ref: f8ddcb23b9dd969875dd4e961591700c79b7d5f7
dir: /sys/lib/ghostscript/gs_dps2.ps/
% Copyright (C) 1990, 1996, 1997, 1998, 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_dps2.ps,v 1.5 2002/02/21 21:49:28 giles Exp $
% Initialization file for basic Display PostScript functions
% that are also included in Level 2.
level2dict begin
% ------ Halftones ------ %
/.makestackdict
{ { counttomark -1 roll } forall .dicttomark
} bind def
/currenthalftone % - currenthalftone <dict>
{ mark .currenthalftone
{ { exch pop } % halftone
{ /HalftoneType 1 % screen
{ /Frequency /Angle /SpotFunction }
.makestackdict
}
{ /HalftoneType 2 % colorscreen
{ /RedFrequency /RedAngle /RedSpotFunction
/GreenFrequency /GreenAngle /GreenSpotFunction
/BlueFrequency /BlueAngle /BlueSpotFunction
/GrayFrequency /GrayAngle /GraySpotFunction
}
.makestackdict
}
}
exch get exec
} odef
% Define sethalftone so it converts types 1-4 to type 5.
/.makehalftoneRGBV { % <dict> <type> <keys> <keysRGBV>
4 -1 roll exch { 1 index exch get exch } forall 15 1 roll
14 -2 roll mark 15 1 roll { /Gray /Blue /Green /Red } {
% stack: v0 v1 v2 type keys comp
mark
2 index 0 get 8 -1 roll
4 index 1 get 9 -1 roll
6 index 2 get 10 -1 roll
% stack: type keys comp mark k0 v0 k1 v1 k2 v2
/HalftoneType 10 index .dicttomark
counttomark 2 roll
} forall pop pop
/Default 1 index .dicttomark exch pop { .sethalftone5 }
} bind def
% The value of each entry in .halftonetypes is a procedure:
% <setdict> <htdict> <<proc>> <setdict'> <htdict'> <sethalftoneproc>
% This allows us to use these procedures both for actually implementing
% sethalftone and for converting subsidiary dictionaries of HalftoneType 5
% halftones.
systemdict begin
15 dict /.halftonetypes 1 index def begin
1 {
mark exch /Default exch .dicttomark { .sethalftone5 }
} bind def
2 {
1 { /Frequency /Angle /SpotFunction } {
/RedFrequency /RedAngle /RedSpotFunction
/GreenFrequency /GreenAngle /GreenSpotFunction
/BlueFrequency /BlueAngle /BlueSpotFunction
/GrayFrequency /GrayAngle /GraySpotFunction
} .makehalftoneRGBV
} bind def
3 {
mark exch /Default exch .dicttomark { .sethalftone5 }
} bind def
4 {
3 { /Width /Height /Thresholds } {
/RedWidth /RedHeight /RedThresholds
/GreenWidth /GreenHeight /GreenThresholds
/BlueWidth /BlueHeight /BlueThresholds
/GrayWidth /GrayHeight /GrayThresholds
} .makehalftoneRGBV
} bind def
5 {
pop dup length dict copy
mark 1 index {
% Even HalftoneType 5 dictionaries have entries other than
% subsidiary halftone dictionaries.
dup type /dicttype ne {
0
} {
dup /HalftoneType .knownget not { 0 } if
} ifelse dup 5 gt {
% Stack: dict mark ... keyN dictN httypeN
% Assume that all HalftoneTypes > 5 convert to 5.
1 index 3 1 roll
//.halftonetypes exch get exec pop /Default get
% Stack: dict mark ... keyN setdict'N htdict'N
counttomark 1 add index 3 index 4 -1 roll put
} {
pop
} ifelse
} forall .dicttomark { .sethalftone5 }
} bind def
end
end
/sethalftone { % <dict> sethalftone -
% We must create the new dictionary in the same VM as the
% operand; otherwise, invalidaccess errors may occur.
.currentglobal 1 index dup gcheck .setglobal
dup //.halftonetypes 1 index /HalftoneType get get exec exec
.setglobal pop
} odef
% Redefine setscreen and setcolorscreen to recognize halftone dictionaries,
% and to insert the Frequency and Angle into Type 1 halftones, per
% Adobe TN 5085.
/.fixsethalftonescreen % <freq> <angle> <dict> .fix...screen
% <freq> <angle> <dict> <dict'>
{ dup dup /HalftoneType get 1 eq
{ dup wcheck not { dup length .copydict } if
dup /Frequency 5 index put
dup /Angle 4 index put
}
if
} bind def
/setscreen % <ignore*2> <dict> setscreen -
{ dup type /dicttype eq
{ .fixsethalftonescreen sethalftone pop pop pop }
{ //setscreen }
ifelse
} odef
/setcolorscreen % <ignore*11> <dict> setcolorscreen -
{ dup type /dicttype eq
{ .fixsethalftonescreen sethalftone 12 { pop } repeat }
{ //setcolorscreen }
ifelse
} odef
% Redefine currentscreen and currentcolorscreen to extract the Frequency
% and Angle from Type 1 halftones, per Adobe TN 5085.
/.fixcurrenthalftonescreen % <dict> .fix... <freq> <angle> <proc>
{ dup /HalftoneType get 1 eq
{ dup /Frequency get 1 index /Angle get }
{ 60 0 }
ifelse 3 2 roll
} bind def
/currentscreen % - currentscreen 60 0 <dict>
{ .currenthalftone
{ { .fixcurrenthalftonescreen } % halftone
{ } % screen
{ 12 3 roll 9 { pop } repeat % colorscreen
dup type /dicttype eq { .fixcurrenthalftonescreen } if
}
}
exch get exec
} odef
/currentcolorscreen % - currentcolorscreen (60 0 <dict>)*4
{ .currenthalftone
{ { .fixcurrenthalftonescreen 3 copy 6 copy } % halftone
{ 3 copy 6 copy } % screen
{ } % colorscreen
}
exch get exec
} odef
% ------ User objects ------ %
/.UserObjects {
.userdict /UserObjects
} odef
% In order to get proper error recovery behavior, we need to be careful
% not to pop any operands from the stack until we're done.
% The code below faithfully duplicates the apparent array-growing
% behavior of Adobe interpreters.
/defineuserobject { % <index> <value> defineuserobject -
.UserObjects .knownget {
length dup 3 index le {
% Stack: index value len
2 index eq { 1 index 2 mul } { 1 index 1 add } ifelse
.localvmarray .UserObjects get
1 index copy pop
.UserObjects 3 -1 roll put
} {
pop
} ifelse
} {
.UserObjects 3 index 1 add 10 .max .localvmarray put
} ifelse
.UserObjects get 2 index 2 index put pop pop
} odef
/execuserobject { % <index> execuserobject -
.UserObjects get 1 index get exch pop exec
} odef
/undefineuserobject { % <index> undefineuserobject -
.UserObjects get 1 index null put pop
} odef
% ------ Cache control ------ %
% Dummy definitions for cache control operators
/ucachestatus { % - ucachestatus -mark- ? ? ? ? <size>
mark 0 0 0 0 .userdict /.ucachesize .knownget not { 0 } if
} odef
/setucacheparams { % -mark- ... <size> setucacheparams -
% Provoke an appropriate error if needed.
counttomark 1 lt { () 0 get } if
0 or .userdict /.ucachesize 2 index 0 .max put cleartomark
} odef
end % level2dict