plan9fox/sys/lib/ghostscript/gs_setpd.ps

%    Copyright (C) 1994, 2000 Aladdin Enterprises.  All rights reserved.
% 
% This software is provided AS-IS with no warranty, either express or
% implied.
% 
% This software is distributed under license and may not be copied,
% modified or distributed except as expressly authorized under the terms
% of the license contained in the file LICENSE in this distribution.
% 
% For more information about licensing, please refer to
% http://www.ghostscript.com/licensing/. For information on
% commercial licensing, go to http://www.artifex.com/licensing/ or
% contact Artifex Software, Inc., 101 Lucas Valley Road #110,
% San Rafael, CA  94903, U.S.A., +1(415)492-9861.

% $Id: gs_setpd.ps,v 1.27 2005/06/09 19:47:18 ray Exp $
% The current implementation of setpagedevice has the following limitations:
%	- It doesn't attempt to "interact with the user" for Policy = 2.

languagelevel 1 .setlanguagelevel
level2dict begin

% ---------------- Redefinitions ---------------- %

% Redefine .beginpage and .endpage so that they call BeginPage and
% EndPage respectively if appropriate.

% We have to guard against the BeginPage procedure not popping its operand.
% This is really stupid, but the Genoa CET does it.
/.beginpage {		% - .beginpage -
  .currentshowpagecount {
    .currentpagedevice pop
    dup //null ne { /BeginPage .knownget } { pop //false } ifelse {
		% Stack: ... pagecount proc
       count 2 .execn
		% Stack: ... ..???.. oldcount
       count 1 add exch sub { pop } repeat
    } {
      pop
    } ifelse
  } if
} bind odef

% Guard similarly against EndPage not popping its operand.
/.endpage {		% <reason> .endpage <print_bool>
  .currentshowpagecount {
    1 index .currentpagedevice pop
    dup //null ne { /EndPage .knownget } { pop //false } ifelse {
		% Stack: ... reason pagecount reason proc
      count 2 .execn
		% Stack: ... ..???.. print oldcount
      count 2 add exch sub { exch pop } repeat
    } {
      pop pop 2 ne
    } ifelse
  } {
    2 ne
  } ifelse
} bind odef

% Define interpreter callouts for handling gstate-saving operators,
% to make sure that they create a page device dictionary for use by
% the corresponding gstate-restoring operator.
% We'd really like to avoid the cost of doing this, but we don't see how.
% The names %gsavepagedevice, %savepagedevice, %gstatepagedevice,
% %copygstatepagedevice, and %currentgstatepagedevice are known to the
% interpreter.

(%gsavepagedevice) cvn
 { currentpagedevice pop gsave
 } bind def

(%savepagedevice) cvn
 { currentpagedevice pop save
 } bind def

(%gstatepagedevice) cvn
 { currentpagedevice pop gstate
 } bind def

(%copygstatepagedevice) cvn
 { currentpagedevice pop copy
 } bind def

(%currentgstatepagedevice) cvn
 { currentpagedevice pop currentgstate
 } bind def

% Define interpreter callouts for handling gstate-restoring operators
% when the current page device needs to be changed.
% The names %grestorepagedevice, %grestoreallpagedevice,
% %restorepagedevice, %restore1pagedevice, and %setgstatepagedevice
% are known to the interpreter.

/.installpagedevice
 {	% Since setpagedevice doesn't create new device objects,
	% we must (carefully) reinstall the old parameters in
	% the same device.
   .currentpagedevice pop //null currentdevice //null .trysetparams
   dup type /booleantype eq
    { pop pop }
    {		% This should never happen!
      SETPDDEBUG { (Error in .trysetparams!) = pstack flush } if
      cleartomark pop pop pop
      /.installpagedevice cvx /rangecheck signalerror
    }
   ifelse pop pop
	% A careful reading of the Red Book reveals that an erasepage
	% should occur, but *not* an initgraphics.
   erasepage .beginpage
 } bind def

/.uninstallpagedevice
 { 2 .endpage { .currentnumcopies //false .outputpage } if
   nulldevice
 } bind def

(%grestorepagedevice) cvn
 { .uninstallpagedevice grestore .installpagedevice
 } bind def

