jump keyframe on on on on on on on peek peek progress seek step tween tween tween_value_t

keyframe() template<typename FirstValueType, typename... RemainingValueTypes> auto keyframe ( ) const -> std::size_t nodiscard Returns the index of the keyframe segment the tween is currently in. The index identifies the keyframe the current frame has most recently reached or passed: 0 while between the first and second keyframes, 1 between the second and third, and so on. At the very end of the tween it is the index of the last keyframe, matching jump(). It is updated before any listener runs, so it is safe to read from inside step, seek, jump, update, and complete callbacks. Returns Zero-based index of the current keyframe auto t = tweeny::from(0).to(50).during(30U).to(100).during(30U).build(); t.on(event::step, [](auto& tween) { printf("In keyframe %zu\n", tween.keyframe()); return event::response::ok; }); t.step(10); // Prints: "In keyframe 0" t.step(25); // Prints: "In keyframe 1"