_______________

{ These procedures generate AUTOCAD readable files in .DXF -format

init (filename) opens the file and outputs the first introductory
                remarks to it. The filename should have the extension .DXF.

movea(x,y)       moves the pen to a position x,y without drawing

drawa(x,y)       draws a line from the current position to x,y

finit            closes the file

}

type dxaugrafiletype=string[20];

var xmomaugraf,ymomaugraf:real;
    dxaugrafile:text;

procedure init(filename:dxaugrafiletype);
{open the file for output }

begin
  assign(dxaugrafile,filename);
  rewrite(dxaugrafile);
  xmomaugraf:=0.;
  ymomaugraf:=0.;
  writeln(dxaugrafile,'0');
  writeln(dxaugrafile,'SECTION');
  writeln(dxaugrafile,'2');
  writeln(dxaugrafile,'ENTITIES');
end;

procedure finit;
{close the file}
begin
  writeln(dxaugrafile,'0');
  writeln(dxaugrafile,'ENDSEC');
  writeln(dxaugrafile,'0');
  writeln(dxaugrafile,'EOF');
  close(dxaugrafile);
end;

procedure movea(x,y:real);
{ moves the current pointer to a new position }
begin
  xmomaugraf:=x;
  ymomaugraf:=y;
end;

procedure drawa(x,y:real);
{ Draws a line from the current position to x,y }
begin
  writeln(dxaugrafile,'0');
  writeln(dxaugrafile,'LINE');
  writeln(dxaugrafile,'  8');
  writeln(dxaugrafile,'0');
  writeln(dxaugrafile,' 10');
  writeln(dxaugrafile,xmomaugraf:8:6);
  writeln(dxaugrafile,' 20');
  writeln(dxaugrafile,ymomaugraf:8:6);
  writeln(dxaugrafile,' 11');
  writeln(dxaugrafile,x:8:6);
  writeln(dxaugrafile,' 21');
  writeln(dxaugrafile,y:8:6);
  xmomaugraf:=x;
  ymomaugraf:=y;
end;

_____________________________

C
C   These subroutines produce output to a file that can be read by
C   the AUTOCAD package as .DXF files with the command DXFIN.
C
C   CALL INIT(filename,ichannel) opens the file on channel
C        ICHANNEL and outputs the first introductory lines
C        to it. Filename should have the extension '.DXF'.
C
C   CALL MOVEA(X,Y)  moves the pen to a position X,Y without
C        drawing
C
C   CALL DRAWA(X,Y)  draws a line from the last current position
C        to X,Y
C
C   CALL FINIT closes the file
C
C
      SUBROUTINE INIT(FILNAM,ICHAN)
C
C  *** Program was written for Fortran 77 - modify the following
C      line for FIV.    
      CHARACTER*20 FILNAM
      COMMON /AUTOGR/ICHAN1,XMOM,YMOM
C
C     OPENING THE FILE FOR DXF
      OPEN(ICHAN,FILE=FILNAM,STATUS='UNKNOWN' )
      ICHAN1=ICHAN
      XMOM=0
      YMOM=0
C
      WRITE(ICHAN,1000)
1000  FORMAT('0',/'SECTION'/,'2',/'ENTITIES')
      RETURN
      END


      SUBROUTINE FINIT
      COMMON /AUTOGR/ICHAN1,XMOM,YMOM
      WRITE(ICHAN1,1000)
1000  FORMAT('0'/ 'ENDSEC' /'0'/'EOF'/)
      CLOSE(ICHAN1)
      RETURN
      END

      SUBROUTINE MOVEA(X,Y)
C
C     MOVES THE CURRENT POINTER TO A NEW POSITION
      COMMON /AUTOGR/ICHAN1,XMOM,YMOM
      XMOM=X
      YMOM=Y
      RETURN
      END

      SUBROUTINE DRAWA(X,Y)
C
C     DRAWS A LINE FROM THE CURRENT POSITION  TO X,Y
      COMMON /AUTOGR/ICHAN1,XMOM,YMOM
      WRITE(ICHAN1,1000) XMOM,YMOM,X,Y
1000  FORMAT('0' / 'LINE' /'  8'/ '0' / ' 10' /F15.7 /' 20' /
     %  F15.7/ ' 11'/ F15.7 / ' 21' / F15.7)
     XMOM=X
     YMOM=Y
     RETURN
     END