1 files changed, 639 insertions, 73 deletions
diff --git a/Ryujinx.Graphics.Texture/BCnDecoder.cs b/Ryujinx.Graphics.Texture/BCnDecoder.cs
index b8b04bac..b840cac8 100644
--- a/Ryujinx.Graphics.Texture/BCnDecoder.cs
+++ b/Ryujinx.Graphics.Texture/BCnDecoder.cs
@@ -1,7 +1,9 @@
 using Ryujinx.Common;
 using System;
-using System.Runtime.CompilerServices;
+using System.Buffers.Binary;
 using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.X86;
 
 namespace Ryujinx.Graphics.Texture
 {
@@ -10,6 +12,286 @@ namespace Ryujinx.Graphics.Texture
         private const int BlockWidth = 4;
         private const int BlockHeight = 4;
 
+        public static byte[] DecodeBC1(ReadOnlySpan<byte> data, int width, int height, int depth, int levels, int layers)
+        {
+            int size = 0;
+
+            for (int l = 0; l < levels; l++)
+            {
+                size += Math.Max(1, width >> l) * Math.Max(1, height >> l) * Math.Max(1, depth >> l) * layers * 4;
+            }
+
+            byte[] output = new byte[size];
+
+            Span<byte> tile = stackalloc byte[BlockWidth * BlockHeight * 4];
+
+            Span<uint> tileAsUint = MemoryMarshal.Cast<byte, uint>(tile);
+            Span<uint> outputAsUint = MemoryMarshal.Cast<byte, uint>(output);
+
+            Span<Vector128<byte>> tileAsVector128 = MemoryMarshal.Cast<byte, Vector128<byte>>(tile);
+
+            Span<Vector128<byte>> outputLine0 = default;
+            Span<Vector128<byte>> outputLine1 = default;
+            Span<Vector128<byte>> outputLine2 = default;
+            Span<Vector128<byte>> outputLine3 = default;
+
+            int imageBaseOOffs = 0;
+
+            for (int l = 0; l < levels; l++)
+            {
+                int w = BitUtils.DivRoundUp(width, BlockWidth);
+                int h = BitUtils.DivRoundUp(height, BlockHeight);
+
+                for (int l2 = 0; l2 < layers; l2++)
+                {
+                    for (int z = 0; z < depth; z++)
+                    {
+                        for (int y = 0; y < h; y++)
+                        {
+                            int baseY = y * BlockHeight;
+                            int copyHeight = Math.Min(BlockHeight, height - baseY);
+                            int lineBaseOOffs = imageBaseOOffs + baseY * width;
+
+                            if (copyHeight == 4)
+                            {
+                                outputLine0 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs));
+                                outputLine1 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs + width));
+                                outputLine2 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs + width * 2));
+                                outputLine3 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs + width * 3));
+                            }
+
+                            for (int x = 0; x < w; x++)
+                            {
+                                int baseX = x * BlockWidth;
+                                int copyWidth = Math.Min(BlockWidth, width - baseX);
+
+                                BC1DecodeTileRgb(tile, data);
+
+                                if ((copyWidth | copyHeight) == 4)
+                                {
+                                    outputLine0[x] = tileAsVector128[0];
+                                    outputLine1[x] = tileAsVector128[1];
+                                    outputLine2[x] = tileAsVector128[2];
+                                    outputLine3[x] = tileAsVector128[3];
+                                }
+                                else
+                                {
+                                    int pixelBaseOOffs = lineBaseOOffs + baseX;
+
+                                    for (int tY = 0; tY < copyHeight; tY++)
+                                    {
+                                        tileAsUint.Slice(tY * 4, copyWidth).CopyTo(outputAsUint.Slice(pixelBaseOOffs + width * tY, copyWidth));
+                                    }
+                                }
+
+                                data = data.Slice(8);
+                            }
+                        }
+
+                        imageBaseOOffs += width * height;
+                    }
+                }
+
+                width = Math.Max(1, width >> 1);
+                height = Math.Max(1, height >> 1);
+                depth = Math.Max(1, depth >> 1);
+            }
+
+            return output;
+        }
+
+        public static byte[] DecodeBC2(ReadOnlySpan<byte> data, int width, int height, int depth, int levels, int layers)
+        {
+            int size = 0;
+
+            for (int l = 0; l < levels; l++)
+            {
+                size += Math.Max(1, width >> l) * Math.Max(1, height >> l) * Math.Max(1, depth >> l) * layers * 4;
+            }
+
+            byte[] output = new byte[size];
+
+            Span<byte> tile = stackalloc byte[BlockWidth * BlockHeight * 4];
+
+            Span<uint> tileAsUint = MemoryMarshal.Cast<byte, uint>(tile);
+            Span<uint> outputAsUint = MemoryMarshal.Cast<byte, uint>(output);
+
+            Span<Vector128<byte>> tileAsVector128 = MemoryMarshal.Cast<byte, Vector128<byte>>(tile);
+
+            Span<Vector128<byte>> outputLine0 = default;
+            Span<Vector128<byte>> outputLine1 = default;
+            Span<Vector128<byte>> outputLine2 = default;
+            Span<Vector128<byte>> outputLine3 = default;
+
+            int imageBaseOOffs = 0;
+
+            for (int l = 0; l < levels; l++)
+            {
+                int w = BitUtils.DivRoundUp(width, BlockWidth);
+                int h = BitUtils.DivRoundUp(height, BlockHeight);
+
+                for (int l2 = 0; l2 < layers; l2++)
+                {
+                    for (int z = 0; z < depth; z++)
+                    {
+                        for (int y = 0; y < h; y++)
+                        {
+                            int baseY = y * BlockHeight;
+                            int copyHeight = Math.Min(BlockHeight, height - baseY);
+                            int lineBaseOOffs = imageBaseOOffs + baseY * width;
+
+                            if (copyHeight == 4)
+                            {
+                                outputLine0 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs));
+                                outputLine1 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs + width));
+                                outputLine2 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs + width * 2));
+                                outputLine3 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs + width * 3));
