midi.cpp

软件类别:多 媒 体 软件大小:12KB 运行环境:windows/ 软件 类别:多 媒 体 软件大小:12KB 运行环境:windows/

/////////////////////////////////////////////////////////////////////////////
// Copyright (C) 1998 by J鰎g K鰊ig
// All rights reserved
//
// This file is part of the completely free tetris clone "CGTetris".
//
// This is free software.
// You may redistribute it by any means providing it is not sold for profit
// without the authors written consent.
//
// No warrantee of any kind, expressed or implied, is included with this
// software; use at your own risk, responsibility for damages (if any) to
// anyone resulting from the use of this software rests entirely with the
// user.
//
// Send bug reports, bug fixes, enhancements, requests, flames, etc., and
// I'll try to keep a version up to date.  I can be reached as follows:
//    [e-mail]                 (company site)
//    [e-mail]    (private site)
/////////////////////////////////////////////////////////////////////////////


// Midi.cpp
//


// The CMIDI class is based on a sample in the DirectX SDK (mstream)

#include "stdafx.h"
#include "Midi.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif


#define MThd		0x6468544D		// Start of file
#define MTrk		0x6B72544D		// Start of track


#define BUFFER_TIME_LENGTH		60   // Amount to fill in milliseconds


// These structures are stored in MIDI files; they need to be byte aligned.
//
#pragma pack(1)

// Contents of MThd chunk.
struct MIDIFILEHDR
{
    WORD	wFormat;			// Format (hi-lo)
    WORD	wTrackCount;		// # tracks (hi-lo)
    WORD	wTimeDivision;		// Time division (hi-lo)
};

#pragma pack() // End of need for byte-aligned structures


// Macros for swapping hi/lo-endian data
//
#define WORDSWAP(w)		(((w) >> 8) | \
						(((w) << 8) & 0xFF00))

#define DWORDSWAP(dw)	(((dw) >> 24) | \
						(((dw) >> 8) & 0x0000FF00) | \
						(((dw) << 8) & 0x00FF0000) | \
						(((dw) << 24) & 0xFF000000))


static char gteBadRunStat[] 	= "Reference to missing running status.";
static char gteRunStatMsgTrunc[]= "Running status message truncated";
static char gteChanMsgTrunc[]	= "Channel message truncated";
static char gteSysExLenTrunc[]	= "SysEx event truncated (length)";
static char gteSysExTrunc[]	= "SysEx event truncated";
static char gteMetaNoClass[]	= "Meta event truncated (no class byte)";
static char gteMetaLenTrunc[]	= "Meta event truncated (length)";
static char gteMetaTrunc[]	= "Meta event truncated";
static char gteNoMem[]		= "Out of memory during malloc call";


//////////////////////////////////////////////////////////////////////
// CMIDI -- Construction/Destruction
//////////////////////////////////////////////////////////////////////

CMIDI::CMIDI()
	: m_dwSoundSize(0)
	, m_pSoundData(0)
	, m_dwFormat(0)
	, m_dwTrackCount(0)
	, m_dwTimeDivision(0)
	, m_bPlaying(FALSE)
	, m_hStream(0)
	, m_dwProgressBytes(0)
	, m_bLooped(FALSE)
	, m_tkCurrentTime(0)
	, m_dwBufferTickLength(0)
	, m_dwCurrentTempo(0)
	, m_dwTempoMultiplier(100)
	, m_bInsertTempo(FALSE)
	, m_bBuffersPrepared(FALSE)
	, m_nCurrentBuffer(0)
	, m_uMIDIDeviceID(MIDI_MAPPER)
	, m_nEmptyBuffers(0)
	, m_bPaused(FALSE)
	, m_uCallbackStatus(0)
	, m_hBufferReturnEvent(0)

	, m_ptsTrack(0)
	, m_ptsFound(0)
	, m_dwStatus(0)
	, m_tkNext(0)
	, m_dwMallocBlocks(0)
{
	m_hBufferReturnEvent = ::CreateEvent(0, FALSE, FALSE, TEXT("Wait For Buffer Return"));
	ASSERT(m_hBufferReturnEvent != 0);
}

CMIDI::~CMIDI()
{
	Stop(FALSE);

	if(m_hBufferReturnEvent)
		::CloseHandle(m_hBufferReturnEvent);
}


BOOL CMIDI::Create(UINT uResID, CWnd * pWndParent /* = NULL */)
{
	return	Create(MAKEINTRESOURCE(uResID), pWndParent);
}


