note
	description: "A {GAME_SOUND} loaded from a sound sub-file inside a custom package file."
	author: "Louis Marchand"
	date: "Wed, 08 Apr 2015 01:04:08 +0000"
	revision: "2.0"

class 
	AUDIO_SOUND_CPF

create 
	make

feature {NONE} -- Initialization

	make (a_cpf: CPF_PACKAGE_FILE; a_index: INTEGER_32)
			-- Initialization for Current.
		require
			sound_cpf_index_valid: a_index > 0 and then a_index <= a_cpf.sub_files_count
		do
			default_create
			make_cpf_ressource (a_cpf, a_index)
			filename := a_cpf.path.name
		end

	make_file (a_filename: READABLE_STRING_GENERAL)
			-- Initialization for Current.
			-- Will use 16 bits signed frames in the buffer.
			-- (from AUDIO_SOUND_FILE_IMP)
		do
			default_create
			bits_per_sample_internal := 16
			is_signed_internal := True
			filename := a_filename
			is_finished := False
		end

	make_cpf_ressource (a_cpf: CPF_PACKAGE_FILE; a_cpf_index: INTEGER_32)
			-- make Current from the BMP image in the custom package file a_cpf at a_cpf_index.
			-- (from CPF_RESSOURCE_MANAGER)
		require -- from CPF_RESSOURCE_MANAGER
			img_cpf_index_valid: a_cpf.is_readable and then a_cpf_index > 0 and then a_cpf_index <= a_cpf.sub_files_count
		do
			cpf := a_cpf
			cpf_index := a_cpf_index
		end
	
feature -- Access

	generating_type: TYPE [detachable AUDIO_SOUND_CPF]
			-- Type of current object
			-- (type of which it is a direct instance)
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			generating_type_not_void: Result /= Void
		end

	generator: STRING_8
			-- Name of current object's generating class
			-- (base class of the type of which it is a direct instance)
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			generator_not_void: Result /= Void
			generator_not_empty: not Result.is_empty
		end

	has_ressource_error: BOOLEAN
			-- Has an error occured while opening Current
			-- (from GAME_RESSOURCE)

	has_error: BOOLEAN
			-- Is the library has generate an error
			-- (from GAME_ERROR_MANAGER)

	is_open: BOOLEAN
			-- Is Current has been properly opened
			-- (from GAME_RESSOURCE)

	is_openable: BOOLEAN
			-- Can Current be open
		require -- from  GAME_RESSOURCE
			True
		do
			Result := cpf.is_readable and then cpf.sub_files_count >= cpf_index
		end

	last_error: READABLE_STRING_GENERAL
			-- The last error generate by the library
			-- (from GAME_ERROR_MANAGER)
		do
			if attached message as la_message then
				Result := la_message
			else
				Result := ""
			end
		end

	open
			-- Open Current
		require -- from GAME_RESSOURCE
			ressource_is_openable: is_openable
			ressource_is_not_open: not is_open and not has_ressource_error
		do
			has_error := False;
			cpf.lock_mutex;
			cpf.select_sub_file (cpf_index)
			last_offset := cpf.current_sub_file_position
			virtual_io := virtual_io.memory_alloc (Sf_virtual_io_size)
			{AUDIO_SND_FILES_EXTERNAL}.set_snd_file_virtual_io (virtual_io)
			file_info := file_info.memory_alloc (Sf_info_size)
			snd_file_ptr := {AUDIO_SND_FILES_EXTERNAL}.sf_open_virtual (virtual_io, {AUDIO_SND_FILES_EXTERNAL}.sfm_read, file_info, cpf.internal_pointer)
			if snd_file_ptr.is_default_pointer then
				has_error := True
			end
			last_offset := cpf.current_sub_file_position;
			cpf.unlock_mutex
			is_open := not has_error
		ensure -- from GAME_RESSOURCE
			ressource_is_open: is_open or has_ressource_error
		end

