Animate 3D graphic

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage x:Class="ArcGIS.Samples.Animate3DGraphic.Animate3DGraphic"
             xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:esriUI="clr-namespace:Esri.ArcGISRuntime.Maui;assembly=Esri.ArcGISRuntime.Maui">
    <Grid Style="{DynamicResource EsriSampleContainer}">
        <esriUI:SceneView x:Name="MySceneView"
                          AtmosphereEffect="Realistic"
                          Style="{DynamicResource EsriSampleGeoView}" />
        <Border Style="{DynamicResource EsriSampleControlPanel}">
            <ScrollView>
                <StackLayout Spacing="5">
                    <Label FontAttributes="Bold" Text="Select a mission:" />
                    <Picker x:Name="MissionSelectionBox" />
                    <Label FontAttributes="Bold" Text="Mission progress:" />
                    <Slider x:Name="MissionProgressBar"
                            Maximum="100"
                            ValueChanged="MissionProgressBar_ValueChanged" />
                    <Label FontAttributes="Bold" Text="Play mission:" />
                    <Switch x:Name="PlaySwitch"
                            HorizontalOptions="Start"
                            Toggled="PlaySwitch_Toggled" />
                    <Label FontAttributes="Bold" Text="Follow plane:" />
                    <Switch x:Name="FollowSwitch"
                            HorizontalOptions="Start"
                            Toggled="FollowSwitch_Toggled" />
                    <Label>
                        <Label.FormattedText>
                            <FormattedString>
                                <Span FontAttributes="Bold" Text="Altitude: " />
                                <Span x:Name="AltitudeLabel" />
                            </FormattedString>
                        </Label.FormattedText>
                    </Label>
                    <Label>
                        <Label.FormattedText>
                            <FormattedString>
                                <Span FontAttributes="Bold" Text="Heading: " />
                                <Span x:Name="HeadingLabel" />
                            </FormattedString>
                        </Label.FormattedText>
                    </Label>
                    <Label>
                        <Label.FormattedText>
                            <FormattedString>
                                <Span FontAttributes="Bold" Text="Pitch: " />
                                <Span x:Name="PitchLabel" />
                            </FormattedString>
                        </Label.FormattedText>
                    </Label>
                    <Label>
                        <Label.FormattedText>
                            <FormattedString>
                                <Span FontAttributes="Bold" Text="Roll: " />
                                <Span x:Name="RollLabel" />
                            </FormattedString>
                        </Label.FormattedText>
                    </Label>
                    <esriUI:MapView x:Name="InsetMapView"
                                    HeightRequest="200"
                                    IsAttributionTextVisible="False" />
                </StackLayout>
            </ScrollView>
        </Border>
    </Grid>
</ContentPage>

// Copyright 2022 Esri.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
// language governing permissions and limitations under the License.

using ArcGIS.Samples.Managers;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI;
using System.Diagnostics;
using System.Globalization;

using Colors = System.Drawing.Color;
using PointCollection = Esri.ArcGISRuntime.Geometry.PointCollection;

namespace ArcGIS.Samples.Animate3DGraphic
{
    [ArcGIS.Samples.Shared.Attributes.Sample(
        name: "Animate 3D graphic",
        category: "GraphicsOverlay",
        description: "An `OrbitGeoElementCameraController` follows a graphic while the graphic's position and rotation are animated.",
        instructions: "Animation Controls:",
        tags: new[] { "animation", "camera", "heading", "pitch", "roll", "rotation", "visualize" })]
    [ArcGIS.Samples.Shared.Attributes.OfflineData("290f0c571c394461a8b58b6775d0bd63", "e87c154fb9c2487f999143df5b08e9b1", "5a9b60cee9ba41e79640a06bcdf8084d", "12509ffdc684437f8f2656b0129d2c13", "681d6f7694644709a7c830ec57a2d72b")]
    public partial class Animate3DGraphic : ContentPage
    {
        // URL to the elevation service - provides terrain elevation.
        private readonly Uri _elevationServiceUrl = new Uri("https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer");

        // Graphic for highlighting the route in the inset map.
        private Graphic _routeGraphic;

        // Graphic for highlighting the airplane in the inset map.
        private Graphic _plane2D;

        // Graphic for showing the 3D plane model in the scene.
        private Graphic _plane3D;

        // Camera controller for centering the camera on the airplane.
        private OrbitGeoElementCameraController _orbitCameraController;

