samer@0: /*
samer@0:  *	Copyright (c) 2000, Samer Abdallah, King's College London.
samer@0:  *	All rights reserved.
samer@0:  *
samer@0:  *	This software is provided AS iS and WITHOUT ANY WARRANTY; 
samer@0:  *	without even the implied warranty of MERCHANTABILITY or 
samer@0:  *	FITNESS FOR A PARTICULAR PURPOSE.
samer@0:  */
samer@0: 
samer@0: package samer.tools;
samer@0: import java.awt.Color;
samer@0: import java.awt.image.ColorModel;
samer@0: import java.awt.image.IndexColorModel;
samer@0: 
samer@0: /**
samer@0: 	Objects of these class could be used directly,
samer@0: 	but main purpose is to help construct an IndexColorModel
samer@0: 	for an image
samer@0:  */
samer@0: 
samer@0: public class ColorRamp implements java.io.Serializable
samer@0: {
samer@0: 	private byte	r[], g[], b[], a[];
samer@0: 	private int	size;
samer@0: 	private	int	lasti;
samer@0: 	private Color	lastc;
samer@0: 
samer@0: 
samer@0: 	public ColorRamp(int sz) 
samer@0: 	{ 
samer@0: 		size=sz;
samer@0: 		r=new byte[size]; 
samer@0: 		g=new byte[size]; 
samer@0: 		b=new byte[size]; 
samer@0: 		a=new byte[size]; 
samer@0: 	}
samer@0: 
samer@0: 	public Color getColor(int i) { 
samer@0: 		int ir = ((int)r[i] & 0xff);
samer@0: 		int ig = ((int)g[i] & 0xff);
samer@0: 		int ib = ((int)b[i] & 0xff);
samer@0: 		return new Color(ir,ig,ib); 
samer@0: 	}
samer@0: 
samer@0: 	public Color[] getColorArray() {
samer@0: 		Color[]	clut=new Color[size];
samer@0: 		for (int i=0; i<size; i++) clut[i]=getColor(i);
samer@0: 		return clut;
samer@0: 	}
samer@0: 	
samer@0: 	public int   getSize() { return size; }
samer@0: 	public IndexColorModel getColorModel() { 
samer@0: 		return new IndexColorModel(8,size,r,g,b); 
samer@0: 	}
samer@0: 
samer@0: 	public void set( int i, Color c) { set(i,c,1); }
samer@0: 	public void set( int i, Color c, double alpha)
samer@0: 	{ 
samer@0: 		r[i]=(byte)c.getRed();
samer@0: 		g[i]=(byte)c.getGreen();
samer@0: 		b[i]=(byte)c.getBlue();
samer@0: 		a[i]=clip(256.0*alpha);
samer@0: 		lasti=i; lastc=c;
samer@0: 	}
samer@0: 
samer@0: 	public void gradientTo( int i, Color c) { 
samer@0: 		gradient(lasti,lastc,1.0,i,c,1.0);
samer@0: 	}
samer@0: 
samer@0: 	public void gradient( Color c1, Color c2) { 
samer@0: 		gradient(0,c1,1.0,size-1,c2,1.0);
samer@0: 	}
samer@0: 
samer@0: 	public void gradient( Color c1, double a1, Color c2, double a2) { 
samer@0: 		gradient(0,c1,a1,size-1,c2,a2); 
samer@0: 	}
samer@0: 
samer@0: 	public void gradient( int i1, Color c1, int i2, Color c2) { 
samer@0: 		gradient(i1,c1,1,i2,c2,1); 
samer@0: 	}
samer@0: 
samer@0: 	public void gradient( int i1, Color c1, double a1, int i2, Color c2, double a2)
samer@0: 	{
samer@0: 		double	_a, _r, _g, _b;
samer@0: 		double	da, dr, dg, db;
samer@0: 		double	di;
samer@0: 		int		i;
samer@0: 
samer@0: 		di = i2-i1-1;
samer@0: 
samer@0: 		_a = 256*a1; 			da = (256*a2-_a)/di;    
samer@0: 		_r = c1.getRed(); 		dr = (c2.getRed()-_r)/di;    
samer@0: 		_g = c1.getGreen(); 	dg = (c2.getGreen()-_g)/di;
samer@0: 		_b = c1.getBlue(); 		db = (c2.getBlue()-_b)/di;  
samer@0: 
samer@0: 		for (i=i1; i<=i2; i++) {
samer@0: 			a[i] = clip(_a);
samer@0: 			r[i] = clip(_r);
samer@0: 			g[i] = clip(_g);
samer@0: 			b[i] = clip(_b);
samer@0: 			_a+=da; _r+=dr; _g+=dg; _b+=db;
samer@0: 		}
samer@0: 
samer@0: 		lasti=i2; lastc=c2;
samer@0: 	}
samer@0: 
samer@0: 	private static byte clip(double t)
samer@0: 	{
samer@0: 		if (t<0) return 0;
samer@0: 		else if (t>=256.0) return (byte)255;
samer@0: 		else return (byte)t;
samer@0: 	}
samer@0: }
samer@0: