename);
		
		get_picture = new PixelGrabber(picture, 0, 0, width, height,
									picture_array, 0, width);
		try {get_picture.grabPixels();}
		catch(Exception e) {}
		
		for (int i = 0; i < width * height; i = i + 1)
		{
            red   = (0xff & (picture_array[i] >> 16));
			green = (0xff & (picture_array[i] >> 8));
			blue  = (0xff & picture_array[i]);
			
			new_red   = 255 * red_constant + red_from_red * red +
				        red_from_green * green + red_from_blue * blue;
			new_green = 255 * green_constant + green_from_red * red +
				        green_from_green * green + green_from_blue * blue;
			new_blue  = 255 * blue_constant + blue_from_red * red +
				        blue_from_green * green + blue_from_blue * blue;
			
			work = java.lang.Math.max(0, java.lang.Math.min(255, new_red));
			work_red = (int) java.lang.Math.round(work);
			work = java.lang.Math.max(0, java.lang.Math.min(255, new_green));
			work_green = (int) java.lang.Math.round(work);
			work = java.lang.Math.max(0, java.lang.Math.min(255, new_blue));
			work_blue = (int) java.lang.Math.round(work);
			
			picture_array[i] = 0xFF000000 |
				               (work_red << 16) |
				               (work_green << 8) |
			                   work_blue;
		}
		
        bI = createImage(
			 new MemoryImageSource(width, height, picture_array, 0, width));
	}

	public void paint(Graphics g)
	{
        g.drawImage(bI, 0, 0, this);
	}
}