ch3p1_playaudio.cpp

游戏开发特殊技巧-special.effects.game.programming

/*
#############################################################################

  Ch3p1_PlayAudio.cpp: a program that demonstrates how to play audio using
  DirectMusic.

  This program is based on the PlayAudio DirectMusic sample program
  contained in the DirectX SDK.

#############################################################################
*/

#define STRICT
#include <windows.h>
#include <basetsd.h>
#include <commdlg.h>
#include <commctrl.h>
#include <dmusicc.h>
#include <dmusici.h>
#include <dxerr8.h>
#include <tchar.h>
#include "Ch3p1_resource.h"
#include "DMUtil.h"
#include "DXUtil.h"

//-----------------------------------------------------------------------------
// Function-prototypes
//-----------------------------------------------------------------------------
INT_PTR CALLBACK MainDlgProc( HWND hDlg, UINT msg, WPARAM wParam, LPARAM lParam );
HRESULT OnInitDialog( HWND hDlg );
HRESULT ProcessDirectMusicMessages( HWND hDlg );
HRESULT LoadSegmentFile( HWND hDlg, TCHAR* strFileName );
HRESULT OnPlayAudio( HWND hDlg );

//-----------------------------------------------------------------------------
// Defines, constants, and global variables
//-----------------------------------------------------------------------------
#define MUSIC_VOLUME_RANGE      ( 0-(DMUS_VOLUME_MIN/4) )

CMusicManager*     g_pMusicManager          = NULL;
CMusicSegment*     g_pMusicSegment          = NULL;
HINSTANCE          g_hInst                  = NULL;
HANDLE             g_hDMusicMessageEvent    = NULL;
char               g_strCmdLine[256];

//-----------------------------------------------------------------------------
// Name: WinMain()
// Desc: Entry point for the application.  Since we use a simple dialog for 
//       user interaction we don't need to pump messages.
//-----------------------------------------------------------------------------
INT APIENTRY WinMain( HINSTANCE hInst, HINSTANCE hPrevInst, LPSTR pCmdLine, 
                      INT nCmdShow )
{
    HWND    hDlg = NULL;
    BOOL    bDone = FALSE;
    int     nExitCode;
    HRESULT hr; 
    DWORD   dwResult;
    MSG     msg;

    g_hInst = hInst;

    strcpy(g_strCmdLine, pCmdLine);

    // Display the main dialog box.
    hDlg = CreateDialog( hInst, MAKEINTRESOURCE(IDD_MAIN), 
                         NULL, MainDlgProc );

    while( !bDone ) 
    { 
        dwResult = MsgWaitForMultipleObjects( 1, &g_hDMusicMessageEvent, 
                                              FALSE, INFINITE, QS_ALLEVENTS );
        switch( dwResult )
        {
            case WAIT_OBJECT_0 + 0:
                // g_hDPMessageEvent is signaled, so there are
                // DirectPlay messages available
                if( FAILED( hr = ProcessDirectMusicMessages( hDlg ) ) ) 
                {
                    DXTRACE_ERR( TEXT("ProcessDirectMusicMessages"), hr );
                    return FALSE;
                }
                break;

            case WAIT_OBJECT_0 + 1:
                // Windows messages are available
                while( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) ) 
                { 
                    if( !IsDialogMessage( hDlg, &msg ) )  
                    {
                        TranslateMessage( &msg ); 
                        DispatchMessage( &msg ); 
                    }

                    if( msg.message == WM_QUIT )
                    {
                        nExitCode = (int)msg.wParam;
                        bDone     = TRUE;
                        DestroyWindow( hDlg );
                    }
                }
                break;
        }
    }

    return nExitCode;
}




//-----------------------------------------------------------------------------
// Name: MainDlgProc()
// Desc: Handles dialog messages
//-----------------------------------------------------------------------------
INT_PTR CALLBACK MainDlgProc( HWND hDlg, UINT msg, WPARAM wParam, LPARAM lParam )
{
    HRESULT hr;

