comparison examples/05-Communication/basic-midi/render.cpp @ 464:8fcfbfb32aa0 prerelease

Examples reorder with subdirectories. Added header to each project. Moved Doxygen to bottom of render.cpp.

+/*
+ ____  _____ _        _    
+| __ )| ____| |      / \   
+|  _ \|  _| | |     / _ \  
+| |_) | |___| |___ / ___ \ 
+|____/|_____|_____/_/   \_\
+
+The platform for ultra-low latency audio and sensor processing
+
+http://bela.io
+
+A project of the Augmented Instruments Laboratory within the
+Centre for Digital Music at Queen Mary University of London.
+http://www.eecs.qmul.ac.uk/~andrewm
+
+(c) 2016 Augmented Instruments Laboratory: Andrew McPherson,
+  Astrid Bin, Liam Donovan, Christian Heinrichs, Robert Jack,
+  Giulio Moro, Laurel Pardue, Victor Zappi. All rights reserved.
+
+The Bela software is distributed under the GNU Lesser General Public License
+(LGPL 3.0), available here: https://www.gnu.org/licenses/lgpl-3.0.txt
+*/
+
+
+#include <Bela.h>
+#include <Midi.h>
+#include <stdlib.h>
+#include <rtdk.h>
+#include <cmath>
+
+float gFreq;
+float gPhaseIncrement = 0;
+bool gIsNoteOn = 0;
+int gVelocity = 0;
+float gSamplingPeriod = 0;
+
+void midiMessageCallback(MidiChannelMessage message, void* arg){
+	if(arg != NULL){
+		rt_printf("Message from midi port %d: ", *(int*)arg);
+	}
+	message.prettyPrint();
+	if(message.getType() == kmmNoteOn){
+		gFreq = powf(2, (message.getDataByte(0)-69)/12.0f) * 440;
+		gVelocity = message.getDataByte(1);
+		gPhaseIncrement = 2 * M_PI * gFreq * gSamplingPeriod;
+		gIsNoteOn = gVelocity > 0;
+		rt_printf("v0:%f, ph: %6.5f, gVelocity: %d\n", gFreq, gPhaseIncrement, gVelocity);
+	}
+}
+// setup() is called once before the audio rendering starts.
+// Use it to perform any initialisation and allocation which is dependent
+// on the period size or sample rate.
+//
+// userData holds an opaque pointer to a data structure that was passed
+// in from the call to initAudio().
+//
+// Return true on success; returning false halts the program.
+Midi midi;
+int gMidiPort0 = 0;
+bool setup(BelaContext *context, void *userData)
+{
+	midi.readFrom(gMidiPort0);
+	midi.writeTo(gMidiPort0);
+	midi.enableParser(true);
+	midi.setParserCallback(midiMessageCallback, &gMidiPort0);
+	if(context->analogFrames == 0) {
+		rt_printf("Error: this example needs the analog I/O to be enabled\n");
+		return false;
+	}
+	gSamplingPeriod = 1/context->audioSampleRate;
+	return true;
+}
+
+// render() is called regularly at the highest priority by the audio engine.
+// Input and output are given from the audio hardware and the other
+// ADCs and DACs (if available). If only audio is available, numMatrixFrames
+// will be 0.
+
+
+enum {kVelocity, kNoteOn, kNoteNumber};
+void render(BelaContext *context, void *userData)
+{
+// one way of getting the midi data is to parse them yourself
+//	(you should set midi.enableParser(false) above):
+/*
+	static midi_byte_t noteOnStatus = 0x90; //on channel 1
+	static int noteNumber = 0;
+	static int waitingFor = kNoteOn;
+	static int playingNote = -1;
+	int message;
+	while ((message = midi.getInput()) >= 0){
+		rt_printf("%d\n", message);
+		switch(waitingFor){
+		case kNoteOn:
+			if(message == noteOnStatus){
+				waitingFor = kNoteNumber;
+			}
+			break;
+		case kNoteNumber:
+			if((message & (1<<8)) == 0){
+				noteNumber = message;
+				waitingFor = kVelocity;
+			}
+			break;
+		case kVelocity:
+			if((message & (1<<8)) == 0){
+				int _velocity = message;
+				waitingFor = kNoteOn;
+				// "monophonic" behaviour, with priority to the latest note on
+				// i.e.: a note off from a previous note does not stop the current note
+				// still you might end up having a key down and no note being played if you pressed and released another
+				// key in the meantime
+				if(_velocity == 0 && noteNumber == playingNote){
+					noteOn = false;
+					playingNote = -1;
+					velocity = _velocity;
+				} else if (_velocity > 0) {
+					noteOn = true;
+					velocity = _velocity;
+					playingNote = noteNumber;
+					f0 = powf(2, (playingNote-69)/12.0f) * 440;
+					phaseIncrement = 2 * M_PI * f0 / context->audioSampleRate;
+				}
+				rt_printf("NoteOn: %d, NoteNumber: %d, velocity: %d\n", noteOn, noteNumber, velocity);
+			}
+			break;
+		}
+	}
+*/
+	/*
+	int num;
+	//alternatively, you can use the built-in parser (only processes channel messages at the moment).
+	while((num = midi.getParser()->numAvailableMessages()) > 0){
+		static MidiChannelMessage message;
+		message = midi.getParser()->getNextChannelMessage();
+		message.prettyPrint();
+		if(message.getType() == kmmNoteOn){
+			f0 = powf(2, (message.getDataByte(0)-69)/12.0f) * 440;
+			velocity = message.getDataByte(1);
+			phaseIncrement = 2 * M_PI * f0 / context->audioSampleRate;
+			noteOn = velocity > 0;
+			rt_printf("v0:%f, ph: %6.5f, velocity: %d\n", f0, phaseIncrement, gVelocity);
+		}
+	}
+	 */
+	// the following block toggles the LED on an Owl pedal
+	// and asks the pedal to return the status of the LED
+	// using MIDI control changes
+	for(unsigned int n = 0; n < context->analogFrames; n++){
+		static int count = 0;
+		static bool state = 0;
+		analogWriteOnce(context, n, 1, state);
+		if(count % 40000 == 0){
+			state = !state;
+			midi_byte_t bytes[6] = {176, 30, (char)(state*127), 176, 67, 30}; // toggle the OWL led and ask for the led status
+			midi.writeOutput(bytes, 6);
+		}
+		count++;
+	}
+	for(unsigned int n = 0; n < context->audioFrames; n++){
+		if(gIsNoteOn == 1){
+			static float phase = 0;
+			phase += gPhaseIncrement;
+			if(phase > 2 * M_PI)
+				phase -= 2 * M_PI;
+			float value = sinf(phase) * gVelocity/128.0f;
+			audioWrite(context, n, 0, value);
+			audioWrite(context, n, 1, value);
+		} else {
+			audioWrite(context, n, 0, 0);
+			audioWrite(context, n, 1, 0);
+		}
+	}
+}
+
+// cleanup() is called once at the end, after the audio has stopped.
+// Release any resources that were allocated in setup().
+
+void cleanup(BelaContext *context, void *userData)
+{
+
+}