#region License /* FNA - XNA4 Reimplementation for Desktop Platforms * Copyright 2009-2016 Ethan Lee and the MonoGame Team * * Released under the Microsoft Public License. * See LICENSE for details. */ #endregion #region Using Statements using System.IO; #endregion namespace Microsoft.Xna.Framework.Graphics { internal static class DxtUtil { #region Internal Static Methods internal static byte[] DecompressDxt1(byte[] imageData, int width, int height) { using (MemoryStream imageStream = new MemoryStream(imageData)) { return DecompressDxt1(imageStream, width, height); } } internal static byte[] DecompressDxt1(Stream imageStream, int width, int height) { byte[] imageData = new byte[width * height * 4]; using (BinaryReader imageReader = new BinaryReader(imageStream)) { int blockCountX = (width + 3) / 4; int blockCountY = (height + 3) / 4; for (int y = 0; y < blockCountY; y++) { for (int x = 0; x < blockCountX; x++) { DecompressDxt1Block(imageReader, x, y, blockCountX, width, height, imageData); } } } return imageData; } internal static byte[] DecompressDxt3(byte[] imageData, int width, int height) { using (MemoryStream imageStream = new MemoryStream(imageData)) { return DecompressDxt3(imageStream, width, height); } } internal static byte[] DecompressDxt3(Stream imageStream, int width, int height) { byte[] imageData = new byte[width * height * 4]; using (BinaryReader imageReader = new BinaryReader(imageStream)) { int blockCountX = (width + 3) / 4; int blockCountY = (height + 3) / 4; for (int y = 0; y < blockCountY; y++) { for (int x = 0; x < blockCountX; x++) { DecompressDxt3Block(imageReader, x, y, blockCountX, width, height, imageData); } } } return imageData; } internal static byte[] DecompressDxt5(byte[] imageData, int width, int height) { using (MemoryStream imageStream = new MemoryStream(imageData)) { return DecompressDxt5(imageStream, width, height); } } internal static byte[] DecompressDxt5(Stream imageStream, int width, int height) { byte[] imageData = new byte[width * height * 4]; using (BinaryReader imageReader = new BinaryReader(imageStream)) { int blockCountX = (width + 3) / 4; int blockCountY = (height + 3) / 4; for (int y = 0; y < blockCountY; y++) { for (int x = 0; x < blockCountX; x++) { DecompressDxt5Block(imageReader, x, y, blockCountX, width, height, imageData); } } } return imageData; } #endregion #region Private Static Methods private static void DecompressDxt1Block(BinaryReader imageReader, int x, int y, int blockCountX, int width, int height, byte[] imageData) { ushort c0 = imageReader.ReadUInt16(); ushort c1 = imageReader.ReadUInt16(); byte r0, g0, b0; byte r1, g1, b1; ConvertRgb565ToRgb888(c0, out r0, out g0, out b0); ConvertRgb565ToRgb888(c1, out r1, out g1, out b1); uint lookupTable = imageReader.ReadUInt32(); for (int blockY = 0; blockY < 4; blockY++) { for (int blockX = 0; blockX < 4; blockX++) { byte r = 0, g = 0, b = 0, a = 255; uint index = (lookupTable >> 2 * (4 * blockY + blockX)) & 0x03; if (c0 > c1) { switch (index) { case 0: r = r0; g = g0; b = b0; break; case 1: r = r1; g = g1; b = b1; break; case 2: r = (byte) ((2 * r0 + r1) / 3); g = (byte) ((2 * g0 + g1) / 3); b = (byte) ((2 * b0 + b1) / 3); break; case 3: r = (byte) ((r0 + 2 * r1) / 3); g = (byte) ((g0 + 2 * g1) / 3); b = (byte) ((b0 + 2 * b1) / 3); break; } } else { switch (index) { case 0: r = r0; g = g0; b = b0; break; case 1: r = r1; g = g1; b = b1; break; case 2: r = (byte) ((r0 + r1) / 2); g = (byte) ((g0 + g1) / 2); b = (byte) ((b0 + b1) / 2); break; case 3: r = 0; g = 0; b = 0; a = 0; break; } } int px = (x << 2) + blockX; int py = (y << 2) + blockY; if ((px < width) && (py < height)) { int offset = ((py * width) + px) << 2; imageData[offset] = r; imageData[offset + 1] = g; imageData[offset + 2] = b; imageData[offset + 3] = a; } } } } private static void DecompressDxt3Block(BinaryReader imageReader, int x, int y, int blockCountX, int width, int height, byte[] imageData) { byte a0 = imageReader.ReadByte(); byte a1 = imageReader.ReadByte(); byte a2 = imageReader.ReadByte(); byte a3 = imageReader.ReadByte(); byte a4 = imageReader.ReadByte(); byte a5 = imageReader.ReadByte(); byte a6 = imageReader.ReadByte(); byte a7 = imageReader.ReadByte(); ushort c0 = imageReader.ReadUInt16(); ushort c1 = imageReader.ReadUInt16(); byte