claunia/Claunia.Encoding
1
0
Fork 0
mirror of https://github.com/claunia/Claunia.Encoding.git synced 2025-12-16 11:14:41 +00:00
Code Issues Packages Projects Releases Wiki Activity

Add suport for Radix-50, fixes #3

Browse Source
This commit is contained in:
Natalia Portillo
2017-12-27 21:36:57 +00:00
parent f7a073cd27
commit 4cdbe9dda9
9 changed files with 647 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
Claunia.Encoding.Tests/Claunia.Encoding.Tests.csproj
View File

@@ -1,4 +1,4 @@
<?xml version="1.0" encoding="utf-8"?>
<?xml version="1.0" encoding="utf-8"?>
<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -8,7 +8,7 @@
<RootNamespace>Claunia.Encoding.Tests</RootNamespace>
<AssemblyName>Claunia.Encoding.Tests</AssemblyName>
<TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
<ReleaseVersion>1.3</ReleaseVersion>
<ReleaseVersion>1.4</ReleaseVersion>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
<DebugSymbols>true</DebugSymbols>
@@ -38,6 +38,7 @@
<Compile Include="ATASCII.cs" />
<Compile Include="AtariST.cs" />
<Compile Include="GetEncs.cs" />
<Compile Include="Radix50.cs" />
</ItemGroup>
<ItemGroup>
<ProjectReference Include="..\Claunia.Encoding\Claunia.Encoding.csproj">

84
Claunia.Encoding.Tests/Radix50.cs Normal file
View File

@@ -0,0 +1,84 @@
//
// LisaRoman.cs
//
// Author:
// Natalia Portillo <claunia@claunia.com>
//
// Copyright © 2016-2018 Natalia Portillo
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using NUnit.Framework;
namespace Claunia.Encoding.Tests
{
[TestFixture]
public class Radix50
{
const string Punctuations = " .$%";
readonly byte[] PunctuationsBytes = {0b00000001, 0b11000110, 0b11011101};
const string Digits = "0123456789";
readonly byte[] DigitsBytes =
{0b01111001, 0b11111000, 0b00100001, 0b10001010, 0b00111001, 0b00100101, 0b10011010, 0b01110000};
const string UpperLatin = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
readonly byte[] UpperLatinBytes =
{
0b00000100, 0b00100000, 0b11000100, 0b00010100, 0b01100001, 0b11001000, 0b00100100, 0b10100010, 0b11001100,
0b00110100, 0b11100011, 0b11010000, 0b01000101, 0b00100100, 0b11010100, 0b01010101, 0b01100101, 0b11011000,
0b01100101, 0b10100000
};
const string Sentence = "THIS IS A TEST$";
const string SentencePadded = "THIS IS A TEST$ "; // It gets space padded when decoding is not multiple
readonly byte[] SentenceBytes =
{
0b01010000, 0b10000010, 0b01010011, 0b00000000, 0b10010100, 0b11000000, 0b00000100, 0b00000101, 0b00000101,
0b01001101, 0b01000110, 0b11000000
};
[Test]
public void RadixToUnicode()
{
string testString;
testString = Encoding.Radix50Encoding.GetString(PunctuationsBytes);
Assert.AreEqual(Punctuations, testString);
testString = Encoding.Radix50Encoding.GetString(DigitsBytes);
Assert.AreEqual(Digits, testString);
testString = Encoding.Radix50Encoding.GetString(UpperLatinBytes);
Assert.AreEqual(UpperLatin, testString);
testString = Encoding.Radix50Encoding.GetString(SentenceBytes);
Assert.AreEqual(SentencePadded, testString);
}
[Test]
public void UnicodeToRadix()
{
byte[] byteArray;
byteArray = Encoding.Radix50Encoding.GetBytes(Punctuations);
Assert.AreEqual(PunctuationsBytes, byteArray);
byteArray = Encoding.Radix50Encoding.GetBytes(Digits);
Assert.AreEqual(DigitsBytes, byteArray);
byteArray = Encoding.Radix50Encoding.GetBytes(UpperLatin);
Assert.AreEqual(UpperLatinBytes, byteArray);
byteArray = Encoding.Radix50Encoding.GetBytes(Sentence);
Assert.AreEqual(SentenceBytes, byteArray);
}
}
}

