/*

     *********************************************************
     *                                                       *
     *                   TekPS - Version 2.0                 *
     *                     September, 1988                   *
     *                                                       *
     *            (c) 1988  by  Arlindo da Silva             *
     *                                                       *
     *           This program takes as input Tektronix       *
     *  instructions and produces the corresponding Post     *
     *  Script code.  Notice that:                           *
     *                                                       *
     *          - the Tektronix alpha mode instructions      *
     *            are ignored; use it only for graphics.     *
     *                                                       *
     *********************************************************


*/

#include <stdio.h>
#include <ctype.h>

/*................................................................*/

   FILE *tek_file;
   FILE *ps_file;

   int    x1, y1, x0, y0, ps_counter;
   int    xoff[4], yoff[4], inext=0;
   char   delimiter, linecap, linewidth, linejoin, nplotsfrm;
   char   first_instruction, frame_flag, c1;
   char   infile[80], outfile[80];
   char   ESC=27, FF=12, US=31, GS=29;


/*

   Global Variables:

   tek_file          -  Tektronix input file
   ps_file           -  Post Script output file
   frame_flag        -  whether or not frame has anything in it
   ps_counter        -  holds counter of Post Script points plotted
   first_instruction -  whether or not first instruction of the frame.
   inext             -  controls position of plot on the frame

*/

/*...................................................................*/


main ( argc, argv )

int argc;
char *argv[];

{

   Setup ( argc, argv );

   Initialization();

   Scan_Tektronix_File();

   Finalization();

   Close_Files();

}


Usage_Note()

{
  fprintf ( stderr, "Usage:  tekps [-options]  [infile [outfile]\n");
  fprintf ( stderr, "Options:\n" );
  fprintf ( stderr, "       -h    displays this message\n" );
  fprintf ( stderr, "       -d n  specifies character n as delimiter");
  fprintf ( stderr," (default=%d)\n", delimiter );
  fprintf ( stderr, "       -f n  specifies n plots per frame; n can only\n");
  fprintf ( stderr, "            be 1, 2 or 4" );
  fprintf ( stderr," (default=%d)\n", nplotsfrm );
  fprintf ( stderr, "       -c n  specifies line cap as n");
  fprintf ( stderr," (default=%d)\n", linecap );
  fprintf ( stderr, "       -w n  specifies line width as n");
  fprintf ( stderr," (default=%d)\n", linewidth );
  fprintf ( stderr, "       -j n  specifies line join as n");
  fprintf ( stderr," (default=%d)\n", linejoin );
}


Setup ( argc, argv )

int  argc;
char *argv[];

{

   int  i;
   char *fin=NULL;
    char *fout=NULL;

   /*---- defaults for internal parameters ---*/
   delimiter = '%';
   nplotsfrm = 1;
   linecap   = 1;   /* change this only if you know what you are doing */
   linewidth = 2;
   linejoin  = 1;
   i=1;

   while (i<argc){
     if (argv[i][0]=='-'){
       switch (argv[i][1]){
       case 'h': Usage_Note();exit(1);
       case 'd': delimiter = atoi ( argv[++i] );break;
       case 'f': nplotsfrm = atoi ( argv[++i] );break;
       case 'c': linecap  = atoi ( argv[++i] );break;
       case 'w': linewidth = atoi ( argv[++i] );break;
       case 'j': linejoin  = atoi ( argv[++i] );break;
       default: Usage_Note();exit(1);
       };
     }
     else 
       {
	 if (fin == NULL) fin=argv[i];
	 else fout=argv[i];
       };
i++;
};


   switch ( nplotsfrm )
   {
      case 1:  break;

      case 2:  xoff[0] = 480+0; yoff[0] = 160+2048;
               xoff[1] = 480+0; yoff[1] = 160+   0;
               break;

      case 4:  xoff[0] = 160+1599; yoff[0] = 160+2048;
               xoff[1] = 160+1599; yoff[1] =      160;
               xoff[2] =      160; yoff[2] = 160+2048;
               xoff[3] =      160; yoff[3] =      160;
               break;

      case 7:  xoff[0] = 160+1599; yoff[0] = 160+2048;
               xoff[1] = 160+1599; yoff[1] =      160;
               xoff[2] =      160; yoff[2] = 160+2048;
               xoff[3] =      160; yoff[3] =      160;
               break;

      case 8:  xoff[0] = 160+1599; yoff[0] = 160+2048;
               xoff[1] = 160+1599; yoff[1] =      160;
               xoff[2] =      160; yoff[2] = 160+2048;
               xoff[3] =      160; yoff[3] =      160;
               break;

      case 9:  xoff[0] = 160+1599; yoff[0] = 160+2048;
               xoff[1] = 160+1599; yoff[1] =      160;
               xoff[2] =      160; yoff[2] = 160+2048;
               xoff[3] =      160; yoff[3] =      160;
               break;

      default:
               fprintf ( stderr,
                         "\ntekps: invalid option -f %d \n", nplotsfrm );
               exit(1);
               break;
   }


