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✏️ Editing: gs_ll3.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.
%

% Initialization file for PostScript LanguageLevel 3 functions.
% This file must be loaded after gs_lev2.ps and gs_res.ps.
% These definitions go into ll3dict or various ProcSets.
% NOTE: the interpreter creates ll3dict.

ll3dict begin

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

% ------ Idiom recognition ------ %

/IdiomRecognition //false .definepsuserparam

% Modify `bind' to apply idiom recognition afterwards.
/.bindscratch 128 string def
% Note that since this definition of `bind' may get bound in,
% it has to function properly even at lower language levels,
% where IdiomRecognition may not be defined.
/.bind_ {		% <proc> .bind <proc'>
  //.bind currentuserparams /IdiomRecognition
  .knownget not { //false } if
  {
    //false
    /IdiomSet //.findcategory exec .Instances
    {
      exch pop                                    % pop the IdiomSet identifying key. Stack /proc /false [-dict- status size]
      0 get                                       % get resource instance, a dictionary. Stack : /proc false -dict-
      {
        exch pop                                  % pop the instance identifying key
                                                  % Stack: proc //false [template substitute]
        dup 1 get exch 0 get                      % Stack: proc //false substitute template
        3 index .eqproc {
                                                  % Stack: proc //false substitute
            3 -1 roll pop exch not                % Stack: substitute true
        } {
          pop                                     % Stack: proc //false
        } ifelse
      } forall
      dup {exit} if                               % Stack proc <bool>
    } forall

not                                           % Not matched in global resources
    currentglobal not and                         % must not match local resources if currentglobal is true
    {
      //false
      .LocalInstances
      {
        exch pop                                  % pop IdiomSet identifying key. Stack /proc /false [-dict- status size]
        0 get                                     % get resource instance, a dictionary Stack : /proc false -dict-
        {
          exch pop                                % pop instance identifier key
                                                  % Stack: proc //false [template substitute]
          dup 1 get exch 0 get                    % Stack: proc //false substitute template
          3 index .eqproc {
                                                  % Stack: proc //false substitute
            2 index gcheck                        % Stack: proc //false substitute _global?_
            1 index gcheck not and                % Stack: proc //false substitute _global?_ _global?_
            {                                     % must not match if candidate in global VM and substitute in local
              pop                                 % Stack: proc //false
            } {
                                                  % Stack: proc //false substitute
              3 -1 roll pop exch not              % Stack: substitute true
            }ifelse
          } {
            pop                                   % Stack: proc //false
          } ifelse
        } forall
        dup {exit} if
      } forall
      pop                                         % Stack: proc/substitute
    } if
    end                                           % .findcategory makes the category dictionary the current dict, so we must pop it from dict stack
  } if
} def
/.bind /.bind_ load odef	% note that .bind_ will get bound
currentdict /.bindscratch .undef

DELAYBIND not {
% We can't just do
%   /bind /.bind load def
% because then /bind load == prints --.bind-- .
  /bind {//.bind_ exec} odef
} if
currentdict /.bind_ undef

/.readbytestring {	% <source> <bytestring> .readbytestring
                        %   <bytestring> <filled>
                % Note that since bytestrings don't implement getinterval,
                % if filled is false, there is no way to tell how much
                % was read.
  //true exch 0 1 2 index length 1 sub {
                % Stack: source true str index
    3 index read not { pop exch not exch exit } if
    3 copy put pop pop
  } for 3 -1 roll pop exch
} bind def

/.bigstring {	% <size> .bigstring <string|bytestring>
  count 1 lt { /.bigstring /stackunderflow signalerror } if
  dup type /integertype ne {
    /.bigstring /typecheck signalerror
  } if
  dup 65400 gt { .bytestring } { string } ifelse
} bind def

% ------ HalftoneTypes 6, 10, 16 and HalftoneMode ------ %

% This code depends on an internal HalftoneType 7 with the following keys:
%	Width, Height, Width2, Height2, TransferFunction:
%	  as for HalftoneType 16.
%	Thresholds: a string or bytestring holding the thresholds,
%	  (Width x Height + Width2 x Height2) x BitsPerSample / 8 bytes,
%	  as for HalftoneType 16 except that the samples may be either
%	  8 or 16 bits wide.
%	BitsPerSample: 8 or 16.

% Note that this HalftoneType never appears in halftone dictionaries given
% to sethalftone, only as a component in those given to .sethalftone5,
% so its numeric value can be chosen ad lib as long as it differs from the
% other values that are legal in component dictionaries for .sethalftone5
% (currently only 1 and 3).