	restart
			-- Restart the sound to the beginning.
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		local
			error: INTEGER_64
		do
			cpf.lock_mutex;
			cpf.select_sub_file (cpf_index)
			if is_seekable then
				error := {AUDIO_SND_FILES_EXTERNAL}.sf_seek (snd_file_ptr, 0, {AUDIO_SND_FILES_EXTERNAL}.seek_set)
				check
						error /= -1
				end
			else
				cpf.select_sub_file (cpf_index);
				cpf.go_in_current_sub_file (0)
			end
			last_offset := cpf.current_sub_file_position;
			cpf.unlock_mutex
		end
	
feature --Access

	album: detachable READABLE_STRING_GENERAL
			-- The media that Current is from
			-- Void if no 'album' available in Current
			-- (from AUDIO_SOUND_FILE_IMP)
		do
			Result := get_metadata_value ({AUDIO_SND_FILES_EXTERNAL}.sf_str_album)
		end

	artist: detachable READABLE_STRING_GENERAL
			-- The name of the creator of Current
			-- Void if no 'artist' available in Current
			-- (from AUDIO_SOUND_FILE_IMP)
		do
			Result := get_metadata_value ({AUDIO_SND_FILES_EXTERNAL}.sf_str_artist)
		end

	bits_per_sample: INTEGER_32
			-- Get the bit resolution of one frame of the sound.
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := bits_per_sample_internal
		end

	channel_count: INTEGER_32
			-- Get the channel number of the sound (1=mono, 2=stereo, etc.).
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := {AUDIO_SND_FILES_EXTERNAL}.get_sf_info_struct_channels (file_info)
		end

	close
			-- Stop the management of the stream
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		local
			l_error: INTEGER_32
		do
			file_info.memory_free
			l_error := {AUDIO_SND_FILES_EXTERNAL}.sf_close (snd_file_ptr)
			create snd_file_ptr
			create file_info
			is_open := False
		ensure -- from AUDIO_SOUND
			sound_is_closed: not is_open
		end

	comment: detachable READABLE_STRING_GENERAL
			-- Anything that can be add to the definition of Current
			-- Void if no 'comment' available in Current
			-- (from AUDIO_SOUND_FILE_IMP)
		do
			Result := get_metadata_value ({AUDIO_SND_FILES_EXTERNAL}.sf_str_comment)
		end

	date: detachable READABLE_STRING_GENERAL
			-- The creation's date of Current
			-- Void if no 'date' available in Current
			-- (from AUDIO_SOUND_FILE_IMP)
		do
			Result := get_metadata_value ({AUDIO_SND_FILES_EXTERNAL}.sf_str_date)
		end

	frequency: INTEGER_32
			-- Get the frequency (sample rate) of the sound.
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := {AUDIO_SND_FILES_EXTERNAL}.get_sf_info_struct_samplerate (file_info)
		end

	genre: detachable READABLE_STRING_GENERAL
			-- The conventional category of Current
			-- Void if no 'genre' available in Current
			-- (from AUDIO_SOUND_FILE_IMP)
		do
			Result := get_metadata_value ({AUDIO_SND_FILES_EXTERNAL}.sf_str_genre)
		end

	is_finished: BOOLEAN
			-- Current has finished it's playback
			-- (from AUDIO_SOUND)

	is_seekable: BOOLEAN
			-- Return true if the sound support the seek functionnality.
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := ({AUDIO_SND_FILES_EXTERNAL}.get_sf_info_struct_seekable (file_info) /= 0)
		end

	is_signed: BOOLEAN
			-- Return true if the frames in the buffer are signed.
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := is_signed_internal
		end

	sample_count: INTEGER_64
			-- The total number of frames in Current
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
		do
			Result := {AUDIO_SND_FILES_EXTERNAL}.get_sf_info_struct_frames (file_info)
		end

	sample_position: INTEGER_64
			-- The number of frames since the beginning of Current
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
		do
			Result := {AUDIO_SND_FILES_EXTERNAL}.sf_seek (snd_file_ptr, 0, {AUDIO_SND_FILES_EXTERNAL}.seek_cur) + 1
		end