2
Claunia.Encoding.sln
View File

@@ -29,6 +29,6 @@ Global
$2.TabsToSpaces = True
$0.CSharpFormattingPolicy = $3
$3.scope = text/x-csharp
version = 1.3
version = 1.4
EndGlobalSection
EndGlobal

2
Claunia.Encoding/Apple2.cs
View File

@@ -36,7 +36,7 @@ namespace Claunia.Encoding
const string _bodyname = "apple2";
const int _codepage = 0;
const string _encodingname = "Western European (Apple II)";
const string _headername = "macintosh";
const string _headername = "apple2";
const string _webname = "";
const int _windowsCodepage = 0;

7
Claunia.Encoding/Claunia.Encoding.csproj
View File

@@ -13,7 +13,7 @@
<TargetFrameworkProfile>Profile136</TargetFrameworkProfile>
<PackOnBuild>true</PackOnBuild>
<PackageId>Claunia.Encoding</PackageId>
<PackageVersion>1.3</PackageVersion>
<PackageVersion>1.4</PackageVersion>
<Authors>Natalia Portillo</Authors>
<PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
<Owners>Natalia Portillo</Owners>
@@ -22,8 +22,8 @@
<Title>Claunia.Encoding</Title>
<Description>Library to provide codepage conversion to and from archaic and old computer systems and Unicode.</Description>
<PackageLicenseUrl>https://raw.githubusercontent.com/claunia/Claunia.Encoding/master/LICENSE.MIT</PackageLicenseUrl>
<ReleaseVersion>1.3</ReleaseVersion>
<PackageReleaseNotes>Added Apple II, IIc, IIe and IIgs.</PackageReleaseNotes>
<ReleaseVersion>1.4</ReleaseVersion>
<PackageReleaseNotes>Added DEC Radix-50.</PackageReleaseNotes>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
<DebugSymbols>true</DebugSymbols>
@@ -56,6 +56,7 @@
<Compile Include="Pangrams.cs" />
<Compile Include="ATASCII.cs" />
<Compile Include="AtariST.cs" />
<Compile Include="Radix50.cs" />
<Compile Include="ZX80.cs" />
<Compile Include="ZX81.cs" />
<Compile Include="ZXSpectrum.cs" />

4
Claunia.Encoding/Encoding.cs
View File

@@ -52,6 +52,10 @@ namespace Claunia.Encoding
/// Static instance for the PETSCII encoding
/// </summary>
public static System.Text.Encoding PETEncoding = new PETSCII();
/// <summary>
/// Static instance for the DEC Radix-50 encoding
/// </summary>
public static System.Text.Encoding Radix50Encoding = new Radix50();
/// <summary>
/// Gets a value indicating whether the current encoding can be used by browser clients for displaying content.

2
Claunia.Encoding/Properties/AssemblyInfo.cs
View File

@@ -44,7 +44,7 @@ using System.Runtime.CompilerServices;
// The form "{Major}.{Minor}.*" will automatically update the build and revision,
// and "{Major}.{Minor}.{Build}.*" will update just the revision.
[assembly: AssemblyVersion ("1.0.*")]
[assembly: AssemblyVersion ("1.4.*")]
// The following attributes are used to specify the signing key for the assembly,
// if desired. See the Mono documentation for more information about signing.

