Animation: added Player::elapsed().

It's not working exactly as it should yet, but the proper update
wouldn't apply so cleanly, so doing that in the next commit.

src/Magnum/Animation/Player.h

@@ -287,6 +287,7 @@ template<class T, class K
          * If the duration was not set explicitly using @ref setDuration(),
          * returns value calculated implicitly from all added tracks. If no
          * tracks are added, returns default-constructed value.
+         * @see @ref elapsed()
          */
         Math::Range1D<K> duration() const { return _duration; }
 
@@ -593,6 +594,24 @@ template<class T, class K
          */
         State state() const { return _state; }
 
+        /**
+         * @brief Elapsed animation iteration and keyframe
+         *
+         * Returns repeat iteration index and elapsed animation keyframe in
+         * given iteration corresponding to @p time. If @ref state() is
+         * @ref State::Stopped and the player was stopped explicitly, the
+         * function returns a default-constructed value (usually
+         * @cpp {0, 0.0f} @ce). If @ref state() is @ref State::Stopped due to
+         * the animation running out, the function returns the iteration count
+         * and duration end keyframe. If @ref state() is @ref State::Paused,
+         * the function returns a time at which the animation was paused.
+         *
+         * Unlike @ref advance(), this function doesn't modify the animation
+         * state in any way, it's merely a query.
+         * @see @ref duration()
+         */
+        std::pair<UnsignedInt, K> elapsed(T time) const;
+
         /**
          * @brief Play
          *
@@ -677,6 +696,7 @@ template<class T, class K
          * to the begin time of @ref duration() to correctly "park" the
          * animation back to its initial state. After that, no more updates are
          * done until the animation is started again.
+         * @see @ref elapsed()
          */
         Player<T, K>& advance(T time);
 
@@ -685,6 +705,8 @@ template<class T, class K
 
         Player<T, K>& addInternal(const TrackViewStorage<K>& track, void (*advancer)(const TrackViewStorage<K>&, K, std::size_t&, void*, void(*)(), void*), void* destination, void(*userCallback)(), void* userCallbackData);
 
+        Containers::Optional<std::pair<UnsignedInt, K>> elapsedInternal(T time, T& updatedStartTime, T& updatedPauseTime, State& updatedState) const;
+
         std::vector<Track> _tracks;
         Math::Range1D<K> _duration;
         UnsignedInt _playCount{1};

src/Magnum/Animation/Player.hpp

@@ -31,6 +31,8 @@
 
 #include "Player.h"
 
+#include <Corrade/Containers/Optional.h>
+
 namespace Magnum { namespace Animation {
 
 namespace Implementation {
@@ -140,7 +142,9 @@ template<class T, class K> Player<T, K>& Player<T, K>::setState(State state, T t
     CORRADE_ASSERT_UNREACHABLE(); /* LCOV_EXCL_LINE */
 }
 
-template<class T, class K> Player<T, K>& Player<T, K>::advance(T time) {
+namespace Implementation {
+
+template<class T, class K> Containers::Optional<std::pair<UnsignedInt, K>> playerElapsed(const K duration, const UnsignedInt playCount, const typename Player<T, K>::Scaler scaler, const T time, T& startTime, T& pauseTime, State& state) {
     /* Time to use for advancing the animation */
     T timeToUse = time;
 
@@ -150,49 +154,81 @@ template<class T, class K> Player<T, K>& Player<T, K>::advance(T time) {
 
        std::chrono::duration doesn't have operator bool, so I need to compare
        to default-constructed value. Ugh. */
-    if(_state == State::Paused && (_pauseTime != T{})) {
-        timeToUse = _pauseTime;
-        _startTime = _pauseTime - _startTime;
-        _pauseTime = {};
+    if(state == State::Paused && (pauseTime != T{})) {
+        timeToUse = pauseTime;
+        startTime = pauseTime - startTime;
+        pauseTime = {};
 
     /* The animation was stopped by the user right before this iteration,
        "park" the animation to the initial time */
-    } else if(_state == State::Stopped && (_startTime != T{})) {
-        _startTime = {};
+    } else if(state == State::Stopped && (startTime != T{})) {
+        startTime = {};
         timeToUse = {};
 
     /* Otherwise, if the player is not playing or scheduled to start playing in
        the future, do nothing */
-    } else if(_state != State::Playing || time < _startTime) return *this;
+    } else if(state != State::Playing || time < startTime)
+        return Containers::NullOpt;
 
