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#ifndef MIDI_IN_DEVICE_H
#define MIDI_IN_DEVICE_H
/*******************************************************************************
* MIDIInDevice.h - Interface for CMIDIInDevice and related classes.
*
* Copyright (C) 2002 Leslie Sanford
*
* 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
*
* Contact: jabberdabber@hotmail.com
*
* Last modified: 07/30/2003
*
* Note: You must link to the winmm.lib to use these classes.
******************************************************************************/
#pragma warning(disable:4786) // Disable annoying template warnings
//--------------------------------------------------------------------
// Dependencies
//--------------------------------------------------------------------
// Necessary for Windows data types
#include "stdafx.h"
#include <mmsystem.h>
// Necessary for exception classes derived from std::exception
#include <exception>
// Necessary for header queue used by CHeaderQueue
#include <queue>
namespace midi
{
//----------------------------------------------------------------
// Class declarations
//----------------------------------------------------------------
//----------------------------------------------------------------
// CMIDIReceiver
//
// An abstract class representing objects that receive messages
// from CMIDIInDevice objects. A CMIDIReceiver object registers
// itself with a CMIDIInDevice object. It will then receive all
// messages that are recorded.
//----------------------------------------------------------------
class CMIDIReceiver
{
public:
virtual ~CMIDIReceiver() {}
// Receives short messages
virtual void ReceiveMsg(DWORD Msg, DWORD TimeStamp) = 0;
// Receives long messages
virtual void ReceiveMsg(LPSTR Msg, DWORD BytesRecorded,
DWORD TimeStamp) = 0;
// Called when an invalid short message is received
virtual void OnError(DWORD Msg, DWORD TimeStamp) = 0;
// Called when an invalid long message is received
virtual void OnError(LPSTR Msg, DWORD BytesRecorded,
DWORD TimeStamp) = 0;
};
//----------------------------------------------------------------
// CMIDIInDevice exception classes
//----------------------------------------------------------------
// Encapsulates the midiInGetErrorText messages
class CMIDIInException : public std::exception
{
public:
CMIDIInException(MMRESULT ErrCode) throw()
{ ::midiInGetErrorText(ErrCode, m_ErrMsg, sizeof m_ErrMsg); }
const char *what() const throw() { return m_ErrMsg; }
private:
char m_ErrMsg[128];
};
// Thrown when memory allocation fails within a CMIDIInDevice
// object
class CMIDIInMemFailure : public std::bad_alloc
{
public:
const char *what() const throw()
{ return "Memory allocation within a CMIDIInDevice object "
"failed."; }
};
// Thrown when a CMIDIInDevice is unable to create a signalling
// event
class CMIDIInEventFailure : public std::exception
{
public:
const char *what() const throw()
{ return "Unable to create a signalling event for "
"CMIDIInDevice object."; }
};
// Thrown when a CMIDIInDevice is unable to create a worker thread
class CMIDIInThreadFailure : public std::exception
{
public:
const char *what() const throw()
{ return "Unable to create worker thread for CMIDIInDevice "
"object."; }
};
//----------------------------------------------------------------
// CMIDIInDevice
//
// This class represents MIDI input devices.
//----------------------------------------------------------------
class CMIDIInDevice
{
public:
// For constructing a CMIDIInDevice object in an closed state
CMIDIInDevice();
// For constructing a CMIDIInDevice object in an closed state and
// initializing the MIDI receiver
CMIDIInDevice(CMIDIReceiver &Receiver);
// For constructing a CMIDIInDevice object in an opened state
CMIDIInDevice(UINT DeviceId, CMIDIReceiver &Receiver);
// Destruction
~CMIDIInDevice();
// Opens the MIDI input device
void Open(UINT DeviceId);
// Closes the MIDI input device
void Close();
// Adds a buffer to receive system exclusive messages
void AddSysExBuffer(LPSTR Buffer, DWORD BufferLength);
// Starts the recording process
void StartRecording();
// Stops the recording process
void StopRecording();
// Sets the current MIDI receiver. Returns the previous
// receiver.
CMIDIReceiver *SetReceiver(CMIDIReceiver &Receiver);
// Returns true if the device is open
bool IsOpen() const;
// Returns true if the device is recording
bool IsRecording() const;
// Gets Id for this device
UINT GetDevID() const;
// Gets the number of MIDI input devices on this system
static UINT GetNumDevs() { return midiInGetNumDevs(); }
// Gets the capabilities of a particular MIDI input device
// The results are stored in the MIDIINCAPS parameter.
static void GetDevCaps(UINT DeviceId, MIDIINCAPS &Caps);
// Private methods
private:
// Copying and assignment not allowed
CMIDIInDevice(const CMIDIInDevice &);
CMIDIInDevice &operator = (const CMIDIInDevice &);
// Creates an event for signalling the header thread
bool CreateEvent();
// Called by Windows when a MIDI input event occurs
static void CALLBACK MidiInProc(HMIDIIN MidiIn, UINT Msg,
DWORD Instance, DWORD Param1,
DWORD Param2);
// Thread function for managing headers
static DWORD WINAPI HeaderProc(LPVOID Parameter);
// Private class declarations
private:
// Encapsulates the MIDIHDR structure for MIDI input
class CMIDIInHeader
{
public:
CMIDIInHeader(HMIDIIN DevHandle, LPSTR Buffer,
DWORD BufferLength);
~CMIDIInHeader();
// Add the buffer for receiving system exclusive messages
void AddSysExBuffer();
private:
HMIDIIN m_DevHandle;
MIDIHDR m_MIDIHdr;
};
// Thread safe queue for storing CMIDIInHeader objects
class CHeaderQueue
{
public:
CHeaderQueue();
~CHeaderQueue();
void AddHeader(CMIDIInHeader *Header);
void RemoveHeader();
void RemoveAll();
bool IsEmpty();
private:
std::queue<CMIDIInHeader *> m_HdrQueue;
CRITICAL_SECTION m_CriticalSection;
};
// Private attributes and constants
private:
HMIDIIN m_DevHandle;
HANDLE m_Event;
CWinThread *m_Thread;
CMIDIReceiver *m_Receiver;
CHeaderQueue m_HdrQueue;
enum State { CLOSED, OPENED, RECORDING } m_State;
};
}
#endif
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Aside from dabbling in BASIC on his old Atari 1040ST years ago, Leslie's programming experience didn't really begin until he discovered the Internet in the late 90s. There he found a treasure trove of information about two of his favorite interests: MIDI and sound synthesis.
After spending a good deal of time calculating formulas he found on the Internet for creating new sounds by hand, he decided that an easier way would be to program the computer to do the work for him. This led him to learn C. He discovered that beyond using programming as a tool for synthesizing sound, he loved programming in and of itself.
Eventually he taught himself C++ and C#, and along the way he immersed himself in the ideas of object oriented programming. Like many of us, he gotten bitten by the design patterns bug and a copy of GOF is never far from his hands.
Now his primary interest is in creating a complete MIDI toolkit using the C# language. He hopes to create something that will become an indispensable tool for those wanting to write MIDI applications for the .NET framework.
Besides programming, his other interests are photography and playing his Les Paul guitars.