⟦b4f01a8a7⟧

TextFile

% Copyright (c) 1988 Stephan v. Bechtolsheim

% This file is part of the TeXPS Software Package.

% The TeXPS Software Package 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 TeXPS Software Package
% General Public License for full details.

% Everyone is granted permission to copy, modify and redistribute
% the TeXPS Software Package, but only under the conditions described in the
% TeXPS Software Package General Public License.   A copy of this license is
% supposed to have been given to you along with TeXPS Software Package so you
% can know your rights and responsibilities.  It should be in a
% file named CopyrightLong.  Among other things, the copyright notice
% and this notice must be preserved on all copies.

% Pixel based fonts
% =================
% Find here all the code associated with pixel fonts.

% @newfont
% ========
% Initialize a new font dictionary. The variable NumCharsInPixelFonts must
% be initialized by the driver's output.
% id @newfont -
/@newfont
  {
    /newname exch def
    newname 7 dict def          % allocate new font dictionary
    newname load begin
        /FontType 3 def
        /FontMatrix [1 0 0 -1 0 0] def
        /FontBBox [0 0 1 1] def
        /BitMaps NumCharsInPixelFonts array def
        /BuildChar {CharBuilder} def
        /Encoding NumCharsInPixelFonts array def
        0 1 NumCharsInPixelFonts 1 sub {Encoding exch /.undef put} for
        end
    newname newname load definefont pop
  } def

% Procedures to setup the character bitmaps of pixel fonts.
% ch-image, ch-width, ch-height, ch-xoff, ch-yoff, ch-tfmw
% ========================================================
% The following is the only character builder we need.  it looks up the
% char data in the BitMaps array, and paints the character if possible.
% char data  -- a bitmap descriptor -- is an array of length 6, of 
%          which the various slots are:
/ch-image {ch-data 0 get} def   % the hex string image
/ch-width {ch-data 1 get} def   % the number of pixels across in the pixel box
/ch-height {ch-data 2 get} def  % the number of rows in the pixel box
/ch-xoff  {ch-data 3 get} def   % x_offset: as defined in emitc.c
/ch-yoff  {ch-data 4 get} def   % y_offset: as defined in emitc.c
/ch-tfmw  {ch-data 5 get} def   % spacing to next character

% CharBuilder
% ===========
% fontdict ch Charbuilder -
% fontdict: dictionary of the current font, for which a character
%	has to be added.
% ch: the character code
%
% Image one character. The current font must be selected.
% The font matrix is defined as [1 0 0 -1 0 0], so positive y is up,
%   in reverse of the direction of the TeX coordinate system.
% The imagemask matrix is defined as [1 0 0 1 . . ], so we scan
% in the standard PS order, meaning starting at the bottom going
% to the top, and within each row we proceed left to right.
/CharBuilder
  {
    /ch-code exch def           % Save the char code
    /font-dict exch def         % Snd the font dict.
    /ch-data font-dict /BitMaps get ch-code get def     % Get the bitmap
							% descriptor for char
    ch-data null eq not
      {
        % Prepare arguments for call to setcachedevice
	ch-tfmw   0		% w_x w_y
        ch-xoff neg		% ll_x
	ch-height ch-yoff sub neg % ll_y
	ch-width  ch-xoff neg add % ur_x
	ch-yoff			% ur_y
        setcachedevice
% Ken's proposal
	0 0 transform round exch round exch itransform translate
        ch-width ch-height true
		[1 0  0 1 ch-xoff ch-height ch-yoff sub] {ch-image} imagemask
      }
    if
} def

% @dc
% ===
% Define a new character bitmap in the current font. That current
% font must be selected.
%
% char-data ch @dc -
% 
% char-data looks as follows:
%    [ <Hex Bitmap>
%	width-in-pixels height-in-pixels
%       number-pixels-below-origin number-pixels-left-origin
%       spacing (= number of pixels to go right after character has been
%		printed)
%    ]
% and
% ch: the character code
%
% Observe that the code of this procedure would not work for
% SliTeX characters (characters with no pixel information) if it
% were not for the driver generating an almost empty bitmap etc
% for this procedure. See "shipc.c" of the driver sources.
/@dc
  {
%   (start @dc\n) print flush
    /ch-code exch def		% Save arguments
    /ch-data exch def
    currentfont /BitMaps get	% get the BitMaps from the font
    ch-code ch-data put		% load the bitmap of this character
    currentfont /Encoding get   % get the encoding vector
    ch-code (   ) cvs   % convert the character code to a string
    cvn   % generate unique name simply from the string of the char number
    ch-code exch put
%   (done @dc\n) print flush
  } def

% @sf
% ===
% newfont @sf -
% Abbreviation for the setfont operator. Can be used by pixel
% based and PS based fonts.
/@sf /setfont load def
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⟦b4f01a8a7⟧ TextFile

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TextFile