     /* If the player duration is empty, we can't call the scaler. If play count
        is infinite, infinitely advance to a key at duration start. If not, stop
        the animation. */
+    UnsignedInt playIteration;
     K key;
-    const K duration = _duration.size()[0];
     if(duration == K{}) {
         key = K{};
-        if(_playCount != 0) {
-            _state = State::Stopped;
-            _startTime = {};
+        playIteration = 0;
+        if(playCount != 0) {
+            state = State::Stopped;
+            startTime = {};
         }
 
     /* Otherwise calculate current play iteration and key value in that
        iteration. If we exceeded play count, stop the animation and give out
        value at duration end. */
     } else {
-        UnsignedInt playCount;
-        std::tie(playCount, key) = _scaler(timeToUse - _startTime, duration);
-        if(_playCount && playCount >= _playCount) {
-            _state = State::Stopped;
-            _startTime = {};
+        std::tie(playIteration, key) = scaler(timeToUse - startTime, duration);
+        if(playCount && playIteration >= playCount) {
+            state = State::Stopped;
+            startTime = {}; /** @todo no? so we can distinguish between stopped by itself and not */
+            playIteration = playCount - 1;
             key = duration;
         }
     }
 
+    return {Containers::InPlaceInit, playIteration, key};
+}
+
+}
+
+template<class T, class K> std::pair<UnsignedInt, K> Player<T, K>::elapsed(const T time) const {
+    /* Get the elapsed time. This is an immutable query, so make copies of the
+       (otherwise to be modified) internal state. */
+    T startTime = _startTime;
+    T pauseTime = _pauseTime;
+    State state = _state;
+    const Containers::Optional<std::pair<UnsignedInt, K>> elapsed = Implementation::playerElapsed(_duration.size()[0], _playCount, _scaler, time, startTime, pauseTime, state);
+    if(elapsed) return *elapsed;
+
+    /* If not advancing, the animation can be paused: calculate the keyframe at
+       which it was paused */
+    if(state == State::Paused) return _scaler(_startTime, _duration.size()[0]);
+
+    /** @todo stopped by itself vs. explicitly */
+
+    /* Otherwise the animation is just stopped: return a zero value */
+    return {0, K{}};
+}
+
+template<class T, class K> Player<T, K>& Player<T, K>::advance(const T time) {
+    /* Get the elapsed time. If we shouldn't advance anything (player already
+       stopped / not yet playing, quit */
+    Containers::Optional<std::pair<UnsignedInt, K>> elapsed = Implementation::playerElapsed(_duration.size()[0], _playCount, _scaler, time, _startTime, _pauseTime, _state);
+    if(!elapsed) return *this;
+
     /* Advance all tracks. Properly handle durations that don't start at 0. */
     for(Track& t: _tracks)
-        t.advancer(t.track, _duration.min()[0] + key, t.hint, t.destination, t.userCallback, t.userCallbackData);
+        t.advancer(t.track, _duration.min()[0] + elapsed->second, t.hint, t.destination, t.userCallback, t.userCallbackData);
 
     return *this;
 }

src/Magnum/Animation/Test/PlayerTest.cpp

@@ -295,11 +295,17 @@ void PlayerTest::advanceNotRunning() {
     player.add(Track, value);
 
     CORRADE_COMPARE(player.state(), State::Stopped);
+    CORRADE_COMPARE(player.elapsed(0.0f), std::make_pair(0, 0.0f));
+    CORRADE_COMPARE(value, -1.0f);
+
+    /* Asking for elapsed doesn't change anything */
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     player.advance(1.75f);
 
     CORRADE_COMPARE(player.state(), State::Stopped);
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 }
 
@@ -311,32 +317,58 @@ void PlayerTest::advancePlaying() {
 
     CORRADE_COMPARE(player.duration().size(), 3.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(0.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Still before starting time, nothing is done */
     player.advance(1.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
+    CORRADE_COMPARE(value, -1.0f);
+
+    /* Asking for elapsed will say it's playing already, but doesn't change
+       anything */
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* 1.75 secs in */
     player.advance(3.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 
     /* 2.67 secs in */
-    player.advance(4.6666667f);
+    player.advance(4.666666667f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    /** @todo make std::pair/std::tuple comparisons respect fuzzyness inside */
+    CORRADE_COMPARE(player.elapsed(4.666666667f).first, 0);
+    CORRADE_COMPARE(player.elapsed(4.666666667f).second, 2.666666667f);
     CORRADE_COMPARE(value, 3.0f);
 