+                            }
+
+                            for (int x = 0; x < w; x++)
+                            {
+                                int baseX = x * BlockWidth;
+                                int copyWidth = Math.Min(BlockWidth, width - baseX);
+
+                                BC23DecodeTileRgb(tile, data.Slice(8));
+
+                                ulong block = BinaryPrimitives.ReadUInt64LittleEndian(data);
+
+                                for (int i = 3; i < BlockWidth * BlockHeight * 4; i += 4, block >>= 4)
+                                {
+                                    tile[i] = (byte)((block & 0xf) | (block << 4));
+                                }
+
+                                if ((copyWidth | copyHeight) == 4)
+                                {
+                                    outputLine0[x] = tileAsVector128[0];
+                                    outputLine1[x] = tileAsVector128[1];
+                                    outputLine2[x] = tileAsVector128[2];
+                                    outputLine3[x] = tileAsVector128[3];
+                                }
+                                else
+                                {
+                                    int pixelBaseOOffs = lineBaseOOffs + baseX;
+
+                                    for (int tY = 0; tY < copyHeight; tY++)
+                                    {
+                                        tileAsUint.Slice(tY * 4, copyWidth).CopyTo(outputAsUint.Slice(pixelBaseOOffs + width * tY, copyWidth));
+                                    }
+                                }
+
+                                data = data.Slice(16);
+                            }
+                        }
+
+                        imageBaseOOffs += width * height;
+                    }
+                }
+
+                width = Math.Max(1, width >> 1);
+                height = Math.Max(1, height >> 1);
+                depth = Math.Max(1, depth >> 1);
+            }
+
+            return output;
+        }
+
+        public static byte[] DecodeBC3(ReadOnlySpan<byte> data, int width, int height, int depth, int levels, int layers)
+        {
+            int size = 0;
+
+            for (int l = 0; l < levels; l++)
+            {
+                size += Math.Max(1, width >> l) * Math.Max(1, height >> l) * Math.Max(1, depth >> l) * layers * 4;
+            }
+
+            byte[] output = new byte[size];
+
+            Span<byte> tile = stackalloc byte[BlockWidth * BlockHeight * 4];
+            Span<byte> rPal = stackalloc byte[8];
+
+            Span<uint> tileAsUint = MemoryMarshal.Cast<byte, uint>(tile);
+            Span<uint> outputAsUint = MemoryMarshal.Cast<byte, uint>(output);
+
+            Span<Vector128<byte>> tileAsVector128 = MemoryMarshal.Cast<byte, Vector128<byte>>(tile);
+
+            Span<Vector128<byte>> outputLine0 = default;
+            Span<Vector128<byte>> outputLine1 = default;
+            Span<Vector128<byte>> outputLine2 = default;
+            Span<Vector128<byte>> outputLine3 = default;
+
+            int imageBaseOOffs = 0;
+
+            for (int l = 0; l < levels; l++)
+            {
+                int w = BitUtils.DivRoundUp(width, BlockWidth);
+                int h = BitUtils.DivRoundUp(height, BlockHeight);
+
+                for (int l2 = 0; l2 < layers; l2++)
+                {
+                    for (int z = 0; z < depth; z++)
+                    {
+                        for (int y = 0; y < h; y++)
+                        {
+                            int baseY = y * BlockHeight;
+                            int copyHeight = Math.Min(BlockHeight, height - baseY);
+                            int lineBaseOOffs = imageBaseOOffs + baseY * width;
+
+                            if (copyHeight == 4)
+                            {
+                                outputLine0 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs));
+                                outputLine1 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs + width));
+                                outputLine2 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs + width * 2));
+                                outputLine3 = MemoryMarshal.Cast<uint, Vector128<byte>>(outputAsUint.Slice(lineBaseOOffs + width * 3));
+                            }
+
+                            for (int x = 0; x < w; x++)
+                            {
+                                int baseX = x * BlockWidth;
+                                int copyWidth = Math.Min(BlockWidth, width - baseX);
+
+                                BC23DecodeTileRgb(tile, data.Slice(8));
+
+                                ulong block = BinaryPrimitives.ReadUInt64LittleEndian(data);
+
+                                rPal[0] = (byte)block;
+                                rPal[1] = (byte)(block >> 8);
+
+                                BCnLerpAlphaUnorm(rPal);
+                                BCnDecodeTileAlphaRgba(tile, rPal, block >> 16);
+
+                                if ((copyWidth | copyHeight) == 4)
+                                {
+                                    outputLine0[x] = tileAsVector128[0];
+                                    outputLine1[x] = tileAsVector128[1];
+                                    outputLine2[x] = tileAsVector128[2];
+                                    outputLine3[x] = tileAsVector128[3];
+                                }
+                                else
+                                {
+                                    int pixelBaseOOffs = lineBaseOOffs + baseX;
+
+                                    for (int tY = 0; tY < copyHeight; tY++)
+                                    {
+                                        tileAsUint.Slice(tY * 4, copyWidth).CopyTo(outputAsUint.Slice(pixelBaseOOffs + width * tY, copyWidth));
+                                    }
+                                }
+
+                                data = data.Slice(16);
+                            }
+                        }
+
+                        imageBaseOOffs += width * height;
+                    }
+                }
+
+                width = Math.Max(1, width >> 1);
+                height = Math.Max(1, height >> 1);
+                depth = Math.Max(1, depth >> 1);
+            }
+
+            return output;
+        }
+
         public static byte[] DecodeBC4(ReadOnlySpan<byte> data, int width, int height, int depth, int levels, int layers, bool signed)
         {
             int size = 0;
@@ -20,12 +302,21 @@ namespace Ryujinx.Graphics.Texture
             }
 
