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