1	!     FILE NAME:  TRIANGLE.BAS
	!        AUTHOR:  R.W.MCDOUGALL
	! CREATION DATE:  3/18/85
	! REVISION DATE:  3/18/85
	!      LOCATION:  HSTC
	!    MAIN FRAME:  VAX 11/780
	!        SYSTEM:  VAX/VMS V3.7
	!      LANGUAGE:  VAX-11 BASIC V2.2
	!   DESCRIPTION:  NUMERICAL CONTROL TRIANGLE
	!---------------------------------------------------------------------!
	OPTION  TYPE = REAL, 		&
	  	SIZE = (REAL DOUBLE)
	EXTERNAL REAL FUNCTION 	 MTH$SIND,	&
				 MTH$COSD,	&
				 MTH$TAND,	&
			 	MTH$ASIND,	&
				MTH$ACOSD,	&
				MTH$ATAND
	!OUTPUT TO FILE NORMAL -----------------------------------------------
	DEF FNG(TABPOS%,ARG)
		!PRINT VALUE GIVEN
		PRINT #2%, CR;TAB(TABPOS%);FORMAT$(ARG," ###.### ");
	FNEND
	!OUTPUT TO FILE IN PARENTHESIS ---------------------------------------
	DEF FNF(TABPOS%,ARG)
		!PRINT VALUE FOUND
		PRINT #2%, CR;TAB(TABPOS%);"(";FORMAT$(ARG,"###.###");")";
	FNEND
	!OUTPUT TO SCREEN IN REVERSE VIDEO -----------------------------------
	DEF FNP$(ARG)=ESC+"[7m"+FORMAT$(ARG,"###.###")+ESC+"[0m"
	!OUTPUT TO SCREEN NORMAL ---------------------------------------------
	DEF FNR$(ARG)=FORMAT$(ARG,"###.###")
	DEF FNI(SPOS$)
	!---------------------------------------------------------------------!
	!USER DEFINED INPUT FUNCTION:                                         !
	!Input:	 a screen postion for input                                   !
	!Output: a posetive real number					      !
	!---------------------------------------------------------------------!
	AA=-1						
	UNTIL(AA>=0)					!STAY IN UNTIL POSETIVE
		PNT=0
		PRINT SPOS$;"        |"			!CLEAR POSITION
		PRINT SPOS$;				!RE POSITION
		LINPUT #1%, AA$				!ACCEPT INPUT
		FOR L = 1 TO LEN(AA$)			!CHECK EVERY CHARACTER
		    	AAA = ASCII(MID(AA$,L,1))	!TAKE ASCII OF Lth CHAR
			PRINT #99%, CHR$(AAA);"-";AAA	!***DEBUG_STATEMENT***
			SELECT AAA			!CASE THE ASCII VAL
			CASE 46				!IF DECIMAL 
				PNT = PNT+1		!COUNT IT
			CASE 48 TO 57			!IF NUMERIC THEN NO-OP
			CASE ELSE			!ANYTHING ELSE
				PNT=2			!FORCE COUNT TOO HIGH
			END SELECT
		NEXT L					
		IF PNT>1				!IF COUNT TOO HIG
		   THEN AA=-1				!SET TO NEGATIVE
			PRINT ESC;"[16;25H";	&
			"POSITIVE NUMERIC INPUT REQUIRED!";BEL;BEL;BEL;
			PRINT #2%, CR;TAB(ERRTAB%);	&
			"POSITIVE NUMERIC INPUT REQUIRED!";
		   ELSE AA=VAL(AA$) 
		END IF
	NEXT	
	FNI=AA
	FNEND
 !
 !
 MAINLINE:
 !
 !
	!---------------------------------------------------------------------!
	!		     R U L E S   A P P L I E D                        !
	! 		SIN(THETA) = OPPOSITE/HYPOTENUSE                      !
	! 		COS(THETA) = ADJACENT/HYPOTENUSE                      !
	! 		TAN(THETA) = OPPOSITE/ADJACENT                        !
	! 		ANGLEA + ANGLEB + ANGLEC = 180 degrees                !
	! 		SIDEA^2 + SIDEB^2 = SIDEC^2                           !
	!_____________________________________________________________________!
