Sampler.nxc

Go to the documentation of this file.

/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 4; tab-width: 4 -*- */
/*
    Sampler.nxc
    Copyright (C) 2008 Naba Kumar   <naba@gnome.org>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/
#ifndef __SAMPLER_H_
#define __SAMPLER_H_

struct SamplerContext
{
    int lastPosition;
    int samplingPeriod;
    int lastOutput;
    int lastInput;
    bool hasMore;
};

void
SamplerInit (SamplerContext &context, int currentPosition, int samplingPeriod)
{
    context.lastPosition = currentPosition;
    context.samplingPeriod = samplingPeriod;
    context.lastOutput = -1;
    context.lastInput = -1;
    context.hasMore = false;
}

int
SamplerGet (SamplerContext &context, int currentPosition, int sampleInput)
{
    /* If current sampling period hasn't arrived, return no sample */
    if (currentPosition < context.lastPosition + context.samplingPeriod)
        return -1;

    context.lastPosition += context.samplingPeriod;
    context.lastOutput = sampleInput;
    context.lastInput = sampleInput;

    if (currentPosition < context.lastPosition + context.samplingPeriod)
        context.hasMore = true;
    else
        context.hasMore = false;
    return sampleInput;
}

#endif