annotate include/Midi.h @ 225:444f6028d6b1 mergingClockSync

Added documentation for Midi and MidiParser

/*
 * Midi.h
 *
 *  Created on: 15 Jan 2016
 *      Author: giulio
 */

#ifndef MIDI_H_
#define MIDI_H_

#include <BeagleRT.h>
#include <vector>

typedef unsigned char midi_byte_t;


typedef enum midiMessageType{
	kmmNoteOff = 0,
	kmmNoteOn,
	kmmPolyphonicKeyPressure,
	kmmControlChange,
	kmmProgramChange,
	kmmChannelPressure,
	kmmPitchBend,
	kmmNone,
	kmmAny,
} MidiMessageType;
#define midiMessageStatusBytesLength 7+2 //2 being kmmNone and kmmAny

extern midi_byte_t midiMessageStatusBytes[midiMessageStatusBytesLength];
extern unsigned int midiMessageNumDataBytes[midiMessageStatusBytesLength];

class MidiChannelMessage{
public:
	MidiChannelMessage();
	MidiChannelMessage(MidiMessageType type);
	virtual ~MidiChannelMessage();
	MidiMessageType getType();
	int getChannel();
	unsigned int getNumDataBytes(){
		return midiMessageNumDataBytes[(unsigned int)_type];
	}
	void setDataByte(unsigned int dataByteIndex, midi_byte_t input){
		_dataBytes[dataByteIndex] = input;
	}
	void setType(MidiMessageType type){
		_type = type;
		_statusByte = midiMessageStatusBytes[_type];
	}
	void setChannel(midi_byte_t channel){
		_channel = channel;
	}
	midi_byte_t getDataByte(unsigned int index){
		return _dataBytes[index];
	}
	void clear(){
		for(int n = 0; n<maxDataBytes; n++){
			_dataBytes[n] = 0;
		}
		_type = kmmNone;
		_statusByte = 0;
	}
	void prettyPrint(){
		rt_printf("MessageType: %x,  ", this->getType());
		rt_printf("channel: %u, ", this->getChannel());
		for(unsigned int n = 0; n < this->getNumDataBytes(); n++){
			rt_printf("data%d: %d, ", n + 1, this->getDataByte(n));
		}
		rt_printf("\n");
	}

private:
	const static int maxDataBytes = 2;
protected:
	midi_byte_t _statusByte;
	midi_byte_t _dataBytes[maxDataBytes]; // where 2 is the maximum number of data bytes for a channel message
	MidiMessageType _type;
	midi_byte_t _channel;
};
/*
class MidiControlChangeMessage : public MidiChannelMessage{
	int number;
	int value;
public:
	int getNumber();
	int getNumDataBytes();
	int setDataByte(midi_byte_t input, unsigned int dataByteIndex);
	int getValue();
	int set(midi_byte_t* input);
};

class MidiNoteMessage : public MidiChannelMessage{
	int note;
	int velocity;
public:
	int getNote();
	int getVelocity();
	int getNumDataBytes();
	int setDataByte(midi_byte_t input, unsigned int dataByteIndex);
};

class MidiProgramChangeMessage : public MidiChannelMessage{
	midi_byte_t program;
public:
	int getNumDataBytes();
	int setDataByte(midi_byte_t input, unsigned int dataByteIndex);
	midi_byte_t getProgram();
};
*/

class MidiParser{
private:
	std::vector<MidiChannelMessage> messages;
	unsigned int writePointer;
	unsigned int readPointer;
	unsigned int elapsedDataBytes;
	bool waitingForStatus;
	void (*messageReadyCallback)(MidiChannelMessage);
	bool callbackEnabled;
public:
	MidiParser(){
		waitingForStatus = true;
		elapsedDataBytes= 0;
		messages.resize(100); // 100 is the number of messages that can be buffered
		writePointer = 0;
		readPointer = 0;
		callbackEnabled = false;
		messageReadyCallback = NULL;
	}

	/**
	 * Parses some midi messages.
	 *
	 * @param input the array to read from
	 * @param length the maximum number of values available at the array
	 *
	 * @return the number of bytes parsed
	 */
	int parse(midi_byte_t* input, unsigned int length);

	/**
	 * Sets the callback to call when a new MidiChannelMessage is available
	 * from the input port.
	 *
	 * In order to deactivate the callback, call this method with NULL as an
	 * argument.
	 * While the callback is enabled, calling numAvailableMessages() and
	 * getNextChannelMessage() is still possible, but it will probably always
	 * return 0 as the callback is called as soon as a new message is available.
	 *
	 * @param newCallback the callback function. This function
	 * should takes one argument: the MidiChannelMessage .
	 *
	 */
	void setCallback(void (*newCallback)(MidiChannelMessage)){
		messageReadyCallback = newCallback;
		if(newCallback != NULL){
			callbackEnabled = true;
		} else {
			callbackEnabled = false;
		}
	};

