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/*
* Copyright (C) 2016 Robin Gareus <robin@gareus.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, 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 _ardour_surfaces_m2encoder_h_
#define _ardour_surfaces_m2encoder_h_
#include <stdint.h>
#include "pbd/signals.h"
namespace ArdourSurface {
class M2EncoderInterface
{
public:
M2EncoderInterface () {}
virtual ~M2EncoderInterface () {}
/* user API */
PBD::Signal1<void, int> changed;
virtual float value () const { return 0.f; }
virtual float range () const { return 0.f; }
/* internal API - called from device thread */
virtual bool set_value (unsigned int v) { return false; }
};
class M2Encoder : public M2EncoderInterface
{
public:
M2Encoder (unsigned int upper = 1000)
: M2EncoderInterface ()
, _upper (upper /* limit, exclusive. eg [0..15]: 16 */)
, _value (0)
, _initialized (false)
{
assert (_upper > 7);
_wrapcnt = std::max (3U, upper / 6);
}
float value () const { return _value / (_upper - 1.f); }
float range () const { return (_upper - 1.f); }
bool set_value (unsigned int v) {
if (!_initialized) {
_initialized = true;
_value = v;
return false;
}
if (v == _value) {
return false;
}
int delta;
if (v < _wrapcnt && _value > _upper - _wrapcnt) {
// wrap around max -> min
delta = v + _upper - _value;
}
else if (_value < _wrapcnt && v > _upper - _wrapcnt) {
// wrap around min -> max
delta = v - _upper - _value;
}
else {
delta = v - _value;
}
_value = v;
changed (delta);
return true;
}
protected:
unsigned int _upper;
unsigned int _value;
unsigned int _wrapcnt;
bool _initialized;
};
} /* namespace */
#endif /* _ardour_surfaces_m2encoder_h_ */
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