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[EDIT] FILE: gs_trap.ps

% Copyright (C) 2001-2019 Artifex Software, Inc.
% 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.
%
% Refer to licensing information at http://www.artifex.com or contact
% Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
% CA 94945, U.S.A., +1(415)492-9861, for further information.
%

% PostScript LanguageLevel 3 in-RIP trapping support.

ll3dict begin

% We need LanguageLevel 2 or higher in order to have setuserparams and
% defineresource.
languagelevel dup 2 .max .setlanguagelevel

% ------ Trapping ------ %

% The PostScript-level trapping parameters are maintained in userdict,
% and explicitly reinstalled upon restore.

/Trapping mark

/settrapparams dup {		% <paramdict> settrapparams -
  /.trapparams .uservar dup length dict .copydict
  dup 2 index {
                        % Stack: paramdict olddict olddict key value
    2 index 2 index known { put dup } { pop pop } ifelse
  } forall pop
  dup .settrapparams	% Let the operator check parameter validity.
  .userdict /.trapparams 3 -1 roll put pop
} bind executeonly .makeoperator

/.copyparams {		% <obj> .copyparams <obj'>
  dup type /dicttype eq {
    dup length dict .copydict
    dup {
      .copyparams 3 copy put pop pop
    } forall
  } {
    dup type /arraytype eq {
      [ exch { .copyparams } forall ]
    } if
  } ifelse
} odef

/currenttrapparams dup {	% - currenttrapparams <paramdict>
  /.trapparams .uservar .copyparams
} bind executeonly .makeoperator

/settrapzone dup {		% - settrapzone -
        % ****** DUMMY ******
  newpath
} bind .makeoperator

% Define initial (dummy) trapping parameters.
% These values are mostly complete guesses.
userdict /.trapparams mark
  /BlackColorLimit 1.0
  /BlackDensityLimit 1.0
  /BlackWidth 1.0
  /ColorantZoneDetails 0 dict
  /Enabled //true
  /HalftoneName //null
  /ImageInternalTrapping //false
  /ImagemaskTrapping //true
  /ImageResolution 1
  /ImageToObjectTrapping //true
  /ImageTrapPlacement /Center
  /SlidingTrapLimit 1.0
  /StepLimit 1.0
  /TrapColorScaling 0.0
  /TrapSetName //null
  /TrapWidth 1.0
.dicttomark readonly put

.dicttomark /ProcSet defineresource pop

% Define the InkParams and TrapParams resource categories.
{ /InkParams /TrapParams } {
  /Generic /Category findresource dup maxlength 3 add dict .copydict begin
    /InstanceType /dicttype def
  currentdict end /Category defineresource pop
} forall

% Define the TrappingType resource category.
/Generic /Category findresource dup maxlength 3 add dict .copydict begin
  /InstanceType /integertype def
/TrappingType currentdict end /Category defineresource pop

{1001} { dup /TrappingType defineresource pop } forall

.setlanguagelevel

end			% ll3dict

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