(*  VERSION 0024 *)

(*.......................................................................*)
(*                           HIDELINE                                    *)
(*  Hideline is a three-dimensional graphics program. The program        *)
(* was written by Franklin C Crow and published as 'Three-Dimensional    *)
(* Computer Graphics', BYTE, March/April 1981. The program was adapted   *)
(* to run with a MicroAngelo graphics terminal by Ray Hopkins, 8         *)
(* Chestnut Hill CT., Cinnaminson N.J. (609) 829-4686.                   *)
(* Hl3.src builds the data files used by hl.src,the main display routine *)
(* Hl1.src and Hl2 are support modules. Note that Hl1.src must have      *)
(* recursion turned on. Hl.cmd is the linker command file                *)
(*.......................................................................*)

(*Z*)
{$K1}
{$K2}
{$K3}
{$K6}
{$K7}
{$K12}
{$K13}
{$K14}
{$K15}

MODULE HIDELINE2;

CONST Dotsacross = 511;
      Dotsdown = 479;
      Maxpts = 200;
      Maxpols = 200;
      Maxvtx = 800;
      Maxsides =14;
      Move = $84;
      Plot = $91;
      Split = $B8;
      Clear = $88;

TYPE  Counter = 0..Maxvtx;
      Point = RECORD
                X,Y,Z : REAL
              END;
      Vertex = 0..Maxpts;
      Polygon = RECORD
                  Numvtx : Vertex;
                  START : Counter;
                END;
      Onepoly = ARRAY [1..Maxsides] OF Point;
      Matrix = ARRAY [1..4,1..4] OF REAL;

VAR   Polygons : EXTERNAL  ARRAY [1..Maxpols] OF Polygon;
      Vertices : EXTERNAL  ARRAY [1..Maxvtx] OF Vertex;
      Points : EXTERNAL  ARRAY [1..Maxpts] OF Point;
      Outpolys : EXTERNAL  ARRAY [1..Maxpols] OF Polygon;
      Outvtces : EXTERNAL  ARRAY [1..Maxvtx] OF Point;
      Eyespace : EXTERNAL  Matrix;
      Window : EXTERNAL  Onepoly;
      Eyept , Cntrint : EXTERNAL  Point;
      Screenscale, Screenctr : EXTERNAL  Point;
      ScreenX, SCREENY : EXTERNAL  REAL;
      Numpols, Numvtces,  Windowsize, I : EXTERNAL  Counter;
      Numpts : EXTERNAL  Counter;
      Nptsr : EXTERNAL  REAL;
      NUMDISPLAY, NumvtxOUT : EXTERNAL  Counter;
      CMDCHAR : EXTERNAL  CHAR;
      Filename : EXTERNAL  STRING;
      DONE : EXTERNAL  BOOLEAN;


procedure outp(B:byte);

begin
  inline("IN/$E1/
         "ANI/1/
         "JNZ/*-4);
   out[$E0]:=B;
end;

procedure micro2(mode:byte;X,Y:real);

var MX,MY:integer;

begin
MX:=trunc(X);
MY:=trunc(Y);
outp(mode);
outp(HI(MX));
outp(LO(MX));
outp(HI(MY));
outp(LO(MY));
end;

PROCEDURE GETPLANES(VAR Poly:Onepoly; Numpts:Counter);

VAR I,LstI : Counter;
    Tmpoly : Onepoly;

BEGIN
  LstI := Numpts;
  FOR I:=1 TO Numpts DO
    BEGIN
      WITH Poly[I] DO
        BEGIN
          Tmpoly[I].X := Y*Poly[LstI].Z-Z*Poly[LstI].Y;
          Tmpoly[I].Y := Z*Poly[LstI].X-X*Poly[LstI].Z;
          Tmpoly[I].Z := X*Poly[LstI].Y-Y*Poly[LstI].X;
        END;
      LstI := I;
    END;
  FOR I:=1 TO Numpts DO
    BEGIN
      WITH Tmpoly[I] DO
        BEGIN
          Poly[I].X := X;
          Poly[I].Y := Y;
          Poly[I].Z := Z;
        END;
    END;
END;