/.makehalftone7 {	% <dict> <dict> <source> <Width> <Height>
                        %   (<Width2> <Height2> | null) <BPS> .makehalftone7
                        %   <setdict> <dict5> { .sethalftone5 }
  8 dict begin
  /HalftoneType 7 def
  /BitsPerSample exch def
  dup //null eq {
    pop 0
  } {
    /Height2 1 index def /Width2 2 index def mul
  } ifelse 3 1 roll
  /Height 1 index def
  /Width 2 index def
  mul add BitsPerSample 8 idiv mul //.bigstring exec
                % Stack: dict dict source str
  dup type /stringtype eq { readstring } { //.readbytestring exec} ifelse
  not { /sethalftone .systemvar /rangecheck signalerror exit } if
  readonly /Thresholds exch def
  /TransferFunction .knownget { /TransferFunction exch def } if
                % If the original Thresholds was a file, replace it with
                % a new one.
  dup /Thresholds get type /filetype eq {
    dup /Thresholds [ Thresholds ] cvx 0 () .subfiledecode put
  } if
  mark /HalftoneType 5 /Default currentdict end .dicttomark
  { .sethalftone5 }
} bind def

/.sethalftone6 {	% <dict> <dict> .sethalftone6 <setdict> <dict5>
                        %   { .sethalftone5 }
                        % Keys: Width, Height, Thresholds, T'Function
  dup /Thresholds get
  1 index /Width get 2 index /Height get
  //null 8 //.makehalftone7 exec
} bind def

/.sethalftone10 {	% <dict> <dict> .sethalftone10 <setdict> <dict5>
                        %   { .sethalftone5 }
                        % Keys: Xsquare, Ysquare, Thresholds, T'Function
                % Note that this is the only one of these three HalftoneTypes
                % that allows either a file or a string for Thresholds.
  dup /Thresholds get dup type /stringtype eq { 0 () .subfiledecode } if
  1 index /Xsquare get dup 3 index /Ysquare get dup
  8 //.makehalftone7 exec
} bind def

/.sethalftone16 {	% <dict> <dict> .sethalftone16 <setdict> <dict5>
                        %   { .sethalftone5 }
                        % Keys: Width, Height, Width2, Height2,
                        %   Thresholds, T'Function
  dup /Thresholds get
  1 index /Width get 2 index /Height get
  3 index /Width2 .knownget {  % 2-rectangle case
    4 index /Height2 get
  } {			% 1-rectangle case
    //null
  } ifelse 16 //.makehalftone7 exec
} bind def

.halftonetypes begin
  6 //.sethalftone6 def
  10 //.sethalftone10 def
  16 //.sethalftone16 def
end

% Redefine the halftone-setting operators to honor HalftoneMode.
/setcolorscreen {
  /HalftoneMode getuserparam 0 eq {
    //setcolorscreen
  } {
    12 { pop } repeat //.getdefaulthalftone exec
    { //sethalftone }
    { .setdefaulthalftone }
    ifelse
  } ifelse
} odef
/setscreen {
  /HalftoneMode getuserparam 0 eq {
    //setscreen
  } {
    pop pop pop //.getdefaulthalftone exec
    { //sethalftone }
    { .setdefaulthalftone }
    ifelse
  } ifelse
} odef
/sethalftone {
  /HalftoneMode getuserparam 0 eq {
    //sethalftone
  } {
    gsave //sethalftone grestore
    //.getdefaulthalftone exec
    { //sethalftone }
    { .setdefaulthalftone }
    ifelse
  } ifelse
} odef

% ------ ImageTypes 3 and 4 (masked images) ------ %

% Put the new data source in the requested dictionary.
% Copy the updated dictionary because it nay be used elsewhere.
% <dict> <data> <name> update_image3 <dict'>
/update_image3 {
  3 -1 roll dup length dict copy dup  % [data] /name <<image>> <<image>>
  2 index get                         % [data] /name <<image>> <<sub-image>>
  dup length dict copy dup            % [data] /name <<image>> <<sub-image>> <<sub-image>>
  /DataSource 6 -1 roll put           % /name <<image>> <<sub-image>>
  exch dup                            % /name <<sub-image>> <<image>> <<image>>
  4 2 roll                            % <<image>> <<image>> /name <<sub-image>>
  put                                 % <<image>>
} bind def

% Copy mask data source to a reusable stream
% <dict> <source> buffer_mask <dict> <file>
/buffer_mask {
  1 index /MaskDict get
  dup /Width get
  1 index /BitsPerComponent get mul 7 add 8 idiv
  exch /Height get mul () /SubFileDecode filter
  /ReusableStreamDecode filter
} bind def

