/// <summary>
/// A class to demonstrate a 3D Text Elements added to the SciChart3D Scene. Created using our BaseSceneEntity and Font3D APIs
/// </summary>
public class TextSceneEntity : BaseSceneEntity
{
    private readonly Color _textColor;
    private readonly TextDisplayMode _textDisplayMode;
    Font3D _font;
    public string Text { get; set; }
    [TypeConverter(typeof(StringToVector3TypeConverter))]
    public Vector3 Location { get; set; }
    public double RotationAngle { get; set; }
    static TextSceneEntity()
    {
        SCRTDllLoader.InitNativeLibs();
    }
    public TextSceneEntity(string text, Color textColor, Vector3 location, TextDisplayMode textDisplayMode = TextDisplayMode.FacingCameraAlways, int fontSize = 8, string fontFamily = "Arial")
    {
        Text = text;
        _textColor = textColor;
        Location = location;
        _textDisplayMode = textDisplayMode;
        _font = new Font3D(fontFamily, (uint) fontSize);
        // Set requires SeletionId to false to exclude this item from selection, tooltips and also 
        // prevent issues with maximum number of selectable meshes 
        this.RequiresSelectionId = false;
    }
    /// <summary>
    /// Determines whether this instance is transparent. When True SciChart internally
    /// </summary>
    /// <returns></returns>
    public override bool IsTransparent()
    {
        return _textColor.A < 255;
    }
    /// <summary>
    /// Called when the 3D Engine wishes to render this element. This is where geometry must be drawn to the 3D scene
    /// </summary>
    /// <param name="e">The <see cref="IRenderPassInfo3D" /> containing parameters for the current render pass.</param>
    public override void RenderScene(IRenderPassInfo3D e)
    {
        if (_font == null) return;
        var currentCamera = RootSceneEntity != null ? RootSceneEntity.Viewport3D.CameraController : null;
        switch (_textDisplayMode)
        {
            case TextDisplayMode.Default:
                {
                    // Just display text
                    _font.Begin();
                    _font.AddText(Text, _textColor, Location.X, Location.Y, Location.Z);
                    _font.End();
                    break;
                }
            case TextDisplayMode.FacingCameraAlways:
                {
                    if (currentCamera == null)
                        goto case TextDisplayMode.Default;
                    // Display billboarded text using camera vectors                
                    Vector3 cameraFwd = currentCamera.Forward;
                    Vector3 cameraUp = currentCamera.Up;
                    // Compute a side vector
                    Vector3 cameraSide = cameraFwd ^ cameraUp;
                    cameraSide.Normalize();
                    // Compute orthogonal up vector
                    cameraUp = cameraSide ^ cameraFwd;
                    cameraUp.Normalize();
                    // Display text billboarded using camera side, up vectors (text will always face camera) 
                    _font.BeginBillboard(cameraSide, cameraUp);
                    _font.AddText(Text, _textColor, Location.X, Location.Y, Location.Z);
                    _font.End();
                    break;
                }
            case TextDisplayMode.SacreenSpace:
                {
                    // Screen space text 2D
                    _font.BeginScreenSpace((float) RotationAngle, Location.X, Location.Y);
                    _font.AddText(Text, _textColor, Location.X, Location.Y, Location.Z);
                    _font.EndScreenSpace();
                    break;
                }
            default:
                throw new ArgumentOutOfRangeException();
        }
    }
    /// <summary>
    /// Releases unmanaged and - optionally - managed resources.
    /// </summary>
    public override void Dispose()
    {
        _font.SafeDispose();
        _font = null;
        base.Dispose();
    }
    /// <summary>
    /// Called when the 3D Engine wishes to update the geometry in this element. This is where we need to cache geometry before draw.
    /// </summary>
    /// <param name="e">The <see cref="IRenderPassInfo3D" /> containing parameters for the current render pass.</param>
    public override void UpdateScene(IRenderPassInfo3D e)
    {
    }

    /// <summary>
    /// Performs selection on this entity, setting the IsSelected flag to True or False on the specified <see cref="VertexId">Vertex Ids</see>
    /// </summary>
    /// <param name="isSelected">if set to <c>true</c> the vertices become .</param>
    /// <param name="vertexIds">The vertex ids.</param>
    public override void PerformSelection(bool isSelected, List<VertexId> vertexIds)
    {
    }
}

// Add some text labels to the scene 
var textA = new TextSceneEntity("Teeny Block", Color.FromArgb(255, 0, 225, 0), new Vector3(75f, 100f, 75f), TextDisplayMode.FacingCameraAlways, 9, "Segoe UI");

var textB = new TextSceneEntity("Big Block", Color.FromArgb(255, 255, 255, 255), new Vector3(-50f,200f,-50f), TextDisplayMode.FacingCameraAlways, 10, "Tahoma");
sciChart3DSurface.Viewport3D.RootEntity.Children.Add(textA);
sciChart3DSurface.Viewport3D.RootEntity.Children.Add(textB);