Category : DeskTop Publishing in the 1990's
Archive   : GS252INI.ZIP
Filename : TYPE1OPS.PS

% Copyright (C) 1992 Aladdin Enterprises. All rights reserved.
% Distributed by Free Software Foundation, Inc.
%
% This file is part of Ghostscript.
%
% Ghostscript is distributed in the hope that it will be useful, but
% WITHOUT ANY WARRANTY. No author or distributor accepts responsibility
% to anyone for the consequences of using it or for whether it serves any
% particular purpose or works at all, unless he says so in writing. Refer
% to the Ghostscript General Public License for full details.
%
% Everyone is granted permission to copy, modify and redistribute
% Ghostscript, but only under the conditions described in the Ghostscript
% General Public License. A copy of this license is supposed to have been
% given to you along with Ghostscript so you can know your rights and
% responsibilities. It should be in a file named COPYING. Among other
% things, the copyright notice and this notice must be preserved on all
% copies.

% type1ops.ps
% Define the Type 1 font opcodes for use by Ghostscript utilities.

% Define lenIV (the number of initial random bytes in the encoded outlines).
% This should be zero, but we set it to 4 for compatibility with PostScript.

/lenIV 4 def

% Define the Type 1 opcodes we care about.

/Type1encode 18 dict
/c_hstem 1 def dup /hstem <01> put
/c_vstem 3 def dup /vstem <03> put
/c_vmoveto 4 def dup /vmoveto <04> put
/c_rlineto 5 def dup /rlineto <05> put
/c_hlineto 6 def dup /hlineto <06> put
/c_vlineto 7 def dup /vlineto <07> put
/c_rrcurveto 8 def dup /rrcurveto <08> put
/c_closepath 9 def dup /closepath <09> put
/c_callsubr 10 def /s_callsubr <0a> def dup /callsubr s_callsubr put
/c_return 11 def dup /return <0b> put
/c_escape 12 def
/ce_dotsection 0 def /s_dotsection <0c06> def dup /dotsection s_dotsection put
/ce_vstem3 1 def /s_vstem3 <0c01> def dup /vstem3 s_vstem3 put
/ce_hstem3 2 def /s_hstem3 <0c02> def dup /hstem3 s_hstem3 put
/ce_seac 6 def /s_seac <0c06> def dup /seac s_seac put
/ce_sbw 7 def /s_sbw <0c07> def dup /sbw s_sbw put
/ce_div 12 def /s_div <0c0c> def dup /div s_div put
/ce_callothersubr 16 def /s_callothersubr <0c10> def dup /callothersubr s_callothersubr put
/ce_pop 17 def /s_pop <0c11> def dup /pop s_pop put
/ce_setcurrentpoint 33 def /s_setcurrentpoint <0c21> def dup /setcurrentpoint s_setcurrentpoint put
/c_hsbw 13 def /s_hsbw <0d> def dup /hsbw s_hsbw put
/c_endchar 14 def /s_endchar <0e> def dup /endchar s_endchar put
/c_rmoveto 21 def dup /rmoveto <15> put
/c_hmoveto 22 def dup /hmoveto <16> put
/s_setcurrentpoint_hmoveto s_setcurrentpoint <8b16> concatstrings def
/c_vhcurveto 30 def dup /vhcurveto <1e> put
/c_hvcurveto 31 def dup /hvcurveto <1f> put
def

% Define the encoding of numbers.
/c_num1 32 def
/c_num2 247 def
/c_num3 251 def
/c_num4 255 def
/min_enc_num1 c_num1 c_num2 sub 1 add 2 idiv def
/max_enc_num1 c_num2 c_num1 sub 1 sub 2 idiv def
/min_enc_num2 max_enc_num1 1 add def
/max_enc_num2 min_enc_num2 c_num3 c_num2 sub 256 mul add 1 sub def
/min_enc_num3 max_enc_num2 neg def
/max_enc_num3 min_enc_num2 neg def

% ------ CharString encoding ------ %

% For these utilities, a CharString is represented by a sequence of
% integers or names, either in an array or on the stack.
% Integers represent themselves; names are CharString operator names.
% A CharString in an array is called a "charproc"; a CharString on
% the stack is called a "charstack", and is delimited by a mark.
% Individual elements are called "chartokens".

