extended RcStackArray up to 512 elements (#41)

src/DotRecast.Core/Collections/RcStackArray16.cs

@@ -0,0 +1,95 @@
+using System;
+using System.Runtime.CompilerServices;
+
+namespace DotRecast.Core.Collections
+{
+    public struct RcStackArray16<T>
+    {
+        public static RcStackArray16<T> Empty => new RcStackArray16<T>();
+
+        private const int Size = 16;
+        public int Length => Size;
+
+        public T V0;
+        public T V1;
+        public T V2;
+        public T V3;
+        public T V4;
+        public T V5;
+        public T V6;
+        public T V7;
+        public T V8;
+        public T V9;
+        public T V10;
+        public T V11;
+        public T V12;
+        public T V13;
+        public T V14;
+        public T V15;
+
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void ThrowExceptionIfIndexOutOfRange(int index)
+        {
+            if (0 > index || index >= Size)
+            {
+                throw new IndexOutOfRangeException($"{index}");
+            }
+        }
+
+        public T this[int index]
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                ThrowExceptionIfIndexOutOfRange(index);
+
+                return index switch
+                {
+                    0 => V0,
+                    1 => V1,
+                    2 => V2,
+                    3 => V3,
+                    4 => V4,
+                    5 => V5,
+                    6 => V6,
+                    7 => V7,
+                    8 => V8,
+                    9 => V9,
+                    10 => V10,
+                    11 => V11,
+                    12 => V12,
+                    13 => V13,
+                    14 => V14,
+                    15 => V15,
+                    _ => throw new IndexOutOfRangeException($"{index}")
+                };
+            }
+
+            set
+            {
+                ThrowExceptionIfIndexOutOfRange(index);
+
+                switch (index)
+                {
+                    case 0: V0 = value; break;
+                    case 1: V1 = value; break;
+                    case 2: V2 = value; break;
+                    case 3: V3 = value; break;
+                    case 4: V4 = value; break;
+                    case 5: V5 = value; break;
+                    case 6: V6 = value; break;
+                    case 7: V7 = value; break;
+                    case 8: V8 = value; break;
+                    case 9: V9 = value; break;
+                    case 10: V10 = value; break;
+                    case 11: V11 = value; break;
+                    case 12: V12 = value; break;
+                    case 13: V13 = value; break;
+                    case 14: V14 = value; break;
+                    case 15: V15 = value; break;
+                }
+            }
+        }
+    }
+}

src/DotRecast.Core/Collections/RcStackArray2.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Runtime.CompilerServices;
+
+namespace DotRecast.Core.Collections
+{
+    public struct RcStackArray2<T>
+    {
+        public static RcStackArray2<T> Empty => new RcStackArray2<T>();
+
+        private const int Size = 2;
+        public int Length => Size;
+
+        public T V0;
+        public T V1;
+
+        public T this[int index]
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                ThrowHelper.ThrowExceptionIfIndexOutOfRange(index, Length);
+
+                return index switch
+                {
+                    0 => V0,
+                    1 => V1,
+                    _ => throw new IndexOutOfRangeException($"{index}")
+                };
+            }
+
+            set
+            {
+                ThrowHelper.ThrowExceptionIfIndexOutOfRange(index, Length);
+
+                switch (index)
+                {
+                    case 0: V0 = value; break;
+                    case 1: V1 = value; break;
+                }
+            }
+        }
+    }
+}