text.c

/* $Id: text.c,v 1.5 2000/10/10 14:46:22 jholder Exp $   
 * --------------------------------------------------------------------
 * see doc/License.txt for License Information   
 * --------------------------------------------------------------------
 * 
 * File name: $Id: text.c,v 1.5 2000/10/10 14:46:22 jholder Exp $  
 *   
 * Description:    
 *    
 * Modification history:      
 * $Log: text.c,v $
 * Revision 1.5  2000/10/10 14:46:22  jholder
 * Fixed text wrap bug when printing array w/ \r chars in it
 *
 * Revision 1.4  2000/10/04 23:07:57  jholder
 * fixed redirect problem with isolatin1 range chars
 *
 * Revision 1.3  2000/07/05 15:20:34  jholder
 * Updated code to remove warnings.
 *
 * Revision 1.2  2000/05/25 22:28:56  jholder
 * changes routine names to reflect zmachine opcode names per spec 1.0
 *
 * Revision 1.1.1.1  2000/05/10 14:21:34  jholder
 *
 * imported
 *
 *
 * --------------------------------------------------------------------
 */

/*
 * text.c
 *
 * Text manipulation routines
 *
 */

#include "ztypes.h"

static int saved_formatting = ON;
static int story_buffer = 0;
static int story_pos = 0;
static int story_count = 0;

static int line_pos = 0;
static int char_count = 0;

/*
 * decode_text
 *
 * Convert ZSCII encoded text to ASCII. Text is encoded by squeezing each character
 * into 5 bits. 3 x 5 bit encoded characters can fit in one word with a spare
 * bit left over. The spare bit is used to signal to end of a string. The 5 bit
 * encoded characters can either be actual character codes or prefix codes that
 * modifier the following code.
 *
 */

void decode_text( unsigned long *address )
{
   int i, synonym_flag, synonym = 0, zscii_flag, zscii = 0;
   int data, code, shift_state, shift_lock;
   unsigned long addr;

   /* Set state variables */

   shift_state = 0;
   shift_lock = 0;
   zscii_flag = 0;
   synonym_flag = 0;

   do
   {

      /*
       * Read one 16 bit word. Each word contains three 5 bit codes. If the
       * high bit is set then this is the last word in the string.
       */

      data = read_data_word( address );

      for ( i = 10; i >= 0; i -= 5 )
      {

         /* Get code, high bits first */

         code = ( data >> i ) & 0x1f;

         /* Synonym codes */

         if ( synonym_flag )
         {

            synonym_flag = 0;
            synonym = ( synonym - 1 ) * 64;
            addr = ( unsigned long ) get_word( h_synonyms_offset + synonym + ( code * 2 ) ) * 2;
            decode_text( &addr );
            shift_state = shift_lock;

         }
         /* ZSCII codes */
         else if ( zscii_flag )
         {

            /*
             * If this is the first part ZSCII ten-bit code then remember it.
             * Because the codes are only 5 bits you need two codes to make
             * one eight bit ASCII character. The first code contains the
             * top 5 bits (although only 3 bits are used at the moment).
             * The second code contains the bottom 5 bits.
             */

            if ( zscii_flag++ == 1 )
            {
               zscii = code << 5;
            }
            /*
             * If this is the second part of a ten-bit ZSCII code then assemble the
             * character from the two codes and output it.
             */
            else
            {
               zscii_flag = 0;
               write_zchar( ( unsigned char ) ( zscii | code ) );
            }

         }

         /* Character codes */
         else if ( code > 5 )
         {

            code -= 6;

            /*
             * If this is character 0 in the punctuation set then the next two
             * codes make a ten-bit ZSCII character. (Std. Sec. 3.4)
             */

            if ( shift_state == 2 && code == 0 )
            {
               zscii_flag = 1;
            }