/* Open files */

   /*-------------- Tektronix File ---------------*/

   if (fin==NULL)tek_file=stdin;
   else if((tek_file = fopen ( fin, "r" ))== NULL )
	 {
	   fprintf ( stderr,
		    "\ntekps: cannot open Tektronix file %s\n", fin);
	   exit(1);
	 };
   if (fout==NULL)ps_file=stdout;
   else if((ps_file = fopen ( fout, "w" ))== NULL )
	 {
	   fprintf ( stderr,
		    "\ntekps: cannot open Postscript file %s\n", fout);
	   exit(1);
	 };
}

Close_Files()

{
   fclose ( tek_file );
   fclose (  ps_file );

}


Scan_Tektronix_File()

/*
       This procedure scans the Tektronix file and plots it on the screen.

    Notes:  Not a 100% Tek 4014.
    -----   CR is ignored.
            ESC 8, 9, :, and ; (font size) not handled.
            FS and ESC FS (point plot mode and special point plot mode)
             not handled.
            RS (incremental plot mode) not implemented.

            Alpha mode stuff ignored.


Local parameters:
----------------

   graph_mode        -  indicates whether graphic mode or not
   pen_down          -  indicates whether pen is down or not
   after_low_y       -  indicates if current byte is after a low y
   hx / lx           -  high/low x
   hy / ly           -  high/low y
   lxy               -  low x y
   OneByte           -  byte being processed

*/


{

   char   graph_mode=0, pen_down=0, after_low_y=0;
   char   hx=0, lx=0, hy=0, ly=0, lxy=0;

   register int OneByte;
   register int  frame;


   /*------------- initialize control parameters --------------*/
   ps_counter        = 0;
   frame             = 1;
   first_instruction = 1;


   /*--------------------  m a i n    l o o p  -------------------------*/
   while (  ( OneByte = getc ( tek_file ) ) != EOF )
   {

      if ( OneByte == ESC )                   /* Handles escape sequence */
      {

         OneByte = getc ( tek_file );         /* get next byte */

         if ( OneByte == FF )                 /* Clear screen */
         {

            End_Page();


            frame++;
                                              /* reset control parameters */
            frame_flag      = 0;
            pen_down          = 0;
            after_low_y       = 0;
            lxy               = 0;
            first_instruction = 1;

         }

      }

      else if ( ! graph_mode )                  /* text mode */
      {
          if ( OneByte == GS )                  /* switch to graph mode */
          {
             graph_mode  = 1;
             pen_down    = 0;
             after_low_y = 0;
          }

          else;                                /* Ignore text.  To included it
                                                  recall that OneByte is the
                                                  character to be written.  */

      }


      else                                      /* graph mode */
      {

         if ( OneByte == GS )
         {
              after_low_y = 0;
              pen_down    = 0;
         }

         else if ( OneByte == US )
         {
              after_low_y = 0;
              graph_mode  = 0;
         }
                                                /* Set High x / High y */

         else if ( ( OneByte >= 32 ) && ( OneByte <= 63 ) )
         {
              if ( after_low_y )  hx = OneByte - 32;
              else                hy = OneByte - 32;
              after_low_y = 0;
         }

                                                 /* Set low x */

         else if ( ( OneByte >= 64 ) && ( OneByte <= 95 ) )
         {
              lx = OneByte - 64;
              x0 = hx * 128 + lx * 4 + ( lxy &  3 );
              y0 = hy * 128 + ly * 4 + ( lxy >> 2 );

              if ( pen_down ) Plot ( x0, y0, 'L' );
              else
              {
                  Plot ( x0, y0, 'M' );
                  pen_down = 1;
              }

              after_low_y = 0;
         }

                                             /* Set low y / extra byte */

         else if ( ( OneByte >= 96 ) && ( OneByte <= 127 ) )
         {
              if ( after_low_y ) lxy = ( ly & 15 );
              ly          = OneByte - 96;
              after_low_y = 1;
         }