             byte[] output = new byte[size];
+            Span<byte> outputSpan = new Span<byte>(output);
 
             ReadOnlySpan<ulong> data64 = MemoryMarshal.Cast<byte, ulong>(data);
 
+            Span<byte> tile = stackalloc byte[BlockWidth * BlockHeight];
             Span<byte> rPal = stackalloc byte[8];
 
-            int baseOOffs = 0;
+            Span<uint> tileAsUint = MemoryMarshal.Cast<byte, uint>(tile);
+
+            Span<uint> outputLine0 = default;
+            Span<uint> outputLine1 = default;
+            Span<uint> outputLine2 = default;
+            Span<uint> outputLine3 = default;
+
+            int imageBaseOOffs = 0;
 
             for (int l = 0; l < levels; l++)
             {
@@ -39,11 +330,21 @@ namespace Ryujinx.Graphics.Texture
                         for (int y = 0; y < h; y++)
                         {
                             int baseY = y * BlockHeight;
+                            int copyHeight = Math.Min(BlockHeight, height - baseY);
+                            int lineBaseOOffs = imageBaseOOffs + baseY * width;
+
+                            if (copyHeight == 4)
+                            {
+                                outputLine0 = MemoryMarshal.Cast<byte, uint>(outputSpan.Slice(lineBaseOOffs));
+                                outputLine1 = MemoryMarshal.Cast<byte, uint>(outputSpan.Slice(lineBaseOOffs + width));
+                                outputLine2 = MemoryMarshal.Cast<byte, uint>(outputSpan.Slice(lineBaseOOffs + width * 2));
+                                outputLine3 = MemoryMarshal.Cast<byte, uint>(outputSpan.Slice(lineBaseOOffs + width * 3));
+                            }
 
