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.core.util;
samer@0: 
samer@0: /**
samer@0: 	Integer map:
samer@0: 	This class maps a given interval of real numbers
samer@0: 	to the interval [0,1], returning either the real
samer@0: 	number, or converting it to an integer between 0
samer@0: 	and a given value (defaults to 256). 
samer@0:  */
samer@0: 
samer@0: public class IMap
samer@0: {
samer@0: 	double	a, b;
samer@0: 	double	ia, ib;
samer@0: 	int		maxi;
samer@0: 	double	c;
samer@0: 	boolean  clipped;
samer@0: 
samer@0: 	public IMap copy() { try { return (IMap)this.clone(); } catch (Exception ex) {} return null; }
samer@0: 
samer@0: 	public String toString() { return "["+getDomainMin()+","+getDomainMax()+")->{0.."+(maxi-1)+"}"; }
samer@0: 	public double getDomainMin() { return b/a; }
samer@0: 	public double getDomainMax() { return (1+b)/a; }
samer@0: 	public void setDomain( double t1, double t2)
samer@0: 	{
samer@0: 		a	= 1/(t2-t1);
samer@0: 		b	= a*t1;
samer@0: 		ia  = c*a;
samer@0: 		ib  = c*b;
samer@0: 	}
samer@0: 
samer@0: 	public int	getIntRange() { return maxi+1; }
samer@0: 	public void setIntRange( int m)
samer@0: 	{ 
samer@0: 		maxi= m-1; 
samer@0: 		c   = m;
samer@0: 		ia  = c*a;
samer@0: 		ib  = c*b;
samer@0: 	}
samer@0: 
samer@0: 	public double map( double t) { return a*t-b; }
samer@0: 	public int clipInt( double t)
samer@0: 	{
samer@0: 		double x=ia*t-ib;
samer@0: 		if (x<0)	return 0;
samer@0: 		if (x>=c)	return maxi;
samer@0: 		return (int)x;
samer@0: 	}
samer@0: 
samer@0: 	// sets a flag if clipped
samer@0: 	public int toInt( double t)
samer@0: 	{
samer@0: 		double x=ia*t-ib;
samer@0: 		clipped = (x<0 || x>=c);
samer@0: 		return (int)x;
samer@0: 	}
samer@0: 
samer@0: 	// inverse mapping
samer@0: 	public double inverse(double y) { return (y+b)/a; }
samer@0: 	public double inverseFromInt(int y) { return (y+ib)/ia; }
samer@0: 
samer@0: 	public boolean wasClipped() { return clipped; }
samer@0: 	protected IMap() {}
samer@0: }
samer@0: 
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samer@0: 	
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samer@0: