;;;;;;;;;;;;;;;;;;; -*- Mode: Lisp; Package: Macsyma -*- ;;;;;;;;;;;;;;;;;;;
;;;     (c) Copyright 1980 Massachusetts Institute of Technology         ;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(macsyma-module ards)

;; Package for drawing lines on terminals supporting the Advanced Remote
;; Display Station (ARDS) protocol.  See .INFO.;ARDS > for a description of
;; this crock.  The screen is addressed as -512. <= X, Y <= 511.  Note that
;; drawing from (-511, 0) to (512, 0) on plasma consoles will work for some
;; random reason.  Keep ibase set at 8 since Macsyma has it at 10.

(EVAL-WHEN (EVAL COMPILE) (SETQ OLD-IBASE IBASE IBASE 8))

;; Read-time parameters.  These aren't real TD codes.

#.(SETQ %TDCHR #+ITS 234 #-ITS 34)
#.(SETQ %TDSET #+ITS 235 #-ITS 35)
#.(SETQ %TDLNG #+ITS 236 #-ITS 36)
#.(SETQ %TDSHR #+ITS 237 #-ITS 37)

;; The ARDS-X and ARDS-Y variables are only valid when inside one of the
;; graphics modes.  When entering a graphics mode, we always move the cursor to
;; where we want it without looking to see where it is already.  This may want
;; to be fixed later.

(DEFVAR ARDS-X)
(DEFVAR ARDS-Y)
(DEFVAR ARDS-STATE #.%TDCHR)

;; I can think of few things less optimal.

(DEFUN ARDS-SEND-X-Y (S X Y INVISIBLE DOTTED 4-CHARS &AUX (SIGN-X 0) (SIGN-Y 0))
       (DECLARE (FIXNUM X Y SIGN-X SIGN-Y))
       (SETQ SIGN-X (IF (< X 0) 1 0))
       (SETQ SIGN-Y (IF (< Y 0) 1 0))
       (SETQ X (ABS X) Y (ABS Y))
       (+TYO (+ (LSH (LOGAND X 37) 1) SIGN-X 100) S)
       (IF 4-CHARS
	   (+TYO (+ (LOGAND (LSH X -5) 37) 100 (IF INVISIBLE 40 0)) S))
       (+TYO (+ (LSH (LOGAND Y 37) 1) SIGN-Y 100) S)
       (IF 4-CHARS
	   (+TYO (+ (LOGAND (LSH Y -5) 37) 100 (IF DOTTED 40 0)) S)))

(DEFUN ARDS-SET-POINT (S X Y)
       (DECLARE (FIXNUM X Y))
       (COND ((AND (NOT (= ARDS-STATE #.%TDCHR))
		   (= ARDS-X X)
		   (= ARDS-Y Y)))
	     (T (UNLESS (= ARDS-STATE #.%TDSET)
			(+TYO #.%TDSET S)
			(SETQ ARDS-STATE #.%TDSET))
		(SETQ ARDS-X X ARDS-Y Y)
		(ARDS-SEND-X-Y S X Y NIL NIL T))))

;; Updates global state and figures out if we can draw a short vector.  Even if
;; in long vector mode already, it still wins to go into short vector mode.  If
;; only one short vector is drawn, we break even.

(DEFUN ARDS-DRAW-VECTOR (S X Y INVISIBLE DOTTED)
       (DECLARE (FIXNUM X Y))
       (PSETQ X (- X ARDS-X) ARDS-X X)
       (PSETQ Y (- Y ARDS-Y) ARDS-Y Y)
       (IF (AND (< (ABS X) 40) (< (ABS Y) 40) (NOT INVISIBLE) (NOT DOTTED))
	   (ARDS-DRAW-SHORT-VECTOR S X Y)
	   (ARDS-DRAW-LONG-VECTOR S X Y INVISIBLE DOTTED)))

