Better animation of pauses in speech

src/Shape.h

@@ -29,3 +29,7 @@ protected:
 std::ostream& operator<<(std::ostream& stream, Shape value);
 
 std::istream& operator>>(std::istream& stream, Shape& value);
+
+inline bool isClosed(Shape shape) {
+	return shape == Shape::A || shape == Shape::X;
+}

src/mouthAnimation.cpp

@@ -164,6 +164,36 @@ Timeline<Shape> createTweens(ContinuousTimeline<Shape> shapes) {
 	return tweens;
 }
 
+Timeline<Shape> animatePauses(const ContinuousTimeline<Shape>& shapes) {
+	Timeline<Shape> result;
+
+	// Don't close mouth for short pauses
+	for (const auto& timedShape : shapes) {
+		if (timedShape.getValue() != X) continue;
+
+		const centiseconds maxPausedOpenMouthDuration = 35cs;
+		const TimeRange timeRange = timedShape.getTimeRange();
+		if (timeRange.getLength() <= maxPausedOpenMouthDuration) {
+			result.set(timeRange, B);
+		}
+	}
+
+	// Keep mouth open into pause if it just opened
+	for_each_adjacent(shapes.begin(), shapes.end(), [&](const Timed<Shape>& secondLast, const Timed<Shape>& last, const Timed<Shape>& pause) {
+		if (pause.getValue() != X) return;
+
+		centiseconds lastLength = last.getTimeRange().getLength();
+		const centiseconds minOpenDuration = 20cs;
+		if (isClosed(secondLast.getValue()) && !isClosed(last.getValue()) && lastLength < minOpenDuration) {
+			const centiseconds minSpillDuration = 20cs;
+			centiseconds spillDuration = std::min(minSpillDuration, pause.getTimeRange().getLength());
+			result.set(pause.getStart(), pause.getStart() + spillDuration, B);
+		}
+	});
+
+	return result;
+}
+
 ContinuousTimeline<Shape> animate(const BoundedTimeline<Phone> &phones) {
 	// Convert phones to continuous timeline so that silences aren't skipped when iterating
 	ContinuousTimeline<optional<Phone>> continuousPhones(phones.getRange(), boost::none);
@@ -204,6 +234,12 @@ ContinuousTimeline<Shape> animate(const BoundedTimeline<Phone> &phones) {
 		shapes.set(it->getTimeRange(), shape);
 	}
 
+	// Animate pauses
+	Timeline<Shape> pauses = animatePauses(shapes);
+	for (const auto& pause : pauses) {
+		shapes.set(pause);
+	}
+
 	// Create inbetweens for smoother animation
 	Timeline<Shape> tweens = createTweens(shapes);
 	for (const auto& tween : tweens) {

src/tools.h

@@ -3,6 +3,7 @@
 #include <functional>
 #include <memory>
 #include <chrono>
+#include <deque>
 
 #define UNUSED(x) ((void)(x))
 
@@ -11,4 +12,50 @@ using lambda_unique_ptr = std::unique_ptr<T, std::function<void(T*)>>;
 
 std::string formatDuration(std::chrono::duration<double> seconds);
 
-std::string formatTime(time_t time, const std::string& format);
+std::string formatTime(time_t time, const std::string& format);
+
+template<unsigned int n, typename iterator_type>
+void for_each_adjacent(
+	iterator_type begin,
+	iterator_type end,
+	std::function<void(const std::deque<std::reference_wrapper<const typename iterator_type::value_type>>&)> f)
+{
+	// Get the first n values
+	iterator_type it = begin;
+	using element_type = std::reference_wrapper<const typename iterator_type::value_type>;
+	std::deque<element_type> values;
+	for (unsigned i = 0; i < n; ++i) {
+		if (it == end) return;
+		values.push_back(std::ref(*it));
+		if (i < n - 1) ++it;
+	}
+
+	for (; it != end; ++it) {
+		f(values);
+
+		values.pop_front();
+		values.push_back(*it);
+	}
+}
+
+template<typename iterator_type>
+void for_each_adjacent(
+	iterator_type begin,
+	iterator_type end,
+	std::function<void(const typename iterator_type::reference a, const typename iterator_type::reference b)> f)
+{
+	for_each_adjacent<2>(begin, end, [&](const std::deque<std::reference_wrapper<const typename iterator_type::value_type>>& args) {
+		f(args[0], args[1]);
+	});
+}
+
+template<typename iterator_type>
+void for_each_adjacent(
+	iterator_type begin,
+	iterator_type end,
+	std::function<void(const typename iterator_type::reference a, const typename iterator_type::reference b, const typename iterator_type::reference c)> f)
+{
+	for_each_adjacent<3>(begin, end, [&](const std::deque<std::reference_wrapper<const typename iterator_type::value_type>>& args) {
+		f(args[0], args[1], args[2]);
+	});
+}