	sample_seek (a_frame_number: INTEGER_64)
			-- Seek at the frame a_frame_number from the beginning of Current
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
			is_seek_inside: a_frame_number >= 1 and a_frame_number <= sample_count
		local
			l_error: INTEGER_64
		do
			l_error := {AUDIO_SND_FILES_EXTERNAL}.sf_seek (snd_file_ptr, a_frame_number - 1, {AUDIO_SND_FILES_EXTERNAL}.seek_set)
			is_finished := False
			if l_error = -1 then
				put_error ("Cannot seek in the audio file.", {STRING_32}"The system tried to seek at the frame " + a_frame_number.out.to_string_32 + {STRING_32}" of file " + filename.to_string_32 + {STRING_32}"but it failed.")
			end
		end

	time_count: INTEGER_64
			-- The total number of milliseconds in Current
			-- (from AUDIO_SOUND)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
		do
			Result := (sample_count * 1000) // frequency.to_integer_64
		end

	time_position: INTEGER_64
			-- The number of milliseconds since the beginning of Current
			-- (from AUDIO_SOUND)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
		do
			Result := ((sample_position - 1) * 1000) // frequency.to_integer_64
		end

	time_seek (a_milliseconds: INTEGER_64)
			-- Seek at a_milliseconds from the beginning of Current
			-- (from AUDIO_SOUND)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
			is_seek_inside: a_milliseconds >= 1 and a_milliseconds <= time_count
		do
			sample_seek (((a_milliseconds * frequency.to_integer_64) // 1000) + 1)
		end

	title: detachable READABLE_STRING_GENERAL
			-- The readable identifier of Current
			-- Void if no 'title' available in Current
			-- (from AUDIO_SOUND_FILE_IMP)
		do
			Result := get_metadata_value ({AUDIO_SND_FILES_EXTERNAL}.sf_str_title)
		end

	track_number: INTEGER_32
			-- The number of Current in the album
			-- 0 if no 'track_number' available in Current
			-- (from AUDIO_SOUND_FILE_IMP)
		local
			l_string: READABLE_STRING_GENERAL
		do
			if attached get_metadata_value ({AUDIO_SND_FILES_EXTERNAL}.sf_str_tracknumber) as la_string and then la_string.is_integer_32 then
				Result := la_string.to_integer_32
			else
				Result := 0
			end
		end
	
feature -- Comparison

	frozen deep_equal (a: detachable ANY; b: like arg #1): BOOLEAN
			-- Are a and b either both void
			-- or attached to isomorphic object structures?
			-- (from ANY)
		do
			if a = Void then
				Result := b = Void
			else
				Result := b /= Void and then a.is_deep_equal (b)
			end
		ensure -- from ANY
			instance_free: class
			shallow_implies_deep: standard_equal (a, b) implies Result
			both_or_none_void: (a = Void) implies (Result = (b = Void))
			same_type: (Result and (a /= Void)) implies (b /= Void and then a.same_type (b))
			symmetric: Result implies deep_equal (b, a)
		end

	frozen equal (a: detachable ANY; b: like arg #1): BOOLEAN
			-- Are a and b either both void or attached
			-- to objects considered equal?
			-- (from ANY)
		do
			if a = Void then
				Result := b = Void
			else
				Result := b /= Void and then a.is_equal (b)
			end
		ensure -- from ANY
			instance_free: class
			definition: Result = (a = Void and b = Void) or else ((a /= Void and b /= Void) and then a.is_equal (b))
		end

	frozen is_deep_equal alias "≡≡≡" (other: AUDIO_SOUND_CPF): BOOLEAN
			-- Are Current and other attached to isomorphic object structures?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		ensure -- from ANY
			shallow_implies_deep: standard_is_equal (other) implies Result
			same_type: Result implies same_type (other)
			symmetric: Result implies other.is_deep_equal (Current)
		end