548
Claunia.Encoding/Radix50.cs Normal file
View File

@@ -0,0 +1,548 @@
//
// Apple II.cs
//
// Author:
// Natalia Portillo <claunia@claunia.com>
//
// Copyright © 2016-2018 Natalia Portillo
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using System;
namespace Claunia.Encoding
{
/// <summary>
/// Represents an Radix-50 (PDP-11) character encoding of Unicode characters.
/// </summary>
public class Radix50 : Encoding
{
const string _bodyname = "radix50";
const int _codepage = 0;
const string _encodingname = "Western European (Radix-50)";
const string _headername = "radix50";
const string _webname = "";
const int _windowsCodepage = 0;
const bool browserDisplay = false;
const bool browserSave = false;
const bool mailNewsDisplay = false;
const bool mailNewsSave = false;
const bool readOnly = false;
const bool singleByte = false;
/// <summary>
/// The Radix-50 to Unicode character map, when bits are shifted right
/// </summary>
static readonly char[] Radix50Table =
{
// 0x00
'\u0020', '\u0041', '\u0042', '\u0043', '\u0044', '\u0045', '\u0046', '\u0047',
// 0x08
'\u0048', '\u0049', '\u004A', '\u004B', '\u004C', '\u004D', '\u004E', '\u004F',
// 0x10
'\u0050', '\u0051', '\u0052', '\u0053', '\u0054', '\u0055', '\u0056', '\u0057',
// 0x18
'\u0058', '\u0059', '\u005A', '\u0024', '\u002E', '\u0025', '\u0030', '\u0031',
// 0x20
'\u0032', '\u0033', '\u0034', '\u0035', '\u0036', '\u0037', '\u0038', '\u0039',
// 0x28 (unused but legal)
'\u0000', '\u0000', '\u0000', '\u0000', '\u0000', '\u0000', '\u0000', '\u0000',
// 0x30 (unused but legal)
'\u0000', '\u0000', '\u0000', '\u0000', '\u0000', '\u0000', '\u0000', '\u0000',
// 0x38 (unused but legal)
'\u0000', '\u0000', '\u0000', '\u0000', '\u0000', '\u0000', '\u0000', '\u0000'
};
/// <summary>
/// Gets a value indicating whether the current encoding can be used by browser clients for displaying content.
/// </summary>
public override bool IsBrowserDisplay => browserDisplay;
/// <summary>
/// Gets a value indicating whether the current encoding can be used by browser clients for saving content.
/// </summary>
public override bool IsBrowserSave => browserSave;
/// <summary>
/// Gets a value indicating whether the current encoding can be used by mail and news clients for displaying content.
/// </summary>
public override bool IsMailNewsDisplay => mailNewsDisplay;
/// <summary>
/// Gets a value indicating whether the current encoding can be used by mail and news clients for saving content.
/// </summary>
public override bool IsMailNewsSave => mailNewsSave;
/// <summary>
/// Gets a value indicating whether the current encoding is read-only.
/// </summary>
/// <value>The is single byte.</value>
public override bool IsReadOnly => readOnly;
/// <summary>
/// Gets a value indicating whether the current encoding uses single-byte code points.
/// </summary>
public override bool IsSingleByte => singleByte;
/// <summary>
/// Gets the code page identifier of the current Encoding.
/// </summary>
public override int CodePage => _codepage;
/// <summary>
/// Gets a name for the current encoding that can be used with mail agent body tags
/// </summary>
public override string BodyName => _bodyname;
/// <summary>
/// Gets a name for the current encoding that can be used with mail agent header tags
/// </summary>
public override string HeaderName => _headername;
/// <summary>
/// Ggets the name registered with the Internet Assigned Numbers Authority (IANA) for the current encoding.
/// </summary>
public override string WebName => _webname;
/// <summary>
/// Gets the human-readable description of the current encoding.
/// </summary>
public override string EncodingName => _encodingname;
/// <summary>
/// Gets the Windows operating system code page that most closely corresponds to the current encoding.
/// </summary>
public override int WindowsCodePage => _windowsCodepage;
