midi_sender.ck

//
// Basic midi wrapper class. This will act as a wrapper for the MidiOut
// object to provide all the functionality I want to do more usefriendly
// MIDI handling in ChucK
//
// Bruce Murphy
// rattus.net, July 2006.
//
// Current version: alpha-31july2006


public class MIDIsender
{
	MidiOut midiport;
	MidiMsg midimessage;

	// so we don't have to distinguish external from internal
	// channels, we'll keep this in the people friendly 1-16 format
	1 => int default_channel;

	// this will be used for our notecounting. We'll turn notecounting on by
	// default for now.
	// Note that we have to do it per channel.
	int notecount[16][128];
	1=> int countingp;

	// internally generated MIDI streams will have this spacing to avoid crashing
	// older hardware.
	5::ms => dur midigap;

	// direct wrapper to the midiport's open function.
	fun int open(int portid)
	{
		return midiport.open(portid);
	}

	// This is new. Try to open a MIDI port by finding one whose "name" matches
	// the passed-in string.
	//
	// This is not efficient by a long stretch. Returns 0 on failure 1 on success.
	fun int open(string portname)
	{
		int portret;
		0 => int portnum;
		
		while(1) {
			midiport.open(portnum) => portret;
			if (!portret) {
				<<< "No matching port found" >>>;
				return 0;
			}
			if (midiport.name() == portname) {
				return 1;
			} 
			portnum++;
		}
	}

	// sets the default channel for polymorphic functions.
	fun void set_channel(int channel)
	{
		if (channel < 1 || channel > 16) {
			1 => default_channel;
		} else {
			channel => default_channel;
		}
	}

	///////////////////
	// Utility functions
	//
	// for notecounting etc.

	fun void count_note(int notenum, int channel, int increment)
	{
		notenum & 0x7f => notenum;
		(channel - 1) & 0xf => channel;
		increment +=> notecount[channel][notenum]; 
	}

	// issues noteoffs for all the outstaning notes on a particular channel which 
	// this object has sent, but which haven't been called in yet.
	//
	// as a special case here, if we hand it the channel -1, it will stop the 
	// notes for all the channels. Once finished, it will clear the notecount array.
	fun void stop_hanging_notes()
	{
		stop_hanging_notes(default_channel);
	}
	fun void stop_hanging_notes(int channel)
	{
		if (channel != -1) {
			(channel - 1) & 0xf => channel;
			for (0 => int ii; ii < 128; ii++) {
				if (notecount[channel][ii] > 0) {
					noteoff(ii, channel + 1);
					midigap => now;
				}
			}
		} else { // -1 behavior
			for (0 => int cc; cc < 16; cc++) {
				for (0 => int ii; ii < 128; ii++) {
					if (notecount[cc][ii] > 0) {
						noteoff(ii, cc + 1);
						midigap => now;
					}
				}
			}
		}

		clear_note_counts(channel);
	}
	// This just clears the hanging note count arrays. Has the same -1 channel behavior
	// as clear_hanging_notes().
	fun void clear_note_counts()
	{
		clear_note_counts(default_channel);
	}

	fun void clear_note_counts(int channel)
	{
		if (channel != -1) {
			(channel - 1) & 0xf => channel;
			for (0 => int ii; ii < 128; ii++) {
				0 => notecount[channel][ii];
			}
		} else { // -1 behavior
			for (0 => int cc; cc < 16; cc++) {
				for (0 => int ii; ii < 128; ii++) {
					0 => notecount[cc][ii];
				}
			}
		}
		
	}


	///////////////////
	// Interface functions.
	//
	// These functions map pretty simply onto the MIDI specification messages.


	// polymorphic set of functions supplying default values for the MIDI
	// noteon() function.
	fun void noteon(int notenum)
	{
		noteon(notenum, 127, default_channel);
	}
	fun void noteon(int notenum, int velocity)
	{
		noteon(notenum, velocity, default_channel);
	}
	fun void noteon(int notenum, int velocity, int channel)
	{
		send_3bytes(0x9, channel, notenum, velocity);
	
		if (countingp) {
			velocity & 0x7f => velocity;
			if (velocity != 0) {
				count_note(notenum, channel, 1);
			} else {
				count_note(notenum, channel, -1);
			}
			
		}
	}

	// The basic MIDI noteoff uses noteons with zero velocity.
	fun void noteoff(int notenum)
	{
		noteon(notenum, 0, default_channel);
	}
	fun void noteoff(int notenum, int channel)
	{
		noteon(notenum, 0, channel);
	}