	OPEN "TT:" AS FILE #1%
	OPEN "TRIANGLE.OUT" FOR OUTPUT AS FILE #2%, RECORDSIZE 512%
	!OPEN "TXI7:" AS FILE #99%			 ***DEBUG_STATEMENT***
	OPEN "NLA0:" AS FILE #99%			!***DEBUG_STATEMENT***
	PRINT ESC;"[2J";				!CLEAR SCREEN
	PRINT ESC;"[0;0H";				!HOME CURSOR
	ERRTAB%=64%					!TAB FOR ERRORS TO FILE
	TABB$ = ESC+"[22C"				!POS. FOR PICTURE
	TABBB$ = ESC+"[11C"				!POS. FOR DBL SIZE LINE
	PRINT   ESC;"[7m";				!REVERSE VIDEO
        PRINT 	TABB$;"    TRIANGLE      BY R.W.MCDOUGALL    "
	PRINT 	TABBB$;ESC;"#6 NUMERICAL CONTROL "
	PRINT 	TABBB$;ESC;"#6 TRIANGLE  PROBLEM "
        PRINT 	TABB$;"                                      "
	PRINT 	TABB$;"                 A                    "
        PRINT 	TABB$;"                 |\                   "  
        PRINT 	TABB$;"                 | \                  "
        PRINT 	TABB$;"                 |  \                 "
        PRINT 	TABB$;"               b |   \ c              "
        PRINT 	TABB$;"                 |    \               "
        PRINT 	TABB$;"                 |     \              "    
        PRINT 	TABB$;"                 |_90   \             "
	PRINT	TABB$;"               C |_|_____\ B          "
        PRINT 	TABB$;"                     a                "
        PRINT 	TABB$;"      Return for unknown values.      "
	PRINT   ESC;"[0m"
	PRINT TABBB$;"+---------+---------+---------+---------+---------+---------+"
	PRINT TABBB$;"| SIDE a  | SIDE b  | SIDE c  | ANGLE A | ANGLE B | ANGLE C |"
	PRINT TABBB$;"|         |         |         |         |         |         |"
	PRINT TABBB$;"|         |         |         |         |         |         |"
	PRINT TABBB$;"|         |         |         |         |         |         |"
	PRINT TABBB$;"|         |         |         |         |         |         |"
	PRINT TABBB$;"|         |         |         |         |         |         |"
	PRINT TABBB$;"+---------+---------+---------+---------+---------+---------+";
        PRINT #2%, "               TRIANGLE      BY R.W.MCDOUGALL              "
	PRINT #2%, "             NUMERICAL CONTROL TRIANGLE PROBLEM            "
	PRINT #2%, "  SIDE a    SIDE b    SIDE c    ANGLE A   ANGLE B   ANGLE C "
	PRINT #2%, "  ------    ------    ------    -------   -------   -------"
	SAFTAB%=01%					!SET TAB POSITIONS FOR
	SBFTAB%=11%					!OUTPUT FILE
	SCFTAB%=21%
	AAFTAB%=31%
	ABFTAB%=41%
	ACFTAB%=51%
	PRINT ESC;"[19;24r"				!SET SCROLLING REGION
