feat: marshal DetectionResult (#1089)

* feat: marshal DetectionResult

* refactor: init list if null

Packages/com.github.homuler.mediapipe/Runtime/Scripts/Marshal/NativeCategory.cs

@@ -0,0 +1,38 @@
+// 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;
+using System.Runtime.InteropServices;
+
+namespace Mediapipe
+{
+  [StructLayout(LayoutKind.Sequential)]
+  internal readonly struct NativeCategory
+  {
+    public readonly int index;
+    public readonly float score;
+    private readonly IntPtr _categoryName;
+    private readonly IntPtr _displayName;
+
+    public string categoryName => Marshal.PtrToStringAnsi(_categoryName);
+    public string displayName => Marshal.PtrToStringAnsi(_displayName);
+  }
+
+  [StructLayout(LayoutKind.Sequential)]
+  internal readonly struct NativeCategories
+  {
+    private readonly IntPtr _categories;
+    public readonly uint categoriesCount;
+
+    public ReadOnlySpan<NativeCategory> AsReadOnlySpan()
+    {
+      unsafe
+      {
+        return new ReadOnlySpan<NativeCategory>((NativeCategory*)_categories, (int)categoriesCount);
+      }
+    }
+  }
+}

Packages/com.github.homuler.mediapipe/Runtime/Scripts/Marshal/NativeDetectionResult.cs

@@ -0,0 +1,67 @@
+// 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;
+using System.Runtime.InteropServices;
+
+namespace Mediapipe
+{
+  [StructLayout(LayoutKind.Sequential)]
+  internal readonly struct NativeDetection
+  {
+    private readonly IntPtr _categories;
+
+    public readonly uint categoriesCount;
+
+    public readonly NativeRect boundingBox;
+
+    private readonly IntPtr _keypoints;
+
+    public readonly uint keypointsCount;
+
+    public ReadOnlySpan<NativeCategory> categories
+    {
+      get
+      {
+        unsafe
+        {
+          return new ReadOnlySpan<NativeCategory>((NativeCategory*)_categories, (int)categoriesCount);
+        }
+      }
+    }
+
+    public ReadOnlySpan<NativeNormalizedKeypoint> keypoints
+    {
+      get
+      {
+        unsafe
+        {
+          return new ReadOnlySpan<NativeNormalizedKeypoint>((NativeNormalizedKeypoint*)_keypoints, (int)keypointsCount);
+        }
+      }
+    }
+  }
+
+  [StructLayout(LayoutKind.Sequential)]
+  internal readonly struct NativeDetectionResult
+  {
+    private readonly IntPtr _detections;
+    public readonly uint detectionsCount;
+
+    public ReadOnlySpan<NativeDetection> AsReadOnlySpan()
+    {
+      unsafe
+      {
+        return new ReadOnlySpan<NativeDetection>((NativeDetection*)_detections, (int)detectionsCount);
+      }
+    }
+
+    public void Dispose()
+    {
+      UnsafeNativeMethods.mp_tasks_c_components_containers_CppCloseDetectionResult(this);
+    }
+  }
+}

Packages/com.github.homuler.mediapipe/Runtime/Scripts/Marshal/NativeKeypoint.cs

@@ -0,0 +1,23 @@
+// 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;
+using System.Runtime.InteropServices;
+
+namespace Mediapipe
+{
+  [StructLayout(LayoutKind.Sequential)]
+  internal readonly struct NativeNormalizedKeypoint
+  {
+    public readonly float x;
+    public readonly float y;
+    private readonly IntPtr _label;
+    public readonly float score;
+    public readonly bool hasScore;
+
+    public string label => Marshal.PtrToStringAnsi(_label);
+  }
+}

Packages/com.github.homuler.mediapipe/Runtime/Scripts/Marshal/NativeRect.cs

@@ -0,0 +1,28 @@
+// 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.Runtime.InteropServices;
+
+namespace Mediapipe
+{
+  [StructLayout(LayoutKind.Sequential)]
+  internal readonly struct NativeRect
+  {
+    public readonly int left;
+    public readonly int top;
+    public readonly int bottom;
+    public readonly int right;
+  }
+
+  [StructLayout(LayoutKind.Sequential)]
+  internal readonly struct NativeRectF
+  {
+    public readonly float left;
+    public readonly float top;
+    public readonly float bottom;
+    public readonly float right;
+  }
+}

