feat: port ClassificationResult and Landmark (#991)

* feat: port ClassificationResult and Landmark

* fix: fix compile errors on Unity 2020.3.x

Packages/com.github.homuler.mediapipe/Runtime/Scripts/Tasks/Components/Containers/ClassificationResult.cs

@@ -0,0 +1,106 @@
+// Copyright (c) 2023 homuler
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+using System.Collections.Generic;
+
+namespace Mediapipe.Tasks.Components.Containers
+{
+  /// <summary>
+  ///   Defines classification results for a given classifier head.
+  /// </summary>
+  public readonly struct Classifications
+  {
+    /// <summary>
+    ///   The array of predicted categories, usually sorted by descending scores,
+    ///   e.g. from high to low probability.
+    /// </summary>
+    public readonly IReadOnlyList<Category> categories;
+    /// <summary>
+    ///   The index of the classifier head (i.e. output tensor) these categories
+    ///   refer to. This is useful for multi-head models.
+    /// </summary>
+    public readonly int headIndex;
+    /// <summary>
+    ///   The optional name of the classifier head, as provided in the TFLite Model
+    ///   Metadata [1] if present. This is useful for multi-head models.
+    ///
+    ///   [1]: https://www.tensorflow.org/lite/convert/metadata
+    /// </summary>
+    public readonly string headName;
+
+    internal Classifications(IReadOnlyList<Category> categories, int headIndex, string headName)
+    {
+      this.categories = categories;
+      this.headIndex = headIndex;
+      this.headName = headName;
+    }
+
+    public static Classifications CreateFrom(Proto.Classifications proto)
+    {
+      var categories = new List<Category>(proto.ClassificationList.Classification.Count);
+      foreach (var classification in proto.ClassificationList.Classification)
+      {
+        categories.Add(Category.CreateFrom(classification));
+      }
+      return new Classifications(categories, proto.HeadIndex, proto.HasHeadName ? proto.HeadName : null);
+    }
+
+    public static Classifications CreateFrom(ClassificationList proto, int headIndex = 0, string headName = null)
+    {
+      var categories = new List<Category>(proto.Classification.Count);
+      foreach (var classification in proto.Classification)
+      {
+        categories.Add(Category.CreateFrom(classification));
+      }
+      return new Classifications(categories, headIndex, headName);
+    }
+
+    public override string ToString()
+      => $"{{ \"categories\": {Util.Format(categories)}, \"headIndex\": {headIndex}, \"headName\": {Util.Format(headName)} }}";
+  }
+
+  /// <summary>
+  ///   Defines classification results of a model.
+  /// </summary>
+  public readonly struct ClassificationResult
+  {
+    /// <summary>
+    ///   The classification results for each head of the model.
+    /// </summary>
+    public readonly IReadOnlyList<Classifications> classifications;
+
+    /// <summary>
+    ///   The optional timestamp (in milliseconds) of the start of the chunk of data
+    ///   corresponding to these results.
+    ///
+    ///   This is only used for classification on time series (e.g. audio
+    ///   classification). In these use cases, the amount of data to process might
+    ///   exceed the maximum size that the model can process: to solve this, the
+    ///   input data is split into multiple chunks starting at different timestamps.
+    /// </summary>
+    public readonly long? timestampMs;
+
+    internal ClassificationResult(IReadOnlyList<Classifications> classifications, long? timestampMs)
+    {
+      this.classifications = classifications;
+      this.timestampMs = timestampMs;
+    }
+
+    public static ClassificationResult CreateFrom(Proto.ClassificationResult proto)
+    {
+      var classifications = new List<Classifications>(proto.Classifications.Count);
+      foreach (var classification in proto.Classifications)
+      {
+        classifications.Add(Classifications.CreateFrom(classification));
+      }
+#pragma warning disable IDE0004 // for Unity 2020.3.x
+      return new ClassificationResult(classifications, proto.HasTimestampMs ? (long?)proto.TimestampMs : null);
+#pragma warning restore IDE0004 // for Unity 2020.3.x
+    }
+
+    public override string ToString() => $"{{ \"classifications\": {Util.Format(classifications)}, \"timestampMs\": {Util.Format(timestampMs)} }}";
+  }
+}

Packages/com.github.homuler.mediapipe/Runtime/Scripts/Tasks/Components/Containers/DetectionResult.cs

@@ -5,7 +5,6 @@
 // https://opensource.org/licenses/MIT.
 
 using System.Collections.Generic;
-using System.Linq;
 
 namespace Mediapipe.Tasks.Components.Containers
 {
@@ -81,11 +80,7 @@ public static Detection CreateFrom(Mediapipe.Detection proto)
     }
 
     public override string ToString()
-    {
-      var categoriesStr = $"[{string.Join(", ", categories.Select(category => category.ToString()))}]";
-      var keypointsStr = keypoints == null ? "null" : $"[{string.Join(", ", keypoints.Select(keypoint => keypoint.ToString()))}]";
-      return $"{{\"categories\": {categoriesStr}, \"boundingBox\": {boundingBox}, \"keypoints\": {keypointsStr}}}";
-    }
+      => $"{{ \"categories\": {Util.Format(categories)}, \"boundingBox\": {boundingBox}, \"keypoints\": {Util.Format(keypoints)} }}";
   }
 
   /// <summary>
@@ -113,10 +108,6 @@ public static DetectionResult CreateFrom(IReadOnlyList<Mediapipe.Detection> dete
       return new DetectionResult(detections);
     }
 
-    public override string ToString()
-    {
-      var detectionsStr = string.Join(", ", detections.Select(detection => detection.ToString()));
-      return $"{{ \"detections\": [{detectionsStr}] }}";
-    }
+    public override string ToString() => $"{{ \"detections\": {Util.Format(detections)} }}";
   }
 }

Packages/com.github.homuler.mediapipe/Runtime/Scripts/Tasks/Components/Containers/Keypoint.cs

@@ -36,10 +36,6 @@ internal NormalizedKeypoint(float x, float y, string label, float? score)
       this.score = score;
     }
 
-    public override string ToString()
-    {
-      var scoreStr = score == null ? "null" : $"{score}";
-      return $"{{ \"x\": {x}, \"y\": {y}, \"label\": \"{label}\", \"score\": {scoreStr} }}";
-    }
+    public override string ToString() => $"{{ \"x\": {x}, \"y\": {y}, \"label\": \"{label}\", \"score\": {Util.Format(score)} }}";
   }
 }