        // Timer control enables stopping and starting frame-by-frame animation.
        private bool _animationTimer;

        // Number of frames in the mission animation.
        private int _frameCount;

        // Index of current frame in the animation.
        private int _keyframe;

        // Dictionary of mission file names and the corresponding portal item IDs.
        private readonly Dictionary<string, string> _missionToItemId = new Dictionary<string, string>
        {
            {"GrandCanyon","290f0c571c394461a8b58b6775d0bd63"},
            {"Hawaii", "e87c154fb9c2487f999143df5b08e9b1"},
            {"Pyrenees", "5a9b60cee9ba41e79640a06bcdf8084d"},
            {"Snowdon", "12509ffdc684437f8f2656b0129d2c13"}
        };

        // Array of frames for the current mission.
        // A MissionFrame contains the position of the plane for a single moment in the animation.
        private MissionFrame[] _missionData;

        public Animate3DGraphic()
        {
            InitializeComponent();

            // Create the UI, setup the control references and execute initialization.
            _ = Initialize();
        }

        private async Task Initialize()
        {
            // Apply appropriate basemap styles to geoviews.
            InsetMapView.Map = new Map(BasemapStyle.ArcGISImageryStandard);
            MySceneView.Scene = new Scene(BasemapStyle.ArcGISImageryStandard);

            // Update the mission selection UI.
            MissionSelectionBox.ItemsSource = _missionToItemId.Keys.ToList();
            MissionSelectionBox.SelectedIndex = 0;

            // Wire up the selection change event to call the ChangeMission method.
            // This method resets the animation and starts a new mission.
            MissionSelectionBox.SelectedIndexChanged += async (sender, args) => { await ChangeMission(MissionSelectionBox.SelectedItem.ToString()); };

            // Apply the elevation source.
            var surface = new Surface();
            var elevationSource = new ArcGISTiledElevationSource(_elevationServiceUrl);
            surface.ElevationSources.Add(elevationSource);
            MySceneView.Scene.BaseSurface = surface;

            // Create and add the graphics overlay.
            var sceneOverlay = new GraphicsOverlay
            {
                SceneProperties = { SurfacePlacement = SurfacePlacement.Absolute }
            };
            MySceneView.GraphicsOverlays.Add(sceneOverlay);

            // Create a renderer to handle updating plane's orientation.
            var renderer3D = new SimpleRenderer();
            RendererSceneProperties renderProperties = renderer3D.SceneProperties;

            // Use expressions to keep the renderer properties updated as parameters of the rendered object.
            renderProperties.HeadingExpression = "[HEADING]";
            renderProperties.PitchExpression = "[PITCH]";
            renderProperties.RollExpression = "[ROLL]";

            // Apply the renderer to the scene view's overlay.
            sceneOverlay.Renderer = renderer3D;

            // Create renderer to symbolize plane and update plane orientation in the inset map.
            var renderer2D = new SimpleRenderer();

            // Create the symbol that will be used for the plane.
            var plane2DSymbol = new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Triangle, Colors.Blue, 10);

            // Apply the symbol to the renderer.
            renderer2D.Symbol = plane2DSymbol;

            // Apply a rotation expression to the renderer.
            renderer2D.RotationExpression = "[ANGLE]";

            // Update the inset map with a new GraphicsOverlay based on the renderer.
            var insetMapOperlay = new GraphicsOverlay
            {
                Renderer = renderer2D
            };
            InsetMapView.GraphicsOverlays.Add(insetMapOperlay);

            // Create placeholder graphic for showing the mission route in the inset map.
            var routeSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, Colors.Red, 2);
            _routeGraphic = new Graphic { Symbol = routeSymbol };
            insetMapOperlay.Graphics.Add(_routeGraphic);

            // Create the plane graphic; this is symbolized as a blue triangle because of renderer implemented above.
            // Create the attribute dictionary.
            var plane2DAttributes = new Dictionary<string, object>();
            // Set the angle for the plane graphic.
            plane2DAttributes["ANGLE"] = 0f;
            // Create the graphic from the attributes and the initial point.
            _plane2D = new Graphic(new MapPoint(0, 0, SpatialReferences.Wgs84), plane2DAttributes);
            // Add the plane graphic to the inset map via the overlay.
            insetMapOperlay.Graphics.Add(_plane2D);

            try
            {
                // Create the model graphic for the plane.
                // Get the path to the 3D model.
                string modelPath = GetModelPath();
                // Create the scene symbol from the path to the model.
                ModelSceneSymbol plane3DSymbol = await ModelSceneSymbol.CreateAsync(new Uri(modelPath), 1.0);
                // Create the graphic with an initial location and the plane symbol.
                _plane3D = new Graphic(new MapPoint(0, 0, 0, SpatialReferences.Wgs84), plane3DSymbol);
                // Add the plane to the overlay.
                sceneOverlay.Graphics.Add(_plane3D);

