DEFINITION MODULE Regis;

(*
  ReGIS vector graphics (DEC VT125/VT240/VT340; xterm built with
  --enable-regis-graphics; contour).
  Grounding: VT330/VT340 Programmer Reference Manual Vol.2, via the
  contour ReGIS reference. Canvas 800x480, origin top-left, Y down.
  [x,y] absolute, signed [+-dx,+-dy] relative. Commands emitted
  uppercase (ReGIS is case-insensitive). Wrap pictures in
  Enter ... Exit (DCS ... ST).
  L (Load charset) intentionally omitted: recognised but not
  rendered by common emulators.
*)

PROCEDURE Enter;        (* DCS 1 p : reset graphics state + clear canvas *)
PROCEDURE EnterResume;  (* DCS p   : resume, keep previous state *)
PROCEDURE Exit;         (* ST : back to text mode *)

PROCEDURE ScreenErase;  (* S(E) *)
PROCEDURE AddressWindow(x0, y0, x1, y1 : CARDINAL); (* S(A[x0,y0][x1,y1]) *)

PROCEDURE MoveTo(x, y : CARDINAL);   (* P[x,y] absolute, no drawing *)
PROCEDURE MoveRel(dx, dy : INTEGER); (* P signed relative *)

PROCEDURE LineTo(x, y : CARDINAL);   (* V[x,y] *)
PROCEDURE LineRel(dx, dy : INTEGER); (* V signed relative *)
PROCEDURE Dot;                       (* V[] plot one dot *)
PROCEDURE Rect(x0, y0, x1, y1 : CARDINAL); (* outline via P+V *)

PROCEDURE Circle(edgeX, edgeY : CARDINAL); (* C[x,y], centre = cursor *)
PROCEDURE CircleCenter(cx, cy : CARDINAL); (* C(C)[cx,cy] *)
PROCEDURE Arc(degrees : INTEGER; x, y : CARDINAL); (* C(A deg)[x,y] *)

PROCEDURE FillTriangle(x1, y1, x2, y2 : CARDINAL);
(* F(V[x1,y1][x2,y2]), cursor is the first vertex *)

PROCEDURE TextOut(s : ARRAY OF CHAR); (* T'...' ; avoid quotes in s *)
PROCEDURE TextSize(n : CARDINAL);     (* T(Sn), 0..16 *)
PROCEDURE TextSizeWH(w, h : CARDINAL);(* T(S[w,h]) custom cell *)
PROCEDURE TextDir(deg : CARDINAL);    (* T(D..), 45-degree steps *)
PROCEDURE TextSlant(deg : CARDINAL);  (* T(I..) italic slant *)

PROCEDURE UseColor(reg : CARDINAL); (* W(I reg), 0..15 *)
PROCEDURE ColorName(c : CHAR);      (* W(I(c)), D R G B C Y M W *)
PROCEDURE SetRGB(reg, r, g, b : CARDINAL); (* S(M reg(R..G..B..)), 0..100 *)
PROCEDURE SetHLS(reg, h, l, s : CARDINAL); (* S(M reg(H..L..S..)) *)
PROCEDURE BgRegister(reg : CARDINAL);      (* S(I reg) background *)

PROCEDURE WriteOverlay;    (* W(V) default *)
PROCEDURE WriteReplace;    (* W(R) *)
PROCEDURE WriteComplement; (* W(C) *)
PROCEDURE WriteErase;      (* W(E) *)

PROCEDURE Pattern(n : CARDINAL);          (* W(P n), 0..9, 1 = solid *)
PROCEDURE PatternBits(s : ARRAY OF CHAR); (* W(P bits), custom 0/1 string *)
PROCEDURE LineWidth(n : CARDINAL);        (* W(L n) pixels *)
PROCEDURE PVMult(n : CARDINAL);           (* W(M n) pixel-vector multiplier *)

PROCEDURE ShadeOn;             (* W(S1) *)
PROCEDURE ShadeOff;            (* W(S0) *)
PROCEDURE ShadeRefY(y : CARDINAL); (* W(S[,y]) horizontal reference *)

PROCEDURE MacroDef(name : CHAR); (* @:X ... *)
PROCEDURE MacroEnd;              (* @; *)
PROCEDURE MacroRun(name : CHAR); (* @X *)
PROCEDURE MacroClearAll;         (* @. *)

PROCEDURE ReportPosition; (* R(P) send-only; read reply unbuffered *)
PROCEDURE ReportError;    (* R(E) send-only *)

PROCEDURE Unbuffered;
PROCEDURE Buffered;

END Regis.