--- /dev/null
+/***************************************************************************/
+/* */
+/* ftextend.h */
+/* */
+/* FreeType extensions implementation (specification). */
+/* */
+/* Copyright 1996-2001 by */
+/* David Turner, Robert Wilhelm, and Werner Lemberg. */
+/* */
+/* This file is part of the FreeType project, and may only be used, */
+/* modified, and distributed under the terms of the FreeType project */
+/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
+/* this file you indicate that you have read the license and */
+/* understand and accept it fully. */
+/* */
+/***************************************************************************/
+
+
+#ifndef __FTEXTEND_H__
+#define __FTEXTEND_H__
+
+
+#include <ft2build.h>
+#include FT_INTERNAL_OBJECTS_H
+
+
+FT_BEGIN_HEADER
+
+
+ /*************************************************************************/
+ /* */
+ /* The extensions don't need to be integrated at compile time into the */
+ /* engine, only at link time. */
+ /* */
+ /*************************************************************************/
+
+
+ /*************************************************************************/
+ /* */
+ /* <FuncType> */
+ /* FT_Extension_Initializer */
+ /* */
+ /* <Description> */
+ /* Each new face object can have several extensions associated with */
+ /* it at creation time. This function is used to initialize given */
+ /* extension data for a given face. */
+ /* */
+ /* <InOut> */
+ /* ext :: A typeless pointer to the extension data. */
+ /* */
+ /* face :: A handle to the source face object the extension is */
+ /* associated with. */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ /* <Note> */
+ /* In case of error, the initializer should not destroy the extension */
+ /* data, as the finalizer will get called later by the function's */
+ /* caller. */
+ /* */
+ typedef FT_Error
+ (*FT_Extension_Initializer)( void* ext,
+ FT_Face face );
+
+
+ /*************************************************************************/
+ /* */
+ /* <FuncType> */
+ /* FT_Extension_Finalizer */
+ /* */
+ /* <Description> */
+ /* Each new face object can have several extensions associated with */
+ /* it at creation time. This function is used to finalize given */
+ /* extension data for a given face; it occurs before the face object */
+ /* itself is finalized. */
+ /* */
+ /* <InOut> */
+ /* ext :: A typeless pointer to the extension data. */
+ /* */
+ /* face :: A handle to the source face object the extension is */
+ /* associated with. */
+ /* */
+ typedef void
+ (*FT_Extension_Finalizer)( void* ext,
+ FT_Face face );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Struct> */
+ /* FT_Extension_Class */
+ /* */
+ /* <Description> */
+ /* A simple structure used to describe a given extension to the */
+ /* FreeType base layer. An FT_Extension_Class is used as a parameter */
+ /* for FT_Register_Extension(). */
+ /* */
+ /* <Fields> */
+ /* id :: The extension's ID. This is a normal C string that */
+ /* is used to uniquely reference the extension's */
+ /* interface. */
+ /* */
+ /* size :: The size in bytes of the extension data that must be */
+ /* associated with each face object. */
+ /* */
+ /* init :: A pointer to the extension data's initializer. */
+ /* */
+ /* finalize :: A pointer to the extension data's finalizer. */
+ /* */
+ /* interface :: This pointer can be anything, but should usually */
+ /* point to a table of function pointers which implement */
+ /* the extension's interface. */
+ /* */
+ /* offset :: This field is set and used within the base layer and */
+ /* should be set to 0 when registering an extension */
+ /* through FT_Register_Extension(). It contains an */
+ /* offset within the face's extension block for the */
+ /* current extension's data. */
+ /* */
+ typedef struct FT_Extension_Class_
+ {
+ const char* id;
+ FT_ULong size;
+ FT_Extension_Initializer init;
+ FT_Extension_Finalizer finalize;
+ void* interface;
+
+ FT_ULong offset;
+
+ } FT_Extension_Class;
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FT_Register_Extension */
+ /* */
+ /* <Description> */
+ /* Registers a new extension. */
+ /* */
+ /* <InOut> */
+ /* driver :: A handle to the driver object. */
+ /* */
+ /* class :: A pointer to a class describing the extension. */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ FT_EXPORT( FT_Error )
+ FT_Register_Extension( FT_Driver driver,
+ FT_Extension_Class* clazz );
+
+
+#ifdef FT_CONFIG_OPTION_EXTEND_ENGINE
+
+
+ /* Initialize the extension component */
+ FT_LOCAL FT_Error
+ FT_Init_Extensions( FT_Library library );
+
+ /* Finalize the extension component */
+ FT_LOCAL FT_Error
+ FT_Done_Extensions( FT_Library library );
+
+ /* Create an extension within a face object. Called by the */
+ /* face object constructor. */
+ FT_LOCAL FT_Error
+ FT_Create_Extensions( FT_Face face );
+
+ /* Destroy all extensions within a face object. Called by the */
+ /* face object destructor. */
+ FT_LOCAL FT_Error
+ FT_Destroy_Extensions( FT_Face face );
+
+
+#endif
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FT_Get_Extension */
+ /* */
+ /* <Description> */
+ /* Queries an extension block by an extension ID string. */
+ /* */
+ /* <Input> */
+ /* face :: A handle to the face object. */
+ /* extension_id :: An ID string identifying the extension. */
+ /* */
+ /* <Output> */
+ /* extension_interface :: A generic pointer, usually pointing to a */
+ /* table of functions implementing the */
+ /* extension interface. */
+ /* */
+ /* <Return> */
+ /* A generic pointer to the extension block. */
+ /* */
+ FT_EXPORT( void* )
+ FT_Get_Extension( FT_Face face,
+ const char* extension_id,
+ void** extension_interface );
+
+
+FT_END_HEADER
+
+#endif /* __FTEXTEND_H__ */
+
+
+/* END */
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