public class LogScaleMapping extends ComplexImageMapping
{
    public float hi,lo;
    public boolean reset;
    
    public void sample(Complex a)
    {
        float m = (float)Math.log(a.getMag());
        if (reset)
        {
            hi = m;
            lo = m;
            reset = false;
        } else
        {
            if (m>hi) hi = m; else if (m<lo) lo = m;
        }        
        if (lo<-8) lo = -8;
    }
    public int perform(Complex a)
    {
        // map hi -> lo onto 255 -> 0
        int m = (int)(255*(Math.log(a.getMag())-lo)/(hi-lo));
        if (m<0) m=0;
        if (m>255) m=255;
        return( (255 << 24) | (m<<16) | (m<<8) | m );                       
    }
    public boolean needsPreRun()
    {
        return true;
    }
    public void initialise()
    {
        reset = true;
    }
    public void complete()
    {
        System.out.println("ScaledMapping : hi,lo = "+hi+" "+lo);
    }
}