	ROW = 18					!INIT ROW COUNTER
	ANGLEC = 90					!INIT ANGLE C
	SIDECOUNT=1					!INIT SICE COUNTER
	UNTIL  (ANGLECOUNT=0 AND SIDECOUNT=0)		!EXIT ON ALL ZERO ENTRY
	   SIDECOUNT,ANGLECOUNT,SIDEA,SIDEB,SIDEC,ANGLEA,ANGLEB = 0
	   ROW = ROW + 1				!INC ROW COUNTER
	   IF ROW > 23					!IF ROW 23 
	      THEN ROW = 23				!THEN SCROLL	
		   PRINT ESC;"[19;23r"			!RESET SCROLLING REGION
	   	   PRINT ESC;"[23;0H";			!POSITOIN CURSOR
	   	   PRINT				!PRINT BLANK LINE
	   	   PRINT "           |         |         |         |         |         |         |";
	   	   PRINT ESC;"[19;24r"			!RESET SCROLLING REGION
	   END IF					
	   SAPOS$=ESC+"["+NUM1$(ROW)+";14H"		!SET SCREEN POSITIONS
	   SBPOS$=ESC+"["+NUM1$(ROW)+";24H"		!RELATIVE TO ROW
	   SCPOS$=ESC+"["+NUM1$(ROW)+";34H"
	   AAPOS$=ESC+"["+NUM1$(ROW)+";44H"
	   ABPOS$=ESC+"["+NUM1$(ROW)+";54H"
	   ACPOS$=ESC+"["+NUM1$(ROW)+";64H"
	   PRINT SAPOS$;				!POSTION CURSOR
	   PRINT ACPOS$;FNR$(ANGLEC)			!OUTPUT ANGLE C
	   Y = FNG(ACFTAB%,ANGLEC)
	   SIDEA=FNI(SAPOS$)				!INPUT SIDEA
	   IF SIDEA<>0 
	      THEN Y = FNG(SAFTAB%,SIDEA)
	   END IF
	   PRINT ESC;"[16;0H";ESC;"[2K"			!CLEAR ERROR WINDOW
	   SIDEB=FNI(SBPOS$)				!INPUT SIDEB
	   IF SIDEB<>0 
	      THEN Y = FNG(SBFTAB%,SIDEB)
	   END IF
	   PRINT ESC;"[16;0H";ESC;"[2K"			!CLEAR ERROR WINDOW
	   SIDEC=FNI(SCPOS$)				!INPUT SIDEC
	   IF SIDEC<>0 
	      THEN Y = FNG(SCFTAB%,SIDEC)
	   END IF
	   PRINT ESC;"[16;0H";ESC;"[2K"			!CLEAR ERROR WINDOW
	   ANGLEA=FNI(AAPOS$)				!INPUT ANGLEA
	   IF ANGLEA<>0 
	      THEN Y = FNG(AAFTAB%,ANGLEA)
	   END IF
	   PRINT ESC;"[16;0H";ESC;"[2K"			!CLEAR ERROR WINDOW
	   ANGLEB=FNI(ABPOS$)				!INPUT ANGLEB
	   IF ANGLEB<>0 
	      THEN Y = FNG(ABFTAB%,ANGLEB)
	   END IF
	   PRINT ESC;"[16;0H";ESC;"[2K"			!CLEAR ERROR WINDOW
	   !MINIMUM		1 ANGLE AND 1 SIDE
	   !          OR           2 SIDES
	   SIDECOUNT = SGN(SIDEA)+SGN(SIDEB)+SGN(SIDEC)	!COUNT SIDES
	   ANGLECOUNT = SGN(ANGLEA)+SGN(ANGLEB)		!COUNT ANGLES
	   IF SIDECOUNT>0 OR ANGLECOUNT>0		!CHECK FOR SUFF INFO
	      THEN IF (SIDECOUNT < 1 OR ANGLECOUNT <1) AND &
		      SIDECOUNT<2 
	  	      THEN 
			PRINT ESC;"[16;26H"; &
			"INSUFFICIENT INFORMATION ERROR!";BEL;BEL;BEL;
			PRINT #2%, CR;TAB(ERRTAB%);	&
			"INSUFFICIENT INFORMATION ERROR!";
		      ELSE GOSUB ANALYZE_DATA		!FIND MISSING VALUES
		   END IF
	   END IF
	   PRINT #2%
	NEXT
	GOTO BOT_CODE
 !
 !
 ANALYZE_DATA:
 !
 !