                // Create the orbit camera controller to follow the plane.
                _orbitCameraController = new OrbitGeoElementCameraController(_plane3D, 20.0)
                {
                    CameraPitchOffset = 75.0
                };
                MySceneView.CameraController = _orbitCameraController;

                // Start a timer to animate the plane.
                // The timespan is the length of the timer interval in milliseconds; this controls the animation speed (fps).
                Dispatcher.StartTimer(new TimeSpan(0, 0, 0, 0, 60), AnimatePlane);

                // Set the initial mission for when the sample loads.
                await ChangeMission(_missionToItemId.Keys.First());
            }
            catch (Exception e)
            {
                await Application.Current.Windows[0].Page.DisplayAlert("Error", e.ToString(), "OK");
            }
        }

        private async Task ChangeMission(string mission)
        {
            // Stop animating the current mission.
            PlaySwitch.IsToggled = false;

            // Get mission data,
            _missionData = GetMissionData(mission);

            // Draw mission route on the inset.
            // Create a collection of points to hold the mission.
            var points = new PointCollection(SpatialReferences.Wgs84);
            // Add all of the points from the mission to the point collection.
            points.AddPoints(_missionData.Select(m => m.ToMapPoint()));
            // Create a polyline to symbolize the route from the point collection.
            var route = new Polyline(points);
            // Update the route graphic's geometry with the newly created route polyline.
            _routeGraphic.Geometry = route;
            // Update the inset map's scale.
            await InsetMapView.SetViewpointScaleAsync(100000);

            // Update animation parameters.
            _frameCount = _missionData.Length;
            _keyframe = 0;

            // Play the animation and follow the plane.
            PlaySwitch.IsToggled = true;
            FollowSwitch.IsToggled = true;
        }

        private MissionFrame[] GetMissionData(string mission)
        {
            // Get the path to the file.
            string filePath = GetMissionFilePath(mission);

            // Read the file text.
            string fileContents = File.ReadAllText(filePath);

            // Split the file contents into a list of lines.
            return fileContents.Split('\n')
                // Then for each line, create a MissionFrame object.
                .Select(MissionFrame.Create)
                // Then remove any null MissionFrames.
                .Where(missionPart => missionPart != null)
                // Finally return that list of MissionFrames as an array.
                .ToArray();
        }

        private string GetMissionFilePath(string mission)
        {
            string itemId = _missionToItemId[mission];
            string filename = mission + ".csv";

            return DataManager.GetDataFolder(itemId, filename);
        }

        private bool AnimatePlane()
        {
            // Skip doing anything if animation is paused, or if inset map view is closed.
            if (!_animationTimer || double.IsNaN(InsetMapView.MapScale)) { return true; }

            // Get the next position; % prevents going out of bounds even if the keyframe value is
            // changed unexpectedly (e.g., due to user interaction with the progress slider).
            MissionFrame currentFrame = _missionData[_keyframe % _frameCount];

            // Update the UI.
            double missionProgress = _keyframe / (double)_frameCount;

            try
            {
                // This is needed because the event could be running on a non-UI thread.
                Microsoft.Maui.ApplicationModel.MainThread.BeginInvokeOnMainThread(() =>
                {
                    // Update the progress slider; temporarily remove event subscription to avoid feedback loop.
                    MissionProgressBar.ValueChanged -= MissionProgressBar_ValueChanged;
                    MissionProgressBar.Value = missionProgress * 100;
                    MissionProgressBar.ValueChanged += MissionProgressBar_ValueChanged;

                    // Update stats display.
                    AltitudeLabel.Text = $"{currentFrame.Elevation:F}m";
                    HeadingLabel.Text = $"{currentFrame.Heading:F}\u00b0";
                    PitchLabel.Text = $"{currentFrame.Pitch:F}\u00b0";
                    RollLabel.Text = $"{currentFrame.Pitch:F}\u00b0";
                });
            }
            // This exception is thrown sometimes as a catastrophic error when closing the app (E_UNEXPECTED).
            catch (System.Runtime.InteropServices.COMException) {}

