/// <summary>
/// Is the letter at provided index a finishing letter?
/// </summary>
/// <returns><see langword="true" /> if the letter is a finishing letter</returns>
private static bool IsFinishingLetter(FastStringBuilder letters, int index)
{
int currentIndexLetter = letters.Get(index);
int previousIndexLetter = default;
if (index != 0)
{
previousIndexLetter = letters.Get(index - 1);
}
bool isPreviousLetterConnectable = index != 0 &&
previousIndexLetter != ' ' &&
previousIndexLetter != (int)ArabicGeneralLetters.Dal &&
previousIndexLetter != (int)ArabicGeneralLetters.Thal &&
previousIndexLetter != (int)ArabicGeneralLetters.Ra2 &&
previousIndexLetter != (int)ArabicGeneralLetters.Zeen &&
previousIndexLetter != (int)ArabicGeneralLetters.PersianZe &&
previousIndexLetter != (int)ArabicGeneralLetters.Waw &&
previousIndexLetter != (int)ArabicGeneralLetters.Alef &&
previousIndexLetter != (int)ArabicGeneralLetters.AlefMad &&
previousIndexLetter != (int)ArabicGeneralLetters.AlefHamza &&
previousIndexLetter != (int)ArabicGeneralLetters.AlefMaksoor &&
previousIndexLetter != (int)ArabicGeneralLetters.WawHamza &&
previousIndexLetter != (int)ArabicGeneralLetters.Hamza &&
previousIndexLetter != (int)ArabicGeneralLetters.ZeroWidthNoJoiner &&
previousIndexLetter != (int)ArabicIsolatedLetters.Dal &&
previousIndexLetter != (int)ArabicIsolatedLetters.Thal &&
previousIndexLetter != (int)ArabicIsolatedLetters.Ra2 &&
previousIndexLetter != (int)ArabicIsolatedLetters.Zeen &&
previousIndexLetter != (int)ArabicIsolatedLetters.PersianZe &&
previousIndexLetter != (int)ArabicIsolatedLetters.Waw &&
previousIndexLetter != (int)ArabicIsolatedLetters.Alef &&
previousIndexLetter != (int)ArabicIsolatedLetters.AlefMad &&
previousIndexLetter != (int)ArabicIsolatedLetters.AlefHamza &&
previousIndexLetter != (int)ArabicIsolatedLetters.AlefMaksoor &&
previousIndexLetter != (int)ArabicIsolatedLetters.WawHamza &&
previousIndexLetter != (int)ArabicIsolatedLetters.Hamza &&
(previousIndexLetter < 0xFFFF && TextUtils.IsGlyphFixedArabicCharacter((char)previousIndexLetter));
bool canThisLetterBeFinishing = currentIndexLetter != ' ' &&
currentIndexLetter != (int)ArabicGeneralLetters.ZeroWidthNoJoiner &&
currentIndexLetter != (int)ArabicGeneralLetters.Hamza;
return(isPreviousLetterConnectable && canThisLetterBeFinishing);
}
/// <summary>
/// Fixes the shape of letters based on their position.
/// </summary>
/// <param name="input"></param>
/// <param name="output"></param>
/// <param name="preserveNumbers"></param>
/// <param name="farsi"></param>
/// <returns></returns>
public static void Fix(FastStringBuilder input, FastStringBuilder output, bool preserveNumbers, bool farsi, bool fixTextTags)
{
FixYah(input, farsi);
output.SetValue(input);
for (int i = 0; i < input.Length; i++)
{
bool skipNext = false;
int iChar = input.Get(i);
// For special Lam Letter connections.
if (iChar == (int)ArabicGeneralLetters.Lam)
{
if (i < input.Length - 1)
{
skipNext = HandleSpecialLam(input, output, i);
if (skipNext)
{
iChar = output.Get(i);
}
}
}
// We don't want to fix tatweel or zwnj character
if (iChar == (int)ArabicGeneralLetters.ArabicTatweel ||
iChar == (int)ArabicGeneralLetters.ZeroWidthNoJoiner)
{
continue;
}
if (iChar < 0xFFFF && TextUtils.IsGlyphFixedArabicCharacter((char)iChar))
{
char converted = GlyphTable.Convert((char)iChar);
if (IsMiddleLetter(input, i))
{
output.Set(i, (char)(converted + 3));
}
else if (IsFinishingLetter(input, i))
{
output.Set(i, (char)(converted + 1));
}
else if (IsLeadingLetter(input, i))
{
output.Set(i, (char)(converted + 2));
}
}
// If this letter as Lam and special Lam-Alef connection was made, We want to skip the Alef
// (Lam-Alef occupies 1 space)
if (skipNext)
{
i++;
}
}
if (!preserveNumbers)
{
if (fixTextTags)
{
FixNumbersOutsideOfTags(output, farsi);
}
else
{
FixNumbers(output, farsi);
}
}
}
/// <summary>
/// Is the letter at provided index a middle letter?
