Edit
kc3-lang/freetype/src/base/ftextend.c
Werner Lemberg
- src/base/ftextend.c
-
/***************************************************************************/ /* */ /* ftextend.c */ /* */ /* FreeType extensions implementation (body). */ /* */ /* 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. */ /* */ /***************************************************************************/ /*************************************************************************/ /* */ /* This is an updated version of the extension component, now located */ /* in the main library's source directory. It allows the dynamic */ /* registration/use of various face object extensions through a simple */ /* API. */ /* */ /*************************************************************************/ #include <ft2build.h> #include FT_INTERNAL_EXTEND_H #include FT_INTERNAL_DEBUG_H /*************************************************************************/ /* */ /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ /* messages during execution. */ /* */ #undef FT_COMPONENT #define FT_COMPONENT trace_extend typedef struct FT_Extension_Registry_ { FT_Int num_extensions; FT_Long cur_offset; FT_Extension_Class classes[FT_MAX_EXTENSIONS]; } FT_Extension_Registry; /*************************************************************************/ /* */ /* <Function> */ /* FT_Init_Extensions */ /* */ /* <Description> */ /* Initializes the extension component. */ /* */ /* <InOut> */ /* driver :: A handle to the driver object. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF FT_Error FT_Init_Extensions( FT_Driver driver ) { FT_Error error; FT_Memory memory; FT_Extension_Registry* registry; memory = driver->root.library->memory; if ( ALLOC( registry, sizeof ( *registry ) ) ) return error; registry->num_extensions = 0; registry->cur_offset = 0; driver->extensions = registry; FT_TRACE2(( "FT_Init_Extensions: success\n" )); return FT_Err_Ok; } /*************************************************************************/ /* */ /* <Function> */ /* FT_Done_Extensions */ /* */ /* <Description> */ /* Finalizes the extension component. */ /* */ /* <InOut> */ /* driver :: A handle to the driver object. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF FT_Error FT_Done_Extensions( FT_Driver driver ) { FT_Memory memory = driver->root.memory; FREE( driver->extensions ); return FT_Err_Ok; } /* documentation is in ftextend.h */ FT_EXPORT_DEF( FT_Error ) FT_Register_Extension( FT_Driver driver, FT_Extension_Class* clazz ) { FT_Extension_Registry* registry; if ( !driver ) return FT_Err_Invalid_Driver_Handle; if ( !clazz ) return FT_Err_Invalid_Argument; registry = (FT_Extension_Registry*)driver->extensions; if ( registry ) { FT_Int n = registry->num_extensions; FT_Extension_Class* cur = registry->classes + n; if ( n >= FT_MAX_EXTENSIONS ) return FT_Err_Too_Many_Extensions; *cur = *clazz; cur->offset = registry->cur_offset; registry->num_extensions++; registry->cur_offset += ( cur->size + FT_ALIGNMENT - 1 ) & -FT_ALIGNMENT; FT_TRACE1(( "FT_Register_Extension: `%s' successfully registered\n", cur->id )); } return FT_Err_Ok; } /* documentation is in ftextend.h */ FT_EXPORT_DEF( void* ) FT_Get_Extension( FT_Face face, const char* extension_id, void** extension_interface ) { FT_Extension_Registry* registry; if ( !face || !extension_id || !extension_interface ) return 0; registry = (FT_Extension_Registry*)face->driver->extensions; if ( registry && face->extensions ) { FT_Extension_Class* cur = registry->classes; FT_Extension_Class* limit = cur + registry->num_extensions; for ( ; cur < limit; cur++ ) if ( strcmp( cur->id, extension_id ) == 0 ) { *extension_interface = cur->interface; FT_TRACE1(( "FT_Get_Extension: got `%s'\n", extension_id )); return (void*)((char*)face->extensions + cur->offset); } } /* could not find the extension id */ FT_ERROR(( "FT_Get_Extension: couldn't find `%s'\n", extension_id )); *extension_interface = 0; return 0; } /*************************************************************************/ /* */ /* <Function> */ /* FT_Destroy_Extensions */ /* */ /* <Description> */ /* Destroys all extensions within a face object. */ /* */ /* <InOut> */ /* face :: A handle to the face object. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ /* <Note> */ /* Called by the face object destructor. */ /* */ FT_LOCAL_DEF FT_Error FT_Destroy_Extensions( FT_Face face ) { FT_Extension_Registry* registry; FT_Memory memory; registry = (FT_Extension_Registry*)face->driver->extensions; if ( registry && face->extensions ) { FT_Extension_Class* cur = registry->classes; FT_Extension_Class* limit = cur + registry->num_extensions; for ( ; cur < limit; cur++ ) { char* ext = (char*)face->extensions + cur->offset; if ( cur->finalize ) cur->finalize( ext, face ); } memory = face->driver->root.memory; FREE( face->extensions ); } return FT_Err_Ok; } /*************************************************************************/ /* */ /* <Function> */ /* FT_Create_Extensions */ /* */ /* <Description> */ /* Creates an extension object within a face object for all */ /* registered extensions. */ /* */ /* <InOut> */ /* face :: A handle to the face object. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ /* <Note> */ /* Called by the face object constructor. */ /* */ FT_LOCAL_DEF FT_Error FT_Create_Extensions( FT_Face face ) { FT_Extension_Registry* registry; FT_Memory memory; FT_Error error; face->extensions = 0; /* load extensions registry; exit successfully if none is there */ registry = (FT_Extension_Registry*)face->driver->extensions; if ( !registry ) return FT_Err_Ok; memory = face->driver->root.memory; if ( ALLOC( face->extensions, registry->cur_offset ) ) return error; { FT_Extension_Class* cur = registry->classes; FT_Extension_Class* limit = cur + registry->num_extensions; for ( ; cur < limit; cur++ ) { char* ext = (char*)face->extensions + cur->offset; if ( cur->init ) { error = cur->init( ext, face ); if ( error ) break; } } } return error; } /* END */