comparison src/samer/tools/ColorRamp.java @ 0:bf79fb79ee13

Initial Mercurial check in.

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