Function add_instance_from_prompts

examples/main_video.cpp:290–337

}

static void add_instance_from_prompts(vapp_state& app) {
    if (!app.tracker_created || !app.frame_encoded) return;
    sam3_pvs_params pvs;
    pvs.pos_points = app.init_pos_points;
    pvs.neg_points = app.init_neg_points;
    if (app.has_init_box) {
        pvs.box = app.init_box;
        pvs.use_box = true;
    }
    pvs.multimask = false;

    // sam3_tracker_add_instance runs PVS internally and registers the instance
    // in the tracker's memory bank.  We must NOT call decode_and_track afterwards
    // because sam3_track_frame increments tracker.frame_index, which would
    // desynchronize the tracker's internal counter from the actual frame.
    //
    // Instead, run PVS again (cheap — image is already encoded) to obtain a
    // display mask and append it to the current result.
    int new_id = sam3_tracker_add_instance(*app.tracker, *app.state, *app.model, pvs);
    if (new_id >= 0) {
        snprintf(app.status, sizeof(app.status), "Added instance #%d", new_id);

        // Re-run PVS to get the mask for display (image features are still valid)
        auto pvs_result = sam3_segment_pvs(*app.state, *app.model, pvs);
        if (!pvs_result.detections.empty()) {
            sam3_detection det = pvs_result.detections[0];
            det.instance_id = new_id;
            det.mask.instance_id = new_id;
            app.result.detections.push_back(std::move(det));
        }
        // Update timeline for current frame
        int fi = app.frame_index;
        if (fi >= (int)app.timeline.size())
            app.timeline.resize(fi + 1);
        app.timeline[fi].instances.clear();
        for (const auto& d : app.result.detections)
            app.timeline[fi].instances.push_back({d.instance_id, d.score});
        if (fi > app.timeline_max_frame) app.timeline_max_frame = fi;
    } else {
        snprintf(app.status, sizeof(app.status), "Failed to add instance");
    }

    // Clear pending prompts
    app.init_pos_points.clear();
    app.init_neg_points.clear();
    app.init_box = {0, 0, 0, 0};
    app.has_init_box = false;
}

static void clear_init_prompts(vapp_state& app) {
    app.init_pos_points.clear();