public static string[] WrapWords(string source, int lineWidth, FontMetrics metrics)
{
int pos = 0;
int lastWrap = 0;
int lastPossibleWrap = 0;
int curWidth = 0;
List <string> lines = new List <string>();
while (pos < source.Length)
{
char ch = source[pos];
int charWidth = metrics.GetCharacterWidth(ch);
if (ch == '\n')
{
// wrap here
string line = source.Substring(lastWrap, pos - lastWrap);
lastWrap = lastPossibleWrap = pos;
curWidth = 0;
lines.Add(line.PadRight(line.Length + (lineWidth - StringWidth(line, metrics)) / metrics.HalfWidthHorizontalSpacing));
}
else if (curWidth + charWidth > lineWidth)
{
if (lastPossibleWrap > lastWrap)
{
// check length of current word
int end = pos;
while (end < source.Length && !char.IsWhiteSpace(source[end]) && !IsFullWidthCharacter(source[end]))
{
end++;
}
string curWord = source.Substring(lastPossibleWrap, end - lastPossibleWrap).Trim();
if (StringWidth(curWord, metrics) > lineWidth)
{
// word wouldn't fit in its own line, so we keep its start on the current one and force a hard wrap (no padding)
lines.Add(source.Substring(lastWrap, pos - lastWrap));
lastWrap = lastPossibleWrap = pos;
curWidth = 0;
}
else
{
// push the current word to the next line
string line = source.Substring(lastWrap, lastPossibleWrap - lastWrap);
int curLineWidth = StringWidth(line, metrics);
lastWrap = lastPossibleWrap;
curWidth -= curLineWidth;
// pad and add line
lines.Add(line.PadRight(line.Length + (lineWidth - curLineWidth) / metrics.HalfWidthHorizontalSpacing));
}
}
else
{
// force a hard wrap here (no padding)
lines.Add(source.Substring(lastWrap, pos - lastWrap));
lastWrap = lastPossibleWrap = pos;
curWidth = 0;
}
}
curWidth += charWidth;
pos++;
// allow soft wraps after each full-width character
if (char.IsWhiteSpace(ch) || IsFullWidthCharacter(ch))
{
lastPossibleWrap = pos;
}
}
// add the last line
if (pos > lastWrap)
{
string line = source.Substring(lastWrap, pos - lastWrap);
if (line.Trim().Length > 0)
{
lines.Add(line.PadRight(line.Length + (lineWidth - StringWidth(line, metrics)) / metrics.HalfWidthHorizontalSpacing));
}
}
return(lines.ToArray());
}
public static int StringWidth(string str, FontMetrics metrics)
{
return(str.Aggregate(0, (int l, char ch) => l + metrics.GetCharacterWidth(ch)));
}