Initial work

Ryujinx.Graphics.Texture/SizeInfo.cs

@@ -0,0 +1,58 @@
+using Ryujinx.Common;
+using System;
+
+namespace Ryujinx.Graphics.Texture
+{
+    public struct SizeInfo
+    {
+        private int[] _mipOffsets;
+        private int[] _allOffsets;
+
+        private int _levels;
+
+        public int LayerSize { get; }
+        public int TotalSize { get; }
+
+        public SizeInfo(
+            int[] mipOffsets,
+            int[] allOffsets,
+            int   levels,
+            int   layerSize,
+            int   totalSize)
+        {
+            _mipOffsets = mipOffsets;
+            _allOffsets = allOffsets;
+            _levels     = levels;
+            LayerSize   = layerSize;
+            TotalSize   = totalSize;
+        }
+
+        public int GetMipOffset(int level)
+        {
+            if ((uint)level > _mipOffsets.Length)
+            {
+                throw new ArgumentOutOfRangeException(nameof(level));
+            }
+
+            return _mipOffsets[level];
+        }
+
+        public bool FindView(int offset, int size, out int firstLayer, out int firstLevel)
+        {
+            int index = Array.BinarySearch(_allOffsets, offset);
+
+            if (index < 0)
+            {
+                firstLayer = 0;
+                firstLevel = 0;
+
+                return false;
+            }
+
+            firstLayer = index / _levels;
+            firstLevel = index - (firstLayer * _levels);
+
+            return true;
+        }
+    }
+}