freetype1/lib/ttengine.h

   1 /*******************************************************************
   2  *
   3  *  ttengine.h                                                   1.1
   4  *
   5  *    Engine instance structure definition.
   6  *
   7  *  Copyright 1996-1999 by
   8  *  David Turner, Robert Wilhelm, and Werner Lemberg.
   9  *
  10  *  This file is part of the FreeType project, and may only be used
  11  *  modified and distributed under the terms of the FreeType project
  12  *  license, LICENSE.TXT.  By continuing to use, modify, or distribute
  13  *  this file you indicate that you have read the license and
  14  *  understand and accept it fully.
  15  *
  16  *  New in 1.1 :
  17  *
  18  *    - added the 'raster_lock' mutex field to synchronize
  19  *      scan-line conversion in thread-safe and re-entrant builds.
  20  *
  21  ******************************************************************/
  22
  23 #ifndef TTENGINE_H
  24 #define TTENGINE_H
  25
  26 #include "tttypes.h"
  27 #include "ttconfig.h"
  28 #include "freetype.h"
  29 #include "ttmutex.h"
  30
  31 #ifdef __cplusplus
  32   extern "C" {
  33 #endif
  34
  35   /********************************************************************/
  36   /*                                                                  */
  37   /*  The freetype engine instance structure.                         */
  38   /*                                                                  */
  39   /*  This structure holds all the data that is necessary to run      */
  40   /*  one instance of the freetype engine.  It is needed to get a     */
  41   /*  completely re-entrant version of the library.                   */
  42   /*                                                                  */
  43   /*  The goal is to move _all_ component-specific variables, either  */
  44   /*  static or global in the structure; the component initializers   */
  45   /*  and finalizers will all be called with the address of a valid   */
  46   /*  TEngine_Instance.                                               */
  47   /*                                                                  */
  48   /********************************************************************/
  49
  50   struct  TEngine_Instance_
  51   {
  52      TMutex  lock;               /* engine lock */
  53
  54      void*   list_free_elements;
  55
  56      void*   objs_face_class;       /* the face cache class     */
  57      void*   objs_instance_class;   /* the instance cache class */
  58      void*   objs_execution_class;  /* the context cache class  */
  59      void*   objs_glyph_class;      /* the glyph cache class    */
  60
  61      void*   objs_face_cache;  /* these caches are used to track */
  62      void*   objs_exec_cache;  /* the current face and execution */
  63                                /* context objects                */
  64
  65      void*   file_component;    /* ttfile implementation dependent   */
  66
  67      TMutex  raster_lock;       /* mutex for this engine's render pool   */
  68      void*   raster_component;  /* ttraster implementation depedent      */
  69      Byte    raster_palette[5]; /* gray-levels palette for anti-aliasing */
  70
  71      void*   extension_component;  /* extensions dependent */
  72
  73 #if 0
  74      TT_Glyph_Loader_Callback  glCallback; /* glyph loader callback, if any */
  75 #endif
  76   };
  77
  78   /* NOTE : The raster's lock is only acquired by the Render_Glyph and     */
  79   /*        Render_Gray_Glyph functions, which always release it on exit   */
  80   /*        They do not lock the engine mutex. This means you shouldn't    */
  81   /*        be concerned about deadlocks between the two mutexes, as these */
  82   /*        should never appear..                                          */
  83
  84   typedef struct TEngine_Instance_  TEngine_Instance;
  85   typedef TEngine_Instance*         PEngine_Instance;
  86
  87
  88 #ifdef TT_CONFIG_OPTION_THREAD_SAFE  /* for re-entrant builds */
  89
  90 #define ENGINE_ARG    TEngine_Instance*  _engine
  91 #define ENGINE_ARGS   TEngine_Instance*  _engine,
  92
  93 #define ENGINE_VAR   _engine
  94 #define ENGINE_VARS  _engine,
  95
  96 #define ENGINE  _engine
  97
  98 #else                       /* for thread-safe builds */
  99
 100 #define ENGINE_ARG    /* void */
 101 #define ENGINE_ARGS
 102
 103 #define ENGINE_VAR
 104 #define ENGINE_VARS
 105
 106 #endif /* TT_CONFIG_OPTION_THREAD_SAFE */
 107
 108 #ifdef __cplusplus
 109   }
 110 #endif
 111
 112 #endif /* TTENGINE_H */
 113
 114
 115 /* END */