; FILE:    fmt_crop.ips
; PURPOSE: To perform a crop on an image
; METHOD:
;       Inputs
;               $IPRL_CROP_PARAM      - Holds:   source(l,h), dest(l,h), list(l,h), dpc(low), nword(l,h)
;               $IPRL_CROP_INSTR      - Holds:   source(h), dest(l,h), lpoint, rcount, list(l,h), global
; RESTRICTION:
;	The 1024x1024 extract needs to have already been performed
; HISTORY: Written 16-Jul-96 by M.Morrison
;
QSR_FMT_CROP::
    COPYREG  $IPRL_CROP_PARAM  $IPRL_CROP_OFFSET		;setup the source low word in the offset because
								;source does not include the low word for CROP


    COPYRD2D $IPRL_CROP_PARAM+1 $IPRL_CROP_INSTR 3		;copy source/desination
    COPYRD2D $IPRL_CROP_PARAM+3 $IPRL_CROP_INSTR+4 3		;copy table address (one word before actually)
								;overwrite row length because of >=3 limitation
    SETREGS  $IPRL_CROP_INSTR+3 2 0 1024			;set list pointer to zero and row length

    _CROP    $IPRL_CROP_INSTR

    ;--- do the decoding of the source page

    COPYREG  $IPRL_CROP_PARAM+1 $IPRL_HDECODE_PARAM          ;copy the source page high word into a known fixed parameter place
    COPYREG  $IPRL_CROP_PARAM+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_CROP_PARAM+2    $IPRL_HEAD_WORK+6        ;copy the final dest(l)
    COPYREG  $IPRL_CROP_PARAM+3    $IPRL_HEAD_WORK+7        ;copy the final dest(h)
    COPYREG  $IPRL_CROP_PARAM+6    $IPRL_HEAD_WORK+5        ;overwrite dpc(l)
    COPYREG  $IPRL_CROP_PARAM+7	   $IPRL_HEAD_WORK+8	    ;set the output number of pixels (l,h)
    COPYREG  $IPRL_CROP_PARAM+8	   $IPRL_HEAD_WORK+9	    ;
    COPYRD2I $IPRL_HEAD_WORK $IPRP_HDECODE_ADDR+1 10        ;copy the register list back to the slot

    CALLQUE  $QSR_DO_HEADER

    RTNQUE