                             for (int x = 0; x < w; x++)
                             {
                                 int baseX = x * BlockWidth;
-                                int lineBaseOOffs = baseOOffs + baseX;
+                                int copyWidth = Math.Min(BlockWidth, width - baseX);
 
                                 ulong block = data64[0];
 
@@ -52,45 +353,43 @@ namespace Ryujinx.Graphics.Texture
 
                                 if (signed)
                                 {
-                                    CalculateBC3AlphaS(rPal);
+                                    BCnLerpAlphaSnorm(rPal);
                                 }
                                 else
                                 {
-                                    CalculateBC3Alpha(rPal);
+                                    BCnLerpAlphaUnorm(rPal);
                                 }
 
-                                ulong rI = block >> 16;
+                                BCnDecodeTileAlpha(tile, rPal, block >> 16);
 
-                                for (int texel = 0; texel < BlockWidth * BlockHeight; texel++)
+                                if ((copyWidth | copyHeight) == 4)
                                 {
-                                    int tX = texel & 3;
-                                    int tY = texel >> 2;
+                                    outputLine0[x] = tileAsUint[0];
+                                    outputLine1[x] = tileAsUint[1];
+                                    outputLine2[x] = tileAsUint[2];
+                                    outputLine3[x] = tileAsUint[3];
+                                }
+                                else
+                                {
+                                    int pixelBaseOOffs = lineBaseOOffs + baseX;
 
-                                    if (baseX + tX >= width || baseY + tY >= height)
+                                    for (int tY = 0; tY < copyHeight; tY++)
                                     {
-                                        continue;
+                                        tile.Slice(tY * 4, copyWidth).CopyTo(outputSpan.Slice(pixelBaseOOffs + width * tY, copyWidth));
                                     }
-
-                                    int shift = texel * 3;
-
-                                    byte r = rPal[(int)((rI >> shift) & 7)];
-
-                                    int oOffs = lineBaseOOffs + tY * width + tX;
-
-                                    output[oOffs] = r;
                                 }
 
                                 data64 = data64.Slice(1);
                             }
-
-                            baseOOffs += width * (baseY + BlockHeight > height ? (height & (BlockHeight - 1)) : BlockHeight);
                         }
+
+                        imageBaseOOffs += width * height;
                     }
                 }
 
-                width  = Math.Max(1, width  >> 1);
+                width = Math.Max(1, width >> 1);
                 height = Math.Max(1, height >> 1);
-                depth  = Math.Max(1, depth  >> 1);
+                depth = Math.Max(1, depth >> 1);
             }
 
             return output;
@@ -109,10 +408,22 @@ namespace Ryujinx.Graphics.Texture
 
             ReadOnlySpan<ulong> data64 = MemoryMarshal.Cast<byte, ulong>(data);
 
+            Span<byte> rTile = stackalloc byte[BlockWidth * BlockHeight * 2];
+            Span<byte> gTile = stackalloc byte[BlockWidth * BlockHeight * 2];
             Span<byte> rPal = stackalloc byte[8];
             Span<byte> gPal = stackalloc byte[8];
 
-            int baseOOffs = 0;
+            Span<ushort> outputAsUshort = MemoryMarshal.Cast<byte, ushort>(output);
+
+            Span<uint> rTileAsUint = MemoryMarshal.Cast<byte, uint>(rTile);
+            Span<uint> gTileAsUint = MemoryMarshal.Cast<byte, uint>(gTile);
+
+            Span<ulong> outputLine0 = default;
+            Span<ulong> outputLine1 = default;
+            Span<ulong> outputLine2 = default;
+            Span<ulong> outputLine3 = default;
+
+            int imageBaseOOffs = 0;
 
             for (int l = 0; l < levels; l++)
             {
@@ -126,11 +437,21 @@ namespace Ryujinx.Graphics.Texture
                         for (int y = 0; y < h; y++)
                         {
                             int baseY = y * BlockHeight;
+                            int copyHeight = Math.Min(BlockHeight, height - baseY);
+                            int lineBaseOOffs = imageBaseOOffs + baseY * width;
+
+                            if (copyHeight == 4)
+                            {
+                                outputLine0 = MemoryMarshal.Cast<ushort, ulong>(outputAsUshort.Slice(lineBaseOOffs));
+                                outputLine1 = MemoryMarshal.Cast<ushort, ulong>(outputAsUshort.Slice(lineBaseOOffs + width));
+                                outputLine2 = MemoryMarshal.Cast<ushort, ulong>(outputAsUshort.Slice(lineBaseOOffs + width * 2));
+                                outputLine3 = MemoryMarshal.Cast<ushort, ulong>(outputAsUshort.Slice(lineBaseOOffs + width * 3));
+                            }
 