PROCEDURE GETScreenscale;

VAR I : Counter;
    MAXX,MAXY,MINX,MINY : REAL;

BEGIN
  MAXX := 0.0;
  MAXY := 0.0;
  MINX := 0.0;
  MINY := 0.0;
  FOR I:=1 TO Windowsize DO
    BEGIN
      WITH Window[I] DO
        BEGIN
          IF X/Z > MAXX THEN
            MAXX := X/Z;
          IF X/Z < MINX THEN
            MINX := X/Z;
          IF Y/Z > MAXY THEN
            MAXY := Y/Z;
          IF Y/Z < MINY THEN
            MINY := Y/Z;
        END;
    END;
  MAXX := MAXX-MINX;
  MAXY := MAXY-MINY;
  IF MAXY > (0.75*MAXX) 
    THEN
    Screenscale.Z := MAXY*(4/3)
  ELSE
    Screenscale.Z := MAXX;
  Screenscale.X := Dotsacross/Screenscale.Z;
  Screenscale.Y := (Dotsdown*4/3)/Screenscale.Z
END;

PROCEDURE INITIALIZE;

BEGIN
  DONE := FALSE;
  Numpols := 0;
  NUMDISPLAY := 0;
  Numvtces := 0;
  Numpts := 0;
  WITH Eyept DO
    BEGIN
      X := -5;
      Y := -5;
      Z := 3;
    END;
  WITH Cntrint DO
    BEGIN
      X := 0;
      Y := 0;
-Šp`ppv~:= 0;
    END;
  Windowsize := 4;
  WITH Window[1] DO
    BEGIN
      X := -4;
      Y := -3;
      Z := 16;
    END;
  WITH Window[2] DO
    BEGIN
      X := -4;
      Y := 3;
      Z := 16;
    END;
  WITH Window[3] DO
    BEGIN
      X := 4;
      Y := 3;
      Z := 16;
    END;
  WITH Window[4] DO
    BEGIN
      X := 4;
      Y := -3;
      Z := 16;
    END;
  GETScreenscale;
  GETPLANES(Window,Windowsize);
  WITH SCREENCTR DO
    BEGIN
      X := Dotsacross/2;
      Y := Dotsdown/2;
    END;
  OUTP(Clear);
  OUTP(Split);
  OUTP($01);
END;

PROCEDURE START;

VAR I,J : Counter;

BEGIN
  OUTP(Clear);
END;


PROCEDURE READOBJECT(Filename:STRING);

VAR PTSOBJ,POLSOBJ,PTSPOL,I,J: Counter;
    XPOS,YPOS,ZPOS: REAL;
    OBJFILE: TEXT;

BEGIN
  WRITE('POSITION FOR ',Filename,' X,Y,Z: ');
  READLN(XPOS,YPOS,ZPOS);
  ASSIGN(OBJFILE,Filename);
  RESET(OBJFILE);
  IF IORESULT = 255 THEN
    BEGIN
      WRITELN(Filename,' not found');
      EXIT;
    END;
  READLN(OBJFILE,PTSOBJ,POLSOBJ);
   FOR I:=1 TO PTSOBJ DO
     BEGIN
       WITH Points[I+Numpts] DO
        BEGIN
          READLN(OBJFILE,J,X,Y,Z);
          X := X+XPOS;
          Y := Y+YPOS;
          Z := Z+ZPOS;
        END;
     END;
  FOR I:=1 TO POLSOBJ DO
    BEGIN
      READ(OBJFILE,PTSPOL);
      FOR J:=1 TO PTSPOL DO
        BEGIN
          READ(OBJFILE,Vertices[J+Numvtces]);
          Vertices[J+Numvtces] := Vertices[J+Numvtces]+Numpts;
        END;
      WITH Polygons[I+Numpols] DO
        BEGIN
          START := Numvtces;
          Numvtx := PTSPOL;
        END;
      Numvtces := Numvtces+PTSPOL;
    END;
  Numpts := Numpts+PTSOBJ;
  Numpols := Numpols+POLSOBJ;
END;

MODEND.