(%grestoreallpagedevice) cvn
 { .uninstallpagedevice grestore .installpagedevice grestoreall
 } bind def

(%restore1pagedevice) cvn
 { .uninstallpagedevice grestore .installpagedevice restore
 } bind def

(%restorepagedevice) cvn
 { .uninstallpagedevice restore .installpagedevice
 } bind def

(%setgstatepagedevice) cvn
 { .uninstallpagedevice setgstate .installpagedevice
 } bind def

% Redefine .currentnumcopies so it consults the NumCopies device parameter.
/.numcopiesdict mark
  /NumCopies dup
.dicttomark readonly def

/.currentnumcopies
 { currentdevice //.numcopiesdict .getdeviceparams
   dup type /integertype eq
    { exch pop exch pop }
    { cleartomark #copies }
   ifelse
 } bind odef

% Redefine .currentpagedevice and .setpagedevice so they convert between
% null and a fixed empty directionary.
/.nullpagedevice 0 dict readonly def
/.currentpagedevice {
  //.currentpagedevice exch dup //null eq { pop //.nullpagedevice } if exch
} bind odef
/.setpagedevice {
  dup //.nullpagedevice eq { pop //null } if //.setpagedevice
} bind odef

% ---------------- Auxiliary definitions ---------------- %

% Define the required attributes of all page devices, and their default values.
% We don't include attributes such as .MediaSize, which all devices
% are guaranteed to supply on their own.
/.defaultpolicies mark
  /PolicyNotFound 1
  /PageSize 0
  /PolicyReport {
    dup /.LockSafetyParams known {
	% Only possible error is invalidaccess
      /setpagedevice .systemvar /invalidaccess signalerror
    }
    if
    pop
  } bind
.dicttomark readonly def
% Note that the values of .requiredattrs are executed, not just fetched.
/.requiredattrs mark
  /PageDeviceName //null
  /PageOffset [0 0] readonly
% We populate InputAttributes with all of the known page sizes 
% followed by a dummy media type that handles pages of any size.
% This will create some duplicates, but that only slightly slows
% down the media selection (loop is in zmedia2.c).
%
% Some PostScript creators assume that slot 0 is the default media
% size and some can't handle a non-standard 4-element array which
% is a 'range' type page size (always put last).
%
% Real Devices that can only handle specific page sizes will override this.
  /InputAttributes {
    mark
    % First put the device's default page size in slot 0
    % This satifies those that have devices built with a4 as the default
    0 mark /PageSize currentdevice /PageSize gsgetdeviceprop .dicttomark
    statusdict /.pagetypenames get {
      counttomark 1 sub 2 idiv exch mark exch /PageSize exch
      % stack: mark --dict-- --dict-- ... key mark /PageSize pagetypename
      % see note above about pagetype executable array contents.
      load dup 0 get exch 1 get 2 array astore .dicttomark
    } forall
    % If NORANGEPAGESIZE is defined, (-dNORANGEPAGESIZE), then don't add
    % the 'match any' PageSize entry
    systemdict /NORANGEPAGESIZE known not {
      % Add one last entry which is the 4 element range array (non-standard)
      counttomark 2 idiv 
	% PageSize with either dimension 0 will be detected in
	% match_page_size, so we can allow it here
      mark /PageSize [0 dup 16#7ffff dup] .dicttomark
    } if
    .dicttomark
  }
  (%MediaSource) 0
  /OutputAttributes {
    mark 0 mark .dicttomark readonly .dicttomark
  }
  (%MediaDestination) 0
  /Install {{.callinstall}} bind
  /BeginPage {{.callbeginpage}} bind
  /EndPage {{.callendpage}} bind
  /Policies .defaultpolicies
  /ImagingBBox //null		% default value
  /UseCIEColor /.getuseciecolor load
.dicttomark readonly def