	/**
	 * Checks whether there is a callback currently set to be called
	 * every time a new input MidiChannelMessage is available from the
	 * input port.
	 */
	bool isCallbackEnabled(){
		return callbackEnabled;
	};

	/**
	 * Returns the number of unread MidiChannelMessage available from the
	 * input port.
	 *
	 */

	int numAvailableMessages(){
		int num = (writePointer - readPointer + messages.size() ) % messages.size();
		if(num > 0){
			int a = a +1;
			a = readPointer;
		}
		return num;
	}

	/**
	 * Get the oldest channel message in the buffer.
	 *
	 * If this method is called when numAvailableMessages()==0, then
	 * a message with all fields set to zero is returned.
	 *
	 * @param type the type of the message to retrieve
	 *
	 * @return a copy of the oldest message of the give type in the buffer
	 */
	MidiChannelMessage getNextChannelMessage(/*MidiMessageType type*/){
		MidiChannelMessage message;
		message = messages[readPointer];
		if(message.getType() == kmmNone){
			message.clear();
		}
		messages[readPointer].setType(kmmNone); // do not use it again
		readPointer++;
		if(readPointer == messages.size()){
			readPointer = 0;
		}
		return message;
	};

//	MidiChannelMessage getNextChannelMessage(){
//		getNextChannelMessage(kmmAny);
//	}
//	MidiControlChangeMessage* getNextControlChangeMessage(){
//		return (MidiControlChangeMessage*)getNextChannelMessage(kmmControlChange);
//	};
//	MidiProgramChangeMessage* getNextProgramChangeMessage(){
//		return (MidiProgramChangeMessage*)getNextChannelMessage(kmmProgramChange);
//	};
//	MidiNoteMessage* getNextNoteOnMessage(){
//		return (MidiNoteMessage*)getNextChannelMessage(kmmNoteOn);
//	};
};


class Midi {
public:
	Midi();

	/**
	 * Enable the input MidiParser.
	 *
	 * If the parser is enabled, getInput() will return an error code.
	 * Midi messages should instead be retrieved via, e.g.: getMidiParser()->getNextChannelMessage();
	 *
	 * @param enable true to enable the input MidiParser, false to disable it.
	 */
	void enableParser(bool enable);

	/**
	 * Get access to the input parser in use, if any.
	 *
	 * @return a pointer to the instance of MidiParser, if currently enabled, zero otherwise.
	 */
	MidiParser* getParser();

	/**
	 * Sets the callback to call when a new MidiChannelMessage is available
	 * from the input port.
	 *
	 * Internally, it calls enableParser() and the MidiParser::setCallback();
	 *
	 * @param newCallback the callback function. This function
	 * should takes one argument: the MidiChannelMessage .
	 */
	void setParserCallback(void (*callback)(MidiChannelMessage)){
		// if callback is not NULL, also enable the parser
		enableParser(callback != NULL); //this needs to be first, as it deletes the parser(if exists)
		getParser()->setCallback(callback);
	}

	/**
	 * Open the specified input Midi port and start reading from it.
	 * @param port Midi port to open
	 * @return 1 on success, -1 on failure
	 */
	int readFrom(int port);
	/**
	 * Open the specified output Midi port and prepares to write to it.
	 * @param port Midi port to open
	 * @return 1 on success, -1 on failure
	 */
	int writeTo(int port);

	/**
	 * Get received midi bytes, one at a time.
	 * @return  -1 if no new byte is available, -2 on error,
	 * the oldest not yet retrieved midi byte otherwise
	*/
	int getInput();

	/**
	 * Writes a Midi byte to the output port
	 * @param byte the Midi byte to write
	 * @return 1 on success, -1 on error
	 */
	int writeOutput(midi_byte_t byte);

	/**
	 * Writes Midi bytes to the output port
	 * @param bytes an array of bytes to be written
	 * @param length number of bytes to write
	 * @return 1 on success, -1 on error
	 */
	int writeOutput(midi_byte_t* bytes, unsigned int length);
	/**
	 * Gives access to the midi parser, if it has been activated.
	 *
	 * @return a pointer to the midi parser if active, zero otherwise
	 */
	MidiParser* getMidiParser();
	virtual ~Midi();
	static void midiInputLoop();
	static void midiOutputLoop();
    static bool staticConstructed;
	static void staticConstructor();
private:
	int _getInput();
	void readInputLoop();
	void writeOutputLoop();
	int outputPort;
	int inputPort;
	std::vector<midi_byte_t> inputBytes;
	unsigned int inputBytesWritePointer;
	unsigned int inputBytesReadPointer;
	std::vector<midi_byte_t> outputBytes;
	unsigned int outputBytesWritePointer;
	unsigned int outputBytesReadPointer;
	MidiParser* inputParser;
	bool parserEnabled;
	static std::vector<Midi*> objAddrs[2];
	static AuxiliaryTask midiInputTask;
	static AuxiliaryTask midiOutputTask;
};


#endif /* MIDI_H_ */