BOOL CMIDI::Create(LPCTSTR pszResID, CWnd * pWndParent /* = NULL */)
{
	//////////////////////////////////////////////////////////////////
	// load resource
	HINSTANCE hApp = ::GetModuleHandle(0);
	ASSERT(hApp);

	HRSRC hResInfo = ::FindResource(hApp, pszResID, TEXT("MIDI"));
	if(hResInfo == 0)
		return FALSE;

	HGLOBAL hRes = ::LoadResource(hApp, hResInfo);
	if(hRes == 0)
		return FALSE;

	LPVOID pTheSound = ::LockResource(hRes);
	if(pTheSound == 0)
		return FALSE;

	DWORD dwTheSound = ::SizeofResource(hApp, hResInfo);

	return Create(pTheSound, dwTheSound, pWndParent);
}


BOOL CMIDI::Create(LPVOID pSoundData, DWORD dwSize, CWnd * pWndParent /* = NULL */)
{
	if( m_pSoundData ) {
		// already created
		ASSERT(FALSE);
		return FALSE;
	}

	ASSERT(pSoundData != 0);
	ASSERT(dwSize > 0);

	register LPBYTE p = LPBYTE(pSoundData);

	// check header of MIDI
	if(*(DWORD*)p != MThd) {
		ASSERT(FALSE);
		return FALSE;
	}
	p += sizeof(DWORD);

	// check header size
	DWORD dwHeaderSize = DWORDSWAP(*(DWORD*)p);
	if( dwHeaderSize != sizeof(MIDIFILEHDR) ) {
		ASSERT(FALSE);
		return FALSE;
	}
	p += sizeof(DWORD);

	// get header
	MIDIFILEHDR hdr;
	::CopyMemory(&hdr, p, dwHeaderSize);
	m_dwFormat = DWORD(WORDSWAP(hdr.wFormat));
	m_dwTrackCount = DWORD(WORDSWAP(hdr.wTrackCount));
	m_dwTimeDivision = DWORD(WORDSWAP(hdr.wTimeDivision));
	p += dwHeaderSize;

	// create the array of tracks
	m_Tracks.resize(m_dwTrackCount);
	for(register DWORD i = 0; i < m_dwTrackCount; ++i) {
		// check header of track
		if(*(DWORD*)p != MTrk) {
			ASSERT(FALSE);
			return FALSE;
		}
		p += sizeof(DWORD);

		m_Tracks[i].dwTrackLength = DWORDSWAP(*(DWORD*)p);
		p += sizeof(DWORD);

		m_Tracks[i].pTrackStart = m_Tracks[i].pTrackCurrent = p;
			p += m_Tracks[i].dwTrackLength;

        // Handle bozo MIDI files which contain empty track chunks
		if( !m_Tracks[i].dwTrackLength ) {
			m_Tracks[i].fdwTrack |= ITS_F_ENDOFTRK;
			continue;
		}

		// We always preread the time from each track so the mixer code can
		// determine which track has the next event with a minimum of work
		if( !GetTrackVDWord( &m_Tracks[i], &m_Tracks[i].tkNextEventDue )) {
			TRACE0("Error in MIDI data\n");
			ASSERT(FALSE);
			return FALSE;
		}
	}


	m_pSoundData = pSoundData;
	m_dwSoundSize = dwSize;
	m_pWndParent = pWndParent;

	// allocate volume channels and initialise them
	m_Volumes.resize(NUM_CHANNELS, VOLUME_INIT);

	if( ! StreamBufferSetup() ) {
		ASSERT(FALSE);
		return FALSE;
	}

	return TRUE;
}


BOOL CMIDI :: Play(BOOL bInfinite /* = FALSE */) {
	if( IsPaused() ) {
		Continue();
		return TRUE;
	}

	// calling Play() while it is already playing will restart from scratch
	if( IsPlaying() )
		Stop();

	// Clear the status of our callback so it will handle
	// MOM_DONE callbacks once more
	m_uCallbackStatus = 0;

	if( !m_bLooped )
		m_bInsertTempo = TRUE;