% Define currentpagedevice so it creates the dictionary on demand if needed,
% adding all the required entries defined just above.
% We have to deal specially with entries that the driver may change
% on its own.
/.dynamicppkeys mark
  /.MediaSize dup		% because it changes when PageSize is set
  /PageCount dup
  /Colors dup
  /BitsPerPixel dup
  /ColorValues dup
.dicttomark readonly def
/.makecurrentpagedevice {	% - .makecurrentpagedevice <dict>
  currentdevice //null .getdeviceparams
	% Make the dictionary large enough to add defaulted entries.
  counttomark 2 idiv .requiredattrs length add dict
  counttomark 2 idiv { dup 4 2 roll put } repeat exch pop
	% Add any missing required attributes.
	% Make a writable and (if possible) local copy of any default
	% dictionaries, to work around a bug in the output of WordPerfect,
	% which assumes that these dictionaries are writable and local.
  .currentglobal exch dup gcheck .setglobal
  .requiredattrs {
    2 index 2 index known {
      1 index /Policies eq {
	% Merge policies from the device driver with defaults
	2 index             % <<>> /key value <<>>
	3 2 roll get        % <<>> value <<policies>>
	exch {                
	  2 index 2 index known { 
	    pop pop
	  } { 
	    2 index 3 1 roll put
	  } ifelse
	} forall
	pop
      } {
	pop pop
      } ifelse
    } {
      exec 2 index 3 1 roll put
    } ifelse
  } forall exch .setglobal
  dup .setpagedevice
} bind def
/currentpagedevice {
  .currentpagedevice {
    dup length 0 eq {
      pop .makecurrentpagedevice
    } {
		% If any of the dynamic keys have changed,
		% we must update the page device dictionary.
      currentdevice //.dynamicppkeys .getdeviceparams .dicttomark {
		% Stack: current key value
	    2 index 2 index .knownget { 1 index ne } { //true } ifelse
	     { 2 index wcheck not
		{	% This is the first entry being updated.
			% Copy the dictionary to make it writable.
		  3 -1 roll
		  currentglobal 1 index dup gcheck currentglobal and setglobal
		  length dict
		  exch setglobal
		  .copydict
		  3 1 roll
		}
	       if
	       2 index 3 1 roll put
	     }
	     { pop pop
	     }
	    ifelse
      } forall
      % If the device is the distiller device, update distillerparams that
      % may have been changed by setdistillerparams
      currentdevice .devicename /pdfwrite eq {
	currentdistillerparams {
	      % Stack: current key value
	  2 index 2 index .knownget { 1 index ne } { //true } ifelse
	  { 2 index 3 1 roll put } { pop pop } ifelse
	} forall
      } if
		% If the dictionary was global and is now local, copy
		% any global subsidiary dictionaries to local VM.  This
		% too is to work around the Word Perfect bug (see above).
      dup gcheck not {
	dup {
	  dup type /dicttype eq { dup gcheck } { //false } ifelse {
		% Copy-on-write, see above.
	    2 index wcheck not {
	      3 -1 roll dup length dict .copydict
	      3 1 roll
	    } if
	    .copytree 2 index 3 1 roll put
	  } {
	    pop pop
	  } ifelse
	} forall
      } if
		% We would like to do a .setpagedevice so we don't keep
		% re-creating the dictionary.  Unfortunately, the effect
		% of this is that if any dynamic key changes (PageCount
		% in particular), we will do the equivalent of a
		% setpagedevice at the next restore or grestore.
		% Therefore, we make the dictionary read-only, but
		% we don't store it away.  I.e., NOT:
		% dup wcheck { .setpagedevice .currentpagedevice pop } if
      readonly
    } ifelse
  } if
} bind odef

% Copy a dictionary recursively.
/.copytree {	% <dict> .copytree <dict'>
  dup length dict exch {
    dup type /dicttype eq { .copytree } if 2 index 3 1 roll put
  } forall
} bind def

% The implementation of setpagedevice is quite complex.  Currently,
% everything but the media matching algorithm is implemented here.

% By default, we only present the requested changes to the device,
% but there are some parameters that require special merging action.
% Define those parameters here, with the procedures that do the merging.
% The procedures are called as follows:
%	<merged> <key> <new_value> -proc- <merged> <key> <new_value'>
/.mergespecial mark
  /InputAttributes
   { dup //null eq
      { pop //null
      }
      { 3 copy pop .knownget
	 { dup //null eq
	    { pop dup length dict }
	    { dup length 2 index length add dict .copydict }
	   ifelse
	 }
	 { dup length dict
	 }
        ifelse .copydict readonly
      }
     ifelse
   } bind
  /OutputAttributes 1 index
  /Policies
    { 3 copy pop .knownget
       { dup length 2 index length add dict .copydict }
       { dup length dict }
      ifelse copy readonly
    } bind
.dicttomark readonly def