	!CHECK FOR AMBIGOUS SPECIFICATIONS---------------------
	IF (INT(SIDEC^2+.1)<>INT(SIDEA^2+SIDEB^2+.1) AND SIDECOUNT=3) OR &
	   (INT(ANGLEA+ANGLEB+ANGLEC+.1)<>180% AND ANGLECOUNT=2) OR &
	   (SIDEA >= SIDEC AND SIDEA<>0 AND SIDEC<>0) OR &
	   (SIDEB >= SIDEC AND SIDEB<>0 AND SIDEC<>0)
	   THEN PRINT 	ESC;"[16;23H";	&
			"INVALID RIGHT TRIANGLE SPECIFICATION";BEL;BEL;BEL;
			PRINT #2%, CR;TAB(ERRTAB%);	&
			"INVALID RIGHT TRIANGLE SPECIFICATION";
	        RETURN
	END IF
	!LOOP UNTIL ALL VALUES ARE FOUND ------------------------
	UNTIL  (SIDEA<>0 AND 	&
		SIDEB<>0 AND	&
		SIDEC<>0 AND 	&
		ANGLEA<>0 AND 	&
		ANGLEB<>0)
		IF ANGLEA=0				!GET ANGLE A IF UNKNOWN
		   THEN GOSUB GET_ANGLEA		
			IF ANGLEA<>0
			   THEN PRINT AAPOS$;FNP$(ANGLEA) 
			        Y = FNF(AAFTAB%,ANGLEA)
		   	END IF
		END IF
		IF ANGLEB=0				!GET ANGLE B IF UNKNOWN
		   THEN GOSUB GET_ANGLEB
			IF ANGLEB<>0
			   THEN PRINT ABPOS$;FNP$(ANGLEB) 
			        Y = FNF(ABFTAB%,ANGLEB)
		   	END IF
		END IF
		IF SIDEA=0				!GET SIDE A IF UNKNOWN
		   THEN GOSUB GET_SIDEA
			IF SIDEA<>0
			   THEN PRINT SAPOS$;FNP$(SIDEA) 
			        Y = FNF(SAFTAB%,SIDEA)
		   	END IF
		END IF
		IF SIDEB=0				!GET SIDE B IF UNKNOWN
		   THEN GOSUB GET_SIDEB
			IF SIDEB<>0
			   THEN PRINT SBPOS$;FNP$(SIDEB) 
			        Y = FNF(SBFTAB%,SIDEB)
		   	END IF
		END IF
		IF SIDEC=0				!GET SIDE C IF UNKNOWN
		   THEN GOSUB GET_SIDEC
			IF SIDEC<>0
			   THEN PRINT SCPOS$;FNP$(SIDEC) 
			        Y = FNF(SCFTAB%,SIDEC)
		   	END IF
		END IF
	NEXT
	!CHECK FOR AMBIGOUS SPECIFICATIONS---------------------
	IF (INT(SIDEC^2+.1)<>INT(SIDEA^2+SIDEB^2+.1)) OR &
	   (INT(ANGLEA+ANGLEB+ANGLEC+.1)<>180%) OR &
	   (SIDEA >= SIDEC) OR &
	   (SIDEB >= SIDEC)
	   THEN PRINT 	ESC;"[16;23H";	&
			"INVALID RIGHT TRIANGLE SPECIFICATION";BEL;BEL;BEL;
			PRINT #2%, CR;TAB(ERRTAB%);	&
			"INVALID RIGHT TRIANGLE SPECIFICATION";
	END IF
	RETURN
 !
 !
 GET_ANGLEA:
 !
 !
	PRINT #99%, "GET_ANGLEA:"			!***DEBUG_STATEMENT***
	IF SIDEA<>0 AND SIDEC<>0
	   THEN ANGLEA = MTH$ASIND(SIDEA/SIDEC)		!ASIN(O/H)
		RETURN
	END IF
	IF SIDEB<>0 AND SIDEC<>0
	   THEN ANGLEA = MTH$ACOSD(SIDEB/SIDEC)		!ACOS(A/H)
		RETURN
	END IF
	IF SIDEA<>0 AND SIDEB<>0
	   THEN ANGLEA = MTH$ATAND(SIDEA/SIDEB) 	!ATAN(O/A)
		RETURN
	END IF
	IF ANGLEB<>0
	   THEN ANGLEA=180-ANGLEB-ANGLEC		!A=180-B-C
		RETURN
	END IF
	ANGLEA=0
	RETURN
 !
 !
 GET_ANGLEB:
 !
 !
	PRINT #99%, "GET_ANGLEB:"			!***DEBUG_STATEMENT***
	IF SIDEB<>0 AND SIDEC<>0
	   THEN ANGLEB = MTH$ASIND(SIDEB/SIDEC)		!ASIN(O/H)
		RETURN
	END IF
	IF SIDEA<>0 AND SIDEC<>0
	   THEN ANGLEB = MTH$ACOSD(SIDEA/SIDEC)		!ACOS(A/H)
		RETURN
	END IF
	IF SIDEA<>0 AND SIDEB<>0
	   THEN ANGLEB = MTH$ATAND(SIDEB/SIDEA) 	!ATAN(O/A)
		RETURN
	END IF
	IF ANGLEA<>0
	   THEN ANGLEB=180-ANGLEA-ANGLEC		!B=180-A-C
		RETURN
	END IF
	ANGLEB=0
	RETURN
 !
