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TimelineEngine

Sourcesrc/Timeline/ (5 files)
CMake targetTimelineEngine (static library)
TypeStatic lib (linked into consumers)
FamilyDirectUI engine layer

Integration status (#25): standalone experimental scaffolding. MovieMakerCore no longer constructs or links this stack; MF PlaybackController is the live application playback path. A future integration needs a catalog and UI tick.

At a glance​

The engine-layer timeline: clip placement with snapping and overlap detection, plus a TimelineDispatcher that mediates between the timeline model, the media catalog, and the playback engine for UI clients.

Public surface​

Clip.h — the clip record:

struct Clip {
    std::wstring mediaId;   // reference to MediaCatalog entry
    double start;           // start time on timeline (seconds)
    double duration;        // length (seconds)
    int track;              // track index (0 = video, >0 = audio etc.)
};

TimelineEngine.h — the model:

class TimelineEngine {
public:
    bool AddClip(const Clip& clip);
    bool RemoveClip(const std::wstring& mediaId, double start);
    bool MoveClip(const std::wstring& mediaId, double oldStart, double newStart, int newTrack);
    bool TrimClip(const std::wstring& mediaId, double start, double newDuration);
    const std::vector<Clip>& GetClips() const;
private:
    double Snap(double time) const;      // 0.5 s grid
    bool Overlaps(const Clip& a, const Clip& b) const;
};

TimelineDispatcher.h — the DirectUI::TimelineDispatcher that connects the engine to PlaybackEngine and MediaCatalog for consumers.

Implementation notes​

  • Snapping rounds to a 0.5-second grid (Snap), matching the coarse-drag behavior of the engine-layer demo apps. (The full editor's magnetic timeline lives in MovieMakerCore's Extents arithmetic.)
  • Overlaps guards AddClip/MoveClip — clips cannot collide on a track.
  • The file trio mirrors the ProjectManager/MediaCatalog layering: model in the engine, UI binding via the dispatcher.

Testing​

Built in the CI matrix as TimelineEngine; exercised by engine-layer apps (apps/pipeline-graph and friends).

Analysis artifacts​

Engine-layer reconstruction; the in-engine equivalent analysis lives in analysis/MovieMakerCore/.