Files
MapLibreParticleLab/src/mbgl/util/transition.hpp
2016-05-25 21:35:37 +02:00

76 lines
1.6 KiB
C++

#pragma once
#include <mbgl/util/noncopyable.hpp>
#include <mbgl/util/chrono.hpp>
namespace mbgl {
namespace util {
class transition : private noncopyable {
public:
enum state {
running,
complete
};
inline transition(const TimePoint& start_, const Duration& duration_)
: start(start_),
duration(duration_) {}
inline float progress(const TimePoint& now) const {
if (duration == Duration::zero()) return 1;
if (start > now) return 0;
return std::chrono::duration<float>(now - start) / duration;
}
virtual state update(const TimePoint& now) const = 0;
virtual ~transition();
protected:
const TimePoint start;
const Duration duration;
};
template <typename T>
class ease_transition : public transition {
public:
ease_transition(T from_, T to_, T& value_, const TimePoint& start_, const Duration& duration_)
: transition(start_, duration_),
from(from_),
to(to_),
value(value_) {}
state update(const TimePoint& now) const;
private:
const T from, to;
T& value;
};
template <typename T>
class timeout : public transition {
public:
timeout(T final_value_, T& value_, const TimePoint& start_, const Duration& duration_)
: transition(start_, duration_),
final_value(final_value_),
value(value_) {}
state update(const TimePoint& now) const {
if (progress(now) >= 1) {
value = final_value;
return complete;
} else {
return running;
}
}
private:
const T final_value;
T& value;
};
} // namespace util
} // namespace mbgl