/**************************************************************************** * * ftserv.h * * The FreeType services (specification only). * * Copyright (C) 2003-2024 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_ #include "compiler-macros.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. */ #ifdef __cplusplus #define FT_FACE_FIND_SERVICE( face, ptr, id ) \ FT_BEGIN_STMNT \ FT_Module module = FT_MODULE( FT_FACE( face )->driver ); \ FT_Pointer _tmp_ = NULL; \ FT_Pointer* _pptr_ = (FT_Pointer*)&(ptr); \ \ \ if ( module->clazz->get_interface ) \ _tmp_ = module->clazz->get_interface( module, FT_SERVICE_ID_ ## id ); \ *_pptr_ = _tmp_; \ FT_END_STMNT #else /* !C++ */ #define FT_FACE_FIND_SERVICE( face, ptr, id ) \ FT_BEGIN_STMNT \ FT_Module module = FT_MODULE( FT_FACE( face )->driver ); \ FT_Pointer _tmp_ = NULL; \ \ if ( module->clazz->get_interface ) \ _tmp_ = module->clazz->get_interface( module, FT_SERVICE_ID_ ## id ); \ ptr = _tmp_; \ FT_END_STMNT #endif /* !C++ */ /************************************************************************** * * @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. */ #ifdef __cplusplus #define FT_FACE_FIND_GLOBAL_SERVICE( face, ptr, id ) \ FT_BEGIN_STMNT \ FT_Module module = FT_MODULE( FT_FACE( face )->driver ); \ FT_Pointer _tmp_; \ FT_Pointer* _pptr_ = (FT_Pointer*)&(ptr); \ \ \ _tmp_ = ft_module_get_service( module, FT_SERVICE_ID_ ## id, 1 ); \ *_pptr_ = _tmp_; \ FT_END_STMNT #else /* !C++ */ #define FT_FACE_FIND_GLOBAL_SERVICE( face, ptr, id ) \ FT_BEGIN_STMNT \ FT_Module module = FT_MODULE( FT_FACE( face )->driver ); \ FT_Pointer _tmp_; \ \ \ _tmp_ = ft_module_get_service( module, FT_SERVICE_ID_ ## id, 1 ); \ ptr = _tmp_; \ FT_END_STMNT #endif /* !C++ */ /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** 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; /************************************************************************** * * @macro: * FT_DEFINE_SERVICEDESCREC1 * FT_DEFINE_SERVICEDESCREC2 * FT_DEFINE_SERVICEDESCREC3 * FT_DEFINE_SERVICEDESCREC4 * FT_DEFINE_SERVICEDESCREC5 * FT_DEFINE_SERVICEDESCREC6 * FT_DEFINE_SERVICEDESCREC7 * FT_DEFINE_SERVICEDESCREC8 * FT_DEFINE_SERVICEDESCREC9 * FT_DEFINE_SERVICEDESCREC10 * * @description: * Used to initialize an array of FT_ServiceDescRec structures. * * The array will be allocated in the global scope (or the scope where * the macro is used). */ #define FT_DEFINE_SERVICEDESCREC1( class_, \ serv_id_1, serv_data_1 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { NULL, NULL } \ }; #define FT_DEFINE_SERVICEDESCREC2( class_, \ serv_id_1, serv_data_1, \ serv_id_2, serv_data_2 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { serv_id_2, serv_data_2 }, \ { NULL, NULL } \ }; #define FT_DEFINE_SERVICEDESCREC3( class_, \ serv_id_1, serv_data_1, \ serv_id_2, serv_data_2, \ serv_id_3, serv_data_3 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { serv_id_2, serv_data_2 }, \ { serv_id_3, serv_data_3 }, \ { NULL, NULL } \ }; #define FT_DEFINE_SERVICEDESCREC4( class_, \ serv_id_1, serv_data_1, \ serv_id_2, serv_data_2, \ serv_id_3, serv_data_3, \ serv_id_4, serv_data_4 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { serv_id_2, serv_data_2 }, \ { serv_id_3, serv_data_3 }, \ { serv_id_4, serv_data_4 }, \ { NULL, NULL } \ }; #define FT_DEFINE_SERVICEDESCREC5( class_, \ serv_id_1, serv_data_1, \ serv_id_2, serv_data_2, \ serv_id_3, serv_data_3, \ serv_id_4, serv_data_4, \ serv_id_5, serv_data_5 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { serv_id_2, serv_data_2 }, \ { serv_id_3, serv_data_3 }, \ { serv_id_4, serv_data_4 }, \ { serv_id_5, serv_data_5 }, \ { NULL, NULL } \ }; #define