Q:
PDF format itself does not have any specific support for right-to left languages. Characters within a text run are always placed in left to right order.
So if you want to place some RTL string you should reverse the order of characters in the string.
To determine if a string has any RTL characters you could use the following utility function:
inline bool IsRightToLeftChar(Unicode u) {
return (0x0590 <= u && u <= 0x05FF) || (0x0600 <= u && u <= 0x06FF) || (0x0750 <= u && u <= 0x077F) || (0xFB50 <= u && u <= 0xFDFF) || (0xFE70 <= u && u <= 0xFEFF);
}
PDFNet rasterizers/viewers do not have any issues showing RTL, LTR, or vertical text.