% Define the keys used in input attribute matching.
/.inputattrkeys [
  /PageSize /MediaColor /MediaWeight /MediaType /InsertSheet /ManualFeed
	% The following are documented in Adobe's supplement for v2017.
  /LeadingEdge /MediaClass
] readonly def
% Define other keys used in media selection.
/.inputselectionkeys [
  /MediaPosition /Orientation
] readonly def

% Define the keys used in output attribute matching.
/.outputattrkeys [
  /OutputType
] readonly def

% Define all the parameters that should always be copied to the merged
% dictionary.
/.copiedkeys [
  /OutputDevice
  .mergespecial { pop } forall
  .inputattrkeys aload pop
  .inputselectionkeys aload pop
  .outputattrkeys aload pop
] readonly def

% Define the parameters that should not be presented to the device.
% The procedures are called as follows:
%	<merged> <key> <value> -proc-
% The procedure leaves all its operands on the stack and returns
% true iff the key/value pair should be presented to .putdeviceparams.
/.presentspecial mark
  .dynamicppkeys { pop //false } forall
			% We must ignore an explicit request for .MediaSize,
			% because media matching always handles this.
  /.MediaSize //false
  /Name //false
  /OutputDevice //false
  /PageDeviceName //false
  /PageOffset //false
  /PageSize //false		% obsolete alias for .MediaSize
  /InputAttributes //false
  .inputattrkeys
    { dup /PageSize eq
       { pop }
       { { 2 index /InputAttributes .knownget { //null eq } { //true } ifelse } }
      ifelse
    }
  forall
  .inputselectionkeys { //false } forall
  /OutputAttributes //false
  .outputattrkeys
    { { 2 index /OutputAttributes .knownget { //null eq } { //true } ifelse } }
  forall
  /Install //false
  /BeginPage //false
  /EndPage //false
  /Policies //false
	% Our extensions:
  /HWColorMap
    {			% HACK: don't transmit the color map, because
			% window systems can change the color map on their own
			% incrementally.  Someday we'll have a better
			% solution for this....
      //false
    }
  /ViewerPreProcess //false
  /ImagingBBox //false	% This prevents the ImagingBBox value in the setpagedevice
			% from affecting the device's ImagingBBox parameter, but
			% does retain a 'shadow' copy at the PostScript level.
			% This is done for Adobe compatibility since Adobe does
			% render marks outside the ImagingBBox (and QuarkXpress
			% relies on it).
.dicttomark readonly def

% Define access to device defaults.
/.defaultdeviceparams
 { finddevice //null .getdeviceparams
 } bind def

% Select media (input or output).  The hard work is done in an operator:
%	<pagedict> <attrdict> <policydict> <keys> .matchmedia <key> true
%	<pagedict> <attrdict> <policydict> <keys> .matchmedia false
%	<pagedict> null <policydict> <keys> .matchmedia null true
/.selectmedia		% <orig> <request> <merged> <failed>     <-- retained
			%   <attrdict> <policydict> <attrkeys> <mediakey>
			%   .selectmedia
 { 5 index 5 -2 roll 4 index .matchmedia
		% Stack: orig request merged failed attrkeys mediakey
		%   (key true | false)
    { 4 index 3 1 roll put pop
    }
    {	% Adobe's implementations have a "big hairy heuristic"
	% to choose the set of keys to report as having failed the match.
	% For the moment, we report any keys that are in the request
	% and don't have the same value as in the original dictionary.
      5 index 1 index .knownget
       { 4 index 3 1 roll put }
       { 3 index exch .undef }
      ifelse
       {	% Stack: <orig> <request> <merged> <failed> <attrkey>
	 3 index 1 index .knownget
	  { 5 index 2 index .knownget { ne } { pop //true } ifelse }
	  { //true }
	 ifelse		% Stack: ... <failed> <attrkey> <report>
	  { 2 copy /rangecheck put }
	 if pop
       }
      forall
    }
   ifelse
 } bind def