/// <summary>
/// Calculates the number of bytes produced by encoding the characters in the specified <see cref="string" />.
/// </summary>
/// <returns>The number of bytes produced by encoding the specified characters.</returns>
/// <param name="s">The <see cref="string" /> containing the set of characters to encode.</param>
public override int GetByteCount(string s)
{
if(s == null) throw new ArgumentNullException(nameof(s));
return s.Length * 6 % 8 > 0 ? s.Length * 6 / 8 + 1 : s.Length * 6 / 8;
}
/// <summary>
/// Calculates the number of bytes produced by encoding a set of characters from the specified character array.
/// </summary>
/// <returns>The number of bytes produced by encoding the specified characters.</returns>
/// <param name="chars">The character array containing the set of characters to encode.</param>
/// <param name="index">The index of the first character to encode.</param>
/// <param name="count">The number of characters to encode.</param>
public override int GetByteCount(char[] chars, int index, int count)
{
if(chars == null) throw new ArgumentNullException(nameof(chars));
if(index < 0 || index >= chars.Length) throw new ArgumentOutOfRangeException(nameof(index));
if(count < 0 || index + count > chars.Length) throw new ArgumentOutOfRangeException(nameof(index));
return count * 6 % 8 > 0 ? count * 6 / 8 + 1 : count * 6 / 8;
}
/// <summary>
/// Calculates the number of bytes produced by encoding all the characters in the specified character array.
/// </summary>
/// <returns>The number of bytes produced by encoding all the characters in the specified character array.</returns>
/// <param name="chars">The character array containing the characters to encode.</param>
public override int GetByteCount(char[] chars)
{
if(chars == null) throw new ArgumentNullException(nameof(chars));
return chars.Length * 6 % 8 > 0 ? chars.Length * 6 / 8 + 1 : chars.Length * 6 / 8;
}
/// <summary>
/// Encodes a set of characters from the specified <see cref="string" /> into the specified byte array.
/// </summary>
/// <returns>The actual number of bytes written into bytes.</returns>
/// <param name="s">The <see cref="string" /> containing the set of characters to encode.</param>
/// <param name="charIndex">The index of the first character to encode.</param>
/// <param name="charCount">The number of characters to encode.</param>
/// <param name="bytes">The byte array to contain the resulting sequence of bytes.</param>
/// <param name="byteIndex">The index at which to start writing the resulting sequence of bytes.</param>
public override int GetBytes(string s, int charIndex, int charCount, byte[] bytes, int byteIndex)
{
return GetBytes(s.ToCharArray(), charIndex, charCount, bytes, byteIndex);
}
/// <summary>
/// Encodes all the characters in the specified string into a sequence of bytes.
/// </summary>
/// <returns>A byte array containing the results of encoding the specified set of characters.</returns>
/// <param name="s">The string containing the characters to encode.</param>
public override byte[] GetBytes(string s)
{
if(s == null) throw new ArgumentNullException(nameof(s));
return GetBytes(s.ToCharArray(), 0, s.Length);
}
/// <summary>
/// Encodes a set of characters from the specified character array into the specified byte array.
/// </summary>
/// <returns>The actual number of bytes written into bytes.</returns>
/// <param name="chars">The character array containing the set of characters to encode.</param>
/// <param name="charIndex">The index of the first character to encode.</param>
/// <param name="charCount">The number of characters to encode.</param>
/// <param name="bytes">The byte array to contain the resulting sequence of bytes.</param>
/// <param name="byteIndex">The index at which to start writing the resulting sequence of bytes.</param>
