SF_Convolve.java

/* For Copyright and License see LICENSE.txt and COPYING.txt in the root directory */
package com.nerdscentral.audio.combine;

import java.util.List;

import com.nerdscentral.audio.core.SFSignal;
import com.nerdscentral.sython.Caster;
import com.nerdscentral.sython.SFPL_Operator;
import com.nerdscentral.sython.SFPL_RuntimeException;

public class SF_Convolve implements SFPL_Operator
{
    private static final long serialVersionUID = 1L;

    @Override
    public String Word()
    {
        return Messages.getString("SF_Convolve.0");  //$NON-NLS-1$
    }

    @Override
    public Object Interpret(Object input) throws SFPL_RuntimeException
    {
        List<Object> inList = Caster.makeBunch(input);
        SFSignal sample = Caster.makeSFSignal(inList.get(0));
        SFSignal shape = Caster.makeSFSignal(inList.get(1));
        SFSignal ret = sample.replicateEmpty();

        int ll = sample.getLength();
        int ls = shape.getLength();
        int center = shape.getLength() / 2;
        for (int x = 0; x < ll; ++x)
        {
            double r = 0;
            Thread.yield();
            for (int y = 0; y < ls; ++y)
            {
                double d = shape.getSample(ls - y);
                if (d == 0) continue;
                int pos = x - center + y;
                double q = 0;
                if (pos < 0)
                {
                    q = sample.getSample(pos + ls);
                }
                else if (pos >= ll)
                {
                    q = sample.getSample(pos - ls);
                }
                else
                {
                    q = sample.getSample(pos);
                }
                r = (r + q * d);
            }
            ret.setSample(x, r);
        }
        return ret;
    }
}