% Apply Policies to any unprocessed failed requests.
% As we process each request entry, we replace the error name
% in the <failed> dictionary with the policy value,
% and we replace the key in the <merged> dictionary with its prior value
% (or remove it if it had no prior value).
/.policyprocs mark
% These procedures are called with the following on the stack:
%   <orig> <merged> <failed> <Policies> <key> <policy>
% They are expected to consume the top 2 operands.
% NOTE: we currently treat all values other than 0, 1, or 7 (for PageSize)
% the same as 0, i.e., we signal an error.
  0 {		% Set errorinfo and signal a configurationerror.
	pop dup 4 index exch get 2 array astore
	$error /errorinfo 3 -1 roll put
	cleartomark
	/setpagedevice load /configurationerror signalerror
  } bind
  1 {		% Roll back the failed request to its previous status.
SETPDDEBUG { (Rolling back.) = pstack flush } if
	3 index 2 index 3 -1 roll put
	4 index 1 index .knownget
	 { 4 index 3 1 roll put }
	 { 3 index exch .undef }
	ifelse
  } bind
  7 {		% For PageSize only, just impose the request.
	1 index /PageSize eq
	 { pop pop 1 index /PageSize 7 put }
	 { .policyprocs 0 get exec }
	ifelse
  } bind
.dicttomark readonly def
/.applypolicies		% <orig> <merged> <failed> .applypolicies
			%   <orig> <merged'> <failed'>
 { 1 index /Policies get 1 index
    { type /integertype eq
       { pop		% already processed
       }
       { 2 copy .knownget not { 1 index /PolicyNotFound get } if
			% Stack: <orig> <merged> <failed> <Policies> <key>
			%   <policy>
	 .policyprocs 1 index .knownget not { .policyprocs 0 get } if exec
       }
      ifelse
    }
   forall pop
 } bind def

% Prepare to present parameters to the device, by spreading them onto the
% operand stack and removing any that shouldn't be presented.
/.prepareparams		% <params> .prepareparams -mark- <key1> <value1> ...
 { mark exch dup
    {			% Stack: -mark- key1 value1 ... merged key value
      .presentspecial 2 index .knownget
       { exec { 3 -1 roll } { pop pop } ifelse }
       { 3 -1 roll }
      ifelse
    }
   forall pop
 } bind def

% Put device parameters without resetting currentpagedevice.
% (.putdeviceparams clears the current page device.)
/.putdeviceparamsonly	% <device> <Policies|null> <require_all> -mark-
			%   <key1> <value1> ... .putdeviceparamsonly
			% On success: <device> <eraseflag>
			% On failure: <device> <Policies|null> <req_all> -mark-
			%   <key1> <error1> ...
 { .currentpagedevice
    { counttomark 4 add 1 roll .putdeviceparams
      dup type /booleantype eq { 3 } { counttomark 5 add } ifelse -1 roll
      .setpagedevice
    }
    { pop .putdeviceparams
    }
   ifelse
 } bind def

% Try setting the device parameters from the merged request.
/.trysetparams		% <merged> <(ignored)> <device> <Policies>
			%   .trysetparams
 { //true 4 index .prepareparams
			% Add the computed .MediaSize.
			% Stack: merged (ignored) device Policies -true-
			%   -mark- key1 value1 ...
   counttomark 5 add index .computemediasize
   exch pop exch pop /.MediaSize exch
SETPDDEBUG { (Putting.) = pstack flush } if
   .putdeviceparamsonly
SETPDDEBUG { (Result of putting.) = pstack flush } if
 } bind def

% Compute the media size and initial matrix from a merged request (after
% media selection).
/.computemediasize	% <request> .computemediasize
			%   <request> <matrix> <[width height]>
 { dup /PageSize get					% requested page size
   1 index /InputAttributes get
     2 index (%MediaSource) get get /PageSize get	% media size
							% (may be a range)
   2 index /Policies get
     dup /PageSize .knownget
      { exch pop } { /PolicyNotFound get } ifelse	% PageSize policy,
							% affects scaling
   3 index /Orientation .knownget not { //null } if
   4 index /RollFedMedia .knownget not { //false } if
   matrix .matchpagesize not {
		% This is a "can't happen" condition!
     /setpagedevice load /rangecheck signalerror
   } if
   2 array astore
 } bind def

