PACKET m20 plot DEFINES drawing area,             (*Autor: H. Indenbirken*)
                        begin plot,               (*Stand: 18.11.84      *)
                        end plot, 
                        clear, 
                        pen,
                        move, 
                        draw, 

                        cursor on, cursor off,
                        get cursor,

                        zeichensatz,
                        get screen, put screen: 
 
LET hor faktor   = 22.21739,                 (****** x pixel / x cm ******)
    vert faktor  = 18.61314,                 (****** y pixel / y cm ******)

    delete = 0,                                              (*Farbcodes *)
    std    = 1,
    black  = 5,
    white  = 6,

    nothing          = 0,                                  (*Linientypen *)
    durchgehend      = 1, 
    gepunktet        = 2,
    kurz gestrichelt = 3,
    lang gestrichelt = 4,
    strichpunkt      = 5,

    bit 14           = 16384;

TYPE SCREEN = ROW 32 ROW 256 INT;
LET POS = STRUCT (INT x, y);
LET ZEICHENSATZ = STRUCT (ROW 255 TEXT char, INT width, height);

ZEICHENSATZ VAR zeichen;
BOOL VAR character defined :: FALSE;
TEXT VAR act pen :: "P"1"L"255""255"",
         cursor pos  :: ""0"M"0""0""0""0""0"D"0""0""0""0""0"M"0""0""0""0""0"D"0""0""0""0"", 
         cursor line :: ""0"M"0""0""0""0""0"D"0""0""0""0""0"D"0""0""0""0"";
INT VAR act thick :: 0, i;
POS VAR pos :: POS : (0, 0);
out (""16"" + act pen + ""9"");

PROC zeichensatz (TEXT CONST name):
  IF exists (name)                                     (* H”he:   0.64 cm*)
  THEN BOUND ZEICHENSATZ VAR new zeichen :: old (name);(* Breite: 0.40 cm*)
       zeichen := new zeichen;
       character defined := TRUE
  ELSE errorstop ("Der Zeichensatz """ + name + """ existiert nicht") FI
END PROC zeichensatz;

PROC drawing area (REAL VAR x cm, y cm, INT VAR x pixel, y pixel) : 
   x cm    := 22.0;    y cm    := 13.7; 
   x pixel := 511;     y pixel := 255 
END PROC drawing area;

PROC begin plot : 
  out (""9""16"");
ENDPROC begin plot ;
 
PROC end plot : 
  out (""9"");
ENDPROC end plot ;

PROC clear :
  pos := POS : (0, 0);
  act thick := 0;
  act pen := "P"1"L"255""255"";
  out ("CP"1"L"255""255"M"0""0""0""0"")

END PROC clear;

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

set foreground:
  IF foreground = delete
  THEN act pen := "P"0""
  ELIF foreground < 0
  THEN act pen := "P"2""
  ELSE act pen := "P"1"" FI  .
 
set thickness:
  act thick := thickness  .

set linetype:
  SELECT linetype OF
  CASE nothing          : act pen CAT "L"0""0""
  CASE durchgehend      : act pen CAT "L"255""255""
  CASE gepunktet        : act pen CAT "L"85""85""
  CASE kurz gestrichelt : act pen CAT "L"15""15""
  CASE lang gestrichelt : act pen CAT "L"255""0""
  CASE strichpunkt      : act pen CAT "L"255""16""
  OTHERWISE act pen CAT "L" + intern (linetype) END SELECT  .

END PROC pen;

PROC move (INT CONST x, y) :
  replace (vektor, 1, x);
  replace (vektor, 2, y);

  out ("M");
  out (vektor); 
  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 replace (vektor, 1, x);
       replace (vektor, 2, y);
       out ("D");
       out (vektor)
  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;

INT VAR x fak :: zeichen.width,
        y fak :: zeichen.height;
PROC draw (TEXT CONST record, REAL CONST angle, height, width):
  IF act pen = "L"0""0""
  THEN
  ELIF character defined
  THEN draw graphic character
  ELSE out (""9"");
       pos cursor (pos.x, pos.y);
       get cursor (x pos, y pos);
       outsubtext (record, 1, 79-y pos); 
       out (""16"")
  FI  .

