private bool IsFirstRecognizableCharIsRTL(string s, int i)
{
if (m_AssumeFirstChar != DetectionOption.Depends)
{
return(m_AssumeFirstChar == DetectionOption.AsRTL);
}
while (i < s.Length)
{
var c = s[i];
i++;
if (c == '\\')
{
var f = TexFormulaParser.LookForAWord(s, ref i);
if (f.Length > 1 && i < s.Length && s[i] == '[')
{
TexFormulaParser.ReadGroup(s, ref i, '[', ']');
}
continue;
}
if (InternalChars.Contains(c) || IsIgnoredChar(c))
{
continue;
}
return(IsRTLChar(c));
}
return(false);
}
void GetRichTag(string str, ref int i, StringBuilder dst)
{
if (i >= str.Length || str[i] != '<')
{
return;
}
i++;
var head = TexFormulaParser.LookForAWord(str, ref i);
TexFormulaParser.SkipWhiteSpace(str, ref i);
var param = TexFormulaParser.ReadGroup(str, ref i, '<', '>');
dst.Append(TransparseRichTag(head, param));
dst.Append('{');
var end = str.IndexOf("</" + head + ">", i);
i++;
if (end < 0)
{
end = str.Length;
}
while (i < end)
{
var ii = i;
var c = str[i++];
var n = i < str.Length ? str[i] : '\0';
if (c == '<' && char.IsLetter(n))
{
var cmd = TexFormulaParser.LookForAWord(str, ref i);
if (knownRichTagsHash.Contains(cmd))
{
i = ii;
GetRichTag(str, ref i, dst);
continue;
}
}
dst.Append(c);
}
if (i < str.Length)
{
while (str[i++] != '>')
{
}
}
dst.Append('}');
}
void TranslateLatex(string str, StringBuilder dst)
{
var i = 0;
char n = '\0';
while (i < str.Length)
{
var c = str[i++];
n = i < str.Length ? str[i] : '\0';
if (c == ' ')
{
if (!discardSpaces)
{
dst.Append(c);
}
}
else if (c == '\\')
{
if (TexFormulaParser.IsParserReserved(n))
{
dst.Append(c);
continue;
}
else if (char.IsLetter(n))
{
var cmd = TexFormulaParser.LookForAWord(str, ref i);
TexFormulaParser.SkipWhiteSpace(str, ref i);
// Symbol renames
if (cmd == "to")
{
dst.Append("\\rightarrow");
continue;
}
if (i >= str.Length)
{
dst.Append("\\" + cmd);
continue;
}
// Lim (or other funcs) goes to over/under if even there single script
if (cmd == "lim")
{
c = str[i];
if (c == '^' || c == '_')
{
dst.Append("\\" + cmd + c);
}
else
{
dst.Append("\\" + cmd);
}
continue;
}
// color but the id in braces
if (cmd == "color" && (str[i] == '{'))
{
var arg = TexFormulaParser.ReadGroup(str, ref i, '{', '}');
if (arg.IndexOf(' ') < 0)
{
dst.Append("\\color[" + arg + "]");
}
else
{
dst.Append("\\color{" + arg + "}");
}
continue;
}
// \over... or \under....
int ou = cmd.IndexOf("over") == 0 ? 2 : (cmd.IndexOf("under") == 0 ? 1 : 0);
if (ou != 0)
{
var second = cmd.Substring(ou == 2 ? 4 : 5);
if (second == "line")
{
dst.Append(ou == 2 ? "\\over" : "\\under");
continue;
}
c = str[i];
if (c == '{')
{
var arg1 = "{" + TexFormulaParser.ReadGroup(str, ref i, '{', '}') + "}";
if (second == "brace")
{
// \overbrace or \underbrace
if (i + 1 < str.Length)
{
c = str[i++]; n = str[i];
if ((c == '^' || c == '_') && n == '{')
{
// If there's script we need to think another strategy
var arg2 = TexFormulaParser.ReadGroup(str, ref i, '{', '}');
var arg3 = ou == 2 ? "\\lbrace" : "\\rbrace";
if (c == '^')
{
dst.Append("\\nfrac{\\size[.]{" + arg2 + "}__" + arg3 + "}{" + arg1 + "}");
}
else
{
dst.Append("\\nfrac{" + arg1 + "}{\\size[.]{" + arg2 + "}^^" + arg3 + "}");
}
continue;
}
else
{
i--;
}
}
}
dst.Append(arg1);
dst.Append(ou == 2 ? "^^" : "__");
dst.Append("\\" + second);
continue;
}
}
//Default behav
dst.Append("\\" + cmd);
}
}
else
{
dst.Append(c);
}
}
}
// This function can be called recursively
private string Parse(string original)
{
if (string.IsNullOrEmpty(original))
