ref: a04fd342727c329584a9f443092caf21e3884bdf
dir: /sys/lib/ghostscript/gs_sepr.ps/
% Copyright (C) 2001, 2002 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_sepr.ps,v 1.3 2003/04/26 18:40:16 dan Exp $
% Separation color space method dictionary
% verify that Separation color spaces are supported
/.setseparationspace where
{ pop }
{ currentfile closefile }
ifelse
.currentglobal true .setglobal
.cspace_util begin
%
% <c1> <array> apply_sepr_tint_xform <c1>' ... <cn>' <array>
%
% Apply the tint transform for a Separation color space color intensity
% value.
%
/apply_sepr_tint_xform
{
exch //bound_0_1 exec
mark exch 2 index 3 get exec
counttomark 2 add -2 roll pop
}
bind def
%
% <cspace_array> build_tintxform_function <cspace_array> <proc>
%
% Convert a tint transformation into a function, if possible. If this is
% successful, <proc> will be a function procedure (a two-element,
% execute-only, executable array whose first element is the function
% data structure and whose second element is the operator %execfunction.
% If it is not successful, <proc> will be the same as the tint transform
% in <cspace_array>.
%
% Note that, for PDF files, the tint transform will likely already be a
% function-array. In this case, <proc> will be this array, and thus will
% also be identical to the original tint transform.
%
% This procedure is used for both Separation and DeviceN color spaces.
%
/build_tintxform_function
{
dup 3 get dup .isencapfunction not
{
% Try a FunctionType 4 function first; build the function dictionary
% in local VM.
.currentglobal exch //false .setglobal
% Make the dictionary a couple of elements large in case this fails
% and we need the dictionary to build a sampled function.
6 dict begin
/FunctionType 4 def
/Function exch def
/Domain 2 index //.cs_get_range exec def
/Range 2 index 2 get //.cs_get_range exec def
currentdict end
{ .buildfunction }
.internalstopped % If .buildfunction fails then not type 4 func.
{ % If not then try building a sampled (type 0) func.
% We are using the dictionary which was created before .buildfunction
dup /Order 3 put
dup /BitsPerSample 16 put
{ .buildsampledfunction }
.internalstopped % If .buildsamplefunction fails then invalid func.
{ % Failed - Create a dummy tint transform function
% We are using the dictionary which was created before .buildfunction
dup /Function {} put % Replace invalid tint transform with dummy
.buildfunction
}
if % Check status from .buildsamplefunction/.internalstopped
}
if % check status from .buildfunction/.intermalstopped
% restore the VM mode
exch .setglobal
}
if
}
bind def
%
% <array1> <array2> converttinttransform <array1> <array2'>
%
% Convert a Separation/DeviceN color space to use a function as a tint
% transformation, if this is possible. Possible outcomes are:
%
% 1. The tint transform already is a function, or is a procedure that
% cannot be converted to a function. In either case, <array2> is
% left unchanged (<array2> == <array2'>).
%
% 2. The tint transform is not already a function but can be converted
% to a function, and <array1> != <array2>. In this case, <array2>
% is modified directly.
%
% 3. The tint transform is not already a function but can be converted
% to a function, and <array1> == <array2>. In this case, <array2>
% is copied, and the copy is modified (i.e., after the operation
% <array1> != <array2>
%
% This slightly complex approach avoids creating an extra color space
% array unnecessarily.
%
/converttinttransform
{
% convert the tint transform to a fucntion
//build_tintxform_function exec
% see if anything needs to be modified
1 index 3 get 2 copy eq
{ pop pop }
{
pop
% see if the color space must be copied
3 copy pop eq
{
% copy the array into local VM
.currentglobal //false .setglobal
3 -1 roll dup length array copy 3 1 roll
.setglobal
}
if
1 index exch 3 exch put
}
ifelse
}
bind def
colorspacedict
/Separation
mark
/cs_potential_indexed_base true
/cs_potential_pattern_base true
/cs_potential_alternate false
/cs_potential_icc_alternate false
/cs_get_ncomps //ncomps_1
/cs_get_range //get_range_1
/cs_get_default_color { pop 1 } bind
/cs_get_currentgray
{ //apply_sepr_tint_xform exec 2 get //.cs_get_currentgray exec }
bind
/cs_get_currentrgb
{ //apply_sepr_tint_xform exec 2 get //.cs_get_currentrgb exec }
bind
/cs_get_currentcmyk
{ //apply_sepr_tint_xform exec 2 get //.cs_get_currentcmyk exec }
bind
% a lot of validation is done by the cs_validate method
/cs_validate
{
//check_array exec
dup 1 get type dup /nametype ne exch /stringtype ne and
//setcspace_typecheck
if
dup 2 get //.cs_validate exec //.cs_potential_alternate exec not
//setcspace_rangecheck
if
dup 3 get //check_array exec xcheck not
//setcspace_typecheck
if
}
bind
% substitute the base space if appropriate
/cs_substitute
{
dup 2 get //.cs_substitute exec 2 copy eq
{ pop pop dup }
{
% retain only the new alternate space
exch pop
% build all new structures in local VM
.currentglobal 3 1 roll //false .setglobal
% construct a new array and insert the new base color space
1 index dup length array copy dup 2 4 -1 roll put
% restore VM mode
3 -1 roll .setglobal
}
ifelse
}
bind
%
% The Ghostscript interpreter works better when tinttransform procedures
% are translated into functions. Attempt to do that here.
%
/cs_prepare //converttinttransform
%
% Install the current color space.
%
% The current Ghostscript color space implementation requires that
% color spaces that provide a base or alternative color space set
% that base/alternative color space to be the current color space
% before attempting to set the original color space.
%
/cs_install
{
% save the current color space
currentcolorspace
% set the base color space as the current color space
1 index 2 get //forcesetcolorspace
% set the indexed color space; restore the earlier space on error
mark 2 index
{ .setseparationspace }
stopped
{ cleartomark setcolorspace stop }
{ pop pop pop }
ifelse
}
bind
/cs_prepare_color //validate_1
%
% If a Separation color space is not supported in native mode by
% the current process color model, Adobe implementations will always
% execute the tint transform procedure when setcolor is invoked.
% Ghostscript may have turned this transform into a sampled function,
% and even if this is not the case, will have sampled the transform
% when the color space is first set. Some applications may depend
% on the Adobe behavior, so we implement it via the
% cs_complete_setcolor method.
%
/cs_complete_setcolor
{
.usealternate
{
currentcolor exch 3 get exec
currentcolorspace 2 get //clear_setcolor_operands exec
}
{ pop }
ifelse
}
bind
.dicttomark
put
end % .cspace_util
.setglobal