-    /* When the player gets stopped, the value at the stop time is written */
+    /* Asking for elapsed will say the stop time, but again doesn't change the
+       state */
+    CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(5.5f), std::make_pair(0, 3.0f));
+    CORRADE_COMPARE(value, 3.0f);
+
+    /* When the player gets stopped, the value at the stop time is written.
+       Elapsed time still shows that it stopped by itself. */
     player.advance(5.5f);
     CORRADE_COMPARE(player.state(), State::Stopped);
+    {
+        CORRADE_EXPECT_FAIL("Not yet implemented.");
+        CORRADE_COMPARE(player.elapsed(5.5f), std::make_pair(0, 3.0f));
+    }
     CORRADE_COMPARE(value, 2.0f);
 
     /* But further advancing will not write anything */
     value = -1.0f;
     player.advance(100.0f);
     CORRADE_COMPARE(player.state(), State::Stopped);
+    {
+        CORRADE_EXPECT_FAIL("Not yet implemented.");
+        CORRADE_COMPARE(player.elapsed(100.0f), std::make_pair(0, 3.0f));
+    }
     CORRADE_COMPARE(value, -1.0f);
 }
 
@@ -347,27 +379,32 @@ void PlayerTest::advanceRestart() {
         .play(2.0f);
 
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(0.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Still before starting time, nothing is done */
     player.advance(1.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* 1.75 secs in */
     player.advance(3.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 
     /* Call play again, will restart from the beginning... */
     value = -1.0f;
     player.play(4.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(4.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* ... but only after calling advance() again. Now at 1 sec in. */
     player.advance(5.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(5.0f), std::make_pair(0, 1.0f));
     CORRADE_COMPARE(value, 2.5f);
 }
 
@@ -379,23 +416,29 @@ void PlayerTest::advanceStop() {
 
     player.advance(3.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 
-    /* Stop, should not update anything */
+    /* Stop, should not update anything. Elapsed will report a time from the
+       beginning again. */
     value = -1.0;
     player.stop();
     CORRADE_COMPARE(player.state(), State::Stopped);
+    CORRADE_COMPARE(player.elapsed(5.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
-    /* Advancing will update with a value from beginning of the duration */
+    /* Advancing will update with a value from beginning of the duration.
+       Elapsed shows the same. */
     player.advance(5.0f);
     CORRADE_COMPARE(player.state(), State::Stopped);
+    CORRADE_COMPARE(player.elapsed(5.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, 1.5f);
 
     /* But further advancing will not write anything */
     value = -1.0f;
     player.advance(100.0f);
     CORRADE_COMPARE(player.state(), State::Stopped);
+    CORRADE_COMPARE(player.elapsed(100.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 }
 
@@ -406,43 +449,52 @@ void PlayerTest::advancePauseResume() {
         .play(2.0f);
 
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, -1.0f);
 
     player.advance(3.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 
     /* Pausing should not update anything */
     value = -1.0f;
     player.pause(4.0f);
     CORRADE_COMPARE(player.state(), State::Paused);
+    CORRADE_COMPARE(player.elapsed(4.0f), std::make_pair(0, 2.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Pausing again should be a no-op */
     player.pause(4.1f);
     CORRADE_COMPARE(player.state(), State::Paused);
+    CORRADE_COMPARE(player.elapsed(4.1f), std::make_pair(0, 2.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* But advance() after should. No matter what time is passed to it, it
        should update with time of pause. */
     player.advance(4.5f);
     CORRADE_COMPARE(player.state(), State::Paused);
+    CORRADE_COMPARE(player.elapsed(4.5f), std::make_pair(0, 2.0f));
     CORRADE_COMPARE(value, 5.0f); /* value at 2.0f, not 2.5f */
 
     /* Advancing further should do nothing */
     value = -1.0f;
     player.advance(50.0f);
     CORRADE_COMPARE(player.state(), State::Paused);
+    CORRADE_COMPARE(player.elapsed(50.0f), std::make_pair(0, 2.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Resuming the animation, again should not update anything */
     player.play(100.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(100.0f), std::make_pair(0, 2.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Advancing the animation should update again. It was paused after two
        seconds, so continuing at 2.5 seconds now. */
     player.advance(100.5f);
+    CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(100.5f), std::make_pair(0, 2.5f));
     CORRADE_COMPARE(value, 3.5f);
 }
 
@@ -454,35 +506,41 @@ void PlayerTest::advancePauseStop() {
 
     player.advance(3.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 
     /* Pause, get value from the pause time */
     player.pause(4.0f);
     player.advance(4.5f);
     CORRADE_COMPARE(player.state(), State::Paused);
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 2.0f));
     CORRADE_COMPARE(value, 5.0f);
 