	is_equal (other: AUDIO_SOUND_CPF): BOOLEAN
			-- Is other attached to an object considered
			-- equal to current object?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		ensure -- from ANY
			symmetric: Result implies other ~ Current
			consistent: standard_is_equal (other) implies Result
		end

	frozen standard_equal (a: detachable ANY; b: like arg #1): BOOLEAN
			-- Are a and b either both void or attached to
			-- field-by-field identical objects of the same type?
			-- Always uses default object comparison criterion.
			-- (from ANY)
		do
			if a = Void then
				Result := b = Void
			else
				Result := b /= Void and then a.standard_is_equal (b)
			end
		ensure -- from ANY
			instance_free: class
			definition: Result = (a = Void and b = Void) or else ((a /= Void and b /= Void) and then a.standard_is_equal (b))
		end

	frozen standard_is_equal alias "≜" (other: AUDIO_SOUND_CPF): BOOLEAN
			-- Is other attached to an object of the same type
			-- as current object, and field-by-field identical to it?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		ensure -- from ANY
			same_type: Result implies same_type (other)
			symmetric: Result implies other.standard_is_equal (Current)
		end
	
feature -- Status report

	conforms_to (other: ANY): BOOLEAN
			-- Does type of current object conform to type
			-- of other (as per Eiffel: The Language, chapter 13)?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		end

	same_type (other: ANY): BOOLEAN
			-- Is type of current object identical to type of other?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		ensure -- from ANY
			definition: Result = (conforms_to (other) and other.conforms_to (Current))
		end
	
feature {NONE} -- Status report

	is_in_final_collect: BOOLEAN
			-- Is GC currently performing final collection
			-- after execution of current program?
			-- Safe to use in dispose.
			-- (from DISPOSABLE)
		external
			"C inline use %"eif_memory.h%""
		alias
			"return eif_is_in_final_collect;"
		end
	
feature -- Duplication

	frozen clone (other: detachable ANY): like other
		obsolete "Use `twin' instead. [2017-05-31]"
			-- Void if other is void; otherwise new object
			-- equal to other
			--
			-- For non-void other, clone calls copy;
			-- to change copying/cloning semantics, redefine copy.
			-- (from ANY)
		do
			if other /= Void then
				Result := other.twin
			end
		ensure -- from ANY
			instance_free: class
			equal: Result ~ other
		end

	copy (other: AUDIO_SOUND_CPF)
			-- Update current object using fields of object attached
			-- to other, so as to yield equal objects.
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
			type_identity: same_type (other)
		external
			"built_in"
		ensure -- from ANY
			is_equal: Current ~ other
		end

	frozen deep_clone (other: detachable ANY): like other
		obsolete "Use `deep_twin' instead. [2017-05-31]"
			-- Void if other is void: otherwise, new object structure
			-- recursively duplicated from the one attached to other
			-- (from ANY)
		do
			if other /= Void then
				Result := other.deep_twin
			end
		ensure -- from ANY
			instance_free: class
			deep_equal: deep_equal (other, Result)
		end

	frozen deep_copy (other: AUDIO_SOUND_CPF)
			-- Effect equivalent to that of:
			--		copy (other . deep_twin)
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		do
			copy (other.deep_twin)
		ensure -- from ANY
			deep_equal: deep_equal (Current, other)
		end

	frozen deep_twin: AUDIO_SOUND_CPF
			-- New object structure recursively duplicated from Current.
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			deep_twin_not_void: Result /= Void
			deep_equal: deep_equal (Current, Result)
		end

	frozen standard_clone (other: detachable ANY): like other
		obsolete "Use `standard_twin' instead. [2017-05-31]"
			-- Void if other is void; otherwise new object
			-- field-by-field identical to other.
			-- Always uses default copying semantics.
			-- (from ANY)
		do
			if other /= Void then
				Result := other.standard_twin
			end
		ensure -- from ANY
			instance_free: class
			equal: standard_equal (Result, other)
		end