r0, g0, b0; byte r1, g1, b1; ConvertRgb565ToRgb888(c0, out r0, out g0, out b0); ConvertRgb565ToRgb888(c1, out r1, out g1, out b1); uint lookupTable = imageReader.ReadUInt32(); int alphaIndex = 0; for (int blockY = 0; blockY < 4; blockY++) { for (int blockX = 0; blockX < 4; blockX++) { byte r = 0, g = 0, b = 0, a = 0; uint index = (lookupTable >> 2 * (4 * blockY + blockX)) & 0x03; switch (alphaIndex) { case 0: a = (byte) ((a0 & 0x0F) | ((a0 & 0x0F) << 4)); break; case 1: a = (byte) ((a0 & 0xF0) | ((a0 & 0xF0) >> 4)); break; case 2: a = (byte) ((a1 & 0x0F) | ((a1 & 0x0F) << 4)); break; case 3: a = (byte) ((a1 & 0xF0) | ((a1 & 0xF0) >> 4)); break; case 4: a = (byte) ((a2 & 0x0F) | ((a2 & 0x0F) << 4)); break; case 5: a = (byte) ((a2 & 0xF0) | ((a2 & 0xF0) >> 4)); break; case 6: a = (byte) ((a3 & 0x0F) | ((a3 & 0x0F) << 4)); break; case 7: a = (byte) ((a3 & 0xF0) | ((a3 & 0xF0) >> 4)); break; case 8: a = (byte) ((a4 & 0x0F) | ((a4 & 0x0F) << 4)); break; case 9: a = (byte) ((a4 & 0xF0) | ((a4 & 0xF0) >> 4)); break; case 10: a = (byte) ((a5 & 0x0F) | ((a5 & 0x0F) << 4)); break; case 11: a = (byte) ((a5 & 0xF0) | ((a5 & 0xF0) >> 4)); break; case 12: a = (byte) ((a6 & 0x0F) | ((a6 & 0x0F) << 4)); break; case 13: a = (byte) ((a6 & 0xF0) | ((a6 & 0xF0) >> 4)); break; case 14: a = (byte) ((a7 & 0x0F) | ((a7 & 0x0F) << 4)); break; case 15: a = (byte) ((a7 & 0xF0) | ((a7 & 0xF0) >> 4)); break; } ++alphaIndex; switch (index) { case 0: r = r0; g = g0; b = b0; break; case 1: r = r1; g = g1; b = b1; break; case 2: r = (byte) ((2 * r0 + r1) / 3); g = (byte) ((2 * g0 + g1) / 3); b = (byte) ((2 * b0 + b1) / 3); break; case 3: r = (byte) ((r0 + 2 * r1) / 3); g = (byte) ((g0 + 2 * g1) / 3); b = (byte) ((b0 + 2 * b1) / 3); break; } int px = (x << 2) + blockX; int py = (y << 2) + blockY; if ((px < width) && (py < height)) { int offset = ((py * width) + px) << 2; imageData[offset] = r; imageData[offset + 1] = g; imageData[offset + 2] = b; imageData[offset + 3] = a; } } } } private static void DecompressDxt5Block(BinaryReader imageReader, int x, int y, int blockCountX, int width, int height, byte[] imageData) { byte alpha0 = imageReader.ReadByte(); byte alpha1 = imageReader.ReadByte(); ulong alphaMask = (ulong) imageReader.ReadByte(); alphaMask += (ulong) imageReader.ReadByte() << 8; alphaMask += (ulong) imageReader.ReadByte() << 16; alphaMask += (ulong) imageReader.ReadByte() << 24; alphaMask += (ulong) imageReader.ReadByte() << 32; alphaMask += (ulong) imageReader.ReadByte() << 40; ushort c0 = imageReader.ReadUInt16(); ushort c1 = imageReader.ReadUInt16(); byte r0, g0, b0; byte r1, g1, b1; ConvertRgb565ToRgb888(c0, out r0, out g0, out b0); ConvertRgb565ToRgb888(c1, out r1, out g1, out b1); uint lookupTable = imageReader.ReadUInt32(); for (int blockY = 0; blockY < 4; blockY++) { for (int blockX = 0; blockX < 4; blockX++) { byte r = 0, g = 0, b = 0, a = 255; uint index = (lookupTable >> 2 * (4 * blockY + blockX)) & 0x03; uint alphaIndex = (uint) ((alphaMask >> 3 * (4 * blockY + blockX)) & 0x07); if (alphaIndex == 0) { a = alpha0; } else if (alphaIndex == 1) { a = alpha1; } else if (alpha0 > alpha1) { a = (byte) (((8 - alphaIndex) * alpha0 + (alphaIndex - 1) * alpha1) / 7); } else if (alphaIndex == 6) { a = 0; } else if (alphaIndex == 7) { a = 0xff; } else { a = (byte) (((6 - alphaIndex) * alpha0 + (alphaIndex - 1) * alpha1) / 5); } switch (index) { case 0: r = r0; g = g0; b = b0; break; case 1: r = r1; g = g1; b = b1; break; case 2: r = (byte) ((2 * r0 + r1) / 3); g = (byte) ((2 * g0 + g1) / 3); b = (byte) ((2 * b0 + b1) / 3); break; case 3: r = (byte) ((r0 + 2 * r1) / 3); g = (byte) ((g0 + 2 * g1) / 3); b = (byte) ((b0 + 2 * b1) / 3); break; } int px = (x << 2) + blockX; int py = (y << 2) + blockY; if ((px < width) && (py < height)) { int offset = ((py * width) + px) << 2; imageData[offset] = r; imageData[offset + 1] = g; imageData[offset + 2] = b; imageData[offset + 3] = a; } } } } private static void ConvertRgb565ToRgb888(ushort color, out byte r, out byte g, out byte b) { int temp; temp = (color >> 11) * 255 + 16; r = (byte) ((temp / 32 + temp) / 32); temp = ((color & 0x07E0) >> 5) * 255 + 32; g = (byte) ((temp / 64 + temp) / 64); temp = (color & 0x001F) * 255 + 16; b = (byte) ((temp / 32 + temp) / 32); } #endregion } }