draw graphic character:
(**** Hier werden Texte mit dem Winkel 'angle',der H”he 'height' und ****)
(**** der Breite 'width' gezeichnet. Die Form der Zeichen ist in der ****)
(**** Datei 'STD Zeichensatz' enthalten.                             ****)
  INT CONST x step :: character x step, y step :: character y step;
  INT VAR x pos :: pos.x, y pos :: pos.y, i, n, x, y;
  BOOL VAR move order;
 
  set character height and width;
  out ("L"255""255"");

  FOR i FROM 1 UPTO length (record)
  REP draw character i PER;
  out (act pen);
  pos.x MOVE pos.y .

set character height and width:
  IF width = 0.0 AND height = 0.0
  THEN x fak := zeichen.width;
       y fak := zeichen.height
  ELSE x fak := int (hor faktor * width+0.5);
       y fak := int (vert faktor * height+0.5)
  FI  .

character x step:
  IF width <> 0.0
  THEN int (cosd (angle) * hor faktor * width+0.5)
  ELSE int (cosd (angle) * real (zeichen.width)+0.5) FI  .

character y step:
  IF height <> 0.0
  THEN int (sind (angle) * vert faktor * height+0.5)
  ELSE int (sind (angle) * real (zeichen.height)+0.5) FI  .

draw character i:
  IF code (record SUB i) < 32
  THEN steuerzeichen
  ELSE normale zeichen FI  .

steuerzeichen:
  SELECT code (record SUB i) OF
  CASE  1: x pos := 0;
           y pos := 255-y fak
  CASE  2: x pos INCR x fak 
  CASE  3: y pos INCR y fak 
  CASE  4: out (""9""); pos cursor (x pos, y pos); out (""4""16"")
  CASE  5: out (""9""); pos cursor (x pos, y pos); out (""5""16"")
  CASE  7: out (""9""7""16"")
  CASE  8: x pos DECR x fak 
  CASE 10: y pos DECR y fak 
  CASE 13: x pos := pos.x
  END SELECT  .

normale zeichen:
  TEXT CONST char :: zeichen.char [code (record SUB i)];
  FOR n FROM 1 UPTO length (char) DIV 4
  REP value (char, n, x, y, move order);
      IF move order
      THEN x pos+x MOVE y pos+y
      ELSE x pos+x DRAW y pos+y FI
  PER;
  x pos INCR x step;
  y pos INCR y step  .

END PROC draw;

PROC draw (TEXT CONST record) :
  draw (record, 0.0, 0.0, 0.0)
END PROC draw;
 
PROC value (TEXT CONST char, INT CONST n, INT VAR x, y, BOOL VAR move):
  x := char ISUB n+n-1;
  y := char ISUB n+n;
  IF x < 0
  THEN IF (x AND bit 14) <> 0
       THEN move := FALSE
       ELSE move := TRUE;
            x := x XOR bit 14
       FI
  ELSE IF (x AND bit 14) <> 0
       THEN move := TRUE;
            x := x XOR bit 14
       ELSE move := FALSE FI
  FI;
  x := (x*x fak) DIV zeichen.width;
  y := (y*y fak) DIV zeichen.height

END PROC value;

PROC get cursor (TEXT VAR t, INT VAR x, y) :
  get cursor (t, x, y, -1, -1, -1, -1)
END PROC get cursor;

PROC get cursor (TEXT VAR t, INT VAR x, y, INT CONST x0, y0, x1, y1):
  init cursor;
  out ("P"2""); 
  REP set cursor;
      get step;
      out (cursor pos);
      out (cursor line);
      move cursor
  PER  .

init cursor:
  INT VAR delta :: 1;
  x := pos.x;
  y := pos.y;

  IF x0 >= 0 AND x0 <= 511 AND y0 >= 0 AND y0 <= 255
  THEN replace (cursor line, 2, "M");
       replace (cursor line, 2, x0);
       replace (cursor line, 3, y0);
       replace (cursor line, 8, "D")
  ELSE replace (cursor line, 2, ""0""0""0""0""0""0"M") FI; 

  IF x1 >= 0 AND x1 <= 511 AND y1 >= 0 AND y1 <= 255
  THEN replace (cursor line,14, "D");
       replace (cursor line, 8, x1);
       replace (cursor line, 9, y1);
  ELSE replace (cursor line,14, ""0""0""0""0""0"") FI  .