(DEFUN ARDS-DRAW-SHORT-VECTOR (S X Y)
       (DECLARE (FIXNUM X Y))
       (UNLESS (= ARDS-STATE #.%TDSHR)
	       (+TYO #.%TDSHR S)
	       (SETQ ARDS-STATE #.%TDSHR))
       (ARDS-SEND-X-Y S X Y NIL NIL NIL))

(DEFUN ARDS-DRAW-LONG-VECTOR (S X Y INVISIBLE DOTTED)
       (DECLARE (FIXNUM X Y))
       (UNLESS (= ARDS-STATE #.%TDLNG)
	       (+TYO #.%TDLNG S)
	       (SETQ ARDS-STATE #.%TDLNG))
       (ARDS-SEND-X-Y S X Y INVISIBLE DOTTED T))

(DEFUN ARDS-EXIT-GRAPHICS (S)
       (UNLESS (= ARDS-STATE #.%TDCHR)
	       (+TYO #.%TDCHR S)
	       (SETQ ARDS-STATE #.%TDCHR)))

;; For convenience.  If you are drawing a lot of lines, you
;; should call the procedures defined above.

#+DEBUG
(DEFUN ARDS-DRAW-POINT (S X Y)
       (ARDS-SET-POINT S X Y)
       (ARDS-DRAW-VECTOR S X Y NIL NIL)
       (ARDS-EXIT-GRAPHICS S))

(DEFUN ARDS-DRAW-LINE (S X1 Y1 X2 Y2)
       (ARDS-SET-POINT S X1 Y1)
       (ARDS-DRAW-VECTOR S X2 Y2 NIL NIL)
       (ARDS-EXIT-GRAPHICS S))


;; This file gets loaded when Macsyma is started up and it is determined
;; that an ARDS console is being used.  Communication with Macsyma
;; is through the functions and specials defined after this point.
;; Everything above this point is independent of Macsyma.

(DECLARE (SPECIAL DISPLAY-FILE))

;; These define the size of the character cell in pixels.

(SETQ LG-CHARACTER-X    6.)
(SETQ LG-CHARACTER-Y   10.)
(SETQ LG-CHARACTER-X-2 (// LG-CHARACTER-X 2))
(SETQ LG-CHARACTER-Y-2 (// LG-CHARACTER-Y 2))

;; Coordinate translation from 0 <= X, Y <= 511 to -512 <= X, Y <= 511.  Also,
;; exchange directtion of Y coordinates.  Normally, both constants below would
;; be 512., but there is a one pixel border around the edge of the Plasma TVs.

(DEFMACRO LG-TRANSL-X (X) `(- (LSH ,X 1) 510.))
(DEFMACRO LG-TRANSL-Y (Y) `(- 510. (LSH ,Y 1)))

(DEFUN LG-DRAW-LINE (X1 Y1 X2 Y2)
       (DECLARE (FIXNUM X1 Y1 X2 Y2))
       (LG-SET-POINT X1 Y1)
       (LG-END-VECTOR X2 Y2))

(DEFUN LG-SET-POINT (X Y)
       (ARDS-SET-POINT DISPLAY-FILE (LG-TRANSL-X X) (LG-TRANSL-Y Y)))

(DEFUN LG-DRAW-VECTOR (X Y)
       (ARDS-DRAW-VECTOR DISPLAY-FILE
			 (LG-TRANSL-X X) (LG-TRANSL-Y Y) NIL NIL))

(DEFUN LG-END-VECTOR (X Y)
       (LG-DRAW-VECTOR X Y)
       (ARDS-EXIT-GRAPHICS DISPLAY-FILE))

(EVAL-WHEN (EVAL COMPILE) (SETQ IBASE OLD-IBASE))

;; This should really be set in ALJABR;LOADER and not here, but we're not
;; always able to recognize the terminal type.  So we want things to turn on
;; when the file is loaded by hand.

(SETQ LINE-GRAPHICS-TTY T)