Packages/com.github.homuler.mediapipe/Runtime/Scripts/PInvoke/NativeMethods/Tasks/Components/Containers_Unsafe.cs

@@ -11,6 +11,12 @@ namespace Mediapipe
 {
   internal static partial class UnsafeNativeMethods
   {
+    [DllImport(MediaPipeLibrary, ExactSpelling = true)]
+    public static extern MpReturnCode mp_Packet__GetDetectionResult(IntPtr packet, out NativeDetectionResult value);
+
+    [DllImport(MediaPipeLibrary, ExactSpelling = true)]
+    public static extern void mp_tasks_c_components_containers_CppCloseDetectionResult(NativeDetectionResult data);
+
     [DllImport(MediaPipeLibrary, ExactSpelling = true)]
     public static extern MpReturnCode mp_Packet__GetNormalizedLandmarksVector(IntPtr packet, out NativeNormalizedLandmarksArray value);
 

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

@@ -43,6 +43,14 @@ internal Category(int index, float score, string categoryName, string displayNam
       this.displayName = displayName;
     }
 
+    internal Category(NativeCategory nativeCategory) : this(
+      nativeCategory.index,
+      nativeCategory.score,
+      nativeCategory.categoryName,
+      nativeCategory.displayName)
+    {
+    }
+
     public static Category CreateFrom(Classification proto)
     {
       var categoryName = proto.HasLabel ? proto.Label : null;

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

@@ -4,7 +4,6 @@
 // license that can be found in the LICENSE file or at
 // https://opensource.org/licenses/MIT.
 
-using System;
 using System.Collections.Generic;
 
 namespace Mediapipe.Tasks.Components.Containers
@@ -53,11 +52,11 @@ public static Detection CreateFrom(Mediapipe.Detection proto)
 
     public static void Copy(Mediapipe.Detection proto, ref Detection destination)
     {
-      var categories = destination.categories;
+      var categories = destination.categories ?? new List<Category>(proto.Score.Count);
       categories.Clear();
       for (var idx = 0; idx < proto.Score.Count; idx++)
       {
-        destination.categories.Add(new Category(
+        categories.Add(new Category(
           proto.LabelId.Count > idx ? proto.LabelId[idx] : _DefaultCategoryIndex,
           proto.Score[idx],
           proto.Label.Count > idx ? proto.Label[idx] : "",
@@ -96,6 +95,27 @@ public static void Copy(Mediapipe.Detection proto, ref Detection destination)
       destination = new Detection(categories, boundingBox, keypoints);
     }
 
+    internal static void Copy(in NativeDetection source, ref Detection destination)
+    {
+      var categories = destination.categories ?? new List<Category>((int)source.categoriesCount);
+      categories.Clear();
+      foreach (var nativeCategory in source.categories)
+      {
+        categories.Add(new Category(nativeCategory));
+      }
+
+      var boundingBox = new Rect(source.boundingBox);
+
+      var keypoints = destination.keypoints ?? new List<NormalizedKeypoint>((int)source.keypointsCount);
+      keypoints.Clear();
+      foreach (var nativeKeypoint in source.keypoints)
+      {
+        keypoints.Add(new NormalizedKeypoint(nativeKeypoint));
+      }
+
+      destination = new Detection(categories, boundingBox, keypoints);
+    }
+
     public override string ToString()
       => $"{{ \"categories\": {Util.Format(categories)}, \"boundingBox\": {boundingBox}, \"keypoints\": {Util.Format(keypoints)} }}";
   }
@@ -130,22 +150,28 @@ internal static DetectionResult CreateFrom(List<Mediapipe.Detection> detectionsP
 
     internal static void Copy(List<Mediapipe.Detection> source, ref DetectionResult destination)
     {
-      var detections = destination.detections;
-      if (source.Count < detections.Count)
-      {
-        detections.RemoveRange(source.Count, detections.Count - source.Count);
-      }
-      var copyCount = Math.Min(source.Count, detections.Count);
-      for (var i = 0; i < copyCount; i++)
+      var detections = destination.detections ?? new List<Detection>(source.Count);
+      detections.ResizeTo(source.Count);
+
+      for (var i = 0; i < source.Count; i++)
       {
         var detection = detections[i];
         Detection.Copy(source[i], ref detection);
         detections[i] = detection;
       }
+    }
 
