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191 | --------------------------------------------------------------------------------------------------------------------
-- This source code is subject to the Zlib license, see the LICENCE file in the root of this directory.
--------------------------------------------------------------------------------------------------------------------
-- SDL.Audio.Devices
--
-- Operating system audio device access and control.
--------------------------------------------------------------------------------------------------------------------
with Ada.Finalization;
with SDL.Audio.Sample_Formats;
with System;
generic
type Frame_Type is private;
type Buffer_Index is (<>);
type Buffer_Type is array (Buffer_Index range <>) of Frame_Type;
package SDL.Audio.Devices is
pragma Elaborate_Body;
Audio_Device_Error : exception;
type Audio_Status is (Stopped, Playing, Paused) with Convention => C;
type Changes is mod 2 ** 32 with
Convention => C,
Size => C.int'Size;
None : constant Changes := 16#0000_0000#;
Frequency : constant Changes := 16#0000_0001#;
Format : constant Changes := 16#0000_0002#;
Channels : constant Changes := 16#0000_0004#;
Samples : constant Changes := 16#0000_0008#;
Any : constant Changes := Frequency or Format or Channels or Samples;
-- Allow users to derive new types from this.
type User_Data is tagged private;
type User_Data_Access is access all User_Data'Class;
pragma No_Strict_Aliasing (User_Data_Access);
--
-- The calculated values in this structure are calculated by SDL_OpenAudio().
--
-- For multi-channel audio, the default SDL channel mapping is:
-- 2: FL FR (stereo)
-- 3: FL FR LFE (2.1 surround)
-- 4: FL FR BL BR (quad)
-- 5: FL FR FC BL BR (quad + center)
-- 6: FL FR FC LFE SL SR (5.1 surround - last two can also be BL BR)
-- 7: FL FR FC LFE BC SL SR (6.1 surround)
-- 8: FL FR FC LFE BL BR SL SR (7.1 surround)
--
subtype Channel_Counts is Interfaces.Unsigned_8 with
Static_Predicate => Channel_Counts in 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8;
type Device is new Ada.Finalization.Limited_Controlled with private;
type Audio_Callback is access procedure
(User : in User_Data_Access;
Data : out Buffer_Type);
type Spec_Mode is (Desired, Obtained);
type Spec (Mode : Spec_Mode) is record
Frequency : C.int;
Format : SDL.Audio.Sample_Formats.Sample_Format;
Channels : Channel_Counts;
Samples : Interfaces.Unsigned_16;
case Mode is
when Desired =>
null;
when Obtained =>
Silence : Interfaces.Unsigned_8;
Size : Interfaces.Unsigned_32;
end case;
end record;
subtype Desired_Spec is Spec (Desired);
subtype Obtained_Spec is Spec (Obtained);
type ID is mod 2 ** 32 with
Convention => C;
function Total_Devices (Is_Capture : in Boolean := False) return Positive;
function Get_Name
(Index : in Positive;
Is_Capture : in Boolean := False)
return String;
function Open
(Name : in String := "";
Is_Capture : in Boolean := False;
Desired : in Desired_Spec;
Obtained : out Obtained_Spec;
Callback : in Audio_Callback := null;
User_Data : in User_Data_Access := null;
Allowed_Changes : in Changes := None)
return Device;
procedure Open
(Self : out Device;
Name : in String := "";
Is_Capture : in Boolean := False;
Desired : in Desired_Spec;
Obtained : out Obtained_Spec;
Callback : in Audio_Callback := null;
User_Data : in User_Data_Access := null;
Allowed_Changes : in Changes := None);
procedure Queue
(Self : in Device;
Data : aliased in Buffer_Type);
function Get_Status (Self : in Device) return Audio_Status;
function Get_ID (Self : in Device) return ID;
procedure Pause (Self : in Device; Pause : in Boolean);
function Get_Queued_Size (Self : in Device) return Interfaces.Unsigned_32;
procedure Clear_Queued (Self : in Device);
procedure Close (Self : in out Device);
private
Default_Device : constant C.int := 1;
type User_Data is new Ada.Finalization.Controlled with null record;
type External_Data is record
Callback : Audio_Callback;
User_Data : User_Data_Access;
end record;
type External_Data_Ptr is access all External_Data;
type Internal_Callback_Type is access procedure
(User : in External_Data_Ptr;
Data : in System.Address;
Byte_Length : in Positive)
with Convention => C;
procedure Internal_Callback
(External : in External_Data_Ptr;
Data : in System.Address;
Byte_Length : in Positive)
with Convention => C;
type Internal_Spec is record
Frequency : C.int;
Format : SDL.Audio.Sample_Formats.Sample_Format;
Channels : Channel_Counts;
Silence : Interfaces.Unsigned_8;
Samples : Interfaces.Unsigned_16;
Padding : Interfaces.Unsigned_16;
Size : Interfaces.Unsigned_32;
Callback : Internal_Callback_Type;
User_Data : External_Data_Ptr;
end record with
Convention => C;
type Internal_Spec_Ptr is access all Internal_Spec with
Convention => C;
procedure Internal_Open
(Self : out Device;
Num : in C.int;
Callback : in Audio_Callback;
User_Data : in User_Data_Access);
function To_Internal_Spec
(From : in Desired_Spec;
Callback : in Audio_Callback;
External : in External_Data_Ptr)
return Internal_Spec;
function To_External_Spec (From : Internal_Spec) return Obtained_Spec;
type Device is new Ada.Finalization.Limited_Controlled with
record
Internal : ID := 0;
Is_Open : Boolean := False;
External : aliased External_Data;
end record;
overriding
procedure Finalize (Self : in out Device);
end SDL.Audio.Devices;
|