      }

   }

   if ( inext != 0 )
   {
      inext      = 999;        /* to force end of page */
      frame_flag = 1;
   }
   End_Page();


}


Initialization()

{
   if ( delimiter != '%' ) fputc ( delimiter, ps_file );
   fputs ( "%!\n", ps_file );
   fputs ( "% TekPS Prologue, ver 2.0, (c) 1988 Arlindo da Silva\n", ps_file );
   fputs ( "% RCSID: $Ident$\n", ps_file );
   fputs ( "% definitions:\n", ps_file );
   fputs ( "save /TekPSsave exch def\n", ps_file );
   fputs ( "/M /moveto load def\n", ps_file );
   fputs ( "/L /lineto load def\n", ps_file );
   fputs ( "% scale the coordinate space:\n", ps_file );
   fputs ( "initmatrix 0.18 dup scale\n", ps_file );
   fputs ( "%ps line parameters:\n", ps_file );
   fprintf ( ps_file, "%d setlinecap %d setlinewidth %d setlinejoin\n",
             linecap, linewidth, linejoin );
   fputs ( "erasepage\n", ps_file );
   fputs ( "% ((( end of TekPS prologue )))\n", ps_file );

}


New_Page()

{
     fprintf ( ps_file, "0 0 M \n" );
}



Plot ( XA, YA, com )

int   XA, YA;
char  com;

/*
    This procedure plots or move the pen depending on
     the value of com:

    xa, ya  --  Tektronix coordinates - range: [0,4095]
    com     --  command:  "M" - move to position xa, xb
                          "L" - draw line from previous position
                                 to xa, ya

    NOTE:  The ps_counter is related to the size of the printer
           buffer.  The value used (500) is ok for many printers
           (like Apple, NEC, TI, etc...)

*/


{

   int xa, ya;


   switch ( nplotsfrm )         /* transform coordinates according to the
                                   number of plots per frame */
   {

   case 2:    xa = xoff[inext] + 0.64 *  XA ;
              ya = yoff[inext] + 0.64 *  YA ;
              break;

   case 4:    xa = xoff[inext] + 0.5 * ( YA );
              ya = yoff[inext] + 0.5 * ( 4096 - XA );
              break;

   case 7:    xa = xoff[inext] + 1.024 * ( YA - 1600) + 800.;
              ya = yoff[inext] + 0.8 * ( 2048 - XA) + 1024.;
              break;

   case 8:    xa = xoff[inext] + 1.28 * ( YA - 1600) + 800.;
              ya = yoff[inext] + 1. * ( 2048 - XA) + 1024.;
              break;

   case 9:    xa = xoff[inext] + 1.6 * ( YA - 1600) + 800.;
              ya = yoff[inext] + 1.25 * ( 2048 - XA) + 1024.;
              break;

   default:
              xa = 160 + YA;             
              ya = 160 + 4096 - XA;
              break;
   }



   if ( ! frame_flag )
   {
       if ( first_instruction )     /* consider only frames with more
                                        than 1 instruction */
       {
          x1 = xa;
          y1 = ya;
          c1 = com;
          first_instruction = 0;
       }
       else
       {
          New_Page();
          fprintf ( ps_file, "%d %d %c\n", x1, y1, c1 );
          fprintf ( ps_file, "%d %d %c\n", xa, ya, com );
          frame_flag = 1;
       }
   }

   else
   {

      if ( ps_counter > 500 )
      {
         fprintf ( ps_file, "%d %d %c\n", xa, ya, com );
         fputs ( "stroke\n", ps_file );
         fprintf ( ps_file, "%d %d %c\n", xa, ya, 'M' );
         ps_counter = 0;
      }
      else
      {
         fprintf ( ps_file, "%d %d %c\n", xa, ya, com );
         ps_counter++;
      }

   }

}



End_Page()

{
   if ( frame_flag )
   {
      inext++;
      if ( inext >= nplotsfrm )
      {
         fputs ( "stroke gsave showpage grestore\n", ps_file );
         inext = 0;
      }
   }

}



Finalization()

{
        fputs ( "%%Trailer\n", ps_file );
        fputs ( "grestore\n", ps_file );
        fputs ( "TekPSsave restore\n", ps_file );

}