File: FIGETD.FT of Tape: Various/System-Tapes/eb-plot

(Source file text) 

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	SUBROUTINE FIGETD (ICOM,DX,DY)
C	--------------------------------
C
C  GET DELTA BYTES CORRESPONDING TO ICOM
C
	DATA	STEPS /	1024. /
C
	IDX	= 0
	IDY	= 0
	DX	= 0.
	DY	= 0.
	IC	= ICOM - 16
	NBYTE	= IAND (IC,3) + 1
	IDIAG	= IAND (IC,4) / 4
	ICHGXY	= IAND (IC,8)
	ICHGX	= IAND (IC,16)
C
	IF	(IDIAG .NE. 0) GOTO 20
	IF	(ICHGX .NE. 0) GOTO 40
C
C  GET X
C
20	DO 30	I = 1,NBYTE
	CALL	FIGETB (IB)
30	IDX	= 64*IDX + IB
	DX	= IDX / STEPS
	IF	(IDIAG .EQ. 0) GOTO 60
C
C  GET Y
C
40	DO 50	I = 1,NBYTE
	CALL	FIGETB (IB)
50	IDY	= 64*IDY + IB
	DY	= IDY / STEPS
C
C  SET SIGN
C
60	IF	(ICHGXY .EQ. 0) GOTO 70
	DX	= -DX
	DY	= -DY
70	IF	(ICHGX  .EQ. 0) RETURN
	DX	= -DX
	RETURN
	END

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