/// </summary>
/// <returns><see langword="true" /> if the letter is a middle letter</returns>
private static bool IsMiddleLetter(FastStringBuilder letters, int index)
{
var currentIndexLetter = letters.Get(index);
int previousIndexLetter = default;
if (index != 0)
{
previousIndexLetter = letters.Get(index - 1);
}
int nextIndexLetter = default;
if (index < letters.Length - 1)
{
nextIndexLetter = letters.Get(index + 1);
}
bool middleLetterCheck = index != 0 &&
currentIndexLetter != (int)ArabicGeneralLetters.Alef &&
currentIndexLetter != (int)ArabicGeneralLetters.Dal &&
currentIndexLetter != (int)ArabicGeneralLetters.Thal &&
currentIndexLetter != (int)ArabicGeneralLetters.Ra2 &&
currentIndexLetter != (int)ArabicGeneralLetters.Zeen &&
currentIndexLetter != (int)ArabicGeneralLetters.PersianZe &&
currentIndexLetter != (int)ArabicGeneralLetters.Waw &&
currentIndexLetter != (int)ArabicGeneralLetters.AlefMad &&
currentIndexLetter != (int)ArabicGeneralLetters.AlefHamza &&
currentIndexLetter != (int)ArabicGeneralLetters.AlefMaksoor &&
currentIndexLetter != (int)ArabicGeneralLetters.WawHamza &&
currentIndexLetter != (int)ArabicGeneralLetters.ZeroWidthNoJoiner &&
currentIndexLetter != (int)ArabicGeneralLetters.Hamza;
bool previousLetterCheck = index != 0 &&
previousIndexLetter != (int)ArabicGeneralLetters.Alef &&
previousIndexLetter != (int)ArabicGeneralLetters.Dal &&
previousIndexLetter != (int)ArabicGeneralLetters.Thal &&
previousIndexLetter != (int)ArabicGeneralLetters.Ra2 &&
previousIndexLetter != (int)ArabicGeneralLetters.Zeen &&
previousIndexLetter != (int)ArabicGeneralLetters.PersianZe &&
previousIndexLetter != (int)ArabicGeneralLetters.Waw &&
previousIndexLetter != (int)ArabicGeneralLetters.AlefMad &&
previousIndexLetter != (int)ArabicGeneralLetters.AlefHamza &&
previousIndexLetter != (int)ArabicGeneralLetters.AlefMaksoor &&
previousIndexLetter != (int)ArabicGeneralLetters.WawHamza &&
previousIndexLetter != (int)ArabicGeneralLetters.Hamza &&
previousIndexLetter != (int)ArabicGeneralLetters.ZeroWidthNoJoiner &&
previousIndexLetter != (int)ArabicIsolatedLetters.Alef &&
previousIndexLetter != (int)ArabicIsolatedLetters.Dal &&
previousIndexLetter != (int)ArabicIsolatedLetters.Thal &&
previousIndexLetter != (int)ArabicIsolatedLetters.Ra2 &&
previousIndexLetter != (int)ArabicIsolatedLetters.Zeen &&
previousIndexLetter != (int)ArabicIsolatedLetters.PersianZe &&
previousIndexLetter != (int)ArabicIsolatedLetters.Waw &&
previousIndexLetter != (int)ArabicIsolatedLetters.AlefMad &&
previousIndexLetter != (int)ArabicIsolatedLetters.AlefHamza &&
previousIndexLetter != (int)ArabicIsolatedLetters.AlefMaksoor &&
previousIndexLetter != (int)ArabicIsolatedLetters.WawHamza &&
previousIndexLetter != (int)ArabicIsolatedLetters.Hamza &&
(previousIndexLetter < 0xFFFF && TextUtils.IsGlyphFixedArabicCharacter((char)previousIndexLetter));
bool nextLetterCheck = index < letters.Length - 1 &&
(nextIndexLetter < 0xFFFF && TextUtils.IsGlyphFixedArabicCharacter((char)nextIndexLetter)) &&
nextIndexLetter != (int)ArabicGeneralLetters.ZeroWidthNoJoiner &&
nextIndexLetter != (int)ArabicGeneralLetters.Hamza &&
nextIndexLetter != (int)ArabicIsolatedLetters.Hamza;
return(nextLetterCheck && previousLetterCheck && middleLetterCheck);
}
/// <summary>
/// Is the letter at provided index a leading letter?