            /*
             * If this is character 1 in the punctuation set then this
             * is a new line.
             */

            else if ( shift_state == 2 && code == 1 && h_type > V1 )
            {
               z_new_line(  );
            }
            /*
             * This is a normal character so select it from the character
             * table appropriate for the current shift state.
             */

            else
            {
               write_zchar( lookup_table[shift_state][code] );
            }
            shift_state = shift_lock;

         }

         /* Special codes 0 to 5 */
         else
         {

            /* Space: 0     Output a space character.     */

            if ( code == 0 )
            {
               write_zchar( ' ' );
            }
            else
            {
               /* The use of the synonym and shift codes is the only 
                * difference between the different versions.  
                */

               if ( h_type < V3 )
               {

                  /* Newline or synonym: 1
                   * Output a newline character or set synonym flag.
                   */

                  if ( code == 1 )
                  {
                     if ( h_type == V1 )
                     {
                        z_new_line(  );
                     }
                     else
                     {
                        synonym_flag = 1;
                        synonym = code;
                     }
                  }
                  else
                  {
                     /*
                      * Shift keys: 2, 3, 4 or 5
                      *
                      * Shift keys 2 & 3 only shift the next character and can be used regardless of
                      * the state of the shift lock. Shift keys 4 & 5 lock the shift until reset.
                      *
                      * The following code implements the the shift code state transitions:
                      *               +-------------+-------------+-------------+-------------+
                      *               |       Shift   State       |        Lock   State       |
                      * +-------------+-------------+-------------+-------------+-------------+
                      * | Code        |      2      |       3     |      4      |      5      |
                      * +-------------+-------------+-------------+-------------+-------------+
                      * | lowercase   | uppercase   | punctuation | uppercase   | punctuation |
                      * | uppercase   | punctuation | lowercase   | punctuation | lowercase   |
                      * | punctuation | lowercase   | uppercase   | lowercase   | uppercase   |
                      * +-------------+-------------+-------------+-------------+-------------+
                      */
                     if ( code < 4 )
                     {
                        shift_state = ( shift_lock + code + 2 ) % 3;
                     }
                     else
                     {
                        shift_lock = shift_state = ( shift_lock + code ) % 3;
                     }
                  }

               }
               else /* not V3 */
               {

                  /*
                   * Synonym table: 1, 2 or 3
                   *
                   * Selects which of three synonym tables the synonym
                   * code following in the next code is to use.
                   */
                  if ( code < 4 )
                  {
                     synonym_flag = 1;
                     synonym = code;
                  }
                  /*
                   * Shift key: 4 or 5
                   *
                   * Selects the shift state for the next character,
                   * either uppercase (4) or punctuation (5). The shift
                   * state automatically gets reset back to lowercase for
                   * V3+ games after the next character is output.
                   *
                   */
                  else
                  {
                     shift_state = code - 3;
                     shift_lock = 0;
                  }
               }
            }
         }
      }
   }
   while ( ( data & 0x8000 ) == 0 );

}                               /* decode_text */

/*
 * encode_text
 *
 * Pack a string into up to 9 codes or 3 words.
 *
 */

void encode_text( int len, const char *s, ZINT16 * buffer )
{
   int i, j, prev_table, table, next_table, shift_state, code, codes_count;
   char codes[9];

   /* Initialise codes count and prev_table number */

   codes_count = 0;
   prev_table = 0;

   /* Scan do the string one character at a time */

   while ( len-- )
   {

      /*
       * Set the table and code to be the ASCII character inducer, then
       * look for the character in the three lookup tables. If the
       * character isn't found then it will be an ASCII character.
       */

      table = 2;
      code = 0;
      for ( i = 0; i < 3; i++ )
      {
         for ( j = 0; j < 26; j++ )
         {
            if ( lookup_table[i][j] == *s )
            {
               table = i;
               code = j;
            }
         }
      }