                             for (int x = 0; x < w; x++)
                             {
                                 int baseX = x * BlockWidth;
-                                int lineBaseOOffs = baseOOffs + baseX;
+                                int copyWidth = Math.Min(BlockWidth, width - baseX);
 
                                 ulong blockL = data64[0];
                                 ulong blockH = data64[1];
@@ -142,101 +463,346 @@ namespace Ryujinx.Graphics.Texture
 
                                 if (signed)
                                 {
-                                    CalculateBC3AlphaS(rPal);
-                                    CalculateBC3AlphaS(gPal);
+                                    BCnLerpAlphaSnorm(rPal);
+                                    BCnLerpAlphaSnorm(gPal);
                                 }
                                 else
                                 {
-                                    CalculateBC3Alpha(rPal);
-                                    CalculateBC3Alpha(gPal);
+                                    BCnLerpAlphaUnorm(rPal);
+                                    BCnLerpAlphaUnorm(gPal);
                                 }
 
-                                ulong rI = blockL >> 16;
-                                ulong gI = blockH >> 16;
+                                BCnDecodeTileAlpha(rTile, rPal, blockL >> 16);
+                                BCnDecodeTileAlpha(gTile, gPal, blockH >> 16);
 
-                                for (int texel = 0; texel < BlockWidth * BlockHeight; texel++)
+                                if ((copyWidth | copyHeight) == 4)
                                 {
-                                    int tX = texel & 3;
-                                    int tY = texel >> 2;
+                                    outputLine0[x] = InterleaveBytes(rTileAsUint[0], gTileAsUint[0]);
+                                    outputLine1[x] = InterleaveBytes(rTileAsUint[1], gTileAsUint[1]);
+                                    outputLine2[x] = InterleaveBytes(rTileAsUint[2], gTileAsUint[2]);
+                                    outputLine3[x] = InterleaveBytes(rTileAsUint[3], gTileAsUint[3]);
+                                }
+                                else
+                                {
+                                    int pixelBaseOOffs = lineBaseOOffs + baseX;
 
-                                    if (baseX + tX >= width || baseY + tY >= height)
+                                    for (int tY = 0; tY < copyHeight; tY++)
                                     {
-                                        continue;
-                                    }
-
-                                    int shift = texel * 3;
+                                        int line = pixelBaseOOffs + width * tY;
 
-                                    byte r = rPal[(int)((rI >> shift) & 7)];
-                                    byte g = gPal[(int)((gI >> shift) & 7)];
+                                        for (int tX = 0; tX < copyWidth; tX++)
+                                        {
+                                            int texel = tY * BlockWidth + tX;
 
-                                    int oOffs = (lineBaseOOffs + tY * width + tX) * 2;
-
-                                    output[oOffs + 0] = r;
-                                    output[oOffs + 1] = g;
+                                            outputAsUshort[line + tX] = (ushort)(rTile[texel] | (gTile[texel] << 8));
+                                        }
+                                    }
                                 }
 
                                 data64 = data64.Slice(2);
                             }
-
-                            baseOOffs += width * (baseY + BlockHeight > height ? (height & (BlockHeight - 1)) : BlockHeight);
                         }
+
+                        imageBaseOOffs += width * height;
                     }
                 }
 
-                width  = Math.Max(1, width  >> 1);
+                width = Math.Max(1, width >> 1);
                 height = Math.Max(1, height >> 1);
-                depth  = Math.Max(1, depth  >> 1);
+                depth = Math.Max(1, depth >> 1);
             }
 
