void AGain::subProcess( int bufferOffset, int sampleFrames )
{
    // get parameter value.
    float val = voltVal;

    // get pointers to in/output buffers.
    float* input1   = bufferOffset + X.getBuffer();
    float* input2   = bufferOffset + Y.getBuffer();
    float* output1  = bufferOffset + result.getBuffer();

    float threshLow, threshHi = 0;
    while( --sampleFrames >= 0 )
    {
        threshLow = *input1 - threshold;
        threshHi = *input1 + threshold;

        if((*input2 >= threshLow) && (*input2 <= threshHi))
        {
            *output1 = val;
        }
    }
}