      /*
       * Type 1 and 2 games differ on how the shift keys are used. Switch
       * now depending on the game version.
       */

      if ( h_type < V3 )
      {

         /*
          * If the current table is the same as the previous table then
          * just store the character code, otherwise switch tables.
          */

         if ( table != prev_table )
         {

            /* Find the table for the next character */

            next_table = 0;
            if ( len )
            {
               next_table = 2;
               for ( i = 0; i < 3; i++ )
               {
                  for ( j = 0; j < 26; j++ )
                  {
                     if ( lookup_table[i][j] == s[1] )
                        next_table = i;
                  }
               }
            }

            /*
             * Calculate the shift key. This magic. See the description in
             * decode_text for more information on version 1 and 2 shift
             * key changes.
             */

            shift_state = ( table + ( prev_table * 2 ) ) % 3;

            /* Only store the shift key if there is a change in table */

            if ( shift_state )
            {

               /*
                * If the next character as the uses the same table as
                * this character then change the shift from a single
                * shift to a shift lock. Also remember the current
                * table for the next iteration.
                */

               if ( next_table == table )
               {
                  shift_state += 2;
                  prev_table = table;
               }
               else
                  prev_table = 0;

               /* Store the code in the codes buffer */

               if ( codes_count < 9 )
                  codes[codes_count++] = ( char ) ( shift_state + 1 );
            }
         }
      }
      else
      {

         /*
          * For V3 games each uppercase or punctuation table is preceded
          * by a separate shift key. If this is such a shift key then
          * put it in the codes buffer.
          */

         if ( table && codes_count < 9 )
            codes[codes_count++] = ( char ) ( table + 3 );
      }

      /* Put the character code in the code buffer */

      if ( codes_count < 9 )
         codes[codes_count++] = ( char ) ( code + 6 );

      /*
       * Cannot find character in table so treat it as a literal ASCII
       * code. The ASCII code inducer (code 0 in table 2) is followed by
       * the high 3 bits of the ASCII character followed by the low 5
       * bits to make 8 bits in total.
       */

      if ( table == 2 && code == 0 )
      {
         if ( codes_count < 9 )
            codes[codes_count++] = ( char ) ( ( *s >> 5 ) & 0x07 );
         if ( codes_count < 9 )
            codes[codes_count++] = ( char ) ( *s & 0x1f );
      }

      /* Advance to next character */

      s++;

   }

   /* Pad out codes with shift 5's */

   while ( codes_count < 9 )
      codes[codes_count++] = 5;

   /* Pack codes into buffer */

   buffer[0] = ( ( ZINT16 ) codes[0] << 10 ) | ( ( ZINT16 ) codes[1] << 5 ) | ( ZINT16 ) codes[2];
   buffer[1] = ( ( ZINT16 ) codes[3] << 10 ) | ( ( ZINT16 ) codes[4] << 5 ) | ( ZINT16 ) codes[5];
   buffer[2] = ( ( ZINT16 ) codes[6] << 10 ) | ( ( ZINT16 ) codes[7] << 5 ) | ( ZINT16 ) codes[8];

   /* Terminate buffer at 6 or 9 codes depending on the version */

   if ( h_type < V4 )
      buffer[1] |= 0x8000;
   else
      buffer[2] |= 0x8000;

}                               /* encode_text */

/*
 * write_zchar
 *
 * High level Z-code character output routine. Translates Z-code characters to
 * machine specific character(s) before output. If it cannot translate it then
 * use the default translation. If the character is still unknown then display
 * a '?'.
 *
 */

void write_zchar( int c )
{
   char xlat_buffer[MAX_TEXT_SIZE + 1];
   int i;

   c = ( unsigned int ) ( c & 0xff );

   /* If character is not special character then just write it */

   if ( c >= ' ' && c <= '~' )
   {
      write_char( c );
   }
   else if ( c == 13 )
   {
      write_char( '\r' );
   }
   else
   {
      /* Put default character in translation buffer */
      xlat_buffer[0] = '?';
      xlat_buffer[1] = '\0';