             return output;
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static void CalculateBC3Alpha(Span<byte> alpha)
+        private static ulong InterleaveBytes(uint left, uint right)
+        {
+            return InterleaveBytesWithZeros(left) | (InterleaveBytesWithZeros(right) << 8);
+        }
+
+        private static ulong InterleaveBytesWithZeros(uint value)
+        {
+            ulong output = value;
+            output = (output ^ (output << 16)) & 0xffff0000ffffUL;
+            output = (output ^ (output << 8)) & 0xff00ff00ff00ffUL;
+            return output;
+        }
+
+        private static void BCnLerpAlphaUnorm(Span<byte> alpha)
         {
-            for (int i = 2; i < 8; i++)
+            byte a0 = alpha[0];
+            byte a1 = alpha[1];
+
+            if (a0 > a1)
+            {
+                alpha[2] = (byte)((6 * a0 + 1 * a1) / 7);
+                alpha[3] = (byte)((5 * a0 + 2 * a1) / 7);
+                alpha[4] = (byte)((4 * a0 + 3 * a1) / 7);
+                alpha[5] = (byte)((3 * a0 + 4 * a1) / 7);
+                alpha[6] = (byte)((2 * a0 + 5 * a1) / 7);
+                alpha[7] = (byte)((1 * a0 + 6 * a1) / 7);
+            }
+            else
             {
-                if (alpha[0] > alpha[1])
+                alpha[2] = (byte)((4 * a0 + 1 * a1) / 5);
+                alpha[3] = (byte)((3 * a0 + 2 * a1) / 5);
+                alpha[4] = (byte)((2 * a0 + 3 * a1) / 5);
+                alpha[5] = (byte)((1 * a0 + 4 * a1) / 5);
+                alpha[6] = 0;
+                alpha[7] = 0xff;
+            }
+        }
+
+        private static void BCnLerpAlphaSnorm(Span<byte> alpha)
+        {
+            sbyte a0 = (sbyte)alpha[0];
+            sbyte a1 = (sbyte)alpha[1];
+
+            if (a0 > a1)
+            {
+                alpha[2] = (byte)((6 * a0 + 1 * a1) / 7);
+                alpha[3] = (byte)((5 * a0 + 2 * a1) / 7);
+                alpha[4] = (byte)((4 * a0 + 3 * a1) / 7);
+                alpha[5] = (byte)((3 * a0 + 4 * a1) / 7);
+                alpha[6] = (byte)((2 * a0 + 5 * a1) / 7);
+                alpha[7] = (byte)((1 * a0 + 6 * a1) / 7);
+            }
+            else
+            {
+                alpha[2] = (byte)((4 * a0 + 1 * a1) / 5);
+                alpha[3] = (byte)((3 * a0 + 2 * a1) / 5);
+                alpha[4] = (byte)((2 * a0 + 3 * a1) / 5);
+                alpha[5] = (byte)((1 * a0 + 4 * a1) / 5);
+                alpha[6] = 0x80;
+                alpha[7] = 0x7f;
+            }
+        }
+
+        private unsafe static void BCnDecodeTileAlpha(Span<byte> output, Span<byte> rPal, ulong rI)
+        {
+            if (Avx2.IsSupported)
+            {
+                Span<Vector128<byte>> outputAsVector128 = MemoryMarshal.Cast<byte, Vector128<byte>>(output);
+
+                Vector128<uint> shifts = Vector128.Create(0u, 3u, 6u, 9u);
+                Vector128<uint> masks = Vector128.Create(7u);
+
+                Vector128<byte> vClut;
+
+                fixed (byte* pRPal = rPal)
                 {
-                    alpha[i] = (byte)(((8 - i) * alpha[0] + (i - 1) * alpha[1]) / 7);
+                    vClut = Sse2.LoadScalarVector128((ulong*)pRPal).AsByte();
                 }
-                else if (i < 6)
+
+                Vector128<uint> indices0 = Vector128.Create((uint)rI);
+                Vector128<uint> indices1 = Vector128.Create((uint)(rI >> 24));
+                Vector128<uint> indices00 = Avx2.ShiftRightLogicalVariable(indices0, shifts);
+                Vector128<uint> indices10 = Avx2.ShiftRightLogicalVariable(indices1, shifts);
+                Vector128<uint> indices01 = Sse2.ShiftRightLogical(indices00, 12);
+                Vector128<uint> indices11 = Sse2.ShiftRightLogical(indices10, 12);
+                indices00 = Sse2.And(indices00, masks);
+                indices10 = Sse2.And(indices10, masks);
+                indices01 = Sse2.And(indices01, masks);
+                indices11 = Sse2.And(indices11, masks);
+
+                Vector128<ushort> indicesW0 = Sse41.PackUnsignedSaturate(indices00.AsInt32(), indices01.AsInt32());