            // Update plane's position.
            _plane3D.Geometry = currentFrame.ToMapPoint();
            _plane3D.Attributes["HEADING"] = currentFrame.Heading;
            _plane3D.Attributes["PITCH"] = currentFrame.Pitch;
            _plane3D.Attributes["ROLL"] = currentFrame.Roll;

            // Set plane symbol position.
            _plane2D.Geometry = currentFrame.ToMapPoint();

            // Update inset's viewpoint and heading.
            var vp = new Viewpoint(currentFrame.ToMapPoint(), (double)InsetMapView.MapScale, 360 + currentFrame.Heading);
            InsetMapView.SetViewpoint(vp);

            // Update the keyframe to advance animation.
            _keyframe++;

            // Restart the animation if it has finished.
            if (_keyframe >= _frameCount)
            {
                _keyframe = 0;
            }

            // Keep the animation event going.
            return true;
        }

        private static string GetModelPath()
        {
            return DataManager.GetDataFolder("681d6f7694644709a7c830ec57a2d72b", "Bristol.dae");
        }

        #region Control event handlers

        private void PlaySwitch_Toggled(object sender, ToggledEventArgs e)
        {
            // Stop or play the animation.
            _animationTimer = PlaySwitch.IsToggled;
        }

        private void FollowSwitch_Toggled(object sender, ToggledEventArgs e)
        {
            // Setting the scene view's camera controller to null has the effect of resetting the value to the default.
            MySceneView.CameraController = FollowSwitch.IsToggled ? _orbitCameraController : null;
        }

        private void MissionProgressBar_ValueChanged(object sender, ValueChangedEventArgs e)
        {
            // Stop the animation.
            PlaySwitch.IsToggled = false;

            // Get a reference to the slider that sent the event.
            var sliderControl = (Slider)sender;

            // Get the new mission progress.
            double missionProgress = sliderControl.Value / 100.0;

            // Update the keyframe based on the progress.
            _keyframe = (int)(missionProgress * _frameCount);

            // Restart the animation
            PlaySwitch.IsToggled = true;
        }

        #endregion Control event handlers

        /// <summary>
        /// Private helper class represents a single frame in the animation.
        /// </summary>
        private class MissionFrame
        {
            private double Longitude { get; }
            private double Latitude { get; }
            public double Elevation { get; }
            public double Heading { get; }
            public double Pitch { get; }
            public double Roll { get; }

            /// <summary>
            /// Private constructor ensures that only the factory method (Create) can be called.
            /// </summary>
            /// <param name="missionLine">A string describing a single frame in the mission animation.</param>
            private MissionFrame(string missionLine)
            {
                // Split the string into a list of entries (columns).
                // Example line: -156.3666517,20.6255059,999.999908,83.77659,0.000105,-47.766567.
                string[] missionFrameParameters = missionLine.Split(',');

                // Throw if the line isn't valid.
                if (missionFrameParameters.Length != 6)
                {
                    throw new Exception("Invalid mission part definition");
                }

                // Populate the object's properties from the array of parameters.
                Longitude = Convert.ToDouble(missionFrameParameters[0], CultureInfo.InvariantCulture);
                Latitude = Convert.ToDouble(missionFrameParameters[1], CultureInfo.InvariantCulture);
                Elevation = Convert.ToDouble(missionFrameParameters[2], CultureInfo.InvariantCulture);
                Heading = Convert.ToDouble(missionFrameParameters[3], CultureInfo.InvariantCulture);
                Pitch = Convert.ToDouble(missionFrameParameters[4], CultureInfo.InvariantCulture);
                Roll = Convert.ToDouble(missionFrameParameters[5], CultureInfo.InvariantCulture);
            }

            /// <summary>
            /// Creates a new MissionFrame.
            /// The private constructor + static construction method allows
            /// for keeping the exception-handling logic for the constructor
            /// internal to the class.
            /// </summary>
            /// <param name="missionLine">A string describing a single frame in the mission animation.</param>
            /// <returns>Constructed MissionFrame or null if the line is invalid.</returns>
            public static MissionFrame Create(string missionLine)
            {
                try
                {
                    return new MissionFrame(missionLine);
                }
                catch (Exception ex)
                {
                    Debug.WriteLine(ex.Message);
                    return null;
                }
            }

            public MapPoint ToMapPoint()
            {
                return new MapPoint(Longitude, Latitude, Elevation, SpatialReferences.Wgs84);
            }
        }
    }
}