get step:
  t := incharety (1);
  IF t <> ""
  THEN IF delta < 10
       THEN delta INCR delta
       ELSE delta INCR 1 FI
  ELSE delta := 1;
       inchar (t)
  FI  .

move cursor:
  SELECT code (t) OF
  CASE 2 : x INCR delta                            (*normaler Zehnerblock*) 
  CASE 19: x INCR delta; y INCR delta
  CASE 3 : y INCR delta
  CASE 18: x DECR delta; y INCR delta
  CASE 8 : x DECR delta
  CASE 14: x DECR delta; y DECR delta
  CASE 10: y DECR delta
  CASE 15: x INCR delta; y DECR delta
  OTHERWISE leave get cursor ENDSELECT;
  check  .

set cursor:
  replace (cursor pos, 2, x-4); replace (cursor pos, 3, y);
  replace (cursor pos, 5, x+4); replace (cursor pos, 6, y);
  replace (cursor pos, 8, x);   replace (cursor pos, 9, y-4);
  replace (cursor pos,11, x);   replace (cursor pos,12, y+4);
  out (cursor pos);

  replace (cursor line, 5, x);  replace (cursor line, 6, y);
  out (cursor line)  .

leave get cursor:
  out (act pen);
  pos.x MOVE pos.y;

  LEAVE get cursor  .

check :
  IF x < 0
  THEN x := 0;
       out (""9""7""16"")
  ELIF x > 511
  THEN x := 511;
       out (""9""7""16"")
  FI; 
  IF y < 0
  THEN y := 0;
       out (""9""7""16"")
  ELIF y > 255
  THEN y := 255;
       out (""9""7""16"")
  FI  .

END PROC get cursor;

PROC cursor on (INT CONST x, y):
  out ("P"2""); 
  replace (cursor pos, 2, x-4); replace (cursor pos, 3, y);
  replace (cursor pos, 5, x+4); replace (cursor pos, 6, y);
  replace (cursor pos, 8, x);   replace (cursor pos, 9, y-4);
  replace (cursor pos,11, x);   replace (cursor pos,12, y+4);
  out (cursor pos)

END PROC cursor on;

PROC cursor off:
  out ("P"2"");
  out (cursor pos);
  out (act pen);
  pos.x MOVE pos.y
END PROC cursor off;

(* Bildwiederholspeicheraufbau der M20:                                  *)
(* 32 Bl”cke (0...31) enthalten jeweils 8 Microzeilen. Die Bitbelegung   *)
(* eines Blocks von 256 INT ist 7654321FEDCBA98.                         *)

PROC get screen (DATASPACE VAR ds, INT CONST page):
  INT VAR i, n, begin :: 32*page;
  FOR i FROM 0 UPTO 31
  REP block in (ds, begin+i, -1, i, n) PER
END PROC get screen;

PROC put screen (DATASPACE CONST ds, INT CONST page):
  INT VAR i, n, begin :: 32*page;
  FOR i FROM 0 UPTO 31
  REP block out (ds, begin+i, -1, i, n) PER
END PROC put screen;

TEXT VAR conv :: ""0""0"";
TEXT PROC intern (INT CONST n):
   replace (conv, 1, n);
   conv
END PROC intern;

TEXT VAR vektor :: ""0""0""0""0"";
OP MOVE (INT CONST x, y):
  replace (vektor, 1, x);
  replace (vektor, 2, y);

  out ("M");
  out (vektor)
END OP MOVE;

OP DRAW (INT CONST x, y):
  replace (vektor, 1, x);
  replace (vektor, 2, y);

  out ("D");
  out (vektor)
END OP DRAW;

PROC pos cursor (INT CONST x, y):
  cursor ((x-10) DIV 6, (237-y) DIV 10)
END PROC pos cursor;

END PACKET m20 plot

IF exists ("ZEICHEN 6*10")
THEN zeichensatz ("ZEICHEN 6*10")
ELIF exists ("ZEICHEN 9*12")
THEN zeichensatz ("ZEICHEN 9*12")
ELSE put line ("Warnung: Zeichensatz fehlt") FI