main.cpp

<B>很多DirectX 9.0游戏编程源码例子</B>

//-----------------------------------------------------------------------------
// Name: DShow_PlayMP3
//
// Description: Example code showing how to play a MP3 file
//
// File Function: Main body of the program (main.cpp)
//
// Code:
//		Copyright (c) 2002 LostLogic Corporation. All rights reserved.
//
// Libraries Required:
//		dxguid.lib winmm.lib Strmiids.lib
//
// Local Files Required:
//		main.cpp
//		main.h
//		DXUtil.cpp
//
// DX Files:
//		Copyright (c) 1997-2001 Microsoft Corporation. All rights reserved.
//-----------------------------------------------------------------------------
#include "main.h"

//--------------------------------------------------------------------------------------
//
// Main windows function, ie main()
//
//--------------------------------------------------------------------------------------
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow)
{
	HWND		hWnd;
	MSG			msg;
	WNDCLASSEX	wndclass;
	bool		bRet;
		
    // Set up window class
	wndclass.cbSize			= sizeof(wndclass);
	wndclass.style			= CS_HREDRAW | CS_VREDRAW;
	wndclass.lpfnWndProc	= fnMessageProcessor;
	wndclass.cbClsExtra		= 0;
	wndclass.cbWndExtra		= 0;
	wndclass.hInstance		= hInstance;
	wndclass.hIcon			= LoadIcon( NULL, IDI_APPLICATION );
	wndclass.hCursor		= LoadCursor( NULL, IDC_ARROW );
	wndclass.hbrBackground	= (HBRUSH) GetStockObject (WHITE_BRUSH);
	wndclass.lpszMenuName	= NULL;
	wndclass.lpszClassName	= "Direct Show Demo";	// Registered Class Name
	wndclass.hIconSm		= LoadIcon( NULL, IDI_APPLICATION );

	// Register the window class
	if( RegisterClassEx( &wndclass ) == NULL ) 
	{
		// The program failed, exit
		exit(1);
	}

	// Create the window
	hWnd = CreateWindowEx(	WS_EX_OVERLAPPEDWINDOW,
							"Direct Show Demo",	// Class Name
							"DShow_PlayMP3",		// Name Displayed on Title Bar
							WS_OVERLAPPEDWINDOW,
							0,
							0,
							320,
							200,
							NULL,
							NULL,
							hInstance,
							NULL );

	// Display the window
	ShowWindow( hWnd, iCmdShow );
	
	// Clear out message structure
	ZeroMemory( &msg, sizeof(msg) );
    
	// Play the title music
	bRet = bPlayTitleMusic();
	if( bRet == 0 ) {
		MessageBox( hWnd, "Initialization Failure", 
					"Failed to initialize DirectShow", 
					MB_ICONEXCLAMATION|MB_OK );
		// The program failed, exit
		exit(1);
	}

    // Enter the message loop
    while( msg.message!=WM_QUIT ) {
        if( PeekMessage( &msg, NULL, 0U, 0U, PM_REMOVE ) ) {
            TranslateMessage( &msg );
            DispatchMessage( &msg );
		}
		else {
			if( g_bBackgroundMusicActive ) {
				vCheckMusicStatus();
			}
		}
    }

	// Clean up everything and exit the app
    vCleanup();
    UnregisterClass( "Direct Show Demo", wndclass.hInstance );
    return 0;
}

//--------------------------------------------------------------------------------------
//
// Windows message processor
//
//--------------------------------------------------------------------------------------
LRESULT WINAPI fnMessageProcessor( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
	switch( msg ) 
	{
		case WM_DESTROY:
            PostQuitMessage( 0 );
            return 0;
		default:
			break;
    }
    return DefWindowProc( hWnd, msg, wParam, lParam );
}

//--------------------------------------------------------------------------------------
//
// Function to cleanup allocated objects
//
//--------------------------------------------------------------------------------------
void vCleanup( void )
{
	vStopTitleMusic();
}

//--------------------------------------------------------------------------------------
//
// Function to initialize the the sound graph and load
// the mp3 file
//
//--------------------------------------------------------------------------------------
bool bPlayTitleMusic( void )
{
	HRESULT	hr;
	
	// Initialize COM
	CoInitialize( NULL );

	// Create the graph
	CoCreateInstance(	CLSID_FilterGraph, 
						NULL, 
						CLSCTX_INPROC_SERVER, 
						IID_IGraphBuilder, 
						(void **)&g_pGraph );

	// Query for interface objects
	g_pGraph->QueryInterface( IID_IMediaControl, (void **)&g_pMediaControl );
	g_pGraph->QueryInterface( IID_IMediaEvent, (void **)&g_pEvent );
	g_pGraph->QueryInterface( IID_IMediaSeeking, (void **)&g_pSeeking );

	// Load the song (insert your own file name below)
	hr = g_pGraph->RenderFile(L"c:\\dxsdk\\samples\\media\\track3.mp3", NULL);
	if( hr != S_OK ) {
		return( 0 );
	}
	// Set the playback rate
	g_pSeeking->SetRate( 1.25 );
	// Play the song
	g_pMediaControl->Run();
	// Set background music active flag
	g_bBackgroundMusicActive = 1;
	
	return( 1 );
}

//--------------------------------------------------------------------------------------
//
// Function to clean up the graph and allocated memory
//
//--------------------------------------------------------------------------------------
void vStopTitleMusic( void ) 
{
	// Stop the song if playing
	g_pMediaControl->Stop();
	// Clean up
	g_pMediaControl->Release();
	g_pEvent->Release();
	g_pGraph->Release();
}

//--------------------------------------------------------------------------------------
//
// Function to check the status of the music to see if it is done and
// needs to be restarted
//
//--------------------------------------------------------------------------------------
void vCheckMusicStatus( void )
{
	long		evCode;
	
	// Check the event code
	g_pEvent->WaitForCompletion( 0, &evCode );
	
	// If the music is done, restart it
	if( evCode == EC_COMPLETE ) {
		// Set the starting position to 0
		LONGLONG lStartPos = 0;
		// Stop the music
		g_pMediaControl->Stop();
		// Set the positions
		g_pSeeking->SetPositions( &lStartPos, AM_SEEKING_AbsolutePositioning, NULL, AM_SEEKING_NoPositioning );
		// Run the music
		g_pMediaControl->Run();
	}
}