ref: a7f5ecaf636e38f407c951d0e86dcc4c4f424bd6
dir: /sys/src/cmd/gs/lib/gs_fform.ps/
% Copyright (C) 1995, 1996, 1998, 1999 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_fform.ps,v 1.4 2002/02/21 21:49:28 giles Exp $
% Form caching implemented in PostScript.
% This implementation doesn't do the right thing about halftone or
% Pattern phase, but the Pattern cache doesn't either....
% The Form cache key is the Form dictionary; the value is an array
% of 2 elements [CTM pattern_instance].
%
% In order to prevent restore from clearing the cache, we explicitly
% push the cache entries on the stack before a restore and reinstall them.
currentglobal false setglobal
/.formcachedict 20 dict def % must be local
true setglobal
/restore {
mark .formcachedict { } forall
counttomark 1 add index { //restore } .internalstopped
{ cleartomark //restore }
{ counttomark 2 idiv { .formcachedict 3 1 roll put } repeat pop pop }
ifelse
} bind odef
/.execform1 {
dup /Implementation known not {
dup /FormType get 1 ne { /rangecheck signalerror } if
% The Implementation is a Pattern that will draw the form.
currentglobal 1 index gcheck setglobal
% Stack: form global
10 dict begin
/PatternType 1 def
/PaintType 1 def % colored
/TilingType 1 def % irrelevant
% Copy the BBox to the correct VM.
/BBox 2 index /BBox get 4 array copy exch 1 index def
% Set XStep and YStep to very large numbers,
% so we won't get multiple copies of the form.
/XStep 1 index dup 2 get exch 0 get sub 100 mul def
/YStep exch dup 3 get exch 1 get sub 100 mul def
/PaintProc 2 index /PaintProc get def
currentdict end readonly
% Stack: form global impl
exch setglobal
1 index /Implementation 3 -1 roll .forceput
} if
.formcachedict 1 index .knownget {
% Check whether we can use the cached value.
% Stack: form cachevalue
matrix currentmatrix true 0 1 3 {
% Stack: form cachevalue curmat true index
3 index 0 get 1 index get exch 3 index exch get ne {
pop pop false exit
} if
} for exch pop
} {
false
} ifelse not
{ % Make a new cache entry.
gsave
matrix currentmatrix dup 4 0 put dup 5 0 put dup setmatrix
% Stack: form mat
1 index /Implementation get
2 index /Matrix get
makepattern 2 array astore
.formcachedict 2 index 2 index put
grestore
} if
% Stack: form cachevalue
-1 0 0 transform
2 { exch round cvi } repeat .setscreenphase
1 get setpattern
/BBox get aload pop
exch 3 index sub exch 2 index sub rectfill
} .bind odef % must bind .forceput
.formtypes 1 /.execform1 load put
setglobal