// Copyright 2006 - 2008: Rory Plaire (codekaizen@gmail.com) // // This file is part of GeoAPI. // GeoAPI is free software; you can redistribute it and/or modify // it under the terms of the GNU Lesser General Public License as published by // the Free Software Foundation; either version 2 of the License, or // (at your option) any later version. // // GeoAPI is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU Lesser General Public License for more details. // You should have received a copy of the GNU Lesser General Public License // along with GeoAPI; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA using System; namespace GeoAPI.DataStructures { public static class ByteEncoder { #region Endian conversion helper routines /// <summary> /// Returns the value encoded in Big Endian (PPC, XDR) format. /// </summary> /// <param name="value">Value to encode.</param> /// <returns>Big-endian encoded value.</returns> public static Int32 GetBigEndian(Int32 value) { if (BitConverter.IsLittleEndian) { return swapByteOrder(value); } else { return value; } } /// <summary> /// Returns the value encoded in Big Endian (PPC, XDR) format. /// </summary> /// <param name="value">Value to encode.</param> /// <returns>Big-endian encoded value.</returns> [CLSCompliant(false)] public static UInt16 GetBigEndian(UInt16 value) { if (BitConverter.IsLittleEndian) { return swapByteOrder(value); } else { return value; } } /// <summary> /// Returns the value encoded in Big Endian (PPC, XDR) format. /// </summary> /// <param name="value">Value to encode.</param> /// <returns>Big-endian encoded value.</returns> [CLSCompliant(false)] public static UInt32 GetBigEndian(UInt32 value) { if (BitConverter.IsLittleEndian) { return swapByteOrder(value); } else { return value; } } /// <summary> /// Returns the value encoded in Big Endian (PPC, XDR) format. /// </summary> /// <param name="value">Value to encode.</param> /// <returns>Big-endian encoded value.</returns> public static Double GetBigEndian(Double value) { if (BitConverter.IsLittleEndian) { return swapByteOrder(value); } else { return value; } } /// <summary> /// Returns the value encoded in Little Endian (x86, NDR) format. /// </summary> /// <param name="value">Value to encode.</param> /// <returns>Little-endian encoded value.</returns> public static Int32 GetLittleEndian(Int32 value) { if (BitConverter.IsLittleEndian) { return value; } else { return swapByteOrder(value); } } /// <summary> /// Returns the value encoded in Little Endian (x86, NDR) format. /// </summary> /// <param name="value">Value to encode.</param> /// <returns>Little-endian encoded value.</returns> [CLSCompliant(false)] public static UInt32 GetLittleEndian(UInt32 value) { if (BitConverter.IsLittleEndian) { return value; } else { return swapByteOrder(value); } } /// <summary> /// Returns the value encoded in Little Endian (x86, NDR) format. /// </summary> /// <param name="value">Value to encode.</param> /// <returns>Little-endian encoded value.</returns> [CLSCompliant(false)] public static UInt16 GetLittleEndian(UInt16 value) { if (BitConverter.IsLittleEndian) { return value; } else { return swapByteOrder(value); } } /// <summary> /// Returns the value encoded in Little Endian (x86, NDR) format. /// </summary> /// <param name="value">Value to encode.</param> /// <returns>Little-endian encoded value.</returns> public static Double GetLittleEndian(Double value) { if (BitConverter.IsLittleEndian) { return value; } else { return swapByteOrder(value); } } /// <summary> /// Swaps the Byte order of an <see cref="Int32"/>. /// </summary> /// <param name="value"><see cref="Int32"/> to swap the bytes of.</param> /// <returns>Byte order swapped <see cref="Int32"/>.</returns> private static Int32 swapByteOrder(Int32 value) { Int32 swapped = (Int32)((0x000000FF) & (value >> 24) | (0x0000FF00) & (value >> 8) | (0x00FF0000) & (value << 8) | (0xFF000000) & (value << 24)); return swapped; } /// <summary> /// Swaps the byte order of a <see cref="UInt16"/>. /// </summary> /// <param name="value"><see cref="UInt16"/> to swap the bytes of.</param> /// <returns>Byte order swapped <see cref="UInt16"/>.</returns> private static UInt16 swapByteOrder(UInt16 value) { return (UInt16)((0x00FF & (value >> 8)) | (0xFF00 & (value << 8))); } /// <summary> /// Swaps the byte order of a <see cref="UInt32"/>. /// </summary> /// <param name="value"><see cref="UInt32"/> to swap the bytes of.</param> /// <returns>Byte order swapped <see cref="UInt32"/>.</returns> private static UInt32 swapByteOrder(UInt32 value) { UInt32 swapped = ( (0x000000FF) & (value >> 24) | (0x0000FF00) & (value >> 8) | (0x00FF0000) & (value << 8) | (0xFF000000) & (value << 24)); return swapped; } /// <summary> /// Swaps the byte order of a <see cref="Int64"/>. /// </summary> /// <param name="value"><see cref="Int64"/> to swap the bytes of.</param> /// <returns>Byte order swapped <see cref="Int64"/>.</returns> private static Int64 swapByteOrder(Int64 value) { UInt64 uvalue = (UInt64)value; UInt64 swapped = ( (0x00000000000000FF) & (uvalue >> 56) | (0x000000000000FF00) & (uvalue >> 40) | (0x0000000000FF0000) & (uvalue >> 24) | (0x00000000FF000000) & (uvalue >> 8) | (0x000000FF00000000) & (uvalue << 8) | (0x0000FF0000000000) & (uvalue << 24) | (0x00FF000000000000) & (uvalue << 40) | (0xFF00000000000000) & (uvalue << 56)); return (Int64)swapped; } /// <summary> /// Swaps the byte order of a <see cref="Double"/> (double precision IEEE 754) /// </summary> /// <param name="value"><see cref="Double"/> to swap.</param> /// <returns>Byte order swapped <see cref="Double"/> value.</returns> private static Double swapByteOrder(Double value) { Int64 bits = BitConverter.DoubleToInt64Bits(value); bits = swapByteOrder(bits); return BitConverter.Int64BitsToDouble(bits); } #endregion } }