 !
 GET_SIDEA:
 !
 !
	PRINT #99%, "GET_SIDEA:"			!***DEBUG_STATEMENT***
	IF SIDEB<>0 AND ANGLEA<>0
	   THEN SIDEA=SIDEB*MTH$TAND(ANGLEA)		!O=A*TAN(ANGLEA)
		RETURN
	END IF
	IF SIDEB<>0 AND ANGLEB<>0
	   THEN SIDEA=SIDEB/MTH$TAND(ANGLEB) 		!A=O/TAN(ANGLEB)
		RETURN
	END IF
	IF SIDEC<>0 AND ANGLEA<>0
	   THEN SIDEA=SIDEC*MTH$SIND(ANGLEA)		!O=H*SIN(ANGLEA)
		RETURN
	END IF
	IF SIDEC<>0 AND ANGLEB<>0
	   THEN SIDEA=SIDEC*MTH$COSD(ANGLEB)		!A=H*COS(ANGLEB)
		RETURN
	END IF
	IF SIDEB<>0 AND SIDEC<>0
	   THEN SIDEA=SQR(SIDEC^2-SIDEB^2)		!A=SQR(C^2-B^2)
		RETURN
	END IF
	SIDEA=0
	RETURN
 !
 !
 GET_SIDEB:
 !
 !
	PRINT #99%, "GET_SIDEB:"			!***DEBUG_STATEMENT***
	IF SIDEA<>0 AND ANGLEA<>0
	   THEN SIDEB=SIDEA/MTH$TAND(ANGLEA)		!A=O/TAN(ANGLEA)
		RETURN
	END IF
	IF SIDEA<>0 AND ANGLEB<>0
	   THEN SIDEB=SIDEA*MTH$TAND(ANGLEB) 		!O=A*TAN(ANGLEB)
		RETURN
	END IF
	IF SIDEC<>0 AND ANGLEA<>0
	   THEN SIDEB=SIDEC*MTH$COSD(ANGLEA)		!A=H*COS(ANGLEA)
		RETURN
	END IF
	IF SIDEC<>0 AND ANGLEB<>0
	   THEN SIDEB=SIDEC*MTH$SIND(ANGLEB)		!H=A*SIN(ANGLEB)
		RETURN
	END IF
	IF SIDEA<>0 AND SIDEC<>0
	   THEN SIDEB=SQR(SIDEC^2-SIDEA^2)		!B=SQR(C^2-A^2)
		RETURN
	END IF
	SIDEB=0
	RETURN
 !
 !
 GET_SIDEC:
 !
 !
	PRINT #99%, "GET_SIDEC:"			!***DEBUG_STATEMENT***
	IF SIDEA<>0 AND ANGLEA<>0
	   THEN SIDEC=SIDEA/MTH$SIND(ANGLEA)		!H=O/SIN(ANGLEA)
		RETURN
	END IF
	IF SIDEA<>0 AND ANGLEB<>0
	   THEN SIDEC=SIDEA/MTH$COSD(ANGLEB) 		!H=A/COS(ANGLEB)
		RETURN
	END IF
	IF SIDEB<>0 AND ANGLEA<>0
	   THEN SIDEC=SIDEB/MTH$COSD(ANGLEA)		!H=A/COS(ANGLEA)
		RETURN
	END IF
	IF SIDEB<>0 AND ANGLEB<>0
	   THEN SIDEC=SIDEB/MTH$SIND(ANGLEB)		!H=O/SIN(ANGLEB)
		RETURN
	END IF
	IF SIDEA<>0 AND SIDEB<>0
	   THEN SIDEC=SQR(SIDEA^2+SIDEB^2)		!C=SQR(A^2+B^2)
		RETURN
	END IF
	SIDEC=0
	RETURN
 !
 !
 BOT_CODE:
 !
 !
	PRINT ESC;"[H";
	PRINT ESC;"[0;24r";
	END_MESSAGE$ = "THANKS FOR RUNNING THE TRIANGLE PROGRAM."
	PRINT ESC;"[J";END_MESSAGE$
	PRINT #2%
	PRINT #2%, END_MESSAGE$
	CLOSE #1%, #2%, #99%
	END