	frozen standard_copy (other: AUDIO_SOUND_CPF)
			-- Copy every field of other onto corresponding field
			-- of current object.
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
			type_identity: same_type (other)
		external
			"built_in"
		ensure -- from ANY
			is_standard_equal: standard_is_equal (other)
		end

	frozen standard_twin: AUDIO_SOUND_CPF
			-- New object field-by-field identical to other.
			-- Always uses default copying semantics.
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			standard_twin_not_void: Result /= Void
			equal: standard_equal (Result, Current)
		end

	frozen twin: AUDIO_SOUND_CPF
			-- New object equal to Current
			-- twin calls copy; to change copying/twinning semantics, redefine copy.
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			twin_not_void: Result /= Void
			is_equal: Result ~ Current
		end
	
feature -- Basic operations

	frozen as_attached: attached AUDIO_SOUND_CPF
		obsolete "Remove calls to this feature. [2017-05-31]"
			-- Attached version of Current.
			-- (Can be used during transitional period to convert
			-- non-void-safe classes to void-safe ones.)
			-- (from ANY)
		do
			Result := Current
		end

	frozen default: detachable AUDIO_SOUND_CPF
			-- Default value of object's type
			-- (from ANY)
		do
		end

	frozen default_pointer: POINTER
			-- Default value of type POINTER
			-- (Avoid the need to write p.default for
			-- some p of type POINTER.)
			-- (from ANY)
		do
		ensure -- from ANY
			instance_free: class
		end

	default_rescue
			-- Process exception for routines with no Rescue clause.
			-- (Default: do nothing.)
			-- (from ANY)
		do
		end

	frozen do_nothing
			-- Execute a null action.
			-- (from ANY)
		do
		ensure -- from ANY
			instance_free: class
		end
	
feature {NONE} -- Implementation

	clear_error
			-- Remove error pending in Current
			-- (from GAME_ERROR_MANAGER)
		do
			has_error := False
		ensure -- from GAME_ERROR_MANAGER
			no_error: not has_error
		end

	cpf: CPF_PACKAGE_FILE
			-- (from CPF_RESSOURCE_MANAGER)

	cpf_index: INTEGER_32
			-- (from CPF_RESSOURCE_MANAGER)

	disable_print_on_error
			-- Desactive the print_on_error functionnality.
			-- (from GAME_ERROR_MANAGER)
		do
			Print_on_error_internal.put (False)
		end

	enable_print_on_error
			-- Active the print_on_error functionnality.
			-- (from GAME_ERROR_MANAGER)
		do
			Print_on_error_internal.put (True)
		end

	message: detachable READABLE_STRING_GENERAL
			-- The specific message for the last error
			-- (from GAME_ERROR_MANAGER)

	print_on_error: BOOLEAN
			-- When an error occured, the library will print
			-- informations about the error on the error console
			-- output (default is True).
			-- (from GAME_ERROR_MANAGER)
		do
			Result := Print_on_error_internal.item
		end

	Print_on_error_internal: CELL [BOOLEAN]
			-- True when an error occured,
			-- The library will print it right away.
			-- (from GAME_ERROR_MANAGER)
		once ("PROCESS")
			create Result.put (True)
		end

	put_error (a_general_message, a_specific_error: READABLE_STRING_GENERAL)
			-- Create an error using a_general_error for the debug information
			-- and a_specific_error for the lasting information
			-- (from GAME_ERROR_MANAGER)
		local
			l_converter: UTF_CONVERTER
		do
			message := a_specific_error
			has_error := True
			if Print_on_error_internal.item then
				if a_general_message.is_valid_as_string_8 then
					Io.Error.put_string (a_general_message.to_string_8 + "%N")
				else
					create l_converter;
					Io.Error.put_string (l_converter.string_32_to_utf_8_string_8 (a_general_message.to_string_32) + "%N")
				end
				if a_specific_error.is_valid_as_string_8 then
					Io.Error.put_string (a_specific_error.to_string_8 + "%N")
				else
					create l_converter;
					Io.Error.put_string (l_converter.string_32_to_utf_8_string_8 (a_specific_error.to_string_32) + "%N")
				end
			end
		ensure -- from GAME_ERROR_MANAGER
				has_error
		end

