/***************************************************************************/
/* */
/* ftserv.h */
/* */
/* The FreeType services (specification only). */
/* */
/* Copyright 2003 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. */
/* */
/***************************************************************************/
/*************************************************************************/
/* */
/* Each module can export one or more `services'. Each service is */
/* identified by a constant string and modeled by a pointer; the latter */
/* generally corresponds to a structure containing function pointers. */
/* */
/* Note that a service's data cannot be a mere function pointer because */
/* in C it is possible that function pointers might be implemented */
/* differently than data pointers (e.g. 48 bits instead of 32). */
/* */
/*************************************************************************/
#ifndef __FTSERV_H__
#define __FTSERV_H__
FT_BEGIN_HEADER
/*
* @macro:
* FT_FACE_FIND_SERVICE
*
* @description:
* This macro is used to look up a service from a face's driver module.
*
* @input:
* face ::
* The source face handle.
*
* id ::
* A string describing the service as defined in the service's
* header files (e.g. FT_SERVICE_ID_MULTI_MASTERS which expands to
* `multi-masters'). It is automatically prefixed with
* `FT_SERVICE_ID_'.
*
* @output:
* ptr ::
* A variable that receives the service pointer. Will be NULL
* if not found.
*/
#define FT_FACE_FIND_SERVICE( face, ptr, id ) \
FT_BEGIN_STMNT \
FT_Module module = FT_MODULE( FT_FACE(face)->driver ); \
/* the strange cast is to allow C++ compilation */ \
FT_Pointer* Pptr = (FT_Pointer*) &(ptr); \
\
\
*Pptr = NULL; \
if ( module->clazz->get_interface ) \
*Pptr = module->clazz->get_interface( module, FT_SERVICE_ID_ ## id ); \
FT_END_STMNT
/*
* @macro:
* FT_FACE_FIND_GLOBAL_SERVICE
*
* @description:
* This macro is used to look up a service from all modules.
*
* @input:
* face ::
* The source face handle.
*
* id ::
* A string describing the service as defined in the service's
* header files (e.g. FT_SERVICE_ID_MULTI_MASTERS which expands to
* `multi-masters'). It is automatically prefixed with
* `FT_SERVICE_ID_'.
*
* @output:
* ptr ::
* A variable that receives the service pointer. Will be NULL
* if not found.
*/
#define FT_FACE_FIND_GLOBAL_SERVICE( face, ptr, id ) \
FT_BEGIN_STMNT \
FT_Module module = FT_MODULE( FT_FACE(face)->driver ); \
/* the strange cast is to allow C++ compilation */ \
FT_Pointer* Pptr = (FT_Pointer*) &(ptr); \
\
\
*Pptr = ft_module_get_service( module, FT_SERVICE_ID_ ## id ); \
FT_END_STMNT
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** S E R V I C E D E S C R I P T O R S *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*
* The following structure is used to _describe_ a given service
* to the library. This is useful to build simple static service lists.
*/
typedef struct FT_ServiceDescRec_
{
const char* serv_id; /* service name */
const void* serv_data; /* service pointer/data */
} FT_ServiceDescRec;
typedef const FT_ServiceDescRec* FT_ServiceDesc;
/*
* Parse a list of FT_ServiceDescRec descriptors and look for
* a specific service by ID. Note that the last element in the
* array must be { NULL, NULL }, and that the function should
* return NULL if the service isn't available.
*
* This function can be used by modules to implement their
* `get_service' method.
*/
FT_BASE( FT_Pointer )
ft_service_list_lookup( FT_ServiceDesc service_descriptors,
const char* service_id );
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** S E R V I C E S C A C H E *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/*
* This structure is used to store a cache for several frequently used
* services. It is the type of `face->internal->services'. You
* should only use FT_FACE_LOOKUP_SERVICE to access it.
*
* All fields should have the type FT_Pointer to relax compilation
* dependencies. We assume the developer isn't completely stupid.
*
* Each field must be named `service_XXXX' where `XXX' corresponds to
* the correct FT_SERVICE_ID_XXXX macro. See the definition of
* FT_FACE_LOOKUP_SERVICE below how this is implemented.
*
*/
typedef struct FT_ServiceCacheRec_
{
FT_Pointer service_POSTSCRIPT_FONT_NAME;
FT_Pointer service_MULTI_MASTERS;
FT_Pointer service_GLYPH_DICT;
FT_Pointer service_PFR_METRICS;
FT_Pointer service_WINFNT;
} FT_ServiceCacheRec, *FT_ServiceCache;
/*
* A magic number used within the services cache.
*/
#define FT_SERVICE_UNAVAILABLE ((FT_Pointer)-2) /* magic number */
/*
* @macro:
* FT_FACE_LOOKUP_SERVICE
*
* @description:
* This macro is used to lookup a service from a face's driver module
* using its cache.
*
* @input:
* face::
* The source face handle containing the cache.
*
* field ::
* The field name in the cache.
*
* id ::
* The service ID.
*
* @output:
* ptr ::
* A variable receiving the service data. NULL if not available.
*/
#define FT_FACE_LOOKUP_SERVICE( face, ptr, id ) \
FT_BEGIN_STMNT \
/* the strange cast is to allow C++ compilation */ \
FT_Pointer* pptr = (FT_Pointer*)&(ptr); \
FT_Pointer svc; \
\
\
svc = FT_FACE(face)->internal->services. service_ ## id ; \
if ( svc == FT_SERVICE_UNAVAILABLE ) \
svc = NULL; \
else if ( svc == NULL ) \
{ \
FT_FACE_FIND_SERVICE( face, svc, id ); \
\
FT_FACE(face)->internal->services. service_ ## id = \
(FT_Pointer)( svc != NULL ? svc \
: FT_SERVICE_UNAVAILABLE ); \
} \
*pptr = svc; \
FT_END_STMNT
/*
* A macro used to define new service structure types.
*/
#define FT_DEFINE_SERVICE( name ) \
typedef struct FT_Service_ ## name ## Rec_ \
FT_Service_ ## name ## Rec ; \
typedef struct FT_Service_ ## name ## Rec_ \
const * FT_Service_ ## name ; \
struct FT_Service_ ## name ## Rec_
/* */
/*
* The header files containing the services.
*/
#define FT_SERVICE_MULTIPLE_MASTERS_H <freetype/internal/services/svmm.h>
#define FT_SERVICE_POSTSCRIPT_NAME_H <freetype/internal/services/svpostnm.h>
#define FT_SERVICE_POSTSCRIPT_CMAPS_H <freetype/internal/services/svpscmap.h>
#define FT_SERVICE_POSTSCRIPT_INFO_H <freetype/internal/services/svpsinfo.h>
#define FT_SERVICE_GLYPH_DICT_H <freetype/internal/services/svgldict.h>
#define FT_SERVICE_BDF_H <freetype/internal/services/svbdf.h>
#define FT_SERVICE_XFREE86_NAME_H <freetype/internal/services/svxf86nm.h>
#define FT_SERVICE_SFNT_H <freetype/internal/services/svsfnt.h>
#define FT_SERVICE_PFR_H <freetype/internal/services/svpfr.h>
#define FT_SERVICE_WINFNT_H <freetype/internal/services/svwinfnt.h>
/* */
FT_END_HEADER
#endif /* __FTSERV_H__ */
/* END */