_StyledWidth
float _StyledWidth(int32 fromOffset, int32 length,
width = _StyledWidth(saveOffset, nextInitial - saveOffset);
strWidth += _StyledWidth(offset, deltaBeforeWhitespace, NULL, NULL);
strWidth += _StyledWidth(current, offset - current, &ascent,
width += _StyledWidth(offset, numBytes, &ascent, &descent);