sintonia/ecasound-2.7.2/libecasound/two-stage-linear-envelope.cpp

100 lines
2.7 KiB
C++

// ------------------------------------------------------------------------
// two-stage-linear-envelope.cpp: Two-stage linear envelope
// Copyright (C) 2000-2002,2005,2008 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 <kvu_dbc.h>
#include <kvu_numtostr.h>
#include <kvu_message_item.h>
#include "two-stage-linear-envelope.h"
#include "eca-logger.h"
CONTROLLER_SOURCE::parameter_t TWO_STAGE_LINEAR_ENVELOPE::value(double pos_secs)
{
parameter_t stages_len =
first_stage_length_rep +
second_stage_length_rep;
parameter_t retval;
/* note: position may go beyond stages_len_rep */
/* phase: hold start value */
if (pos_secs < first_stage_length_rep) {
retval = 0.0f;
}
/* phase: linear fade */
else if (pos_secs < stages_len) {
DBC_CHECK(second_stage_length_rep > 0);
retval = ((pos_secs - first_stage_length_rep) /
second_stage_length_rep);
}
/* phase: hold end value */
else
retval = 1.0;
return retval;
}
TWO_STAGE_LINEAR_ENVELOPE::TWO_STAGE_LINEAR_ENVELOPE(void)
{
first_stage_length_rep = 0;
second_stage_length_rep = 0;
}
void TWO_STAGE_LINEAR_ENVELOPE::init(void)
{
MESSAGE_ITEM otemp;
otemp << "Two-stage envelope initialized: ";
otemp.setprecision(3);
otemp << "1. initial hold " << get_parameter(1)
<< "secs, 2. linear ramp len " << get_parameter(2)
<< "secs.";
ECA_LOG_MSG(ECA_LOGGER::user_objects, otemp.to_string());
}
void TWO_STAGE_LINEAR_ENVELOPE::set_parameter(int param, CONTROLLER_SOURCE::parameter_t value)
{
switch (param) {
case 1:
{
first_stage_length_rep = value;
break;
}
case 2:
{
second_stage_length_rep = value;
break;
}
}
}
CONTROLLER_SOURCE::parameter_t TWO_STAGE_LINEAR_ENVELOPE::get_parameter(int param) const
{
switch (param) {
case 1:
return first_stage_length_rep;
case 2:
return second_stage_length_rep;
}
return 0.0;
}