80 lines
2.3 KiB
C++
80 lines
2.3 KiB
C++
/* This file is part of Evoral.
|
|
* Copyright (C) 2009 David Robillard <http://drobilla.net>
|
|
* Copyright (C) 2009 Paul Davis
|
|
*
|
|
* Evoral 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.
|
|
*
|
|
* Evoral 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 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 St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#ifndef EVORAL_TIME_CONVERTER_HPP
|
|
#define EVORAL_TIME_CONVERTER_HPP
|
|
|
|
#include "evoral/visibility.h"
|
|
|
|
namespace Evoral {
|
|
|
|
/** A bidirectional converter between two different time units.
|
|
*
|
|
* Think of the conversion method names as if they are written in-between
|
|
* the two template parameters (i.e. "A <name> B").
|
|
*
|
|
* _origin_b should be the origin for conversion in the units of B.
|
|
* That is, there is some point in time _origin_b, such that:
|
|
*
|
|
* to() converts a time _origin_b + a into an offset from _origin_b in units of B.
|
|
* from() converts a time _origin_b + b into an offset from _origin_b in units of A.
|
|
*/
|
|
template<typename A, typename B>
|
|
class LIBEVORAL_TEMPLATE_API TimeConverter {
|
|
public:
|
|
TimeConverter () : _origin_b (0) {}
|
|
TimeConverter (B ob) : _origin_b (ob) {}
|
|
virtual ~TimeConverter();
|
|
|
|
/** Convert A time to B time (A to B) */
|
|
virtual B to(A a) const = 0;
|
|
|
|
/** Convert B time to A time (A from B) */
|
|
virtual A from(B b) const = 0;
|
|
|
|
B origin_b () const {
|
|
return _origin_b;
|
|
}
|
|
|
|
void set_origin_b (B o) {
|
|
_origin_b = o;
|
|
}
|
|
|
|
protected:
|
|
B _origin_b;
|
|
};
|
|
|
|
|
|
/** A stub TimeConverter that simple statically casts between types.
|
|
* _origin_b has no bearing here, as there is no time conversion
|
|
* going on.
|
|
*/
|
|
template<typename A, typename B>
|
|
class LIBEVORAL_TEMPLATE_API IdentityConverter : public TimeConverter<A,B> {
|
|
public:
|
|
IdentityConverter() {}
|
|
|
|
B to(A a) const;
|
|
A from(B b) const;
|
|
};
|
|
|
|
|
|
} // namespace Evoral
|
|
|
|
#endif // EVORAL_TIME_CONVERTER_HPP
|