      /* If translation fails then supply a default */
      if ( codes_to_text( c, xlat_buffer ) )
      {
         if ( c > 23 && c < 28 )
         {
            /* Arrow keys - these must the keyboard keys used for input */
            static char xlat[4] = { '\\', '/', '+', '-' };

            xlat_buffer[0] = xlat[c - 24];
            xlat_buffer[1] = '\0';
         }
         else if ( c == 0 )
         {
            /* Null - print nothing */
            xlat_buffer[0] = '\0';
         }
         else if ( c < 32 )
         {
            /* Some other control character: print an octal escape. */
            xlat_buffer[0] = '\\';
            xlat_buffer[1] = ( char ) ( '0' + ( ( c >> 6 ) & 7 ) );
            xlat_buffer[2] = ( char ) ( '0' + ( ( c >> 3 ) & 7 ) );
            xlat_buffer[3] = ( char ) ( '0' + ( c & 7 ) );
            xlat_buffer[4] = '\0';
         }
         else if ( c > 178 && c < 219 )
         {
            /* IBM line drawing characters to ASCII characters */
            if ( c == 179 )
               xlat_buffer[0] = '|';
            else if ( c == 186 )
               xlat_buffer[0] = '#';
            else if ( c == 196 )
               xlat_buffer[0] = '-';
            else if ( c == 205 )
               xlat_buffer[0] = '=';
            else
               xlat_buffer[0] = '+';
            xlat_buffer[1] = '\0';
         }
         else if ( c > 154 && c < 164 )
         {
            /* German character replacements */
            static char xlat[] = "aeoeueAeOeUess>><<";

            xlat_buffer[0] = xlat[( ( c - 155 ) * 2 ) + 0];
            xlat_buffer[1] = xlat[( ( c - 155 ) * 2 ) + 1];
            xlat_buffer[2] = '\0';
         }
      }

      /* Substitute translated characters */

      for ( i = 0; xlat_buffer[i] != '\0'; i++ )
      {
         write_char( ( unsigned char ) xlat_buffer[i] );
      }

   }
}                               /* write_zchar */

/*
 * translate_to_zscii
 *
 *
 */
zbyte_t translate_to_zscii(int c)
{
   int i;

   if( c>= 0xa0 )
   {
      if( h_unicode_table !=0 ) 
      {
         fprintf(stderr,"[[ Unicode support not enabled yet. ]]");
      }
      else 
      {
         for (i = 0x9b; i <= 0xdf; i++)
         {
            if (c == zscii2latin1[i - 0x9b])
            {
               return (zbyte_t) i;
            }
         }
         return '?';
      }
   }   
   return (zbyte_t) c;
}

/*
 * write_char
 *
 * High level character output routine. The write_char routine is slightly
 * complicated by the fact that the output can be limited by a fixed character
 * count, as well as, filling up the buffer.
 *
 */
void write_char( int c )
{
   char *cp;
   int right_len;

   /* Only do if text formatting is turned on */

   if ( redirect_depth )
   {
      /* If redirect is on then write the character to the status line
       * for V1 to V3 games or into the writeable data area for V4+ games */
      if ( h_type < V4 )
      {
         status_line[status_pos++] = ( char ) c;
      }
      else
      {
         set_byte( story_pos++, translate_to_zscii(c) );
         story_count++;
      }
   }
   else if ( formatting == ON && screen_window == TEXT_WINDOW )
   {
      if ( fit_line( line, line_pos, screen_cols - right_margin ) == 0 || char_count < 1 )
      {
         /* Null terminate the line */
         line[line_pos] = '\0';

         /* If the next character is a space then no wrap is neccessary */
         if ( c == ' ' )
         {
            z_new_line(  );
            c = '\0';
         }
         else
         {
            /* Wrap the line. First find the last space */
            cp = strrchr( line, ' ' );

