--- /dev/null
+/***************************************************************************/
+/* */
+/* ftextend.h */
+/* */
+/* FreeType extensions implementation (body). */
+/* */
+/* Copyright 1996-2000 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 <freetype/internal/ftextend.h>
+#include <freetype/internal/ftdebug.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. */
+ /* */
+ LOCAL_FUNC
+ 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. */
+ /* */
+ LOCAL_FUNC
+ FT_Error FT_Done_Extensions( FT_Driver driver )
+ {
+ FT_Memory memory = driver->root.memory;
+
+
+ FREE( driver->extensions );
+ return FT_Err_Ok;
+ }
+
+
+ /*************************************************************************/
+ /* */
+ /* <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_FUNC( 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;
+ }
+
+
+ /*************************************************************************/
+ /* */
+ /* <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_FUNC( 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. */
+ /* */
+ LOCAL_FUNC
+ 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. */
+ /* */
+ LOCAL_FUNC
+ 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 */
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