;
;FILE:    fmt_extract3.ips
;PURPOSE: To perform 3 extracts and make a header
;METHOD:
;	Inputs
;		$IPRL_EXTRACT3_OFFSETS	- Holds    offset1(l,h), offset2(l,h), offset3(l,h)
;		$IPRL_EXTRACT3_PARAM	- Holds:   #pixels(l,h),n/k,dpc(h,l)
;	Internal Use:
;		$IPRL_EXTRACT3_OFFSET	- register which points to the register holding the offset
;		$IPRL_HEAD_WORK		- a working copy of the header information
;		$IPRL_EXTRACT3_INSTR	- the working area to build the instruction
;					  source(l,h),dest(l,h),nx,ny,rowlength, global offset
; HISTORY: Written 25-Apr-96 by M.Morrison

QSR_FMT_EXTRACT3::

        COPYREG  $IPRL_EXTRACT3_OFFSETS   R91			;Save the first lower-left extract corner for data product header
        COPYREG  $IPRL_EXTRACT3_OFFSETS+1 R92

	;(do the header stuff before the extract because EXTRACT will change the addresses)

	;--- do the decoding of the source/destination page
	COPYREG  $IPRL_EXTRACT3_INSTR+1 $IPRL_HDECODE_PARAM	;copy the source page high word into a known fixed parameter place
	COPYREG  $IPRL_EXTRACT3_INSTR+3 $IPRL_HDECODE_PARAM+1	;copy the dest page high word into a known fixed parameter place

	CALLQUE  $QSR_DO_HDECODE				;decode the value 

	;--- now copy the relevant info to the hrdinit slot
	COPYRI2D $IPRP_HDECODE_ADDR+1  $IPRL_HEAD_WORK 10	;copy the register list to a fixed working area
	COPYREG  $IPRL_EXTRACT3_INSTR+2  $IPRL_HEAD_WORK+6	;copy the final dest(l)
	COPYREG  $IPRL_EXTRACT3_INSTR+3  $IPRL_HEAD_WORK+7	;copy the final dest(h)
	COPYREG  $IPRL_EXTRACT3_PARAM+0  $IPRL_HEAD_WORK+8	;set the output number of pixels (l)
	COPYREG  $IPRL_EXTRACT3_PARAM+1  $IPRL_HEAD_WORK+9	;set the output number of pixels (h)
	COPYRD2D $IPRL_EXTRACT3_PARAM+2  $IPRL_HEAD_WORK+3 3	;n/k, dpc(h,l)
	COPYRD2I $IPRL_HEAD_WORK $IPRP_HDECODE_ADDR+1 10	;copy the register list back to the slot

	CALLQUE  $QSR_DO_HEADER

	COPYRD2D $IPRL_EXTRACT3_INSTR    $IPRL_FOCUS3_TMP_PAGE 3 ;save original source page

	SETREG	 $IPRL_EXTRACT3_INSTR+7  $IPRL_EXTRACT3_OFFSETS	;set the extract instr offset reg to off#1
	EXTRACT  $IPRL_EXTRACT3_INSTR				;do the extract
	COPYREG  $IPRL_FOCUS3_TMP_PAGE   $IPRL_EXTRACT3_INSTR	;restore source(l)
	COPYREG  $IPRL_FOCUS3_TMP_PAGE+1 $IPRL_EXTRACT3_INSTR+1	;restore source(h)

	SETREG	 $IPRL_EXTRACT3_INSTR+7  $IPRL_EXTRACT3_OFFSETS+2
	EXTRACT  $IPRL_EXTRACT3_INSTR				;do the extract
	COPYREG  $IPRL_FOCUS3_TMP_PAGE   $IPRL_EXTRACT3_INSTR	;restore source(l)
	COPYREG  $IPRL_FOCUS3_TMP_PAGE+1 $IPRL_EXTRACT3_INSTR+1	;restore source(h)

	SETREG	 $IPRL_EXTRACT3_INSTR+7  $IPRL_EXTRACT3_OFFSETS+4
	EXTRACT  $IPRL_EXTRACT3_INSTR				;do the extract

RTNQUE