+                Vector128<ushort> indicesW1 = Sse41.PackUnsignedSaturate(indices10.AsInt32(), indices11.AsInt32());
+
+                Vector128<byte> indices = Sse2.PackUnsignedSaturate(indicesW0.AsInt16(), indicesW1.AsInt16());
+
+                outputAsVector128[0] = Ssse3.Shuffle(vClut, indices);
+            }
+            else
+            {
+                for (int i = 0; i < BlockWidth * BlockHeight; i++, rI >>= 3)
                 {
-                    alpha[i] = (byte)(((6 - i) * alpha[0] + (i - 1) * alpha[1]) / 7);
+                    output[i] = rPal[(int)(rI & 7)];
                 }
-                else if (i == 6)
+            }
+        }
+
+        private unsafe static void BCnDecodeTileAlphaRgba(Span<byte> output, Span<byte> rPal, ulong rI)
+        {
+            if (Avx2.IsSupported)
+            {
+                Span<Vector256<uint>> outputAsVector256 = MemoryMarshal.Cast<byte, Vector256<uint>>(output);
+
+                Vector256<uint> shifts = Vector256.Create(0u, 3u, 6u, 9u, 12u, 15u, 18u, 21u);
+
+                Vector128<uint> vClut128;
+
+                fixed (byte* pRPal = rPal)
                 {
-                    alpha[i] = 0;
+                    vClut128 = Sse2.LoadScalarVector128((ulong*)pRPal).AsUInt32();
                 }
-                else /* i == 7 */
+
+                Vector256<uint> vClut = Avx2.ConvertToVector256Int32(vClut128.AsByte()).AsUInt32();
+                vClut = Avx2.ShiftLeftLogical(vClut, 24);
+
+                Vector256<uint> indices0 = Vector256.Create((uint)rI);
+                Vector256<uint> indices1 = Vector256.Create((uint)(rI >> 24));
+
+                indices0 = Avx2.ShiftRightLogicalVariable(indices0, shifts);
+                indices1 = Avx2.ShiftRightLogicalVariable(indices1, shifts);
+
+                outputAsVector256[0] = Avx2.Or(outputAsVector256[0], Avx2.PermuteVar8x32(vClut, indices0));
+                outputAsVector256[1] = Avx2.Or(outputAsVector256[1], Avx2.PermuteVar8x32(vClut, indices1));
+            }
+            else
+            {
+                for (int i = 3; i < BlockWidth * BlockHeight * 4; i += 4, rI >>= 3)
                 {
-                    alpha[i] = 0xff;
+                    output[i] = rPal[(int)(rI & 7)];
                 }
             }
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static void CalculateBC3AlphaS(Span<byte> alpha)
+        private unsafe static void BC1DecodeTileRgb(Span<byte> output, ReadOnlySpan<byte> input)
+        {
+            Span<uint> clut = stackalloc uint[4];
+
+            uint c0c1 = BinaryPrimitives.ReadUInt32LittleEndian(input);
+            uint c0 = (ushort)c0c1;
+            uint c1 = (ushort)(c0c1 >> 16);
+
+            clut[0] = ConvertRgb565ToRgb888(c0) | 0xff000000;
+            clut[1] = ConvertRgb565ToRgb888(c1) | 0xff000000;
+            clut[2] = BC1LerpRgb2(clut[0], clut[1], c0, c1);
+            clut[3] = BC1LerpRgb3(clut[0], clut[1], c0, c1);
+
+            BCnDecodeTileRgb(clut, output, input);
+        }
+
+        private unsafe static void BC23DecodeTileRgb(Span<byte> output, ReadOnlySpan<byte> input)
         {
-            for (int i = 2; i < 8; i++)
+            Span<uint> clut = stackalloc uint[4];
+
+            uint c0c1 = BinaryPrimitives.ReadUInt32LittleEndian(input);
+            uint c0 = (ushort)c0c1;
+            uint c1 = (ushort)(c0c1 >> 16);
+
+            clut[0] = ConvertRgb565ToRgb888(c0);
+            clut[1] = ConvertRgb565ToRgb888(c1);
+            clut[2] = BC23LerpRgb2(clut[0], clut[1]);
+            clut[3] = BC23LerpRgb3(clut[0], clut[1]);
+
+            BCnDecodeTileRgb(clut, output, input);
+        }
+
+        private unsafe static void BCnDecodeTileRgb(Span<uint> clut, Span<byte> output, ReadOnlySpan<byte> input)
+        {
+            if (Avx2.IsSupported)
             {
-                if ((sbyte)alpha[0] > (sbyte)alpha[1])
-                {
-                    alpha[i] = (byte)(((8 - i) * (sbyte)alpha[0] + (i - 1) * (sbyte)alpha[1]) / 7);
-                }