    switch( msg ) 
    {
        case WM_INITDIALOG:
            if( FAILED( hr = OnInitDialog( hDlg ) ) )
            {
                DXTRACE_ERR( TEXT("OnInitDialog"), hr );
                MessageBox( hDlg, "Error initializing DirectMusic.  Sample will now exit.", 
                                  "DirectMusic Sample", MB_OK | MB_ICONERROR );
                EndDialog( hDlg, 0 );
                return TRUE;
            }
            break;

        case WM_COMMAND:
            switch( LOWORD(wParam) )
            {
                case IDCANCEL:
                    PostQuitMessage( IDCANCEL );
                    break;

                default:
                    return FALSE; // Didn't handle message
            }
            break;

        case WM_DESTROY:
            // Cleanup everything
            SAFE_DELETE( g_pMusicSegment );
            SAFE_DELETE( g_pMusicManager );
            CloseHandle( g_hDMusicMessageEvent );
            break; 

        default:
            return FALSE; // Didn't handle message
    }

    return TRUE; // Handled message
}




//-----------------------------------------------------------------------------
// Name: OnInitDialog()
// Desc: Initializes the dialogs (sets up UI controls, etc.)
//-----------------------------------------------------------------------------
HRESULT OnInitDialog( HWND hDlg )
{
    HRESULT hr; 

    // Load the icon
    HICON hIcon = LoadIcon( g_hInst, MAKEINTRESOURCE( IDR_MAINFRAME ) );

    // Set the icon for this dialog.
    SendMessage( hDlg, WM_SETICON, ICON_BIG,   (LPARAM) hIcon );  // Set big icon
    SendMessage( hDlg, WM_SETICON, ICON_SMALL, (LPARAM) hIcon );  // Set small icon

    g_hDMusicMessageEvent = CreateEvent( NULL, FALSE, FALSE, NULL );
    g_pMusicManager = new CMusicManager();

    if( FAILED( hr = g_pMusicManager->Initialize( hDlg ) ) )
        return DXTRACE_ERR( TEXT("Initialize"), hr );

    // Register segment notification
    IDirectMusicPerformance* pPerf = g_pMusicManager->GetPerformance();
    GUID guid = GUID_NOTIFICATION_SEGMENT;
    pPerf->AddNotificationType( guid );
    pPerf->SetNotificationHandle( g_hDMusicMessageEvent, 0 );  

    // Load a default music segment 
    
    TCHAR strFileName[MAX_PATH];

    if (!strlen(g_strCmdLine)) {
      strcpy( strFileName, DXUtil_GetDXSDKMediaPath() );
      strcat( strFileName, "sample.sgt" );
    }
    else strcpy(strFileName, g_strCmdLine);
    
    if( S_FALSE == LoadSegmentFile( hDlg, strFileName ) )
    {
        // Set the UI controls
        SetDlgItemText( hDlg, IDC_FILENAME, TEXT("No file loaded.") );
    }
    OnPlayAudio(hDlg);

    return S_OK;
}


//-----------------------------------------------------------------------------
// Name: LoadSegmentFile()
// Desc: 
//-----------------------------------------------------------------------------
HRESULT LoadSegmentFile( HWND hDlg, TCHAR* strFileName )
{
    HRESULT hr;

    SetDlgItemText( hDlg, IDC_FILENAME, TEXT("") );

    // Free any previous segment, and make a new one
    SAFE_DELETE( g_pMusicSegment );

    // Have the loader collect any garbage now that the old 
    // segment has been released
    g_pMusicManager->CollectGarbage();

    // Set the media path based on the file name (something like C:\MEDIA)
    // to be used as the search directory for finding DirectMusic content
    // related to this file.
    TCHAR strMediaPath[MAX_PATH];
    _tcscpy( strMediaPath, strFileName );
    TCHAR* strLastSlash = _tcsrchr(strMediaPath, TEXT('\\'));
    *strLastSlash = 0;
    if( FAILED( hr = g_pMusicManager->SetSearchDirectory( strMediaPath ) ) )
        return DXTRACE_ERR( TEXT("SetSearchDirectory"), hr );