{
return(original);
}
original = original.Replace("\r", "");
var b = new StringBuilder();
int l = 0, e = 0, i = 0;
bool onRTL = IsFirstRecognizableCharIsRTL(original, 0), commonlyRTL = onRTL;
while (l < original.Length)
{
var c = original[l];
var p = l == 0 ? '\0' : original[l - 1];
var n = l == original.Length - 1 ? '\0' : original[l + 1];
bool ignored = IsIgnoredChar(c);
// If character is a new line
if (c == '\n')
{
if (e != l)
{
// This means something is left behind. Lets clear-em-up
Insert(b, original.Substring(e, l - e), onRTL, commonlyRTL, ref i);
e = l;
}
b.Append('\n');
e = ++l;
i = b.Length;
if (l < original.Length)
{
onRTL = commonlyRTL = IsFirstRecognizableCharIsRTL(original, l);
}
}
// If character is an opening brace
else if (c == '{' && p != '\\' && n != '}' && n != '\0')
{
if (e != l)
{
Insert(b, original.Substring(e, l - e), onRTL, commonlyRTL, ref i);
e = l;
}
var substring = TexFormulaParser.ReadGroup(original, ref l, '{', '}');
e = l;
var parsed = "{" + Parse(substring) + "}";
Insert(b, parsed, false, commonlyRTL, ref i);
}
// If character is a backslash (signals a command) (absolutely specific to TEXDraw behaviour)
else if (c == '\\' && p != '\\' && char.IsLetter(n))
{
if (e != l)
{
Insert(b, original.Substring(e, l - e), onRTL, commonlyRTL, ref i);
e = l;
}
l++;
var command = TexFormulaParser.LookForAWord(original, ref l);
var param1 = string.Empty;
var param2 = string.Empty;
if (l >= original.Length)
{
break;
}
else if (command.Contains("frac"))
{
param1 = "{" + Parse(TexFormulaParser.ReadGroup(original, ref l, '{', '}')) + "}";
param2 = "{" + Parse(TexFormulaParser.ReadGroup(original, ref l, '{', '}')) + "}";
}
else if (command == "rtl" || command == "ltr")
{
if (e != (l - 4))
{
Insert(b, original.Substring(e, (l - 4) - e), onRTL, commonlyRTL, ref i);
}
SkipWhiteSpace(original, ref l);
e = l;
onRTL = commonlyRTL = command == "rtl";
continue;
}
else if (TexFormulaParser.isCommandRegistered(command) || TEXPreference.main.GetFontIndexByID(command) >= 0)
{
if (original[l] == '[')
{
if (command == "root")
{
param1 = "[" + Parse(TexFormulaParser.ReadGroup(original, ref l, '[', ']')) + "]";
}
else
{
param1 = "[" + (TexFormulaParser.ReadGroup(original, ref l, '[', ']')) + "]";
}
}
if (l < original.Length && original[l] != '{' || !command.Contains("hold"))
{
param2 = "{" + Parse(TexFormulaParser.ReadGroup(original, ref l, '{', '}')) + "}";
}
}
var parsed = "\\" + command + param1 + param2;
Insert(b, parsed, false, commonlyRTL, ref i);
e = l;
}
// If character is a script sign (also specific to TEXDraw behaviour)
else if (c == '_' || c == '^' && p != '\\')
{
if (e != l)
{
Insert(b, original.Substring(e, l - e), onRTL, false, ref i);
e = l;
}
var iBackup = i;
while (c == '_' || c == '^')
{
l++;
var parsed = Parse(TexFormulaParser.ReadScriptGroup(original, ref l));
Insert(b, new string(c, 1) + parsed, onRTL, false, ref i);
c = l == original.Length ? '\0' : original[l];
}
e = l;
if (commonlyRTL)
{
i = iBackup;
}
}
// If character/space is different than current RTL mode
else if ((IsRTLChar(c) != onRTL && !ignored) ||
(ignored && l < original.Length - 1 && (onRTL ^ commonlyRTL) &&
((IsRTLChar(c = original[l + 1])) != onRTL)))
{
Insert(b, original.Substring(e, l - e), onRTL, commonlyRTL, ref i);
onRTL = IsRTLChar(c);
e = l++;
}
else
{
l++;
}
}
Insert(b, original.Substring(e), onRTL, commonlyRTL, ref i);
var result = b.ToString();
b.Length = 0;
return(result);
}