include/freetype/ftmodule.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftmodule.h                                                             */
   4 /*                                                                         */
   5 /*    FreeType modules public interface (specification).                   */
   6 /*                                                                         */
   7 /*  Copyright 1996-2000 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 /***************************************************************************/
  17
  18
  19 #ifndef FTMODULE_H
  20 #define FTMODULE_H
  21
  22 #include <freetype/freetype.h>
  23
  24
  25 #ifdef __cplusplus
  26   extern "C" {
  27 #endif
  28
  29
  30   /* module bit flags */
  31   typedef enum  FT_Module_Flags_
  32   {
  33     ft_module_font_driver         = 1,     /* this module is a font driver  */
  34     ft_module_renderer            = 2,     /* this module is a renderer     */
  35     ft_module_hinter              = 4,     /* this module is a glyph hinter */
  36     ft_module_styler              = 8,     /* this module is a styler       */
  37
  38     ft_module_driver_scalable     = 0x100, /* the driver supports scalable  */
  39                                            /* fonts                         */
  40     ft_module_driver_no_outlines  = 0x200, /* the driver does not support   */
  41                                            /* vector outlines               */
  42     ft_module_driver_has_hinter   = 0x400  /* the driver provides its own   */
  43                                            /* hinter                        */
  44
  45   } FT_Module_Flags;
  46
  47
  48   typedef void  (*FT_Module_Interface)( void );
  49
  50   typedef FT_Error  (*FT_Module_Constructor)( FT_Module  module );
  51
  52   typedef void  (*FT_Module_Destructor)( FT_Module  module );
  53
  54   typedef FT_Module_Interface (*FT_Module_Requester)( FT_Module    module,
  55                                                       const char*  name );
  56
  57
  58   /*************************************************************************/
  59   /*                                                                       */
  60   /* <Struct>                                                              */
  61   /*    FT_Module_Class                                                    */
  62   /*                                                                       */
  63   /* <Description>                                                         */
  64   /*    The module class descriptor.                                       */
  65   /*                                                                       */
  66   /* <Fields>                                                              */
  67   /*    module_flags      :: Bit flags describing the module.              */
  68   /*                                                                       */
  69   /*    module_size       :: The size of one module object/instance in     */
  70   /*                         bytes.                                        */
  71   /*                                                                       */
  72   /*    module_name       :: The name of the module.                       */
  73   /*                                                                       */
  74   /*    module_version    :: The version, as a 16.16 fixed number          */
  75   /*                         (major.minor).                                */
  76   /*                                                                       */
  77   /*    module_requires   :: The version of FreeType this module requires  */
  78   /*                         (starts at version 2.0, i.e 0x20000)          */
  79   /*                                                                       */
  80   /*    module_init       :: A function used to initialize (not create) a  */
  81   /*                         new module object.                            */
  82   /*                                                                       */
  83   /*    module_done       :: A function used to finalize (not destroy) a   */
  84   /*                         given module object                           */
  85   /*                                                                       */
  86   /*    get_interface     :: Queries a given module for a specific         */
  87   /*                         interface by name.                            */
  88   /*                                                                       */
  89   typedef struct  FT_Module_Class_
  90   {
  91     FT_ULong               module_flags;
  92     FT_Int                 module_size;
  93     const FT_String*       module_name;
  94     FT_Fixed               module_version;
  95     FT_Fixed               module_requires;
  96
  97     const void*            module_interface;
  98
  99     FT_Module_Constructor  module_init;
 100     FT_Module_Destructor   module_done;
 101     FT_Module_Requester    get_interface;
 102
 103   } FT_Module_Class;
 104
 105
 106   /*************************************************************************/
 107   /*                                                                       */
 108   /* <Function>                                                            */
 109   /*    FT_Add_Module                                                      */
 110   /*                                                                       */
 111   /* <Description>                                                         */
 112   /*    Adds a new module to a given library instance.                     */
 113   /*                                                                       */
 114   /* <Input>                                                               */
 115   /*    library :: A handle to the library object.                         */
 116   /*                                                                       */
 117   /*    clazz   :: A pointer to class descriptor for the module.           */
 118   /*                                                                       */
 119   /* <Return>                                                              */
 120   /*    FreeType error code.  0 means success.                             */
 121   /*                                                                       */
 122   /* <Note>                                                                */
 123   /*    An error will be returned if a module already exists by that name, */
 124   /*    or if the module requires a version of FreeType that is too great. */
 125   /*                                                                       */
 126   FT_EXPORT_DEF( FT_Error )  FT_Add_Module( FT_Library              library,
 127                                             const FT_Module_Class*  clazz );
 128
 129
 130   /*************************************************************************/
 131   /*                                                                       */
 132   /* <Function>                                                            */
 133   /*    FT_Get_Module                                                      */
 134   /*                                                                       */
 135   /* <Description>                                                         */
 136   /*    Finds a module by its name.                                        */
 137   /*                                                                       */
 138   /* <Input>                                                               */
 139   /*    library     :: A handle to the library object.                     */
 140   /*                                                                       */
 141   /*    module_name :: The module's name (as an ASCII string).             */
 142   /*                                                                       */
 143   /* <Return>                                                              */
 144   /*    A module handle.  0 if none was found.                             */
 145   /*                                                                       */
 146   /* <Note>                                                                */
 147   /*    You should better be familiar with FreeType internals to know      */