% ---------------- setpagedevice itself ---------------- %

/setpagedevice
 {		% We mustn't pop the argument until the very end,
		% so that the pseudo-operator machinery can restore the stack
		% if an error occurs.
   mark 1 index currentpagedevice

		% Check whether we are changing OutputDevice;
		% also handle the case where the current device
		% is not a page device.
		% Stack: mark <request> <current>
SETPDDEBUG { (Checking.) = pstack flush } if

   dup /OutputDevice .knownget
    {		% Current device is a page device.
      2 index /OutputDevice .knownget
       {	% A specific OutputDevice was requested.
	 2 copy eq
	  { pop pop //null }
	  { exch pop }
	 ifelse
       }
       { pop //null
       }
      ifelse
    }
    {		% Current device is not a page device.
		% Use the default device.
      1 index /OutputDevice .knownget not { .defaultdevicename } if
    }
   ifelse
   dup //null eq
    { pop
    }
    { exch pop .defaultdeviceparams
		% In case of duplicate keys, .dicttomark takes the entry
		% lower on the stack, so we can just append the defaults here.
      .requiredattrs { exec } forall .dicttomark
    }
   ifelse

		% Check whether a viewer wants to intervene.
		% We must check both the request (which takes precedence)
		% and the current dictionary.
		% Stack: mark <request> <orig>
   exch dup /ViewerPreProcess .knownget
    { exec }
    { 1 index /ViewerPreProcess .knownget { exec } if }
   ifelse exch

		% Construct a merged request from the actual request plus
		% any keys that should always be propagated.
		% Stack: mark <request> <orig>
SETPDDEBUG { (Merging.) = pstack flush } if

   exch 1 index length 1 index length add dict
   .copiedkeys
    {		% Stack: <orig> <request> <merged> <key>
      3 index 1 index .knownget { 3 copy put pop } if pop
    }
   forall
		% Stack: <orig> <request> <merged>
   dup 2 index
    {		% stack: <orig> <request> <merged> <merged> <rkey> <rvalue>
      .mergespecial 2 index .knownget { exec } if
      put dup
    }
   forall pop
		% Hack: if FIXEDRESOLUTION is true, discard any attempt to
		% change HWResolution.
   FIXEDRESOLUTION { dup /HWResolution .undef } if
		% Hack: if FIXEDMEDIA is true, discard any attempt to change
		% PageSize or HWSize.
   FIXEDMEDIA
    { dup /PageSize 4 index /PageSize get put
      dup /HWSize 4 index /HWSize get put
    } if
		% Hack: to work around some files that take a PageSize
		% from InputAttributes and impose it, discard any attempt
		% to set PageSize to a 4-element value.
		% Stack: mark <orig> <request> <merged>
    dup /PageSize .knownget {
      length 2 ne {
	dup /PageSize 4 index /PageSize get put
      } if
    } if

		% Select input and output media.
		% Stack: mark <orig> <request> <merged>
SETPDDEBUG { (Selecting.) = pstack flush } if

   0 dict	% <failed>
   1 index /InputAttributes .knownget
    { 2 index /Policies get
      .inputattrkeys (%MediaSource) cvn .selectmedia
    } if
   1 index /OutputAttributes .knownget
    { 2 index /Policies get
      .outputattrkeys (%MediaDestination) cvn .selectmedia
     } if
   3 -1 roll 4 1 roll		% temporarily swap orig & request
   .applypolicies
   3 -1 roll 4 1 roll		% swap back

		% Construct the new device, and attempt to set its attributes.
		% Stack: mark <orig> <request> <merged> <failed>
SETPDDEBUG { (Constructing.) = pstack flush } if

   currentdevice .devicename 2 index /OutputDevice get eq
    { currentdevice }
    { 1 index /OutputDevice get finddevice }
   ifelse
		%**************** We should copy the device here,
		%**************** but since we can't close the old device,
		%**************** we don't.  This is WRONG.
	%****************copydevice
   2 index /Policies get
   .trysetparams
   dup type /booleantype ne
    {		% The request failed.
		% Stack: ... <orig> <request> <merged> <failed> <device>
		%   <Policies> true mark <name> <errorname> ...
SETPDDEBUG { (Recovering.) = pstack flush } if
      counttomark 4 add index
      counttomark 2 idiv { dup 4 -2 roll put } repeat
      pop pop pop
		% Stack: mark ... <orig> <request> <merged> <failed> <device>
		%   <Policies>
      6 2 roll 3 -1 roll 4 1 roll
      .applypolicies
      3 -1 roll 4 1 roll 6 -2 roll
      .trysetparams		% shouldn't fail!
      dup type /booleantype ne
       { 2 { counttomark 1 add 1 roll cleartomark } repeat
         /setpagedevice load exch signalerror
       }
      if
    }
   if