            /* If no spaces in the lines then cannot do wrap */
            if ( cp == NULL )
            {
               /* Output the buffer and a new line */
               z_new_line(  );
            }
            
            if (cp != NULL) 
            {
               /* Terminate the line at the last space */
               *cp++ = '\0';

               /* Calculate the text length after the last space */
               right_len = &line[line_pos] - cp;

               /* Output the buffer and a new line */
               z_new_line(  );

               /* If any text to wrap then move it to the start of the line */
               if ( right_len > 0 )
               {
                  memmove( line, cp, right_len );
                  line_pos = right_len;
               }
            }
         }
      }
      /* Put the character into the buffer and count it.
       * Decrement line width if the character is visible */
      if ( c )
      {
         line[line_pos++] = ( char ) c;

         /* Wrap the line when there is a newline in the stream. */
         cp = strrchr( line, 13 );
         if ( cp!= NULL )
         {
            /* Terminate the line at the last space */
            *cp++ = '\0';

            /* Calculate the text length after the last space */
            right_len = &line[line_pos] - cp;

            /* Output the buffer and a new line */
            z_new_line(  );

            /* If any text to wrap then move it to the start of the line */
            if ( right_len > 0 )
            {
               memmove( line, cp, right_len );
               line_pos = right_len;
            }
         }

         if ( isprint( c ) )
         {
            char_count--;
         }
      }
   }
   else
   {
      /* No formatting or output redirection, so just output the character */
      script_char( c );
      output_char( c );
   }

}                               /* write_char */

/*
 * z_set_text_style
 *
 * Set a video attribute. Write the video mode, from 0 to 8, incremented.
 * This is so the output routines don't confuse video attribute 0 as the
 * end of the string.
 *
 */

void z_set_text_style( zword_t mode )
{
   if ( mode >= MIN_ATTRIBUTE  && mode <= MAX_ATTRIBUTE )
   {
      set_attribute( mode );
   }
   else
   {
      fatal( "@set_text_style called with invalid mode." );
   }
}                               /* z_set_text_style */

/*
 * write_string
 *
 * Output a string
 *
 */

void write_string( const char *s )
{
   while ( *s )
      write_char( *s++ );

}                               /* write_string */

/*
 * flush_buffer
 *
 * Send output buffer to the screen.
 *
 */

void flush_buffer( int flag )
{
   /* Terminate the line */
   line[line_pos] = '\0';

   /* Send the line buffer to the printer */
   script_string( line );
   flush_script(  );            

   /* Send the line buffer to the screen */
   output_string( line );

   /* Reset the character count only if a carriage return is expected */
   if ( flag == TRUE )
   {
      char_count = screen_cols - right_margin;
   }

   /* Reset the buffer pointer */
   line_pos = 0;

}                               /* flush_buffer */

/*
 * z_buffer_mode
 *
 * Set the format mode flag. Formatting disables writing into the output buffer.
 * If set to 1, text output in the lower window on stream one is buffered so that 
 * it can be word-wrapped properly.  If set to 0, it isn't.
 *
 */

void z_buffer_mode( zword_t flag )
{
   /* Flush any current output */
   flush_buffer( FALSE );

   /* Set formatting depending on the flag */
   if ( flag )
      formatting = ON;
   else
      formatting = OFF;

}                               /* z_buffer_mode */

/*
 * z_output_stream
 *
 * Set various printing modes. These can be: disabling output, scripting and
 * redirecting output. Redirection is peculiar. I use it to format the status
 * line for V1 to V3 games, otherwise it wasn't used. V4 games format the
 * status line themselves in an internal buffer in the writeable data area.
 * To use the normal text decoding routines they have to redirect output to
 * the writeable data area. This is done by passing in a buffer pointer.
 * The first word of the buffer will receive the number of characters
 * written since the output was redirected. The remainder of the buffer
 * will contain the redirected text.
 *
 */

typedef struct redirect_stash_struct
{
   zword_t count;
   zword_t buffer;
   zword_t pos;
}
redirect_stash_t;