/// </summary>
/// <returns><see langword="true" /> if the letter is a leading letter</returns>
private static bool IsLeadingLetter(FastStringBuilder letters, int index)
{
var currentIndexLetter = letters.Get(index);
int previousIndexLetter = default;
if (index != 0)
{
previousIndexLetter = letters.Get(index - 1);
}
int nextIndexLetter = default;
if (index < letters.Length - 1)
{
nextIndexLetter = letters.Get(index + 1);
}
bool isPreviousLetterNonConnectable = index == 0 ||
(previousIndexLetter < 0xFFFF && !TextUtils.IsGlyphFixedArabicCharacter((char)previousIndexLetter)) ||
previousIndexLetter == (int)ArabicGeneralLetters.Alef ||
previousIndexLetter == (int)ArabicGeneralLetters.Dal ||
previousIndexLetter == (int)ArabicGeneralLetters.Thal ||
previousIndexLetter == (int)ArabicGeneralLetters.Ra2 ||
previousIndexLetter == (int)ArabicGeneralLetters.Zeen ||
previousIndexLetter == (int)ArabicGeneralLetters.PersianZe ||
previousIndexLetter == (int)ArabicGeneralLetters.Waw ||
previousIndexLetter == (int)ArabicGeneralLetters.AlefMad ||
previousIndexLetter == (int)ArabicGeneralLetters.AlefHamza ||
previousIndexLetter == (int)ArabicGeneralLetters.Hamza ||
previousIndexLetter == (int)ArabicGeneralLetters.AlefMaksoor ||
previousIndexLetter == (int)ArabicGeneralLetters.ZeroWidthNoJoiner ||
previousIndexLetter == (int)ArabicGeneralLetters.WawHamza ||
previousIndexLetter == (int)ArabicIsolatedLetters.Alef ||
previousIndexLetter == (int)ArabicIsolatedLetters.Dal ||
previousIndexLetter == (int)ArabicIsolatedLetters.Thal ||
previousIndexLetter == (int)ArabicIsolatedLetters.Ra2 ||
previousIndexLetter == (int)ArabicIsolatedLetters.Zeen ||
previousIndexLetter == (int)ArabicIsolatedLetters.PersianZe ||
previousIndexLetter == (int)ArabicIsolatedLetters.Waw ||
previousIndexLetter == (int)ArabicIsolatedLetters.AlefMad ||
previousIndexLetter == (int)ArabicIsolatedLetters.AlefHamza ||
previousIndexLetter == (int)ArabicIsolatedLetters.Hamza ||
previousIndexLetter == (int)ArabicIsolatedLetters.AlefMaksoor;
bool canThisLetterBeLeading = currentIndexLetter != ' ' &&
currentIndexLetter != (int)ArabicGeneralLetters.Dal &&
currentIndexLetter != (int)ArabicGeneralLetters.Thal &&
currentIndexLetter != (int)ArabicGeneralLetters.Ra2 &&
currentIndexLetter != (int)ArabicGeneralLetters.Zeen &&
currentIndexLetter != (int)ArabicGeneralLetters.PersianZe &&
currentIndexLetter != (int)ArabicGeneralLetters.Alef &&
currentIndexLetter != (int)ArabicGeneralLetters.AlefHamza &&
currentIndexLetter != (int)ArabicGeneralLetters.AlefMaksoor &&
currentIndexLetter != (int)ArabicGeneralLetters.AlefMad &&
currentIndexLetter != (int)ArabicGeneralLetters.WawHamza &&
currentIndexLetter != (int)ArabicGeneralLetters.Waw &&
currentIndexLetter != (int)ArabicGeneralLetters.ZeroWidthNoJoiner &&
currentIndexLetter != (int)ArabicGeneralLetters.Hamza;
bool isNextLetterConnectable = index < letters.Length - 1 &&
(nextIndexLetter < 0xFFFF && TextUtils.IsGlyphFixedArabicCharacter((char)nextIndexLetter)) &&
nextIndexLetter != (int)ArabicGeneralLetters.Hamza &&
nextIndexLetter != (int)ArabicGeneralLetters.ZeroWidthNoJoiner;
return(isPreviousLetterNonConnectable &&
canThisLetterBeLeading &&
isNextLetterConnectable);
}