PACKET hrz plot DEFINES drawing area,               {Autor: H. Indenbirken}
                        begin plot,                 {Stand: 16.01.85      }
                        end plot, 
                        clear, 
                        pen,
                        move, 
                        draw:
 
LET delete = 0,                         {Farbcodes}
    std    = 1,
    red    = 2,
    green  = 3,
    blue   = 4,
    black  = 5,
    white  = 6,

    nothing          = 0;               {Linientypen}

LET POS = STRUCT (INT x, y);

FILE VAR tr;
TEXT VAR dummy;
INT VAR act thick :: 0, i;
POS VAR pos :: POS : (0, 0);

PROC drawing area (REAL VAR x cm, y cm, INT VAR x pixel, y pixel) : 
   x cm    := 39.1;    y cm    := 27.6; 
   x pixel := 3910;    y pixel := 2760
END PROC drawing area;

PROC begin plot : 
ENDPROC begin plot ;
 
PROC end plot : 
ENDPROC end plot ;

PROC clear :
  IF exists ("Plotter")
  THEN put line (tr, "NEXT 1;")
  ELSE init tr file FI;

  pos := POS : (0, 0);
  act thick := 0  .

init tr file:
  tr := sequential file (output, "Plotter");
  put line (tr, "#XBA,BEN=7800017 0029 UHRZS012 Graphik#.");
  put line (tr, "ECCO  ");
  put line (tr, "#ANFANG,GRAFIK");
  put line (tr, "#ZEICHNE,PL(1,9),MOD.=ZCH123,DINAF.=3.2,AUSS.=0'0'4200'2970,STIFTE=1'2'3'4'5'6,DATEI=/");
  put line (tr, "CLEAR;BOX;")  .

END PROC clear;

PROC pen (INT CONST background, foreground, thickness, linetype):
  set foreground;
  set thickness  .

set foreground:
  put line (tr, "PEN " + text (foreground) + ";")  .
 
set thickness:
  act thick := thickness * 2  .

END PROC pen;

PROC move (INT CONST x, y) :
  put (tr, text (x) + "!" + text (y) + ";"); 
  pos := POS  : (x, y)
END PROC move;
 
PROC draw (INT CONST x, y) :
  IF act thick <> 0
  THEN IF horizontal line
       THEN thick y
       ELSE thick x FI;
       x MOVE y
  ELSE put (tr, text (x) + "&" + text (y) + ";") FI;
  pos := POS : (x, y)   .

horizontal line:
  abs (pos.x-x) > abs (pos.y-y)  .

thick y:
  INT VAR dy, old x :: pos.x-x ausgleich, new x :: x+x ausgleich;
  old x MOVE pos.y;
  new x DRAW     y;
  FOR dy FROM 1 UPTO act thick
  REP old x MOVE pos.y+dy;
      new x DRAW     y+dy;
      old x MOVE pos.y-dy;
      new x DRAW y-dy;
  PER  . 

x ausgleich:
  IF pos.x <= x
  THEN  act thick
  ELSE -act thick FI  .

thick x:
  INT VAR dx, old y :: pos.y-y ausgleich, new y :: y+y ausgleich;
  pos.x MOVE old y;
      x DRAW new y; 
  FOR dx FROM 1 UPTO act thick
  REP pos.x+dx MOVE old y;
          x+dx DRAW new y;
      pos.x-dx MOVE old y;
          x-dx DRAW new y;
  PER  . 

y ausgleich:
  IF pos.y <= y
  THEN  act thick
  ELSE -act thick FI  .

END PROC draw;

PROC draw (TEXT CONST record, REAL CONST angle, height, width):
  put (tr, height symbol + angle symbol + " SYMB """ + double record + """;")  .

height symbol:
  IF height = 0.0
  THEN ""
  ELSE "H" + text (height) FI  .

angle symbol:
  IF angle = 0.0
  THEN ""
  ELSE "A" + text (angle) FI  .

double record:
  dummy := record;
  change all (dummy, """", """""");
  dummy  .

END PROC draw;

PROC draw (TEXT CONST record) :
  draw (record, 0.0, 0.0, 0.0)
END PROC draw;
 
OP MOVE (INT CONST x, y):
  put (tr, text (x) + "!" + text (y) + ";") 
END OP MOVE;

OP DRAW (INT CONST x, y):
  put (tr, text (x) + "&" + text (y) + ";")
END OP DRAW;

END PACKET hrz plot