%    Copyright (C) 1992, 1996 Aladdin Enterprises.  All rights reserved.% % This file is part of AFPL Ghostscript.% % AFPL Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author or% distributor accepts any responsibility for the consequences of using it, or% for whether it serves any particular purpose or works at all, unless he or% she says so in writing.  Refer to the Aladdin Free Public License (the% "License") for full details.% % Every copy of AFPL Ghostscript must include a copy of the License, normally% in a plain ASCII text file named PUBLIC.  The License grants you the right% to copy, modify and redistribute AFPL Ghostscript, but only under certain% conditions described in the License.  Among other things, the License% requires that the copyright notice and this notice be preserved on all% copies. % $Id: impath.ps,v 1.2 2000/09/19 18:29:11 lpd Exp $% impath.ps% Reverse-rasterize a bitmap to produce a Type 1 outline.% (This was formerly a Ghostscript operator implemented in C.) %	<image> <width> <height> <wx> <wy> <ox> <oy> <string>%	  type1imagepath <substring>%		Converts an image (bitmap) description of a character into%		  a scalable description in Adobe Type 1 format.  The%		  current transformation matrix should be the same as the%		  FontMatrix of the font in which this character will be%		  used: this establishes the scaling relationship between%		  image pixels (the image is assumed to be 1 unit high in%		  user space) and the character coordinate system used in%		  the scalable description.  wx and wy are the character%		  width, and ox and oy are the character origin relative%		  to the lower left corner of the bitmap, in *pixels*.%		The image is assumed to be stored in left-to-right,%		  top-to-bottom order.  Note that this is not consistent%		  with the `image' operator's interpretation of the CTM.%		All coordinates in the scalable description are rounded to%		  integers, so the coefficients in the FontMatrix should%		  be on the order of 1/N for some value of N that is%		  either a multiple of the height/width or is large%		  compared to the width and height.  (There is a%		  convention, which some PostScript programs rely on, that%		  N=1000.)%		Note that the encoded description has *not* been subjected%		  to CharString encryption, which is necessary before the%		  description can be given to type1addpath: to do this,%		  follow the type1imagepath with%			4330 exch dup .type1encrypt exch pop%		If the description is too complex to fit into the supplied%		  string, a limitcheck error results.  A good rule of%		  thumb is that the size of the string should be about 6%		  times the number of 1-bits in the image that are not%		  completely surrounded by other 1-bits. % Import the Type 1 opcodes.(type1ops.ps) runlibfile 100 dictdup /type1imagepath_dict exch defbegin /rc { round cvi } bind def/moving [/rmoveto /hmoveto /vmoveto] def/drawing [/rlineto /hlineto /vlineto] def % Convert the current path to a Type 1 token array./putxy			% x y ops -> cs_elements { 3 -1 roll dup x sub rc exch /x exch def   3 -1 roll dup y sub rc exch /y exch def   % stack: ops dx dy   dup 0 eq    { % dy = 0, use hmoveto/lineto      pop exch 1 get    }    { 1 index 0 eq       { % dx = 0, use vmoveto/lineto         exch pop exch 2 get       }       { % use rmoveto/rlineto         3 -1 roll 0 get       }      ifelse    }   ifelse } bind def/pathtotype1		% -> charstack { 3 dict begin /x 0 def /y 0 def   mark   { moving putxy   }   { drawing putxy   }   { % Convert curve to relative form     x y 3      { exch neg 7 index add rc	exch neg 6 index add rc	8 -2 roll      }     repeat /y exch def /x exch def     1 index 0 eq 5 index 0 eq and	% dy1=dx3=0, hv      { 5 -1 roll pop exch pop /hvcurveto      }      { dup 0 eq 6 index 0 eq and	% dx1=dy3=0, vh         { 6 -1 roll pop pop /vhcurveto	 }	 { /rrcurveto			% none of the above	 }	ifelse      }     ifelse   }   { /closepath   }   pathforall end } bind def end	% type1imagepath_dict % The main program/type1imagepath		% image width height wx wy ox oy string ->			% substring { type1imagepath_dict begin   /tsave save def   /ostring exch def   /oy exch def   /ox exch def   /wy exch def   /wx exch def   /height exch def   /width exch def   /data exch def    /ofilter ostring /NullEncode filter def   /raster width 7 add 8 idiv def % Construct the coordinate transformation.   height dup scale     matrix currentmatrix matrix invertmatrix setmatrix % Determine the left side bearing.   /lsbx width   0 1 width 1 sub    { dup dup 8 idiv 0 exch      raster raster height mul 1 sub       { data exch get or }      for exch 8 mod bitshift 128 and 0 ne       { exch pop exit }      if pop    }   for def % Compute and encode the origin, width, and side bearing.   mark   ox oy dtransform     rc /opty exch def   rc /optx exch def   wx wy dtransform     rc /iwy exch def	rc /iwx exch def   lsbx ox sub 0 dtransform     rc /ilsby exch def   rc /ilsbx exch def   ilsbx   iwy 0 ne ilsby 0 ne or    { ilsby iwx iwy /sbw }    { iwx /hsbw }   ifelse   ofilter charstack_write % Flip over the Y axis, because the image is stored top-to-bottom.   [1 0 0 -1 0 height] concat% Account for the character origin.   lsbx oy translate% Trace the outline.   newpath   width height data .imagepath   gsave matrix setmatrix pathtotype1 grestore   ofilter charstack_write% Terminate the output   mark /endchar ofilter charstack_write    ofilter fileposition ofilter closefile	% flush buffers   ostring 0 3 -1 roll getinterval   tsave restore   end } bind def