    // For DirectMusic must know if the file is a standard MIDI file or not
    // in order to load the correct instruments.
    BOOL bMidiFile = FALSE;
    if( strstr( strFileName, ".mid" ) != NULL ||
        strstr( strFileName, ".rmi" ) != NULL ) 
    {
        bMidiFile = TRUE;
    }

    // Load the file into a DirectMusic segment 
    if( FAILED( g_pMusicManager->CreateSegmentFromFile( &g_pMusicSegment, strFileName, 
                                                        TRUE, bMidiFile ) ) )
    {
        // Not a critical failure, so just update the status
        return S_FALSE; 
    }

    // Update the UI controls to show the segment is loaded
    SetDlgItemText( hDlg, IDC_FILENAME, strFileName );
    
    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: ProcessDirectMusicMessages()
// Desc: Handle DirectMusic notification messages
//-----------------------------------------------------------------------------
HRESULT ProcessDirectMusicMessages( HWND hDlg )
{
    HRESULT hr;
    IDirectMusicPerformance8* pPerf = NULL;
    DMUS_NOTIFICATION_PMSG* pPMsg;
        
    if( NULL == g_pMusicManager )
        return S_OK;

    pPerf = g_pMusicManager->GetPerformance();

    // Get waiting notification message from the performance
    while( S_OK == pPerf->GetNotificationPMsg( &pPMsg ) )
    {
        switch( pPMsg->dwNotificationOption )
        {
        case DMUS_NOTIFICATION_SEGEND:
            if( pPMsg->punkUser )
            {
                IDirectMusicSegmentState8* pSegmentState   = NULL;
                IDirectMusicSegment*       pNotifySegment   = NULL;
                IDirectMusicSegment8*      pNotifySegment8  = NULL;
                IDirectMusicSegment8*      pPrimarySegment8 = NULL;

                // The pPMsg->punkUser contains a IDirectMusicSegmentState8, 
                // which we can query for the segment that the SegmentState refers to.
                if( FAILED( hr = pPMsg->punkUser->QueryInterface( IID_IDirectMusicSegmentState8,
                                                                  (VOID**) &pSegmentState ) ) )
                    return DXTRACE_ERR( TEXT("QueryInterface"), hr );

                if( FAILED( hr = pSegmentState->GetSegment( &pNotifySegment ) ) )
                {
                    // Sometimes the segend arrives after the segment is gone
                    // This can happen when you load another segment as 
                    // a motif or the segment is ending
                    if( hr == DMUS_E_NOT_FOUND )
                    {
                        SAFE_RELEASE( pSegmentState );
                        return S_OK;
                    }

                    return DXTRACE_ERR( TEXT("GetSegment"), hr );
                }

                if( FAILED( hr = pNotifySegment->QueryInterface( IID_IDirectMusicSegment8,
                                                                 (VOID**) &pNotifySegment8 ) ) )
                    return DXTRACE_ERR( TEXT("QueryInterface"), hr );

                // Get the IDirectMusicSegment for the primary segment
                pPrimarySegment8 = g_pMusicSegment->GetSegment();

                // Cleanup
                SAFE_RELEASE( pSegmentState );
                SAFE_RELEASE( pNotifySegment );
                SAFE_RELEASE( pNotifySegment8 );
            }
            break;
        }

        pPerf->FreePMsg( (DMUS_PMSG*)pPMsg ); 
    }

    return S_OK;
}



//-----------------------------------------------------------------------------
// Name: OnPlayAudio()
// Desc: 
//-----------------------------------------------------------------------------
HRESULT OnPlayAudio( HWND hDlg )
{
    HRESULT hr;

    // Set the segment to repeat many times
    if( FAILED( hr = g_pMusicSegment->SetRepeats( DMUS_SEG_REPEAT_INFINITE ) ) )
        return DXTRACE_ERR( TEXT("SetRepeats"), hr );

    if( FAILED( hr = g_pMusicSegment->Play( 0) ) )
        return DXTRACE_ERR( TEXT("Play"), hr );

    return S_OK;
}