Option Strict Off
Option Explicit On 
Imports System.Runtime.InteropServices
Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    ' Direct Sound access
    Dim DX As DxVBLibA.DirectX8
    Dim DS As DxVBLibA.DirectSound8
    Dim dsToneBuffer As DxVBLibA.DirectSoundSecondaryBuffer8
    Dim desc As DxVBLibA.DSBUFFERDESC
    '
    ' Global variables
    Const PI As Double = 3.14159265358979
    Const SRATE As Integer = 44100            ' Sampling Rate
    Dim Tone(25) As Double
    Dim Major(15) As Integer
    Dim Minor(15) As Integer
    Dim Harmonics(7) As Integer

    ' 

    Private Sub frmMain_Load(ByVal eventSender As System.Object, _
        ByVal eventArgs As System.EventArgs) Handles MyBase.Load
        '
        ' initialise DirectSound
        DX = New DxVBLibA.DirectX8
        DS = DX.DirectSoundCreate("")
        DS.SetCooperativeLevel(Me.Handle.ToInt32, _
            DxVBLibA.CONST_DSSCLFLAGS.DSSCL_NORMAL)
        '
        ' create a buffer
        desc.fxFormat.nFormatTag = DxVBLibA.CONST_DSOUND.WAVE_FORMAT_PCM
        desc.fxFormat.nSize = 0
        desc.fxFormat.lExtra = 0
        desc.fxFormat.nChannels = 1
        desc.fxFormat.lSamplesPerSec = SRATE
        desc.fxFormat.nBitsPerSample = 16
        desc.fxFormat.nBlockAlign = 2
        desc.fxFormat.lAvgBytesPerSec = 2 * SRATE
        desc.lFlags = 0
        desc.lBufferBytes = 2 * 1 * SRATE
        dsToneBuffer = DS.CreateSoundBuffer(desc)
        ' Setup tones and scale
        Dim M As Double = Math.Exp(Math.Log(2) / 12)
        Tone(0) = 220
        Dim i As Integer
        For i = 1 To 24
            Tone(i) = Tone(i - 1) * M
        Next
        Major(0) = 0
        Major(1) = 2
        Major(2) = 4
        Major(3) = 5
        Major(4) = 7
        Major(5) = 9
        Major(6) = 11
        Major(7) = 12
        Major(8) = 14
        Major(9) = 16
        Major(10) = 17
        Major(11) = 19
        Major(12) = 21
        Major(13) = 23
        Major(14) = 24

        Minor(0) = 0
        Minor(1) = 2
        Minor(2) = 3
        Minor(3) = 5
        Minor(4) = 7
        Minor(5) = 9
        Minor(6) = 10
        Minor(7) = 12
        Minor(8) = 14
        Minor(9) = 15
        Minor(10) = 17
        Minor(11) = 19
        Minor(12) = 21
        Minor(13) = 22
        Minor(14) = 24

        Harmonics(0) = 0
        Harmonics(1) = 4
        Harmonics(2) = 7
        Harmonics(3) = 12
        Harmonics(4) = 16
        Harmonics(5) = 19
        Harmonics(6) = 24
    End Sub

    Private Sub playTone(ByVal DUR As Double, ByVal FREQ As Double)
        Dim i As Integer, f As Integer, cnt As Integer
        Dim sbuf(DUR * SRATE) As Short
        Dim hmem As GCHandle = GCHandle.Alloc(sbuf, GCHandleType.Pinned)

        ' build the tone
        For i = 0 To DUR * SRATE
            sbuf(i) = 10000 * System.Math.Sin(2 * PI * FREQ * i / SRATE)
        Next i

        ' copy tone to buffer
        desc.lBufferBytes = 2 * DUR * SRATE
        dsToneBuffer = DS.CreateSoundBuffer(desc)
        dsToneBuffer.WriteBuffer(0, 2 * DUR * SRATE, hmem.AddrOfPinnedObject(), _
            DxVBLibA.CONST_DSBLOCKFLAGS.DSBLOCK_DEFAULT)
        'hmem.Free()

        ' play the tone
        dsToneBuffer.Play(DxVBLibA.CONST_DSBPLAYFLAGS.DSBPLAY_DEFAULT)
        While (dsToneBuffer.GetStatus <> 0)
        End While
    End Sub

    Private Sub Play_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Play.Click
        Dim i As Integer
        Dim r As Integer
        For i = 0 To 10
            r = Rnd() * 15
            playTone(0.1, Tone(Minor(r)))
        Next i
    End Sub

    Private Sub butExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles butExit.Click
        End
    End Sub

    Private Sub btnHarmony_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnHarmony.Click
        Dim i As Integer
        Dim r As Integer, d As Integer
        For i = 0 To 10
            r = Rnd() * 7
            d = Rnd() * 3 + 1
            playTone(d * 0.1, Tone(Harmonics(r)))
        Next i
    End Sub
End Class