| /***************************************************************************/ |
| /* */ |
| /* 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 */ |
