source/texk/web2c/luatexdir/luafontloader/fontforge/fontforge/plugins.h

   1 /* Copyright (C) 2005-2008 by George Williams */
   2 /*
   3  * Redistribution and use in source and binary forms, with or without
   4  * modification, are permitted provided that the following conditions are met:
   5
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  10  * this list of conditions and the following disclaimer in the documentation
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  13  * The name of the author may not be used to endorse or promote products
  14  * derived from this software without specific prior written permission.
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  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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  19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 /* If a user wants to write a fontforge plugin s/he should include this file */
  29
  30 /*
  31     I envision that there will eventually be three types of plug-ins. At the
  32     moment I am only supporing two of them.
  33
  34     * A plug in which adds a new encoding to the encoding/force encoding
  35         menus.
  36     * A plug in which adds a new scripting command
  37     * A plug in which adds a new menu item.
  38         (I haven't figure out how I want to do this last. So I'm not currently
  39          supporting it.)
  40
  41     A plug-in should be a dynamic library.
  42     Plug-ins will be loaded at start up if they are in the default plugin
  43         directory, or a script may explicitly invoke a LoadPlugin() call
  44         and pass a filename.
  45     Each plug-in should contain an entry-point:
  46         void FontForgeInit(void);
  47     When FF loads a plug-in it will call this entry point.
  48     I expect that this routine in term will call one (or more) of the install
  49         routines (though it can do whatever it likes):
  50         * AddEncoding(name,enc-to-unicode-func,unicode-to-enc-func)
  51         * AddScriptingCommand(name,func,needs-font)
  52
  53     Once loaded, there is no way to remove a plug in -- but you can map a
  54     plug in's name to do something else.
  55
  56     I am presuming that plugins will be linked against libfontforge and
  57     that it will have access to all routines declared in fontforge's
  58     header files. I do not expect to turn this into a real library with
  59     a true API. It's just a catch all bag of routines I have needed.
  60     It's not documented either.
  61 */
  62
  63  /* Entry point all plugins must contain */
  64 extern int FontForgeInit(void);
  65     /* If the load fails, then this routine should return 0, else 1 */
  66     /*  if it returns 0, fontforge will dlclose the shared lib      */
  67     /*  FontForge will not complain itself. FontForgeInit should    */
  68     /*  call LogError (or gwwv_post_error or whatever) if it wants  */
  69     /*  to report failure */
  70
  71  /* AddScriptingCommand is documented within */
  72 #include "scripting.h"
  73
  74  /* AddEncoding is documented here */
  75 typedef int (*EncFunc)(int);
  76 extern int AddEncoding(char *name,EncFunc enc_to_uni,EncFunc uni_to_enc,int max);
  77         /* The "Encoding" here is a little different from what you normally see*/
  78         /*  It isn't a mapping from a byte stream to unicode, but from an int */
  79         /*  to unicode. If we have an 8/16 encoding (EUC or SJIS) then the */
  80         /*  single byte entries will be numbers less than <256 and the */
  81         /*  multibyte entries will be numbers >=256. So an encoding might be */
  82         /*  valid for the domain [0x20..0x7f] [0xa1a1..0xfefe] */
  83         /* In other words, we're interested in the ordering displayed in the */
  84         /*  fontview. Nothing else */
  85         /* The max value need not be exact (though it should be at least as big)*/
  86         /*  if you create a new font with the given encoding, then the font will */
  87         /*  have max slots in it by default */
  88         /* A return value of -1 (from an EncFunc) indicates no mapping */
  89         /* AddEncoding returns 1 if the encoding was added, 2 if it replaced */
  90         /*  an existing encoding, 0 if you attempt to replace a builtin */
  91         /*  encoding */
  92
  93
  94  /* Internal routines. Plugins shouldn't need these */
  95 extern void LoadPlugin(char *dynamic_lib_name);
  96     /* Loads a single plugin file */
  97 extern void LoadPluginDir(char *dir);
  98     /* Loads any dynamic libs from this directory. if dir is NULL loads from */
  99     /*  default directory */