;
; FILE:    track_rot.ips
; PURPOSE: Adjust the extract location to adjust for rotation
; METHOD:
;	IPRL_TRACK_NMIN		- number of minutes before increment
;	IPRL_TRACK_NPIX		- number of pixels to move extract
;	IPRL_TRACK_NPIX_MAX	- maximum number of pixels to move
;
;	IPRL_TRACK_IMIN		- counter for N minutes (count down)
;	IPRL_TRACK_EXTRACT (2)	- offset location (low/high)
;	IPRL_TRACK_OFFSET	- number of pixels to add to extract
; HISTORY: Written 1-Oct-96 by M.Morrison
;
QSR_TRACK_ROT::
    BRANCHNE R3072 1 &SET_EXTRACT				;only count minutes on frame 1

    ADDREGD  $IPRL_TRACK_IMIN -1
    BRANCHGT $IPRL_TRACK_IMIN 0 &SET_EXTRACT			;not time to increment offset

    REGSUB   $IPRL_TRACK_NPIX_MAX $IPRL_TRACK_OFFSET $IPRL_JUNK_REG
    BRANCHLT $IPRL_JUNK_REG 1 &SET_EXTRACT			;no incrementing of offset pixel
								;if equal 0 (reached max) or less

    REGADD   $IPRL_TRACK_OFFSET $IPRL_TRACK_NPIX $IPRL_TRACK_OFFSET
    COPYREG  $IPRL_TRACK_NMIN $IPRL_TRACK_IMIN    

SET_EXTRACT:							;overwrite copy in camera header
    REGADD   $IPRL_TRACK_OFFSET $IPRL_TRACK_EXTRACT R3078	;low - there should be no wrap around on
								;the 16 bit number because IPRL_TRACK_NPIX_MAX
								;will be less than 1024
    COPYREG  $IPRL_TRACK_EXTRACT+1  R3079			;high

DONE:
    RTNQUE