     /* Stop, should not update anything */
     value = -1.0;
     player.stop();
     CORRADE_COMPARE(player.state(), State::Stopped);
+    CORRADE_COMPARE(player.elapsed(5.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Advancing will update with a value from beginning of the duration */
     player.advance(5.0f);
     CORRADE_COMPARE(player.state(), State::Stopped);
+    CORRADE_COMPARE(player.elapsed(5.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, 1.5f);
 
     /* But further advancing will not write anything */
     value = -1.0f;
     player.advance(100.0f);
     CORRADE_COMPARE(player.state(), State::Stopped);
+    CORRADE_COMPARE(player.elapsed(100.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Pause while stopped is a no-op */
     player.pause(101.0f);
     player.advance(101.0f);
     CORRADE_COMPARE(player.state(), State::Stopped);
+    CORRADE_COMPARE(player.elapsed(101.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 }
 
@@ -494,37 +552,50 @@ void PlayerTest::advancePlayCount() {
         .play(2.0f);
 
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Still before starting time, nothing is done */
     player.advance(1.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* 1.75 secs in */
     player.advance(3.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 
     /* 2 secs in, second round */
     player.advance(7.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(7.0f), std::make_pair(1, 2.0f));
     CORRADE_COMPARE(value, 5.0f);
 
     /* 1.75 secs in, third round */
     player.advance(9.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(9.75f), std::make_pair(2, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 
     /* When the player gets stopped, the value at the stop time is written */
     player.advance(11.5f);
     CORRADE_COMPARE(player.state(), State::Stopped);
+    {
+        CORRADE_EXPECT_FAIL("Not yet implemented.");
+        CORRADE_COMPARE(player.elapsed(11.5f), std::make_pair(2, 3.0f));
+    }
     CORRADE_COMPARE(value, 2.0f);
 
     /* But further advancing will not write anything */
     value = -1.0f;
     player.advance(100.0f);
     CORRADE_COMPARE(player.state(), State::Stopped);
+    {
+        CORRADE_EXPECT_FAIL("Not yet implemented.");
+        CORRADE_COMPARE(player.elapsed(100.0f), std::make_pair(2, 3.0f));
+    }
     CORRADE_COMPARE(value, -1.0f);
 }
 
@@ -536,26 +607,31 @@ void PlayerTest::advancePlayCountInfinite() {
         .play(2.0f);
 
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Still before starting time, nothing is done */
     player.advance(1.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* 1.75 secs in */
     player.advance(3.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(3.75f), std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 
     /* 2 secs in, second round */
     player.advance(7.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(7.0f), std::make_pair(1, 2.0f));
     CORRADE_COMPARE(value, 5.0f);
 
-    /* 1.75 secs in, 10th round */
+    /* 1.75 secs in, 11th round */
     player.advance(33.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(33.75f), std::make_pair(10, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 }
 
@@ -567,16 +643,22 @@ void PlayerTest::advanceChrono() {
 
     CORRADE_COMPARE(player.duration().size(), 3.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(std::chrono::milliseconds{1750}),
+        std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Still before starting time, nothing is done */
     player.advance(std::chrono::milliseconds{1750});
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(std::chrono::milliseconds{1750}),
+        std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* 1.75 secs in */
     player.advance(std::chrono::milliseconds{3750});
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(std::chrono::milliseconds{3750}),
+        std::make_pair(0, 1.75f));
     CORRADE_COMPARE(value, 4.0f);
 }
 
@@ -591,16 +673,19 @@ void PlayerTest::advanceZeroDuration() {
 
     CORRADE_COMPARE(player.duration().size(), 0.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Still before starting time, nothing is done */
     player.advance(1.75f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(1.75f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* After that, the value at 1.75 secs is returned independent of time */
     player.advance(100.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(100.0f), std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, 4.0f);
 }
 
@@ -615,17 +700,23 @@ void PlayerTest::advanceZeroDurationChrono() {
 
     CORRADE_COMPARE(player.duration().size(), 0.0f);
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(std::chrono::milliseconds{1750}),
+        std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* Still before starting time, nothing is done */
     player.advance(std::chrono::milliseconds{1750});
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(std::chrono::milliseconds{1750}),
+        std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, -1.0f);
 
     /* After that, the value at 1.75 seconds is returned independent of the
        time */
     player.advance(std::chrono::seconds{100});
     CORRADE_COMPARE(player.state(), State::Playing);
+    CORRADE_COMPARE(player.elapsed(std::chrono::seconds{100}),
+        std::make_pair(0, 0.0f));
     CORRADE_COMPARE(value, 4.0f);
 }