sintonia/library/ecasound-2.7.2/libecasound/osc-sine.cpp

92 lines
2.5 KiB
C++

// ------------------------------------------------------------------------
// osc-sine.cpp: Sine oscillator
// Copyright (C) 1999,2001,2008 Kai Vehmanen
//
// Attributes:
// eca-style-version: 3 (see Ecasound Programmer's Guide)
//
// This program is fre 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
// ------------------------------------------------------------------------
#include <cmath>
#include <kvu_numtostr.h>
#include <kvu_message_item.h>
#include "oscillator.h"
#include "osc-sine.h"
#include "eca-logger.h"
CONTROLLER_SOURCE::parameter_t SINE_OSCILLATOR::value(double pos_secs)
{
parameter_t retval, phase;
phase = 2.0 * M_PI * (pos_secs / period_len_rep);
retval = sin(phase + phase_offset());
/* note: scale return value to proper [0,1] range */
retval += 1.0;
retval /= 2.0;
return retval;
}
SINE_OSCILLATOR::SINE_OSCILLATOR (double freq, double initial_phase) :
OSCILLATOR(freq, initial_phase)
{
set_parameter(1, get_parameter(1));
set_parameter(2, get_parameter(2));
}
void SINE_OSCILLATOR::init(void)
{
MESSAGE_ITEM otemp;
otemp << "Sine oscillator created; frequency ";
otemp.setprecision(3);
otemp << frequency();
otemp << " and initial phase of ";
otemp << phase_offset() << ".";
ECA_LOG_MSG(ECA_LOGGER::user_objects, otemp.to_string());
}
void SINE_OSCILLATOR::set_parameter(int param, CONTROLLER_SOURCE::parameter_t v)
{
switch (param) {
case 1:
frequency(v);
/* note: cache length of one period in seconds */
if (v > 0)
period_len_rep = 1.0 / frequency();
else
period_len_rep = 0;
break;
case 2:
phase_offset(static_cast<double>(v * M_PI));
break;
}
}
CONTROLLER_SOURCE::parameter_t SINE_OSCILLATOR::get_parameter(int param) const
{
switch (param) {
case 1:
return frequency();
case 2:
return phase_offset() / M_PI;
}
return(0.0);
}