% Data type vs. mask type decission table.
% All procedures have the signature:
% <image dict> <data DataSource> <mask DataSource> proc <image dict'>
/data_mask_dict mark
  /stringtype mark % data is a string
    /stringtype { pop pop } bind
    /arraytype { % convert data to proc, don't buffer mask
      pop
      dup type dup /arraytype eq exch /packedarraytype eq or {
        [ exch { 1 array astore cvx } forall ]
      } {
        1 array astore cvx
      } ifelse
      /DataDict //update_image3 exec
    } bind
    /packedarraytype 1 index
    /filetype { % convert data to file, don't buffer mask
      pop
      dup type dup /arraytype eq exch /packedarraytype eq or {
        [ exch { 1 array astore cvx 0 () /SubFileDecode filter } forall ]
      } {
        1 array astore cvx 0 () /SubFileDecode filter
      } ifelse
      /DataDict //update_image3 exec
    } bind
  .dicttomark readonly
  /arraytype mark  % data is a proc
    /stringtype { % convert mask to proc
      exch pop
      1 array astore cvx
      /MaskDict //update_image3 exec
    } bind
    /arraytype { % buffer mask in reusable stream and convert back to proc
      exch pop
      //buffer_mask exec
      500 string
      { readstring pop } aload pop
      4 packedarray cvx
      /MaskDict //update_image3 exec
    } bind
    /packedarraytype 1 index
    /filetype 1 index
  .dicttomark readonly
  /packedarraytype 1 index
  /filetype mark  % data is a file
    /stringtype { % convert mask to file
      exch pop
      1 array astore cvx 0 () /SubFileDecode filter
      /MaskDict //update_image3 exec
    } bind
    /arraytype { % buffer the mask and convert to file
      exch pop
      //buffer_mask exec
      /MaskDict //update_image3 exec
    } bind
    /packedarraytype 1 index
    /filetype {
      //systemdict /userdict get /PDFTopSave known {
        pop pop   % mask is already buffered by PDF interpreter
      } {
        exch pop  % buffer the mask
        //buffer_mask exec
        /MaskDict //update_image3 exec
      } ifelse
    } bind
  .dicttomark readonly
.dicttomark readonly def

.imagetypes
  dup 3 {
    dup /InterleaveType get 3 eq {
      % .image3 requires data sources of the image and mask to be of the
      % same type. Work around this restriction here.
      dup /DataDict get /DataSource get
      1 index /MaskDict get /DataSource get  % <<>> data mask
      dup type                               % <<>> data mask mask_type
      2 index
      4 index /DataDict get /MultipleDataSources .knownget {
        { 0 get } if
      } if
      type                                   % <<>> data mask mask_type data_type
      //data_mask_dict exch .knownget {
        exch .knownget {
          exec
        } {
          pop pop   % pass wrong type as is to .image3
        } ifelse
      } {
        pop pop pop % pass wrong type as is to .image3
      } ifelse
    } if
    .image3
  } bind put
  dup 4 /.image4 load put
% We also detect ImageType 103 here: it isn't worth making a separate file
% just for this.
  /.image3x where { pop dup 103 /.image3x load put } if
pop

currentdict /data_mask_dict undef
currentdict /update_image3 undef
currentdict /buffer_mask undef

% ------ Functions ------ %

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

{0 2 3} { dup /FunctionType defineresource pop } forall

% ------ Smooth shading ------ %

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

systemdict /.shadingtypes mark		% not ll3dict
  1 /.buildshading1 load
  2 /.buildshading2 load
  3 /.buildshading3 load
  4 /.buildshading4 load
  5 /.buildshading5 load
  6 /.buildshading6 load
  7 /.buildshading7 load
.dicttomark put