% Compute the length of a CharString.
/chartoken_length % chartoken -> length
{ dup type /nametype eq
{ Type1encode exch get length
}
{ dup dup -107 ge exch 107 le and
{ pop 1
}
{ dup -1131 ge exch 1131 le and { 2 } { 5 } ifelse
}
ifelse
}
ifelse
} bind def
/charproc_length % charproc -> length
{ 0 exch { chartoken_length add } forall
} bind def
/charstack_length % charstack -> charstack length
{ counttomark 0 exch -1 1 { index chartoken_length add } for
} bind def

% Write a CharString to a file. Normally this will be a NullEncode filter
% writing on a string of the correct length.
/chartoken_write % file chartoken ->
{ dup type /nametype eq
{ Type1encode exch get writestring
}
{ dup dup -107 ge exch 107 le and
{ 139 add
}
{ dup dup -1131 lt exch 1131 gt or
{ 1 index 255 write
2 copy -24 bitshift 255 and write
2 copy -16 bitshift 255 and write
2 copy -8 bitshift 255 and write
255 and
}
{ dup 0 ge { 16#f694 } { neg 16#fa94 } ifelse add
2 copy -8 bitshift write 255 and
}
ifelse
}
ifelse write
}
ifelse
} bind def
/charproc_write % file charproc ->
{ { 1 index exch chartoken_write } forall pop
} bind def
/charstack_write % charstack file ->
{ counttomark 1 sub -1 1 { index 1 index exch chartoken_write } for
cleartomark
} bind def

% Convert a charproc or charstack to a proper encrypted CharString.
/charproc_string % charproc -> string
{ mark exch aload pop charstack_string
} bind def
/charstack_string % charstack -> string
{ charstack_length lenIV add string
dup dup length lenIV sub lenIV exch getinterval % skip lenIV
/NullEncode filter
exch 1 index counttomark 1 add 2 roll
charstack_write closefile
% 4330 exch dup type1encrypt exch pop readonly
} bind def

% ------ CharString decoding ------ %

/Type1decode 256 array
dup 0 32 getinterval
null /hstem null /vstem /vmoveto /rlineto /hlineto /vlineto
/rrcurveto /closepath /callsubr /return null /hsbw /endchar null
null null null null null /rmoveto /hmoveto null
null null null null null null /vhcurveto /hvcurveto
33 -1 roll astore pop
dup 12
{ dup read pop dup Type1escape exch known
{ Type1escape exch get }
{ pop null }
ifelse exch
} put
32 1 246 { 2 copy dup 139 sub put pop } for
dup 247 { dup read pop 108 add exch } put
dup 248 { dup read pop 364 add exch } put
dup 249 { dup read pop 620 add exch } put
dup 250 { dup read pop 876 add exch } put
dup 251 { dup read pop 108 add neg exch } put
dup 252 { dup read pop 364 add neg exch } put
dup 253 { dup read pop 620 add neg exch } put
dup 254 { dup read pop 876 add neg exch } put
dup 255 { 0 4 { 8 bitshift 1 index read pop add } repeat exch } put
def
/Type1escape 9 dict
dup ce_dotsection /dotsection put
dup ce_vstem3 /vstem3 put
dup ce_hstem3 /hstem3 put
dup ce_seac /seac put
dup ce_sbw /sbw put
dup ce_div /div put
dup ce_callothersubr /callothersubr put
dup ce_pop /pop put
dup ce_setcurrentpoint /setcurrentpoint put
def

% Decode a CharString (unencrypted).
/charstack_read % file -> (NO MARK) charstack
{ { dup read not { pop exit } if
Type1decode exch get
dup type /arraytype eq { exec } { exch } ifelse
} loop
} bind def