From 74af58587359206ef92249d18e4830c40cac0bc5 Mon Sep 17 00:00:00 2001
From: Jedidiah Barber <contact@jedbarber.id.au>
Date: Mon, 19 Jun 2023 22:15:44 +1200
Subject: Initial commit

---
 example/aao_example.adb | 101 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 example/aao_example.adb

(limited to 'example/aao_example.adb')

diff --git a/example/aao_example.adb b/example/aao_example.adb
new file mode 100644
index 0000000..7d12b56
--- /dev/null
+++ b/example/aao_example.adb
@@ -0,0 +1,101 @@
+
+
+--  Programmed by Jedidiah Barber
+--  Released into the public domain
+
+--  This program opens the default libao driver and plays a 440 Hz tone for one second
+
+
+with
+
+    Ada.Command_Line,
+    Ada.Numerics.Elementary_Functions,
+    Ada.Text_IO,
+    Libao;
+
+
+procedure AAO_Example is
+
+    package ACom renames Ada.Command_Line;
+    package Math renames Ada.Numerics.Elementary_Functions;
+    package TIO renames Ada.Text_IO;
+
+    My_Device : Libao.Device;
+    My_Format : Libao.Sample_Format;
+
+    Default_Driver : Libao.Driver_ID_Number;
+
+begin
+
+    --  Initialize
+
+    TIO.Put_Line ("libao example program");
+
+    Libao.Startup;
+
+
+    --  Setup for default driver
+
+    Default_Driver := Libao.Default_Driver_ID;
+
+    My_Format := Libao.Create
+       (Bits           => 16,
+        Rate           => 44100,
+        Channels       => 2,
+        Byte_Format    => Libao.Little_Endian,
+        Channel_Matrix => Libao.Stereo);
+
+
+    --  Open driver
+
+    begin
+        My_Device := Libao.Open_Live
+           (Driver_ID => Default_Driver,
+            Format    => My_Format,
+            Options   => Libao.Empty_Options);
+    exception
+        when Libao.Open_Device_Error | Libao.General_Failure =>
+            TIO.Put_Line ("Error opening device.");
+            ACom.Set_Exit_Status (ACom.Failure);
+            return;
+    end;
+
+
+    --  Play some stuff
+
+    --  This sine wave generation was directly translated from the C example,
+    --  but it ends up being a little messy playing fast and loose like this.
+
+    declare
+        Buffer : Libao.Data_Buffer (1 .. 16 / 8 * 2 * 44100);
+
+        type Wraparound is mod 65536;
+        Sample : Wraparound;
+    begin
+        for I in Integer range 0 .. 44100 - 1 loop
+            Sample := Wraparound (Integer (0.75 * 32768.0 *
+                Math.Sin (2.0 * Ada.Numerics.Pi * 440.0 * Float (I) / 44100.0)) mod 65536);
+
+            --  Put the same stuff in left and right channel
+            Buffer (4 * I + 1) := Character'Val (Sample and 16#FF#);
+            Buffer (4 * I + 2) := Character'Val ((Sample / 256) and 16#FF#);
+            Buffer (4 * I + 3) := Character'Val (Sample and 16#FF#);
+            Buffer (4 * I + 4) := Character'Val ((Sample / 256) and 16#FF#);
+        end loop;
+
+        Libao.Play (My_Device, Buffer);
+    end;
+
+
+    --  Close and shutdown
+
+    --  Technically the binding will take care of closing open devices at shutdown,
+    --  but it is always good practice to close them anyway.
+
+    Libao.Close (My_Device);
+
+    Libao.Shutdown;
+
+end AAO_Example;
+
+
-- 
cgit