Merge pull request #39 from B3zaleel/implement-MPEG_viewport_recommen…

…ded-extension

Implement MPEG_viewport_recommended Gltf extension

src/ThreeDModels/Format/Gltf/Extensions/MPEG_viewport_recommended.cs

@@ -0,0 +1,179 @@
+using System.Text.Json;
+using ThreeDModels.Format.Gltf.Elements;
+using ThreeDModels.Format.Gltf.IO;
+using static ThreeDModels.Format.Gltf.IO.Utf8JsonReaderHelpers;
+
+namespace ThreeDModels.Format.Gltf.Extensions;
+
+/// <summary>
+/// Represents an object for specifying an set of recommended viewports.
+/// </summary>
+public class MPEG_viewport_recommended : IGltfProperty
+{
+    public required List<MpegViewportRecommended> Viewports { get; set; }
+    public Dictionary<string, object?>? Extensions { get; set; }
+    public object? Extras { get; set; }
+}
+
+/// <summary>
+/// Represents an object for specifying a recommended viewport.
+/// </summary>
+public class MpegViewportRecommended
+{
+    /// <summary>
+    /// Provides a reference to `accessor` where the timed data for the translation of camera object will be made available.
+    /// </summary>
+    public int? Translation { get; set; }
+    /// <summary>
+    /// Provides a reference to an `accessor` where the timed data for the rotation of camera object will be made available.
+    /// </summary>
+    public int? Rotation { get; set; }
+    /// <summary>
+    /// Provides the type of camera.
+    /// </summary>
+    public string? Type { get; set; }
+    /// <summary>
+    /// Provides a reference to `accessor` where the timed data for the perspective or orthographic camera parameters will be made available.
+    /// </summary>
+    public int? Parameters { get; set; }
+    /// <summary>
+    /// The user-defined name of this object.
+    /// </summary>
+    public string? Name { get; set; }
+    public Dictionary<string, object?>? Extensions { get; set; }
+    public object? Extras { get; set; }
+}
+
+public class MpegViewportRecommendedExtension : IGltfExtension
+{
+    public string Name => nameof(MPEG_viewport_recommended);
+
+    public object? Read(ref Utf8JsonReader jsonReader, GltfReaderContext context, Type parentType)
+    {
+        List<MpegViewportRecommended>? viewports = null;
+        Dictionary<string, object?>? extensions = null;
+        object? extras = null;
+        if (jsonReader.TokenType == JsonTokenType.PropertyName && jsonReader.Read())
+        {
+        }
+        if (jsonReader.TokenType == JsonTokenType.Null)
+        {
+            return null;
+        }
+        else if (jsonReader.TokenType != JsonTokenType.StartObject)
+        {
+            throw new InvalidDataException("Failed to find start of property.");
+        }
+        while (jsonReader.Read())
+        {
+            if (jsonReader.TokenType == JsonTokenType.EndObject)
+            {
+                break;
+            }
+            var propertyName = jsonReader.GetString();
+            if (propertyName == nameof(viewports))
+            {
+                viewports = ReadObjectList(ref jsonReader, context, (ref Utf8JsonReader reader, GltfReaderContext ctx) => MpegViewportRecommendedSerialization.Read(ref reader, ctx)!);
+            }
+            else if (propertyName == nameof(extensions))
+            {
+                extensions = ExtensionsSerialization.Read<MPEG_viewport_recommended>(ref jsonReader, context);
+            }
+            else if (propertyName == nameof(extras))
+            {
+                extras = JsonSerialization.Read(ref jsonReader, context);
+            }
+            else
+            {
+                throw new InvalidDataException($"Unknown property: {propertyName}");
+            }
+        }
+        if (viewports == null || viewports.Count < 1)
+        {
+            throw new InvalidDataException("MPEG_viewport_recommended.viewports must contain at least 1 element.");
+        }
+        return new MPEG_viewport_recommended()
+        {
+            Viewports = viewports!,
+            Extensions = extensions,
+            Extras = extras,
+        };
+    }
+}
+
+public class MpegViewportRecommendedSerialization
+{
+    public const string Default_Type = "perspective";
+
+    public static MpegViewportRecommended? Read(ref Utf8JsonReader jsonReader, GltfReaderContext context)
+    {
+        int? translation = null;
+        int? rotation = null;
+        string? type = null;
+        int? parameters = null;
+        string? name = null;
+        Dictionary<string, object?>? extensions = null;
+        object? extras = null;
+        if (jsonReader.TokenType == JsonTokenType.PropertyName && jsonReader.Read())
+        {
+        }
+        if (jsonReader.TokenType == JsonTokenType.Null)
+        {
+            return null;
+        }
+        else if (jsonReader.TokenType != JsonTokenType.StartObject)
+        {
+            throw new InvalidDataException("Failed to find start of property.");
+        }
+        while (jsonReader.Read())
+        {
+            if (jsonReader.TokenType == JsonTokenType.EndObject)
+            {
+                break;
+            }
+            var propertyName = jsonReader.GetString();
+            if (propertyName == nameof(translation))
+            {
+                translation = ReadInteger(ref jsonReader);
+            }
+            else if (propertyName == nameof(rotation))
+            {
+                rotation = ReadInteger(ref jsonReader);
+            }
+            else if (propertyName == nameof(type))
+            {
+                type = ReadString(ref jsonReader);
+            }
+            else if (propertyName == nameof(parameters))
+            {
+                parameters = ReadInteger(ref jsonReader);
+            }
+            else if (propertyName == nameof(name))
+            {
+                name = ReadString(ref jsonReader);
+            }
+            else if (propertyName == nameof(extensions))
+            {
+                extensions = ExtensionsSerialization.Read<MpegViewportRecommended>(ref jsonReader, context);
+            }
+            else if (propertyName == nameof(extras))
+            {
+                extras = JsonSerialization.Read(ref jsonReader, context);
+            }
+            else
+            {
+                throw new InvalidDataException($"Unknown property: {propertyName}");
+            }
+        }
+        return new()
+        {
+            Name = name,
+            Translation = translation,
+            Rotation = rotation,
+            Type = type ?? Default_Type,
+            Parameters = parameters,
+            Extensions = extensions,
+            Extras = extras,
+        };
+    }
+}