Developing MIDI applications with DirectMusic

/*
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| |_| || || |> /|  _| | <__   | |   | |\/| || || |_| || | 
|____/ |_||_|\_\|____\\____/  |_|   |_|  |_||_||____/ |_|			 

////////////////////////////////////////////////////////////////////////
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
 
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 
Copyright (c) 2002-2003 by Carlos Jim�nez de Parga  
All rights reserved.
For any suggestion or failure report, please contact me by:
e-mail: cjimenez@servitel.es

Note: I would appreciate very much if you could provide a brief description of your project, 
as well as any report on bugs or errors. This will help me improve the code for the benefit of your
application and the other users    
///////////////////////////////////////////////////////////////////////
Version: 2.1b
Module : CDLSLoader.cpp
Purpose: Code implementation for CDLSLoader class
Created: CJP / 02-08-2002
History: CJP / 03-25-2003 
	
	Update: 09/20/2002

	1. Improved class destructors

	2. Check member variables for NULL values before performing an operation
		
	3. Restructured the class system
	
	4. Better method to enumerate and select MIDI ports
	
	5. Adapted the external thread to a pure virtual function

	6. SysEx reception and sending enabled

	7. Added flexible conversion functions

	8. Find out how to activate the Microsoft software synth. 

	9. Added DLS support

  Update: 03/25/2003

	10. Added exception handling

    11. Fixed bugs with channel groups
  
    12. Redesigned class hierarchy
	
    13. DirectMidi wrapped in the directmidi namespace
  
    14. UNICODE/MBCS support for instruments and ports

	15. Added DELAY effect to software synthesizer ports
	
	16. Project released under GNU (General Public License) terms		 

*/

#include "CDirectMidi.h"

using namespace directmidi;


// The constructor of the class

CDLSLoader::CDLSLoader()
{
	m_pLoader		= NULL;
	
}

// Initialize the object, create the instance of DirectMusicLoader object

HRESULT CDLSLoader::Initialize() 
{
	HRESULT hr;
	TCHAR strMembrFunc[] = _T("CDLSLoader::Initialize");
	
	if (FAILED(hr = CoCreateInstance(CLSID_DirectMusicLoader,NULL,
	    CLSCTX_INPROC_SERVER,IID_IDirectMusicLoader8,(LPVOID*)&m_pLoader))) 
			 throw CDMusicException(strMembrFunc,hr,__LINE__); 

	return S_OK;
}


// Loads a DLS file and initializes a Collection object

HRESULT CDLSLoader::LoadDLS(LPCTSTR lpFileName,CCollection &pCollection)
{
	HRESULT hr = DM_FAILED;
	DMUS_OBJECTDESC dmusdesc;
	TCHAR strMembrFunc[] = _T("CDLSLoader::LoadDLS");

	// Sets to 0 the DMUS structure
	
	ZeroMemory(&dmusdesc,sizeof(DMUS_OBJECTDESC));
	dmusdesc.dwSize = sizeof(DMUS_OBJECTDESC);
	dmusdesc.guidClass = CLSID_DirectMusicCollection; 

	if (lpFileName == NULL)	// Load the synthesizer default GM set
	{
		dmusdesc.guidObject	= GUID_DefaultGMCollection;
		dmusdesc.dwValidData = DMUS_OBJ_CLASS | DMUS_OBJ_OBJECT;
	}
	else
	{
		#ifdef _UNICODE
			_tcscpy(dmusdesc.wszFileName,lpFileName);
		#else
			mbstowcs(dmusdesc.wszFileName,lpFileName,_MAX_PATH); // Convert to wide-char
		#endif

		dmusdesc.dwValidData = DMUS_OBJ_CLASS | DMUS_OBJ_FILENAME | DMUS_OBJ_FULLPATH;
	}

	UnLoadCollection(pCollection);	// In case the object is already with data

	if (m_pLoader)	// Load the DLS file
	{
		if (FAILED(hr = m_pLoader->GetObject(&dmusdesc,IID_IDirectMusicCollection,(void**)&pCollection.m_pCollection)))
			throw CDMusicException(strMembrFunc,hr,__LINE__);
	} else throw CDMusicException(strMembrFunc,hr,__LINE__);

	return S_OK;

}

// Unload a collection from the loader

HRESULT CDLSLoader::UnLoadCollection(CCollection &pCollection)
{
	HRESULT hr = DM_FAILED;
	TCHAR strMembrFunc[] = _T("CDLSLoader::UnLoadCollection");
	
	if ((m_pLoader) && (pCollection.m_pCollection))
	{
		if (FAILED(hr = m_pLoader->ReleaseObjectByUnknown(pCollection.m_pCollection)))
			throw CDMusicException(strMembrFunc,hr,__LINE__);
		SAFE_RELEASE(pCollection.m_pCollection);
	} else return hr;	
	return S_OK;
}


// Class destructor 
// Clear the references to a collection in the loader

CDLSLoader::~CDLSLoader()
{
	if (m_pLoader)
	{	
		m_pLoader->ClearCache(CLSID_DirectMusicCollection);
		// Remove from the cache objects that are no longer in use
		m_pLoader->CollectGarbage();
	}

	SAFE_RELEASE(m_pLoader);
}