/// <summary>
/// Removes tashkeel. Converts general RTL letters to isolated form. Also fixes Farsi and Arabic ی letter.
/// </summary>
/// <param name="input">Input to prepare</param>
/// <returns>Prepared input in char array</returns>
protected virtual char[] PrepareInput(string input)
{
input = RemoveTashkeel(input);
char[] letters = input.ToCharArray();
for (int i = 0; i < letters.Length; i++)
{
if (Farsi && letters[i] == (int)GeneralLetters.Ya)
{
letters[i] = (char)GeneralLetters.PersianYa;
}
else if (Farsi == false && letters[i] == (int)GeneralLetters.PersianYa)
{
letters[i] = (char)GeneralLetters.Ya;
}
letters[i] = (char)GlyphTable.Convert(letters[i]);
}
return(letters);
}
/// <summary>
/// Fixes the shape of letters based on their position.
/// </summary>
/// <param name="letters"></param>
/// <returns></returns>
protected virtual char[] FixGlyphs(char[] letters)
{
// We copy the letters into final letters and fix the ones that actually need a fix
char[] lettersFinal = new char[letters.Length];
Array.Copy(letters, lettersFinal, letters.Length);
for (int i = 0; i < letters.Length; i++)
{
bool skipNext = false;
// For special Lam Letter connections.
if (letters[i] == (char)GeneralLetters.Lam)
{
if (i < letters.Length - 1)
{
skipNext = HandleSpecialLam(letters, lettersFinal, i);
}
}
// We don't want to fix tatweel or zwnj character
if (letters[i] == (int)GeneralLetters.ArabicTatweel || letters[i] == (int)GeneralLetters.ZeroWidthNoJoiner)
{
continue;
}
if (IsRTLCharacter(letters[i]))
{
if (IsMiddleLetter(letters, i))
{
letters[i] = (char)GlyphTable.Convert(letters[i]);
lettersFinal[i] = (char)(letters[i] + 3);
}
else if (IsFinishingLetter(letters, i))
{
letters[i] = (char)GlyphTable.Convert(letters[i]);
lettersFinal[i] = (char)(letters[i] + 1);
}
else if (IsLeadingLetter(letters, i))
{
letters[i] = (char)GlyphTable.Convert(letters[i]);
lettersFinal[i] = (char)(letters[i] + 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++;
continue;
}
if (!PreserveNumbers && char.IsDigit(letters[i]))
{
lettersFinal[i] = FixNumbers(letters[i]);
}
}
//Restore tashkeel to their places.
lettersFinal = RestoreTashkeel(lettersFinal);
return(lettersFinal);
}
/// <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);
}
}
}