	set_print_on_error (a_value: BOOLEAN)
			-- Assign to print_on_error the value of a_value
			-- (from GAME_ERROR_MANAGER)
		do
			if a_value then
				enable_print_on_error
			else
				disable_print_on_error
			end
		ensure -- from GAME_ERROR_MANAGER
			is_assign: print_on_error ~ a_value
		end
	
feature {AUDIO_SOURCE}{AUDIO_SOURCE}{AUDIO_SOURCE} 

	fill_buffer (a_buffer: POINTER; a_max_length: INTEGER_32)
			-- Fill the next data samples in a_buffer (no more than a_max_length byte)
			-- The actual number of byte placed in a_buffer will be available in last_buffer_size
			-- Warning: side effect on a_buffer
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			cpf.lock_mutex
			if cpf.current_sub_file_index /= cpf_index or else not cpf.is_position_in_selected_sub_file then
				cpf.select_sub_file (cpf_index)
			end
			if cpf.current_sub_file_position /= last_offset then
				cpf.go_in_current_sub_file (last_offset)
			end
			Precursor (a_buffer, a_max_length)
			if cpf.is_position_in_selected_sub_file then
				last_offset := cpf.current_sub_file_position
			else
				last_offset := 0
			end;
			cpf.unlock_mutex
		end
	
feature {AUDIO_SOURCE}{AUDIO_SOURCE} 

	byte_per_buffer_sample: INTEGER_32
			-- The number of byte for one frame of Current.
			-- (from AUDIO_SOUND_FILE_IMP)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := 2
		end
	
feature {AUDIO_SOURCE} 

	last_buffer_size: INTEGER_32
			-- The size of the last buffer filled by fill_buffer
			-- (from AUDIO_SOUND)
	
feature {NONE} -- Implementation - Methodes

	get_metadata_value (a_flag: INTEGER_32): detachable READABLE_STRING_GENERAL
			-- Get the text of a Metadata in Current using a_flag to know which metadata to retrieve.
			-- (from AUDIO_SOUND_FILE_IMP)
		local
			l_pointer: POINTER
			l_c_string: C_STRING
			l_utf_converter: UTF_CONVERTER
		do
			l_pointer := {AUDIO_SND_FILES_EXTERNAL}.sf_get_string (snd_file_ptr, a_flag)
			if not l_pointer.is_default_pointer then
				create l_c_string.make_shared_from_pointer (l_pointer)
				Result := l_utf_converter.utf_8_string_8_to_string_32 (l_c_string.string)
			end
		end

	open_from_file (a_filename: READABLE_STRING_GENERAL)
			-- open Current using a_filename
			-- (from AUDIO_SOUND_FILE)
		local
			l_converter: UTF_CONVERTER
			l_filename_c, l_error_c: C_STRING
		do
			create l_converter
			file_info := file_info.memory_alloc (Sf_info_size)
			create l_filename_c.make (l_converter.string_32_to_utf_8_string_8 (a_filename.to_string_32))
			snd_file_ptr := {AUDIO_SND_FILES_EXTERNAL}.sf_open (l_filename_c.item, {AUDIO_SND_FILES_EXTERNAL}.sfm_read, file_info)
			if snd_file_ptr.is_default_pointer then
				create l_error_c.make_by_pointer ({AUDIO_SND_FILES_EXTERNAL}.sf_strerror (snd_file_ptr));
				Io.Error.put_string (l_error_c.string + "%N")
				has_error := True
			end
		end