public override int GetBytes(char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex)
{
if(chars == null) throw new ArgumentNullException(nameof(chars));
if(bytes == null) throw new ArgumentNullException(nameof(bytes));
if(charIndex < 0) throw new ArgumentOutOfRangeException(nameof(charIndex));
if(charCount < 0) throw new ArgumentOutOfRangeException(nameof(charCount));
if(byteIndex < 0) throw new ArgumentOutOfRangeException(nameof(byteIndex));
if(charIndex >= chars.Length) throw new ArgumentOutOfRangeException(nameof(charIndex));
if(charCount + charIndex > chars.Length) throw new ArgumentOutOfRangeException(nameof(charCount));
if(byteIndex >= bytes.Length) throw new ArgumentOutOfRangeException(nameof(byteIndex));
if(byteIndex + charCount > bytes.Length) throw new ArgumentException(nameof(bytes));
byte[] temp = GetBytes(chars, charIndex, charCount);
for(int i = 0; i < temp.Length; i++) bytes[i + byteIndex] = temp[i];
return charCount;
}
/// <summary>
/// Encodes a set of characters from the specified character array into a sequence of bytes.
/// </summary>
/// <returns>A byte array containing the results of encoding the specified set of characters.</returns>
/// <param name="chars">The character array containing the set of characters to encode.</param>
/// <param name="index">The index of the first character to encode.</param>
/// <param name="count">The number of characters to encode.</param>
public override byte[] GetBytes(char[] chars, int index, int count)
{
if(chars == null) throw new ArgumentNullException(nameof(chars));
if(index < 0) throw new ArgumentOutOfRangeException(nameof(index));
if(count < 0) throw new ArgumentOutOfRangeException(nameof(count));
if(count + index > chars.Length) throw new ArgumentOutOfRangeException(nameof(count));
byte[] bytes = new byte[count * 6 % 8 > 0 ? count * 6 / 8 + 1 : count * 6 / 8];
int outPos = 0;
for(int i = 0; i < count; i++)
{
byte thisByte = GetByte(chars[index + i]);
switch(i % 4)
{
case 0:
if(outPos >= bytes.Length) break;
bytes[outPos] = (byte)(thisByte << 2);
break;
case 1:
if(outPos + 1 >= bytes.Length) break;
bytes[outPos] += (byte)((thisByte & 0x30) >> 4);
bytes[outPos + 1] = (byte)((thisByte & 0xF) << 4);
break;
case 2:
if(outPos + 2 >= bytes.Length) break;
bytes[outPos + 1] += (byte)((thisByte & 0x3C) >> 2);
bytes[outPos + 2] = (byte)((thisByte & 0x3) << 6);
break;
case 3:
if(outPos + 2 >= bytes.Length) break;
bytes[outPos + 2] += (byte)(thisByte & 0x3F);
outPos += 3;
break;
}
}
return bytes;
}
/// <summary>
/// Encodes all the characters in the specified character array into a sequence of bytes.
/// </summary>
/// <returns>A byte array containing the results of encoding the specified set of characters.</returns>
/// <param name="chars">The character array containing the characters to encode.</param>
public override byte[] GetBytes(char[] chars)
{
return GetBytes(chars, 0, chars.Length);
}
/// <summary>
/// Calculates the number of characters produced by decoding all the bytes in the specified byte array.
/// </summary>
/// <returns>The number of characters produced by decoding the specified sequence of bytes.</returns>
/// <param name="bytes">The byte array containing the sequence of bytes to decode.</param>
public override int GetCharCount(byte[] bytes)
{
return GetCharCount(bytes, 0, bytes.Length);
}
/// <summary>
/// Calculates the number of characters produced by decoding a sequence of bytes from the specified byte array.
/// </summary>
/// <returns>The number of characters produced by decoding the specified sequence of bytes.</returns>
/// <param name="bytes">The byte array containing the sequence of bytes to decode.</param>
/// <param name="index">The index of the first byte to decode.</param>
/// <param name="count">The number of bytes to decode.</param>
public override int GetCharCount(byte[] bytes, int index, int count)
{
