Using double-byte characters for graphics text

GDDM V3R2 Base Application Programming Guide

Using double-byte characters for graphics text

GDDM V3R2 Base Application Programming Guide
SC33-0867-01

You can use all three modes of graphics text to display the double-byte character set (DBCS) characters used in some Asian countries. (On the IBM PS/55 workstation or 5550 Multistation, you can use the device's hardware symbol set to display DBCS characters in alphanumeric fields, and receive DBCS alphanumeric input, as explained in "Using procedural alphanumerics for double-byte characters" in topic 13.6.) The same hardware symbol set can be used for mode-1 graphics text. With the GSLSS call, you can load other DBCS symbol sets for use with mode-2 and mode-3 graphics text.

If you use mode-3 graphics text in your program, and load the appropriate vector symbol set into storage, you can display double-byte characters on any device.

Each DBCS character is represented by a two-byte code instead of the single-byte EBCDIC-type code used for Latin characters. You must specify the hexadecimal codes in a GSCHAR or GSCHAP call. The length you specify in these calls must be the number of bytes - twice the number of DBCS characters.

GDDM supplies three special multipage, double-byte symbol sets for Kanji graphic text - an image symbol set for mode-2 text, a vector symbol set for mode-3 text, and a special, high-quality vector symbol set, also for use with mode-3 text.

GDDM also supplies three single-byte character sets for Kanji graphics text - two image symbol sets for use with mode-2 text, and one vector symbol set for mode-3 text.

| GDDM supplies a similar multipage, mode-3 text vector symbol set for
| Simplified Chinese graphic text.

If you require the default double-byte symbol set, you can specify a special symbol-set identifier of 8 on a GSCS call. An example is given in the program below, which was written for a device, such as the IBM PS/55 workstation, that supports DBCS characters.





     /****************************************************************/
     /*           FIRST SET UP HEX CODES IN AN ARRAY                 */
     /****************************************************************/
     DCL KC(65:254) CHAR(1);    /* Array to hold hexadecimal numbers */
     DCL INDEX FIXED BIN(15);                      /* Local variable */
     DCL BIT16 BIT(16);                            /* Local variable */

     DO INDEX=65 TO 254;/* Initialize array with hex'41' through 'FE'*/
       BIT16=UNSPEC(INDEX);                   /* Convert to bit      */
       UNSPEC(KC(INDEX))=SUBSTR(BIT16,9,8);   /* Extract last 8 bits */
     END;

     /****************************************************************/
     /*           NOW WRITE THE KANJI CHARACTERS                     */
     /****************************************************************/
     CALL GSCM(3);                       /* Vector symbol mode       */
     CALL GSCS(8);                       /* Default DBCS symbol set  */
                                         /* ( Kanji on the PS/55 )   */

     DECLARE KANJI_DATA5 CHARACTER(10);  /* String for 5             */
                                         /* Kanji characters         */
     KANJI_DATA5=KC(65)  || KC(192) ||   /* Assign                   */
                 KC(...) || KC(...) ||   /*     five                 */
                 KC(...) || KC(...) ||   /*       two-byte           */
                 KC(...) || KC(...) ||   /*           Kanji          */
                 KC(...) || KC(...);     /*               characters */

     CALL GSCHAR(8,8,10,KANJI_DATA5);    /* Write the Kanji          */




   Figure 73. Routine to add graphics text to the page using double-byte
              characters.

Another method, which enables ordinary single-byte characters to be mixed in a single string with double-byte characters, is to use the special shift-out (SO) and shift-in (SI) characters. The data between these two special characters is interpreted by GDDM as double-byte. Other characters are interpreted as single-byte. With this method, you do not need a GSCS(8) call.

The SO code is X'0E' and the SI is X'0F'. You must allow one byte for each of these and two bytes for each Kanji character. Within any string, only SO/SI pairs are allowed, in that order.

Here is an example:





     /****************************************************************/
     /*           SET UP SO/SI CHARACTERS                            */
     /****************************************************************/
     DCL (SO,SI) CHAR(1);                /* Shift-out & shift-in     */
     SO='0E'X;                          /* Set shift-out codepoint   */
     SI='0F'X;                          /* Set shift-in codepoint    */

     /****************************************************************/
     /*           WRITE MIXED KANJI AND LATIN DATA                   */
     /****************************************************************/
     CALL GSCM(2);                              /* Image symbol mode */

     DECLARE MIXED_DATA28 CHARACTER(28);/*String for mixed characters*/
                                          /*                    bytes*/
     MIXED_DATA28='LATIN'||               /* 5 Latin characters   5  */
                   SO ||                  /* Shift-out            1  */
                   KC(65)  || KC(192) ||  /* 3 Kanji characters   6  */
                   KC(...) || KC(...) ||
                   KC(...) || KC(...) ||
                   SI ||                  /* Shift-in             1  */
                   'LATIN AGAIN' ||       /* 11 Latin characters 11  */
                   SO ||                  /* Shift-out            1  */
                   KC(...) || KC(...) ||  /* 1 Kanji character    2  */
                   SI;                    /* Shift-in             1  */
                                          /*        Total bytes  28  */

     CALL GSSEN(2);
     CALL GSCHAR(8,1,28,MIXED_DATA28);




   Figure 74. Routine to add graphics text to the page mixing single- and
              double-byte characters.

If you left out the GSSEN call from the above code, the character positions used by the SO and SI codes would be output to the display as blanks. GSSEN applies to the current page, and its one parameter determines whether the SO and SI characters are to be represented by blanks between the single-byte and double-byte characters or whether the single-byte and double-byte characters are to be adjacent.

Before executing such a program, you need to specify a GDDM external default.

Subtopics:

12.10.1 GDDM default required for Kanji and Simplified Chinese

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