typedef FT_Error
  (*FT_Module_Constructor)( FT_Module  module );

A function used to initialize (not create) a new module object.

  typedef void
  (*FT_Module_Destructor)( FT_Module  module );

A function used to finalize (not destroy) a given module object.

  typedef FT_Module_Interface
  (*FT_Module_Requester)( FT_Module    module,
                          const char*  name );

A function used to query a given module for a specific interface.

  typedef struct  FT_Module_Class_
  {
    FT_ULong               module_flags;
    FT_Long                module_size;
    const FT_String*       module_name;
    FT_Fixed               module_version;
    FT_Fixed               module_requires;

    const void*            module_interface;

    FT_Module_Constructor  module_init;
    FT_Module_Destructor   module_done;
    FT_Module_Requester    get_interface;

  } FT_Module_Class;

The module class descriptor.

  FT_EXPORT( FT_Error )
  FT_Add_Module( FT_Library              library,
                 const FT_Module_Class*  clazz );

Add a new module to a given library instance.

FreeType error code. 0 means success.

An error will be returned if a module already exists by that name, or if the module requires a version of FreeType that is too great.

  FT_EXPORT( FT_Module )
  FT_Get_Module( FT_Library   library,
                 const char*  module_name );

Find a module by its name.

A module handle. 0 if none was found.

FreeType's internal modules aren't documented very well, and you should look up the source code for details.

  FT_EXPORT( FT_Error )
  FT_Remove_Module( FT_Library  library,
                    FT_Module   module );

Remove a given module from a library instance.

FreeType error code. 0 means success.

The module object is destroyed by the function in case of success.

  FT_EXPORT( FT_Error )
  FT_Reference_Library( FT_Library  library );

A counter gets initialized to 1 at the time an FT_Library structure is created. This function increments the counter. FT_Done_Library then only destroys a library if the counter is 1, otherwise it simply decrements the counter.

This function helps in managing life-cycles of structures which reference FT_Library objects.

FreeType error code. 0 means success.

2.4.2

  FT_EXPORT( FT_Error )
  FT_New_Library( FT_Memory    memory,
                  FT_Library  *alibrary );

This function is used to create a new FreeType library instance from a given memory object. It is thus possible to use libraries with distinct memory allocators within the same program.

Normally, you would call this function (followed by a call to FT_Add_Default_Modules or a series of calls to FT_Add_Module) instead of FT_Init_FreeType to initialize the FreeType library.

Don't use FT_Done_FreeType but FT_Done_Library to destroy a library instance.

FreeType error code. 0 means success.

See the discussion of reference counters in the description of FT_Reference_Library.

  FT_EXPORT( FT_Error )
  FT_Done_Library( FT_Library  library );

Discard a given library object. This closes all drivers and discards all resource objects.

FreeType error code. 0 means success.

See the discussion of reference counters in the description of FT_Reference_Library.

  FT_EXPORT( void )
  FT_Set_Debug_Hook( FT_Library         library,
                     FT_UInt            hook_index,
                     FT_DebugHook_Func  debug_hook );

Set a debug hook function for debugging the interpreter of a font format.

Currently, four debug hook slots are available, but only two (for the TrueType and the Type 1 interpreter) are defined.

Since the internal headers of FreeType are no longer installed, the symbol ‘FT_DEBUG_HOOK_TRUETYPE’ isn't available publicly. This is a bug and will be fixed in a forthcoming release.

  FT_EXPORT( void )
  FT_Add_Default_Modules( FT_Library  library );

Add the set of default drivers to a given library object. This is only useful when you create a library object with FT_New_Library (usually to plug a custom memory manager).

  typedef struct  FT_Renderer_Class_
  {
    FT_Module_Class            root;

    FT_Glyph_Format            glyph_format;

    FT_Renderer_RenderFunc     render_glyph;
    FT_Renderer_TransformFunc  transform_glyph;
    FT_Renderer_GetCBoxFunc    get_glyph_cbox;
    FT_Renderer_SetModeFunc    set_mode;

    FT_Raster_Funcs*           raster_class;

  } FT_Renderer_Class;

The renderer module class descriptor.

  FT_EXPORT( FT_Renderer )
  FT_Get_Renderer( FT_Library       library,
                   FT_Glyph_Format  format );

Retrieve the current renderer for a given glyph format.

A renderer handle. 0 if none found.

An error will be returned if a module already exists by that name, or if the module requires a version of FreeType that is too great.

To add a new renderer, simply use FT_Add_Module. To retrieve a renderer by its name, use FT_Get_Module.

  FT_EXPORT( FT_Error )
  FT_Set_Renderer( FT_Library     library,
                   FT_Renderer    renderer,
                   FT_UInt        num_params,
                   FT_Parameter*  parameters );

Set the current renderer to use, and set additional mode.

FreeType error code. 0 means success.

In case of success, the renderer will be used to convert glyph images in the renderer's known format into bitmaps.

This doesn't change the current renderer for other formats.

Currently, only the B/W renderer, if compiled with FT_RASTER_OPTION_ANTI_ALIASING (providing a 5-levels anti-aliasing mode; this option must be set directly in ‘ftraster.c’ and is undefined by default) accepts a single tag ‘pal5’ to set its gray palette as a character string with 5 elements. Consequently, the third and fourth argument are zero normally.