if(bytes == null) throw new ArgumentNullException(nameof(bytes));
if(index < 0) throw new ArgumentOutOfRangeException(nameof(index));
if(count < 0) throw new ArgumentOutOfRangeException(nameof(count));
if(count + index > bytes.Length) throw new ArgumentOutOfRangeException(nameof(count));
return count * 8 / 6;
}
/// <summary>
/// Decodes a sequence of bytes from the specified byte array into the specified character array.
/// </summary>
/// <returns>The actual number of characters written into chars.</returns>
/// <param name="bytes">The byte array containing the sequence of bytes to decode.</param>
/// <param name="byteIndex">The index of the first byte to decode.</param>
/// <param name="byteCount">The number of bytes to decode.</param>
/// <param name="chars">The character array to contain the resulting set of characters.</param>
/// <param name="charIndex">The index at which to start writing the resulting set of characters.</param>
public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex)
{
if(bytes == null) throw new ArgumentNullException(nameof(bytes));
if(chars == null) throw new ArgumentNullException(nameof(chars));
if(byteIndex < 0) throw new ArgumentOutOfRangeException(nameof(byteIndex));
if(byteCount < 0) throw new ArgumentOutOfRangeException(nameof(byteCount));
if(charIndex < 0) throw new ArgumentOutOfRangeException(nameof(charIndex));
if(byteIndex >= bytes.Length) throw new ArgumentOutOfRangeException(nameof(byteIndex));
if(byteCount + byteIndex > bytes.Length) throw new ArgumentOutOfRangeException(nameof(byteCount));
if(charIndex >= chars.Length) throw new ArgumentOutOfRangeException(nameof(charIndex));
if(charIndex + byteCount > chars.Length) throw new ArgumentException(nameof(chars));
char[] temp = GetChars(bytes, byteIndex, byteCount);
for(int i = 0; i < temp.Length; i++) chars[i + charIndex] = temp[i];
return byteCount;
}
/// <summary>
/// Decodes all the bytes in the specified byte array into a set of characters.
/// </summary>
/// <returns>A character array containing the results of decoding the specified sequence of bytes.</returns>
/// <param name="bytes">The byte array containing the sequence of bytes to decode.</param>
public override char[] GetChars(byte[] bytes)
{
return GetChars(bytes, 0, bytes.Length);
}
/// <summary>
/// Decodes a sequence of bytes from the specified byte array into a set of characters.
/// </summary>
/// <returns>The chars.</returns>
/// <param name="bytes">The byte array containing the sequence of bytes to decode.</param>
/// <param name="index">The index of the first byte to decode.</param>
/// <param name="count">The number of bytes to decode.</param>
public override char[] GetChars(byte[] bytes, int index, int count)
{
if(bytes == null) throw new ArgumentNullException(nameof(bytes));
if(index < 0) throw new ArgumentOutOfRangeException(nameof(index));
if(count < 0) throw new ArgumentOutOfRangeException(nameof(count));
if(count + index > bytes.Length) throw new ArgumentOutOfRangeException(nameof(count));
char[] chars = new char[count * 8 / 6];
// aaaaaabb bbbbcccc ccdddddd
int outPos = 0;
for(int i = 0; i < count; i++)
{
byte rd50;
switch(i % 3)
{
case 0:
rd50 = (byte)((bytes[index + i] & 0xFC) >> 2);
chars[outPos] = GetChar(rd50);
outPos++;
break;
case 1:
rd50 = (byte)(((bytes[index + i - 1] & 0x03) << 4) + ((bytes[index + i] & 0xF0) >> 4));
chars[outPos] = GetChar(rd50);
outPos++;
break;
case 2:
rd50 = (byte)(((bytes[index + i - 1] & 0x0F) << 2) + ((bytes[index + i] & 0xC0) >> 6));
chars[outPos] = GetChar(rd50);
chars[outPos + 1] = GetChar((byte)(bytes[index + i] & 0x3F));
outPos += 2;
break;
}
}
return chars;
}
/// <summary>
/// Calculates the maximum number of bytes produced by encoding the specified number of characters.
/// </summary>
/// <returns>The maximum number of bytes produced by encoding the specified number of characters.</returns>
