ImageTimeline example

main.cpp

/*** PASTE ME OVER osgearth_imgui.cpp ***/

#include <osgEarth/ImGui/ImGui>
#include <osgEarth/EarthManipulator>
#include <osgEarth/ImageLayer>

#include <osg/ImageSequence>
#include <osgDB/ReadFile>
#include <osgViewer/Viewer>

using namespace osgEarth;
using namespace osgEarth::Util;

struct App
{
    DateTime _time;
};

class ImageTimeline : public osg::Image
{
public:
    using Sequence = std::map<TimeStamp, osg::ref_ptr<const osg::Image>>;

    Sequence _images;
    Sequence::iterator _ptr;

    void insert(const DateTime& dt, const osg::Image* image)
    {
        _images.insert(std::make_pair(dt.asTimeStamp(), image));

        if (_images.size() == 1)
        {
            setDateTime(dt);
        }
    }

    void insert(const DateTime& dt, osg::ref_ptr<osg::Image> image)
    {
        insert(dt, image.get());
    }

    bool requiresUpdateCall() const override
    {
        return true;
    }

    void update(osg::NodeVisitor* nv) override
    {
        DateTime dt(nv->getFrameStamp()->getSimulationTime());
        setDateTime(dt);
    }

    void setDateTime(const DateTime& dt)
    {
        _ptr = _images.lower_bound(dt.asTimeStamp());

        if (_ptr != _images.end())
        {
            const osg::Image* image = _ptr->second.get();

            setImage(image->s(), image->t(), image->r(),
                image->getInternalTextureFormat(),
                image->getPixelFormat(), image->getDataType(),
                const_cast<unsigned char*>(image->data()),
                osg::Image::NO_DELETE,
                image->getPacking());

            setMipmapLevels(image->getMipmapLevels());
        }
    }
};

class TimelineLayer : public ImageLayer
{
public:
    META_LayerNoOptions(osgEarth, TimelineLayer, ImageLayer, TimelineLayer);

    void init() override
    {
        ImageLayer::init();
        setProfile(Profile::create(Profile::GLOBAL_GEODETIC));
        setAsyncLoading(false);
    }

    GeoImage createImageImplementation(const TileKey& key, ProgressCallback* c) const override
    {
        ImageTimeline* timeline = new ImageTimeline();
        timeline->insert(DateTime(0), osgDB::readRefImageFile("../data/icon.png"));
        timeline->insert(DateTime(1), osgDB::readRefImageFile("../data/placemark32.png"));
        timeline->insert(DateTime(2), osgDB::readRefImageFile("../data/hospital.png"));
        return GeoImage(timeline, key.getExtent());
    }
};

struct TimeGUI : public GUI::BaseGUI
{
    App& _app;
    float _time;
    TimeGUI(App& app) : BaseGUI("Time Control"), _app(app), _time(0.0f) { }

    void draw(osg::RenderInfo& ri) override
    {
        if (!isVisible()) return;
        ImGui::Begin(name(), visible());
        if (ImGui::SliderFloat("Time", &_time, 0.0f, 3.0f))
            _app._time = DateTime(_time);
        ImGui::End();
    }
};

int
main(int argc, char** argv)
{
    osgEarth::initialize();

    App app;

    osg::ArgumentParser arguments(&argc, argv);
    osgViewer::Viewer viewer(arguments);
    viewer.setThreadingModel(viewer.SingleThreaded);
    viewer.setCameraManipulator(new EarthManipulator(arguments));
    viewer.setRealizeOperation(new GUI::ApplicationGUI::RealizeOperation);

    auto gui = new GUI::ApplicationGUI(arguments, true);
    gui->add(new TimeGUI(app), true);
    viewer.getEventHandlers().push_front(gui);

    auto map = new Map();
    map->addLayer(new TimelineLayer());
    auto mapNode = new MapNode(map);

    viewer.setSceneData(mapNode);
    viewer.realize();
    while (!viewer.done()) {
        viewer.frame(app._time.asTimeStamp());
    }
    return 0;
}