-                else if (i < 6)
+                Span<Vector256<uint>> outputAsVector256 = MemoryMarshal.Cast<byte, Vector256<uint>>(output);
+
+                Vector256<uint> shifts0 = Vector256.Create(0u, 2u, 4u, 6u, 8u, 10u, 12u, 14u);
+                Vector256<uint> shifts1 = Vector256.Create(16u, 18u, 20u, 22u, 24u, 26u, 28u, 30u);
+                Vector256<uint> masks = Vector256.Create(3u);
+
+                Vector256<uint> vClut;
+
+                fixed (uint* pClut = &clut[0])
                 {
-                    alpha[i] = (byte)(((6 - i) * (sbyte)alpha[0] + (i - 1) * (sbyte)alpha[1]) / 7);
+                    vClut = Sse2.LoadVector128(pClut).ToVector256Unsafe();
                 }
-                else if (i == 6)
+
+                Vector256<uint> indices0;
+
+                fixed (byte* pInput = input)
                 {
-                    alpha[i] = 0x80;
+                    indices0 = Avx2.BroadcastScalarToVector256((uint*)(pInput + 4));
                 }
-                else /* i == 7 */
+
+                Vector256<uint> indices1 = indices0;
+
+                indices0 = Avx2.ShiftRightLogicalVariable(indices0, shifts0);
+                indices1 = Avx2.ShiftRightLogicalVariable(indices1, shifts1);
+                indices0 = Avx2.And(indices0, masks);
+                indices1 = Avx2.And(indices1, masks);
+
+                outputAsVector256[0] = Avx2.PermuteVar8x32(vClut, indices0);
+                outputAsVector256[1] = Avx2.PermuteVar8x32(vClut, indices1);
+            }
+            else
+            {
+                Span<uint> outputAsUint = MemoryMarshal.Cast<byte, uint>(output);
+
+                uint indices = BinaryPrimitives.ReadUInt32LittleEndian(input.Slice(4));
+
+                for (int i = 0; i < BlockWidth * BlockHeight; i++, indices >>= 2)
                 {
-                    alpha[i] = 0x7f;
+                    outputAsUint[i] = clut[(int)(indices & 3)];
                 }
             }
         }
+
+        private static uint BC1LerpRgb2(uint color0, uint color1, uint c0, uint c1)
+        {
+            if (c0 > c1)
+            {
+                return BC23LerpRgb2(color0, color1) | 0xff000000;
+            }
+
+            uint carry = color0 & color1;
+            uint addHalve = ((color0 ^ color1) >> 1) & 0x7f7f7f;
+            return (addHalve + carry) | 0xff000000;
+        }
+
+        private static uint BC23LerpRgb2(uint color0, uint color1)
+        {
+            uint r0 = (byte)color0;
+            uint g0 = color0 & 0xff00;
+            uint b0 = color0 & 0xff0000;
+
+            uint r1 = (byte)color1;
+            uint g1 = color1 & 0xff00;
+            uint b1 = color1 & 0xff0000;
+
+            uint mixR = (2 * r0 + r1) / 3;
+            uint mixG = (2 * g0 + g1) / 3;
+            uint mixB = (2 * b0 + b1) / 3;
+
+            return mixR | (mixG & 0xff00) | (mixB & 0xff0000);
+        }
+
+        private static uint BC1LerpRgb3(uint color0, uint color1, uint c0, uint c1)
+        {
+            if (c0 > c1)
+            {
+                return BC23LerpRgb3(color0, color1) | 0xff000000;
+            }
+
+            return 0;
+        }
+
+        private static uint BC23LerpRgb3(uint color0, uint color1)
+        {
+            uint r0 = (byte)color0;
+            uint g0 = color0 & 0xff00;
+            uint b0 = color0 & 0xff0000;
+
+            uint r1 = (byte)color1;
+            uint g1 = color1 & 0xff00;
+            uint b1 = color1 & 0xff0000;
+
+            uint mixR = (2 * r1 + r0) / 3;
+            uint mixG = (2 * g1 + g0) / 3;
+            uint mixB = (2 * b1 + b0) / 3;
+
+            return mixR | (mixG & 0xff00) | (mixB & 0xff0000);
+        }
+
+        private static uint ConvertRgb565ToRgb888(uint value)
+        {
+            uint b = (value & 0x1f) << 19;
+            uint g = (value << 5) & 0xfc00;
+            uint r = (value >> 8) & 0xf8;
+
+            b |= b >> 5;
+            g |= g >> 6;
+            r |= r >> 5;
+
+            return r | (g & 0xff00) | (b & 0xff0000);
+        }
     }
 }
 \ No newline at end of file