98 lines
2.3 KiB
C++
98 lines
2.3 KiB
C++
/*
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* Copyright (C) 2016 Robin Gareus <robin@gareus.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef _ardour_surfaces_m2encoder_h_
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#define _ardour_surfaces_m2encoder_h_
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#include <stdint.h>
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#include "pbd/signals.h"
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namespace ArdourSurface {
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class M2EncoderInterface
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{
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public:
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M2EncoderInterface () {}
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virtual ~M2EncoderInterface () {}
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/* user API */
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PBD::Signal<void(int)> changed;
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virtual float value () const { return 0.f; }
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virtual float range () const { return 0.f; }
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/* internal API - called from device thread */
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virtual bool set_value (unsigned int v) { return false; }
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};
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class M2Encoder : public M2EncoderInterface
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{
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public:
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M2Encoder (unsigned int upper = 1000)
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: M2EncoderInterface ()
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, _upper (upper /* limit, exclusive. eg [0..15]: 16 */)
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, _value (0)
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, _initialized (false)
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{
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assert (_upper > 7);
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_wrapcnt = std::max (3U, upper / 6);
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}
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float value () const { return _value / (_upper - 1.f); }
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float range () const { return (_upper - 1.f); }
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bool set_value (unsigned int v) {
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if (!_initialized) {
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_initialized = true;
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_value = v;
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return false;
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}
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if (v == _value) {
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return false;
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}
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int delta;
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if (v < _wrapcnt && _value > _upper - _wrapcnt) {
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// wrap around max -> min
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delta = v + _upper - _value;
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}
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else if (_value < _wrapcnt && v > _upper - _wrapcnt) {
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// wrap around min -> max
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delta = v - _upper - _value;
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}
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else {
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delta = v - _value;
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}
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_value = v;
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changed (delta);
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return true;
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}
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protected:
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unsigned int _upper;
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unsigned int _value;
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unsigned int _wrapcnt;
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bool _initialized;
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};
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} /* namespace */
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#endif /* _ardour_surfaces_m2encoder_h_ */
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