	// Some rare synths make use of release velocity. For those we use a different
	// MIDI message type.
	fun void noteoff_velocity(int notenum, int velocity)
	{
		noteoff_velocity(notenum, velocity, default_channel);
	}
	fun void noteoff_velocity(int notenum, int velocity, int channel)
	{
		send_3bytes(0x8, channel, notenum, velocity);
		
		if (countingp) {
			count_note(notenum, channel, -1);
		}
	}

	// 
	// Polyphonic aftertouch message. This controls aftertouch level for individual
	// notes.
	fun void aftertouch(int notenum, int level)
	{
		aftertouch(notenum, level, default_channel);
	}
	fun void aftertouch(int notenum, int level, int channel)
	{
		send_3bytes(0xa, channel, notenum, level);
	}


	fun void controller(int controllernum, int value)
	{
		controller(controllernum, value, default_channel);
	}
	fun void controller(int controllernum, int value, int channel)
	{
		send_3bytes(0xb, channel, controllernum, value);
	}

	// basic program change functionality. We need to have bank and subbank changes
	// available as well, but they're convenience functions.
	fun void program_change(int prognum)
	{
		program_change(prognum, default_channel);
	}
	fun void program_change(int program, int channel)
	{
		send_2bytes(0xc, channel, program);
	}

	// channel pressure is what most synths implement to do aftertouch. It isn't
	// specific to any one note.
	fun void channel_pressure(int pressure)
	{
		channel_pressure(pressure, default_channel);
	}
	fun void channel_pressure(int pressure, int channel)
	{
		send_2bytes(0xd, channel, pressure);
	}

	// pitchbending is actually complicated. We'll take a value of -64 to 63
	// for now. This will only send coarse bends, to avoid overwhelming MIDI.
	fun void pitchbend(int bend)
	{
		pitchbend(bend, default_channel);
	}
	fun void pitchbend(int bend, int channel)
	{
		bend + 64 => bend;
		if (bend > 127) { 127 => bend; }

		send_3bytes(0xe, channel, 0, bend);
	}
	// We'll use these to generate fine bends. Input is a float varying from -1
	// to 1.
	fun void pitchbend_fine(float bend)
	{
		pitchbend_fine(bend, default_channel);
	}
	fun void pitchbend_fine(float bend, int channel)
	{
		((bend + 1) * 8192) $ int => int bendval;
		if (bendval < 0) {
			0 => bendval;
		}
		if (bendval > 0x3fff) {
			0x3fff => bendval;
		}
		
		send_3bytes(0xe, channel, bendval & 0x7f, (bendval >> 7) & 0x7f);
	}

	/////////////////////////////
	// Convenience functions.
	//
	// These functions are just calls to the main interface functions with certain
	// magic parameters. They are handy to have so you don't have to remember the
	// magic parameters.


	// This is the MIDI panic message that should turn all MIDI generated notes off
	// on the device.
	fun void all_notes_off()
	{
		all_notes_off(default_channel);
	}
	fun void all_notes_off(int channel)
	{
		controller(123, 0, channel);
	}

	// Another panic, this one is supposed to kill sound, not just emulate
	// note offs and so ignore sustain and long envelopes.
	// Less typically implemented.
	fun void all_sound_off()
	{
		all_sound_off(default_channel);
	}
	fun void all_sound_off(int channel)
	{
		controller(120, 0, channel);
	}

	// Bank select is magic. Consult synth documentation to figure out which 
	// order of bank and program changes your device requires.
	//	
	// It'll usually be Bank, Sub, Prog. or Sub, Bank, Prog, but some use only one
	// of bank or sub :)
	fun void select_bank(int bank) 
	{
		select_bank(bank, default_channel);
	}
	fun void select_bank(int bank, int channel)
	{
		controller(0, bank, channel);
	}
	fun void select_subbank(int bank) 
	{
		select_subbank(bank, default_channel);
	}
	fun void select_subbank(int bank, int channel)
	{
		controller(32, bank, channel);
	}


	// Uses only the coarse volume since few things both to implement fine.
	fun void volume(int level)
	{
		volume(level, default_channel);
	}
	fun void volume(int level, int channel)
	{
		controller(7, level, channel);
	}
	
	
	
	////////////////////////////
	// basic interface functions.
	//
	// These generate the low-level MIDI messages.
	
	// Basically all the MIDI functions break down into sending one of these
	// two things.
	fun void send_3bytes(int command, int channel, int byte1, int byte2)
	{
		((command & 0xf) << 4) | ((channel - 1) & 0xf) => midimessage.data1;
		command | channel => command;
		byte1 & 0x7f  => midimessage.data2;
		byte2 & 0x7f => midimessage.data3;
		midiport.send(midimessage);

	}
	// not sure what dance is required to make this only send two bytes.
	fun void send_2bytes(int command, int channel, int byte1)
	{
		((command & 0x0f) << 4) | ((channel - 1) & 0xf) => midimessage.data1;
		byte1 & 0x7f => midimessage.data2;
		midiport.send(midimessage);
	}

}