		% The attempt succeeded.  Install the new device.
		% Stack: mark ... <merged> <failed> <device> <eraseflag>
SETPDDEBUG { (Installing.) = pstack flush } if

   pop 2 .endpage
    { 1 //true .outputpage
      (>>setpagedevice, press <return> to continue<<\n) .confirm
    }
   if
		% .setdevice clears the current page device!
   .currentpagedevice pop exch
   .setdevice pop
   .setpagedevice

		% Implement UseCIEColor directly if this is a LL3 system.
		% The color substitution feature is now implemented in
		% the interpreter, and this is used as an optimization.
		%
		% NB: This shoud be the only use of the .setuseciecolor
		%     operator anywhere.
		%
		% If UseCIEColor is transitioned to false, set some
		% color space other than /DeviceGray, to insure that
		% initgraphics will actually perform a setcolorspace
		% operation (there is an optimization in setcolorspace
		% that does nothing if the operand and current color
		% spaces are the same, and UseCIEColor is false).

    /.setuseciecolor where
      {
        pop 1 index /UseCIEColor .knownget
          {
            dup .setuseciecolor not
              { /DeviceRGB setcolorspace }
            if
          }
        if
      }
    if

		% Merge the request into the current page device,
		% unless we're changing the OutputDevice.
		% Stack: mark ... <merged> <failed>
   exch currentpagedevice dup length 2 index length add dict
		% Stack: mark ... <failed> <merged> <current> <newdict>
   2 index /OutputDevice .knownget {
     2 index /OutputDevice .knownget not { //null } if eq
   } {
     //true
   } ifelse {
		% Same OutputDevice, merge the dictionaries.
     .copydict
   } {
		% Different OutputDevice, discard the old dictionary.
     exch pop
   } ifelse .copydict
		% Initialize the default matrix, taking media matching
		% into account.
   .computemediasize pop initmatrix concat
   dup /PageOffset .knownget
    {		% Translate by the given number of 1/72" units in device X/Y.
      dup 0 get exch 1 get
      2 index /HWResolution get dup 1 get exch 0 get
      4 -1 roll mul 72 div   3 1 roll mul 72 div
      idtransform translate
    }
   if
		% We must install the new page device dictionary
		% before calling the Install procedure.
  dup .setpagedevice
  .setdefaulthalftone	% Set the default screen before calling Install.
  dup /Install .knownget {
    { .execinstall } stopped { .postinstall stop } { .postinstall } ifelse
  } {
    .postinstall
  } ifelse
} odef

% We break out the code after calling the Install procedure into a
% separate procedure, since it is executed even if Install causes an error.
% By making .execinstall a separate operator procedure, we get the stacks
% restored if it fails.

/.execinstall {		% <proc> .execinstall -
	% Because the interpreter optimizes tail calls, we can't just let
	% the body of this procedure be 'exec', because that would lose
	% the stack protection that is the whole reason for having the
	% procedure in the first place.  We hack this by adding a couple
	% of extra tokens to ensure that the operator procedure is still
	% on the stack during the exec.
  exec
  0 pop	% See above.
} odef
/.postinstall {		% mark ... <failed> <merged> .postinstall -
   matrix currentmatrix .setdefaultmatrix
		% Erase and initialize the page.
   initgraphics
   currentoverprint //false setoverprint 1 setcolor
   .fillpage
   0 setcolor setoverprint
   .beginpage

		% Clean up, calling PolicyReport if needed.
		% Stack: mark ... <failed> <merged>
SETPDDEBUG { (Finishing.) = pstack flush } if

   exch dup length 0 ne
    { 1 index /Policies get /PolicyReport get
      counttomark 1 add 2 roll cleartomark
      exec
    }
    { cleartomark
    }
   ifelse pop

} odef

end				% level2dict
.setlanguagelevel