void z_output_stream( zword_t type, zword_t option )
{
   static int redirect_size = 0;
   static redirect_stash_t *stash = NULL;

   if ( ( ZINT16 ) type == 1 )
   {
      /* Turn on text output */
      outputting = ON;
   }
   else if ( ( ZINT16 ) type == 2 )
   {
      /* Turn on scripting */
      open_script(  );
   }
   else if ( ( ZINT16 ) type == 3 )
   {
      /* Turn on output redirection */
      if ( redirect_depth == 0 )
      {
         /* Disable text formatting during redirection */
         saved_formatting = formatting;
         formatting = OFF;

         /* Enable text redirection */
         redirect_depth = 1;
      }
      else
      {
         if ( redirect_size == 0 )
         {
            redirect_size = 4;
            stash = ( redirect_stash_t * ) malloc( redirect_size * sizeof ( redirect_stash_t ) );
         }
         if ( redirect_depth > redirect_size )
         {
            redirect_size *= 2;
            stash = ( redirect_stash_t * ) realloc( stash, redirect_size * sizeof ( redirect_stash_t ) );
         }

         if ( h_type < V4 )
         {
            stash[redirect_depth - 1].pos = status_pos;
         }
         else
         {
            stash[redirect_depth - 1].pos = story_pos;
            stash[redirect_depth - 1].buffer = story_buffer;
            stash[redirect_depth - 1].count = story_count;
         }

         redirect_depth++;
      }

      /* Set up the redirection pointers */

      if ( h_type < V4 )
      {
         status_pos = 0;
      }
      else
      {
         story_count = 0;
         story_buffer = option;
         story_pos = option + 2;
      }

   }
   else if ( ( ZINT16 ) type == 4 )
   {
      /* Turn on input recording */
      open_record(  );
   }
   else if ( ( ZINT16 ) type == -1 )
   {
      /* Turn off text output */
      outputting = OFF;
   }
   else if ( ( ZINT16 ) type == -2 )
   {
      /* Turn off scripting */
      close_script(  );
   }
   else if ( ( ZINT16 ) type == -3 )
   {
      /* Turn off output redirection */
      if ( redirect_depth )
      {
         if ( redirect_depth == 1 )
         {
            /* Restore the format mode and turn off redirection */
            formatting = saved_formatting;
            redirect_depth = 0;

            /* Terminate the redirection buffer and store the count of
             * character in the buffer into the first word of the buffer */
            if ( h_type > V3 )
            {
               set_word( story_buffer, story_count );
            }
         }
         else
         {
            if ( h_type > V3 )
            {
               set_word( story_buffer, story_count );
            }

            redirect_depth--;

            if ( h_type < V4 )
            {
               status_pos = stash[redirect_depth - 1].pos;
            }
            else
            {
               story_pos = stash[redirect_depth - 1].pos;
               story_buffer = stash[redirect_depth - 1].buffer;
               story_count = stash[redirect_depth - 1].count;
            }

         }
      }

   }
   else if ( ( ZINT16 ) type == -4 )
   {
      /* Turn off input recording */
      close_record(  );
   }
}                               /* z_output_stream */

/*
 * z_print_char
 *
 * Write a character.
 *
 */

void z_print_char( zword_t c )
{
   write_zchar( ( char ) c );
}                               /* z_print_char */

/*
 * z_print_num
 *
 * Write a signed number.
 *
 */

void z_print_num( zword_t num )
{
   int i, count;
   char buffer[10];

   i = ( ZINT16 ) num;
   sprintf( buffer, "%d", i );
   count = strlen( buffer );
   for ( i = 0; i < count; i++ )
      write_char( buffer[i] );

}                               /* z_print_num */

/*
 * z_print_paddr
 *
 * Print using a packed address. Packed addresses are used to save space and
 * reference addresses outside of the data region.
 *
 */

void z_print_paddr( zword_t packed_address )
{
   unsigned long address;