	MMRESULT mmResult;
	if( (mmResult = midiStreamRestart(m_hStream)) != MMSYSERR_NOERROR ) {
		MidiError(mmResult);
		return FALSE;
	}

	m_bPlaying = TRUE;
	m_bLooped = bInfinite;

	return m_bPlaying;
}


BOOL CMIDI :: Stop(BOOL bReOpen /*=TRUE*/) {
	MMRESULT mmrRetVal;

	if( IsPlaying()	|| (m_uCallbackStatus != STATUS_CALLBACKDEAD) ) {
		m_bPlaying = m_bPaused = FALSE;
		if( m_uCallbackStatus != STATUS_CALLBACKDEAD && m_uCallbackStatus != STATUS_WAITINGFOREND )
			m_uCallbackStatus = STATUS_KILLCALLBACK;

		if( (mmrRetVal = midiStreamStop(m_hStream) ) != MMSYSERR_NOERROR ) {
			MidiError(mmrRetVal);
			return FALSE;
		}
		if( (mmrRetVal = midiOutReset((HMIDIOUT)m_hStream)) != MMSYSERR_NOERROR ) {
			MidiError(mmrRetVal);
			return FALSE;
		}
		// Wait for the callback thread to release this thread, which it will do by
		// calling SetEvent() once all buffers are returned to it
		if( WaitForSingleObject( m_hBufferReturnEvent, DEBUG_CALLBACK_TIMEOUT ) == WAIT_TIMEOUT ) {
			// Note, this is a risky move because the callback may be genuinely busy, but
			// when we're debugging, it's safer and faster than freezing the application,
			// which leaves the MIDI device locked up and forces a system reset...
			TRACE0("Timed out waiting for MIDI callback\n");
			m_uCallbackStatus = STATUS_CALLBACKDEAD;
		}
	}

	if( m_uCallbackStatus == STATUS_CALLBACKDEAD ) {
		m_uCallbackStatus = 0;
		FreeBuffers();
		if( m_hStream ) {
			if( (mmrRetVal = midiStreamClose(m_hStream) ) != MMSYSERR_NOERROR ) {
				MidiError(mmrRetVal);
			}
			m_hStream = 0;
		}

		if( bReOpen ) {
			if( !StreamBufferSetup() ) {
				// Error setting up for MIDI file
				// Notification is already taken care of...
				return FALSE;
			}
			if( ! m_bLooped ) {
				Rewind();
				m_dwProgressBytes = 0;
				m_dwStatus = 0;
			}
		}
	}
	return TRUE;
}


BOOL CMIDI :: Pause() {
	if( ! m_bPaused && m_bPlaying && m_pSoundData && m_hStream ) {
		midiStreamPause(m_hStream);
		m_bPaused = TRUE;
	}
	return FALSE;
}


BOOL CMIDI :: Continue() {
	if( m_bPaused && m_bPlaying && m_pSoundData && m_hStream ) {
		midiStreamRestart(m_hStream);
		m_bPaused = FALSE;
	}
	return FALSE;
}


BOOL CMIDI :: Rewind() {
	if( ! m_pSoundData )
		return FALSE;

	for(register DWORD i = 0; i < m_dwTrackCount; ++i) {
		m_Tracks[i].pTrackCurrent = m_Tracks[i].pTrackStart;
		m_Tracks[i].byRunningStatus = 0;
		m_Tracks[i].tkNextEventDue = 0;
		m_Tracks[i].fdwTrack = 0;

        // Handle bozo MIDI files which contain empty track chunks
		if( !m_Tracks[i].dwTrackLength ) {
			m_Tracks[i].fdwTrack |= ITS_F_ENDOFTRK;
			continue;
		}

		// We always preread the time from each track so the mixer code can
		// determine which track has the next event with a minimum of work
		if( !GetTrackVDWord( &m_Tracks[i], &m_Tracks[i].tkNextEventDue )) {
			TRACE0("Error in MIDI data\n");
			ASSERT(FALSE);
			return FALSE;
		}
	}

	return TRUE;
}


DWORD CMIDI :: GetChannelCount() const {
	return m_Volumes.size();
}


void CMIDI :: SetVolume(DWORD dwPercent) {
	const DWORD dwSize = m_Volumes.size();
	for( register DWORD i = 0; i < dwSize; ++i )
		SetChannelVolume(i, dwPercent);
}


DWORD CMIDI :: GetVolume() const {
	DWORD dwVolume = 0;
	const DWORD dwSize = m_Volumes.size();
	for( register DWORD i = 0; i < dwSize; ++i )
		dwVolume += GetChannelVolume(i);

	return dwVolume / GetChannelCount();