iTextSharp.text.pdf.ArabicLigaturizer.Ligature C# (CSharp) Метод

        static int Ligature(char newchar, Charstruct oldchar)
        {
            /* 0 == no ligature possible; 1 == vowel; 2 == two chars; 3 == Lam+Alef */
            int retval = 0;

            if (oldchar.basechar == 0)
                return 0;
            if (IsVowel(newchar)) {
                retval = 1;
                if ((oldchar.vowel != 0) && (newchar != SHADDA)) {
                    retval = 2;           /* we eliminate the old vowel .. */
                }
                switch (newchar) {
                    case SHADDA:
                        if (oldchar.mark1 == 0) {
                            oldchar.mark1 = SHADDA;
                        }
                        else {
                            return 0;         /* no ligature possible */
                        }
                        break;
                    case HAMZABELOW:
                        switch (oldchar.basechar) {
                            case ALEF:
                                oldchar.basechar = ALEFHAMZABELOW;
                                retval = 2;
                                break;
                            case LAM_ALEF:
                                oldchar.basechar = LAM_ALEFHAMZABELOW;
                                retval = 2;
                                break;
                            default:
                                oldchar.mark1 = HAMZABELOW;
                                break;
                        }
                        break;
                    case HAMZAABOVE:
                        switch (oldchar.basechar) {
                            case ALEF:
                                oldchar.basechar = ALEFHAMZA;
                                retval = 2;
                                break;
                            case LAM_ALEF:
                                oldchar.basechar = LAM_ALEFHAMZA;
                                retval = 2;
                                break;
                            case WAW:
                                oldchar.basechar = WAWHAMZA;
                                retval = 2;
                                break;
                            case YEH:
                            case ALEFMAKSURA:
                            case FARSIYEH:
                                oldchar.basechar = YEHHAMZA;
                                retval = 2;
                                break;
                            default:           /* whatever sense this may make .. */
                                oldchar.mark1 = HAMZAABOVE;
                                break;
                        }
                        break;
                    case MADDA:
                        switch (oldchar.basechar) {
                            case ALEF:
                                oldchar.basechar = ALEFMADDA;
                                retval = 2;
                                break;
                        }
                        break;
                    default:
                        oldchar.vowel = newchar;
                        break;
                }
                if (retval == 1) {
                    oldchar.lignum++;
                }
                return retval;
            }
            if (oldchar.vowel != 0) {  /* if we already joined a vowel, we can't join a Hamza */
                return 0;
            }

            switch (oldchar.basechar) {
                case LAM:
                    switch (newchar) {
                        case ALEF:
                            oldchar.basechar = LAM_ALEF;
                            oldchar.numshapes = 2;
                            retval = 3;
                            break;
                        case ALEFHAMZA:
                            oldchar.basechar = LAM_ALEFHAMZA;
                            oldchar.numshapes = 2;
                            retval = 3;
                            break;
                        case ALEFHAMZABELOW:
                            oldchar.basechar = LAM_ALEFHAMZABELOW;
                            oldchar.numshapes = 2;
                            retval = 3;
                            break;
                        case ALEFMADDA:
                            oldchar.basechar = LAM_ALEFMADDA;
                            oldchar.numshapes = 2;
                            retval = 3;
                            break;
                    }
                    break;
                case (char)0:
                    oldchar.basechar = newchar;
                    oldchar.numshapes = Shapecount(newchar);
                    retval = 1;
                    break;
            }
            return retval;
        }