/// <param name="charCount">The number of characters to encode.</param>
public override int GetMaxByteCount(int charCount)
{
if(charCount < 0) throw new ArgumentOutOfRangeException(nameof(charCount));
return charCount * 6 % 8 > 0 ? charCount * 6 / 8 + 1 : charCount * 6 / 8;
}
/// <summary>
/// Calculates the maximum number of characters produced by decoding the specified number of bytes.
/// </summary>
/// <returns>The maximum number of characters produced by decoding the specified number of bytes.</returns>
/// <param name="byteCount">The number of bytes to decode.</param>
public override int GetMaxCharCount(int byteCount)
{
if(byteCount < 0) throw new ArgumentOutOfRangeException(nameof(byteCount));
return byteCount * 8 / 6;
}
/// <summary>
/// Returns a sequence of bytes that specifies the encoding used.
/// </summary>
/// <returns>A byte array of length zero, as a preamble is not required.</returns>
public override byte[] GetPreamble()
{
return new byte[0];
}
/// <summary>
/// Decodes all the bytes in the specified byte array into a string.
/// </summary>
/// <returns>A string that contains the results of decoding the specified sequence of bytes.</returns>
/// <param name="bytes">The byte array containing the sequence of bytes to decode.</param>
public string GetString(byte[] bytes)
{
return GetString(bytes, 0, bytes.Length);
}
/// <summary>
/// Decodes a sequence of bytes from the specified byte array into a string.
/// </summary>
/// <returns>A string that contains the results of decoding the specified sequence of bytes.</returns>
/// <param name="bytes">The byte array containing the sequence of bytes to decode.</param>
/// <param name="index">The index of the first byte to decode.</param>
/// <param name="count">The number of bytes to decode.</param>
public override string GetString(byte[] bytes, int index, int count)
{
return new string(GetChars(bytes, index, count));
}
/// <summary>
/// Converts a Apple II character to an Unicode character
/// </summary>
/// <returns>Unicode character.</returns>
/// <param name="character">Apple II character.</param>
static char GetChar(byte character)
{
return Radix50Table[character & 0x3F];
}
/// <summary>
/// Converts a Unicode character to an Apple II character
/// </summary>
/// <returns>Apple II character.</returns>
/// <param name="character">Unicode character.</param>
static byte GetByte(char character)
{
switch(character)
{
case '\u0020': return 0x00;
case '\u0041': return 0x01;
case '\u0042': return 0x02;
case '\u0043': return 0x03;
case '\u0044': return 0x04;
case '\u0045': return 0x05;
case '\u0046': return 0x06;
case '\u0047': return 0x07;
case '\u0048': return 0x08;
case '\u0049': return 0x09;
case '\u004A': return 0x0A;
case '\u004B': return 0x0B;
case '\u004C': return 0x0C;
case '\u004D': return 0x0D;
case '\u004E': return 0x0E;
case '\u004F': return 0x0F;
case '\u0050': return 0x10;
case '\u0051': return 0x11;
case '\u0052': return 0x12;
case '\u0053': return 0x13;
case '\u0054': return 0x14;
case '\u0055': return 0x15;
case '\u0056': return 0x16;
case '\u0057': return 0x17;
case '\u0058': return 0x18;
case '\u0059': return 0x19;
case '\u005A': return 0x1A;
case '\u0024': return 0x1B;
case '\u002E': return 0x1C;
case '\u0025': return 0x1D;
case '\u0030': return 0x1E;
case '\u0031': return 0x1F;
case '\u0032': return 0x20;
case '\u0033': return 0x21;
case '\u0034': return 0x22;
case '\u0035': return 0x23;
case '\u0036': return 0x24;
case '\u0037': return 0x25;
case '\u0038': return 0x26;
case '\u0039': return 0x27;
default:
// Fallback to '.'
return 0x1C;
}
}
}
}

1
README.md
View File

@@ -12,6 +12,7 @@ Supported encodings
* Atari Standard Code for Information Interchange (ATASCII)
* Atari ST character set
* Commodore PET Standard Code for Information Interchange (PETSCII)
* DEC Radix-50
* MacArabic
* MacCentralEuropean
* MacCroatian