FT_DEFINE_SERVICEDESCREC6( class_, \ serv_id_1, serv_data_1, \ serv_id_2, serv_data_2, \ serv_id_3, serv_data_3, \ serv_id_4, serv_data_4, \ serv_id_5, serv_data_5, \ serv_id_6, serv_data_6 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { serv_id_2, serv_data_2 }, \ { serv_id_3, serv_data_3 }, \ { serv_id_4, serv_data_4 }, \ { serv_id_5, serv_data_5 }, \ { serv_id_6, serv_data_6 }, \ { NULL, NULL } \ }; #define FT_DEFINE_SERVICEDESCREC7( class_, \ serv_id_1, serv_data_1, \ serv_id_2, serv_data_2, \ serv_id_3, serv_data_3, \ serv_id_4, serv_data_4, \ serv_id_5, serv_data_5, \ serv_id_6, serv_data_6, \ serv_id_7, serv_data_7 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { serv_id_2, serv_data_2 }, \ { serv_id_3, serv_data_3 }, \ { serv_id_4, serv_data_4 }, \ { serv_id_5, serv_data_5 }, \ { serv_id_6, serv_data_6 }, \ { serv_id_7, serv_data_7 }, \ { NULL, NULL } \ }; #define FT_DEFINE_SERVICEDESCREC8( class_, \ serv_id_1, serv_data_1, \ serv_id_2, serv_data_2, \ serv_id_3, serv_data_3, \ serv_id_4, serv_data_4, \ serv_id_5, serv_data_5, \ serv_id_6, serv_data_6, \ serv_id_7, serv_data_7, \ serv_id_8, serv_data_8 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { serv_id_2, serv_data_2 }, \ { serv_id_3, serv_data_3 }, \ { serv_id_4, serv_data_4 }, \ { serv_id_5, serv_data_5 }, \ { serv_id_6, serv_data_6 }, \ { serv_id_7, serv_data_7 }, \ { serv_id_8, serv_data_8 }, \ { NULL, NULL } \ }; #define FT_DEFINE_SERVICEDESCREC9( class_, \ serv_id_1, serv_data_1, \ serv_id_2, serv_data_2, \ serv_id_3, serv_data_3, \ serv_id_4, serv_data_4, \ serv_id_5, serv_data_5, \ serv_id_6, serv_data_6, \ serv_id_7, serv_data_7, \ serv_id_8, serv_data_8, \ serv_id_9, serv_data_9 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { serv_id_2, serv_data_2 }, \ { serv_id_3, serv_data_3 }, \ { serv_id_4, serv_data_4 }, \ { serv_id_5, serv_data_5 }, \ { serv_id_6, serv_data_6 }, \ { serv_id_7, serv_data_7 }, \ { serv_id_8, serv_data_8 }, \ { serv_id_9, serv_data_9 }, \ { NULL, NULL } \ }; #define FT_DEFINE_SERVICEDESCREC10( class_, \ serv_id_1, serv_data_1, \ serv_id_2, serv_data_2, \ serv_id_3, serv_data_3, \ serv_id_4, serv_data_4, \ serv_id_5, serv_data_5, \ serv_id_6, serv_data_6, \ serv_id_7, serv_data_7, \ serv_id_8, serv_data_8, \ serv_id_9, serv_data_9, \ serv_id_10, serv_data_10 ) \ static const FT_ServiceDescRec class_[] = \ { \ { serv_id_1, serv_data_1 }, \ { serv_id_2, serv_data_2 }, \ { serv_id_3, serv_data_3 }, \ { serv_id_4, serv_data_4 }, \ { serv_id_5, serv_data_5 }, \ { serv_id_6, serv_data_6 }, \ { serv_id_7, serv_data_7 }, \ { serv_id_8, serv_data_8 }, \ { serv_id_9, serv_data_9 }, \ { serv_id_10, serv_data_10 }, \ { NULL, NULL } \ }; /* * 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_METRICS_VARIATIONS; 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. */ /* ensure that value `1' has the same width as a pointer */ #define FT_SERVICE_UNAVAILABLE ((FT_Pointer)~(FT_PtrDist)1) /************************************************************************** * * @macro: * FT_FACE_LOOKUP_SERVICE * * @description: * This macro is used to look up 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. */ #ifdef __cplusplus #define FT_FACE_LOOKUP_SERVICE( face, ptr, id ) \ FT_BEGIN_STMNT \ FT_Pointer svc; \ FT_Pointer* Pptr = (FT_Pointer*)&(ptr); \ \ \ 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 #else /* !C++ */ #define FT_FACE_LOOKUP_SERVICE( face, ptr, id ) \ FT_BEGIN_STMNT \ 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 ); \ } \ ptr = svc; \ FT_END_STMNT #endif /* !C++ */ /* * 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_ /* */ FT_END_HEADER #endif /* FTSERV_H_ */ /* END */