 148   /*    which module to look for :-)                                       */
 149   /*                                                                       */
 150   FT_EXPORT_DEF( FT_Module )  FT_Get_Module( FT_Library   library,
 151                                              const char*  module_name );
 152
 153
 154   /*************************************************************************/
 155   /*                                                                       */
 156   /* <Function>                                                            */
 157   /*    FT_Remove_Module                                                   */
 158   /*                                                                       */
 159   /* <Description>                                                         */
 160   /*    Removes a given module from a library instance.                    */
 161   /*                                                                       */
 162   /* <Input>                                                               */
 163   /*    library :: A handle to a library object.                           */
 164   /*                                                                       */
 165   /*    module  :: A handle to a module object.                            */
 166   /*                                                                       */
 167   /* <Return>                                                              */
 168   /*    FreeType error code.  0 means success.                             */
 169   /*                                                                       */
 170   /* <Note>                                                                */
 171   /*    The module object is destroyed by the function in case of success. */
 172   /*                                                                       */
 173   FT_EXPORT_DEF( FT_Error )  FT_Remove_Module( FT_Library  library,
 174                                                FT_Module   module );
 175
 176
 177   /*************************************************************************/
 178   /*                                                                       */
 179   /* <Function>                                                            */
 180   /*    FT_New_Library                                                     */
 181   /*                                                                       */
 182   /* <Description>                                                         */
 183   /*    This function is used to create a new FreeType library instance    */
 184   /*    from a given memory object.  It is thus possible to use libraries  */
 185   /*    with distinct memory allocators within the same program.           */
 186   /*                                                                       */
 187   /* <Input>                                                               */
 188   /*    memory   :: A handle to the original memory object.                */
 189   /*                                                                       */
 190   /* <Output>                                                              */
 191   /*    alibrary :: A pointer to handle of a new library object.           */
 192   /*                                                                       */
 193   /* <Return>                                                              */
 194   /*    FreeType error code.  0 means success.                             */
 195   /*                                                                       */
 196   FT_EXPORT_DEF( FT_Error )  FT_New_Library( FT_Memory    memory,
 197                                              FT_Library*  library );
 198
 199
 200   /*************************************************************************/
 201   /*                                                                       */
 202   /* <Function>                                                            */
 203   /*    FT_Done_Library                                                    */
 204   /*                                                                       */
 205   /* <Description>                                                         */
 206   /*    Discards a given library object.  This closes all drivers and      */
 207   /*    discards all resource objects.                                     */
 208   /*                                                                       */
 209   /* <Input>                                                               */
 210   /*    library :: A handle to the target library.                         */
 211   /*                                                                       */
 212   /* <Return>                                                              */
 213   /*    FreeType error code.  0 means success.                             */
 214   /*                                                                       */
 215   FT_EXPORT_DEF( FT_Error )  FT_Done_Library( FT_Library  library );
 216
 217
 218
 219   typedef void  (*FT_DebugHook_Func)( void*  arg );
 220
 221
 222   /*************************************************************************/
 223   /*                                                                       */
 224   /* <Function>                                                            */
 225   /*    FT_Set_Debug_Hook                                                  */
 226   /*                                                                       */
 227   /* <Description>                                                         */
 228   /*    Sets a debug hook function for debugging the interpreter of a font */
 229   /*    format.                                                            */
 230   /*                                                                       */
 231   /* <Input>                                                               */
 232   /*    library    :: A handle to the library object.                      */
 233   /*                                                                       */
 234   /*    hook_index :: The index of the debug hook.  You should use the     */
 235   /*                  values defined in ftobjs.h, e.g.                     */
 236   /*                  FT_DEBUG_HOOK_TRUETYPE                               */
 237   /*                                                                       */
 238   /*    debug_hook :: The function used to debug the interpreter.          */
 239   /*                                                                       */
 240   /* <Note>                                                                */
 241   /*    Currently, four debug hook slots are available, but only two (for  */
 242   /*    the TrueType and the Type 1 interpreter) are defined.              */
 243   /*                                                                       */
 244   FT_EXPORT_DEF( void )  FT_Set_Debug_Hook( FT_Library         library,
 245                                             FT_UInt            hook_index,
 246                                             FT_DebugHook_Func  debug_hook );
 247
 248
 249
 250   /*************************************************************************/
 251   /*                                                                       */
 252   /* <Function>                                                            */
 253   /*    FT_Add_Default_Modules                                             */
 254   /*                                                                       */
 255   /* <Description>                                                         */
 256   /*    Adds the set of default drivers to a given library object.         */
 257   /*    This is only useful when you create a library object with          */
 258   /*    FT_New_Library() (usually to plug a custom memory manager).        */
 259   /*                                                                       */
 260   /* <InOut>                                                               */
 261   /*    library :: A handle to a new library object.                       */
 262   /*                                                                       */
 263   FT_EXPORT_DEF( void )  FT_Add_Default_Modules( FT_Library  library );
 264
 265
 266 #ifdef __cplusplus
 267   }
 268 #endif
 269
 270
 271 #endif /* FTMODULE_H */
 272
 273
 274 /* END */