   /* Convert packed address to real address */
   address = ( unsigned long ) packed_address * story_scaler;

   /* Decode and output text at address */
   decode_text( &address );

}                               /* z_print_paddr */

/*
 * z_print_addr
 *
 * Print using a real address. Real addresses are just offsets into the
 * data region.
 *
 */

void z_print_addr( zword_t offset )
{
   unsigned long address;

   address = offset;

   /* Decode and output text at address */
   decode_text( &address );

}                               /* z_print_addr */

/*
 * z_print_obj
 *
 * Print an object description. Object descriptions are stored as ASCII
 * strings at the front of the property list for the object.
 *
 */

void z_print_obj( zword_t obj )
{
   zword_t offset;
   unsigned long address;

   /* Check for NULL object */
   if ( obj == 0 )
      return;

   /* Calculate address of property list */
   offset = get_object_address( obj );
   offset += ( h_type < V4 ) ? O3_PROPERTY_OFFSET : O4_PROPERTY_OFFSET;

   /* Read the property list address and skip the count byte */
   address = ( unsigned long ) get_word( offset ) + 1;

   /* Decode and output text at address */
   decode_text( &address );

}                               /* z_print_obj */

/*
 * z_print
 *
 * Print the string embedded in the instruction stream at this point. All
 * strings that do not need to be referenced by address are embedded in the
 * instruction stream. All strings that can be refered to by address are placed
 * at the end of the code region and referenced by packed address.
 *
 */

void z_print( void )
{

   /* Decode and output text at PC */
   decode_text( &pc );

}                               /* z_print */

/*
 * z_print_ret
 *
 * Print a string embedded in the instruction stream as with print_literal,
 * except flush the output buffer and write a new line. After this return from
 * the current subroutine with a status of true.
 *
 */

void z_print_ret( void )
{

   z_print(  );
   z_new_line(  );
   z_ret( TRUE );

}                               /* z_print_ret */

/*
 * z_new_line
 *
 * Simply flush the current contents of the output buffer followed by a new
 * line.
 *
 */

void z_new_line( void )
{

   /* Only flush buffer if story redirect is off */
   if ( redirect_depth == 0 )
   {
      flush_buffer( TRUE );
      script_new_line(  );
      output_new_line(  );
   }
   else
   {
      write_char( '\r' );
   }

}                               /* z_new_line */

/*
 * print_time
 *
 * Print the time as HH:MM [am|pm]. This is a bit language dependent and can
 * quite easily be changed. If you change the size of the time string output
 * then adjust the status line position in display_status_line.
 *
 */

void print_time( int hours, int minutes )
{
   int pm_indicator;

   /* Remember if time is pm */
   pm_indicator = ( hours < 12 ) ? OFF : ON;

   /* Convert 24 hour clock to 12 hour clock */
   hours %= 12;
   if ( hours == 0 )
      hours = 12;

   /* Write hour right justified */
   if ( hours < 10 )
      write_char( ' ' );
   z_print_num( (zword_t)hours );

   /* Write hours/minutes separator */
   write_char( ':' );

   /* Write minutes zero filled */
   if ( minutes < 10 )
      write_char( '0' );
   z_print_num( (zword_t)minutes );

   /* Write the am or pm string */
   if ( pm_indicator == ON )
      write_string( " pm" );
   else
      write_string( " am" );

}                               /* print_time */

/*
 * z_encode
 *
 * Convert text to packed text.
 *
 */

void z_encode( zword_t word_addr, zword_t word_length, zword_t word_offset, zword_t dest_addr )
{
   ZINT16 word[3];
   int i;

   /* Encode the word */

   encode_text( word_length, ( const char * ) &datap[word_addr + word_offset], word );

   /* Move the encoded word, byte swapped, into the destination buffer */

   for ( i = 0; i < 3; i++, dest_addr += 2 )
      set_word( dest_addr, word[i] );

}                               /* z_encode */