	Sf_info_size: INTEGER_32
			-- The number of byte of a C sf_info structure
			-- (from AUDIO_SOUND_FILE_IMP)
		once
			Result := {AUDIO_SND_FILES_EXTERNAL}.c_sizeof_sf_info
		end
	
feature -- Implementation - Routines

	dispose
			-- Action to be executed just before garbage collection
			-- reclaims an object.
			-- Effect it in descendants to perform specific dispose
			-- actions. Those actions should only take care of freeing
			-- external resources; they should not perform remote calls
			-- on other objects since these may also be dead and reclaimed.
		require -- from  DISPOSABLE
			True
		do
			Precursor;
			virtual_io.memory_free
		end
	
feature {NONE} -- Implementation - Routines

	Sf_virtual_io_size: INTEGER_32
			-- The number of byte of a C sf_virtual_io structure
		once
			Result := {AUDIO_SND_FILES_EXTERNAL}.c_sizeof_snd_file_virtual_io
		end
	
feature {NONE} -- Implementation - Variables

	bits_per_sample_internal: INTEGER_32
			-- The value of the bits_per_sample attributes
			-- (from AUDIO_SOUND_FILE_IMP)

	file_info: POINTER
			-- C pointer to the sound file information
			-- (from AUDIO_SOUND_FILE_IMP)

	filename: READABLE_STRING_GENERAL
			-- The name of the file containing the audio data
			-- (from AUDIO_SOUND_FILE_IMP)

	is_signed_internal: BOOLEAN
			-- The value of the is_signed attributes
			-- (from AUDIO_SOUND_FILE_IMP)

	last_offset: INTEGER_32
			-- The last known position inside the cpf file

	snd_file_ptr: POINTER
			-- C pointer to the sound file handle
			-- (from AUDIO_SOUND_FILE_IMP)

	virtual_io: POINTER
			-- The C pointer to the internal sf_virtual_io structure
	
feature {NONE} -- Initialisation

	default_create
			-- Initialization of Current
			-- (from GAME_RESSOURCE)
		require -- from  ANY
			True
		do
			is_open := False
			has_ressource_error := False
		end
	
feature -- Output

	Io: STD_FILES
			-- Handle to standard file setup
			-- (from ANY)
		once
			create Result;
			Result.set_output_default
		ensure -- from ANY
			instance_free: class
			io_not_void: Result /= Void
		end

	out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- (from ANY)
		do
			Result := tagged_out
		ensure -- from ANY
			out_not_void: Result /= Void
		end

	print (o: detachable ANY)
			-- Write terse external representation of o
			-- on standard output.
			-- (from ANY)
		local
			s: READABLE_STRING_8
		do
			if attached o then
				s := o.out
				if attached {READABLE_STRING_32} s as s32 then
					Io.put_string_32 (s32)
				elseif attached {READABLE_STRING_8} s as s8 then
					Io.put_string (s8)
				else
					Io.put_string_32 (s.as_string_32)
				end
			end
		ensure -- from ANY
			instance_free: class
		end

	frozen tagged_out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			tagged_out_not_void: Result /= Void
		end
	
feature -- Platform

	Operating_environment: OPERATING_ENVIRONMENT
			-- Objects available from the operating system
			-- (from ANY)
		once
			create Result
		ensure -- from ANY
			instance_free: class
			operating_environment_not_void: Result /= Void
		end
	
feature {NONE} -- Retrieval

	frozen internal_correct_mismatch
			-- Called from runtime to perform a proper dynamic dispatch on correct_mismatch
			-- from MISMATCH_CORRECTOR.
			-- (from ANY)
		local
			l_msg: STRING_32
			l_exc: EXCEPTIONS
		do
			if attached {MISMATCH_CORRECTOR} Current as l_corrector then
				l_corrector.correct_mismatch
			else
				create l_msg.make_from_string ("Mismatch: ".as_string_32)
				create l_exc;
				l_msg.append (generating_type.name_32);
				l_exc.raise_retrieval_exception (l_msg)
			end
		end
	
invariant
		-- from AUDIO_SOUND
	errors_valid: has_error ~ has_ressource_error

		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)

		-- from CPF_RESSOURCE_MANAGER
	cpf_valid: cpf.is_readable
	cpf_index_valid: cpf_index > 0 and cpf_index <= cpf.sub_files_count

end -- class AUDIO_SOUND_CPF

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