systemdict /.reuseparamdict mark
  /Intent 2
  /AsyncRead //false
  /CloseSource //true
.dicttomark readonly put
/.buildshading {	% <shadingdict> .buildshading <shading>
  dup rcheck not {
      % Adobe seems to access ColorSpace first and CET 12-14c checks this.
      /$error .systemvar /errorinfo [ /ColorSpace //null ] put
      /shfill .systemvar /invalidaccess signalerror
  } if
        % Unfortunately, we always need to make the DataSource reusable,
        % because if clipping is involved, even shfill may need to read
        % the source data multiple times.  If it weren't for this,
        % we would only need to create a reusable stream if the ultimate
        % source of the data is a procedure (since the library can't
        % suspend shading to do a procedure callout).
  dup /DataSource .knownget {
    dup type /filetype eq {
      //.reuseparamdict /ReusableStreamDecode filter
      % Copy the dictionary to replace the DataSource, but make sure the
      % copy is in the same VM as the original.
      .currentglobal 2 index gcheck .setglobal
                % Stack: shdict rsdfile saveglobal
      2 index dup length dict copy exch .setglobal
      dup /DataSource 4 -1 roll put exch pop
    } {
      pop
    } ifelse
  } if
        % The .buildshading operators use the current color space
        % for ColorSpace.
  dup /ShadingType .knownget not { % error handling for CET 12-14b conformance
     /$error .systemvar /errorinfo [ /ShadingType //null ] put
     /shfill .systemvar /undefined signalerror
  } if
  dup type /integertype ne {
     /$error .systemvar /errorinfo [ /ShadingType 4 index ] put
     /shfill .systemvar /typecheck signalerror
  } if
  //.shadingtypes 1 index .knownget not {
     /$error .systemvar /errorinfo [ /ShadingType 4 index ] put
     /shfill .systemvar /rangecheck signalerror
  } if
  exch pop 1 index /ColorSpace .knownget {
    { setcolorspace } stopped {
       /$error .systemvar /errorinfo [ /ColorSpace 4 index ] put
       /shfill .systemvar /$error .systemvar /errorname get signalerror
    } if
    exec
  } {
    /$error .systemvar /errorinfo [ /ColorSpace //null ] put
    /shfill .systemvar /undefined signalerror
  } ifelse
} bind def

/.buildshading_and_shfill {
  //.buildshading exec .shfill
} bind def

systemdict /.reuseparamdict undef

/.buildpattern2 {	% <template> <matrix> .buildpattern2
                        %   <template> <pattern>
        % We want to build the pattern without doing gsave/grestore,
        % since we want it to load the CIE caches.
  1 index /Shading get
  mark currentcolor currentcolorspace
  counttomark 4 add -3 roll mark 4 1 roll
        % Stack: -mark- ..color.. cspace -mark- template matrix shadingdict
  { //.buildshading exec} stopped {
    cleartomark setcolorspace setcolor pop stop
  } if
  .buildshadingpattern
  3 -1 roll pop counttomark 1 add 2 roll setcolorspace setcolor pop
} bind def

.patterntypes
  2 //.buildpattern2 put

/shfill {		% <shadingdict> shfill -
        % Currently, .shfill requires that the color space
        % in the pattern be the current color space.
        % Disable overprintmode for shfill
  { dup gsave 0 .setoverprintmode .buildshading_and_shfill } stopped
  grestore {
    /$error .systemvar /errorinfo 2 copy known {
      pop pop
    } {
      //null put  % CET 12-14c
    } ifelse
    stop
  } if
  pop
} odef

% Establish an initial smoothness value that matches Adobe RIPs.
0.02 setsmoothness

% ------ DeviceN color space ------ %
% gs_res.ps uses these entries in colorspacedict
% to populate the ColorSpaceFamily resource, so we need
% to add the supported spaces.
%
systemdict /colorspacedict get begin
/CIEBasedDEF [] def
/CIEBasedDEFG [] def
/DeviceN [] def
end

% ------ Miscellaneous ------ %

% Make the setoverprintmode and currentoverprintmode operators visible (3015)
% Because of the requirements of PDF, the .currentoverprintmode and
% .setoverprintmode operators have integer parameters.  Thus we need to
% convert the Postscript bool parameters to integers.
%
/setoverprintmode 		% bool setoverprint -
{
  { 1 } { 0 } ifelse		% convert bool to integer
  //.setoverprintmode
} odef

/currentoverprintmode 		% - currentoverprintmode bool
{
  //.currentoverprintmode
  0 ne				% convert integers to bool
} odef

% Define additional user and system parameters.
/HalftoneMode 0 .definepsuserparam
/MaxSuperScreen 1016 .definepsuserparam
% read-only, so use .forceput
pssystemparams  /MaxDisplayAndSourceList 160000 .forceput

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

(*) {
  dup type /nametype eq not {
    cvn
  } if
  /IdiomSet findresource pop
} 256 string /IdiomSet resourceforall

/languagelevel 3 def
% When running in LanguageLevel 3 mode, this interpreter is supposed to be
% compatible with Adobe version 3010.
/version (3010) readonly def

.setlanguagelevel

% undefine things defined (or used) in this file and not referenced elsewhere
[
    /.buildpattern2
    /.buildshading
    /.buildshading1 /.buildshading2 /.buildshading3 /.buildshading4
    /.buildshading5 /.buildshading6 /.buildshading7 /.buildshadingpattern
    /.makehalftone7 /.sethalftone6 /.sethalftone10 /.sethalftone16
    /.readbytestring /.bigstring
]
dup {currentdict exch .forceundef} forall
{systemdict exch .forceundef} forall

end			% ll3dict

MR SKB