-      for (var i = copyCount; i < source.Count; i++)
+    internal static void Copy(NativeDetectionResult source, ref DetectionResult destination)
+    {
+      var detections = destination.detections ?? new List<Detection>((int)source.detectionsCount);
+      detections.ResizeTo((int)source.detectionsCount);
+
+      var i = 0;
+      foreach (var nativeDetection in source.AsReadOnlySpan())
       {
-        detections.Add(Detection.CreateFrom(source[i]));
+        var detection = detections[i];
+        Detection.Copy(nativeDetection, ref detection);
+        detections[i++] = detection;
       }
     }
 

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

@@ -36,6 +36,16 @@ internal NormalizedKeypoint(float x, float y, string label, float? score)
       this.score = score;
     }
 
+    internal NormalizedKeypoint(NativeNormalizedKeypoint nativeKeypoint) : this(
+      nativeKeypoint.x,
+      nativeKeypoint.y,
+      nativeKeypoint.label,
+#pragma warning disable IDE0004 // for Unity 2020.3.x
+      nativeKeypoint.hasScore ? (float?)nativeKeypoint.score : null)
+#pragma warning restore IDE0004 // for Unity 2020.3.x
+    {
+    }
+
     public override string ToString() => $"{{ \"x\": {x}, \"y\": {y}, \"label\": \"{label}\", \"score\": {Util.Format(score)} }}";
   }
 }

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

@@ -10,6 +10,13 @@ namespace Mediapipe.Tasks.Components.Containers
 {
   public static class PacketExtension
   {
+    public static void GetDetectionResult(this Packet packet, ref DetectionResult value)
+    {
+      UnsafeNativeMethods.mp_Packet__GetDetectionResult(packet.mpPtr, out var detectionResult).Assert();
+      DetectionResult.Copy(detectionResult, ref value);
+      detectionResult.Dispose();
+    }
+
     public static void GetNormalizedLandmarksList(this Packet packet, List<NormalizedLandmarks> outs)
     {
       UnsafeNativeMethods.mp_Packet__GetNormalizedLandmarksVector(packet.mpPtr, out var landmarksArray).Assert();

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

@@ -29,6 +29,8 @@ internal Rect(int left, int top, int right, int bottom)
       this.bottom = bottom;
     }
 
+    internal Rect(NativeRect nativeRect) : this(nativeRect.left, nativeRect.top, nativeRect.right, nativeRect.bottom) { }
+
     public override string ToString() => $"{{ \"left\": {left}, \"top\": {top}, \"right\": {right}, \"bottom\": {bottom} }}";
   }
 
@@ -48,6 +50,16 @@ internal Rect(int left, int top, int right, int bottom)
     public readonly float right;
     public readonly float bottom;
 
+    internal RectF(float left, float top, float right, float bottom)
+    {
+      this.left = left;
+      this.top = top;
+      this.right = right;
+      this.bottom = bottom;
+    }
+
+    internal RectF(NativeRectF nativeRect) : this(nativeRect.left, nativeRect.top, nativeRect.right, nativeRect.bottom) { }
+
 #nullable enable
     public override bool Equals(object? obj) => obj is RectF other && Equals(other);
 #nullable disable

mediapipe_api/BUILD

@@ -164,6 +164,7 @@ cc_library(
         "//mediapipe_api/framework/formats:matrix_data",
         "//mediapipe_api/framework/formats:rect",
         "//mediapipe_api/framework/port:logging",
+        "//mediapipe_api/tasks/c/components/containers:detection_result",
         "//mediapipe_api/tasks/c/components/containers:landmark",
         "//mediapipe_api/tasks/cc/vision/face_geometry/proto:face_geometry",
         "//mediapipe_api/tasks/cc/core:task_runner",