1 files changed, 119 insertions, 0 deletions
diff --git a/src/Ryujinx.Graphics.Texture/SizeInfo.cs b/src/Ryujinx.Graphics.Texture/SizeInfo.cs
new file mode 100644
index 00000000..eb573728
--- /dev/null
+++ b/src/Ryujinx.Graphics.Texture/SizeInfo.cs
@@ -0,0 +1,119 @@
+using System;
+using System.Collections.Generic;
+
+namespace Ryujinx.Graphics.Texture
+{
+    public readonly struct SizeInfo
+    {
+        private readonly int[] _mipOffsets;
+
+        private readonly int _levels;
+        private readonly int _depth;
+        private readonly bool _is3D;
+
+        public readonly int[] AllOffsets;
+        public readonly int[] SliceSizes;
+        public readonly int[] LevelSizes;
+        public int LayerSize { get; }
+        public int TotalSize { get; }
+
+        public SizeInfo(int size)
+        {
+            _mipOffsets = new int[] { 0 };
+            AllOffsets  = new int[] { 0 };
+            SliceSizes  = new int[] { size };
+            LevelSizes  = new int[] { size };
+            _depth      = 1;
+            _levels     = 1;
+            LayerSize   = size;
+            TotalSize   = size;
+            _is3D       = false;
+        }
+
+        internal SizeInfo(
+            int[] mipOffsets,
+            int[] allOffsets,
+            int[] sliceSizes,
+            int[] levelSizes,
+            int   depth,
+            int   levels,
+            int   layerSize,
+            int   totalSize,
+            bool  is3D)
+        {
+            _mipOffsets = mipOffsets;
+            AllOffsets  = allOffsets;
+            SliceSizes  = sliceSizes;
+            LevelSizes  = levelSizes;
+            _depth      = depth;
+            _levels     = levels;
+            LayerSize   = layerSize;
+            TotalSize   = totalSize;
+            _is3D       = is3D;
+        }
+
+        public int GetMipOffset(int level)
+        {
+            if ((uint)level >= _mipOffsets.Length)
+            {
+                throw new ArgumentOutOfRangeException(nameof(level));
+            }
+
+            return _mipOffsets[level];
+        }
+
+        public bool FindView(int offset, out int firstLayer, out int firstLevel)
+        {
+            int index = Array.BinarySearch(AllOffsets, offset);
+
+            if (index < 0)
+            {
+                firstLayer = 0;
+                firstLevel = 0;
+
+                return false;
+            }
+
+            if (_is3D)
+            {
+                firstLayer = index;
+                firstLevel = 0;
+
+                int levelDepth = _depth;
+
+                while (firstLayer >= levelDepth)
+                {
+                    firstLayer -= levelDepth;
+                    firstLevel++;
+                    levelDepth = Math.Max(levelDepth >> 1, 1);
+                }
+            }
+            else
+            {
+                firstLayer = index / _levels;
+                firstLevel = index - (firstLayer * _levels);
+            }
+
+            return true;
+        }
+
+        public IEnumerable<Region> AllRegions()
+        {
+            if (_is3D)
+            {
+                for (int i = 0; i < _mipOffsets.Length; i++)
+                {
+                    int maxSize = TotalSize - _mipOffsets[i];
+                    yield return new Region(_mipOffsets[i], Math.Min(maxSize, LevelSizes[i]));
+                }
+            }
+            else
+            {
+                for (int i = 0; i < AllOffsets.Length; i++)
+                {
+                    yield return new Region(AllOffsets[i], SliceSizes[i % _levels]);
+                }
+            }
+        }
+    }
+}
+\ No newline at end of file