Monday, October 14, 2013

Music class for use with leJOS NXJ playNote and playTone methods

As an exercise I've written a Music class that makes writing NXT melodies easier by allowing note values to be passed instead of frequencies. I used this page as a reference: http://www.phy.mtu.edu/~suits/notefreqs.html. Any suggestions are appreciated. I hope someone finds it useful! Here's a little vid: http://blogs.hewittnet.org/robotics/files/2013/10/IMG_1008.mov

import lejos.nxt.Sound;
public class Music {
    private static String[] notes = { "C3", "C#3", "Db3", "D3", "D#3", "Eb3",
            "E3", "F3", "F#3", "Gb3", "G3", "G#3", "Ab3", "A3", "A#3", "Bb3",
            "B3", "C4", "C#4", "Db4", "D4", "D#4", "Eb4", "E4", "F4", "F#4",
            "Gb4", "G4", "G#4", "Ab4", "A4", "A#4", "Bb4", "B4", "C5", "C#5",
            "Db5", "D5", "D#5", "Eb5", "E5", "F5", "F#5", "Gb5", "G5", "G#5",
            "Ab5", "A5", "A#5", "Bb5", "B5", "C6" };
    private static float[] frequency = { 130.81f, 138.59f, 138.59f, 146.83f,
            155.56f, 155.56f, 164.81f, 174.61f, 185.0f, 185.0f, 196.0f,
            207.65f, 207.65f, 220.0f, 233.08f, 233.08f, 246.94f, 261.63f,
            277.18f, 277.18f, 293.66f, 311.13f, 311.13f, 329.63f, 349.23f,
            369.99f, 369.99f, 392.0f, 415.3f, 415.3f, 440.0f, 466.16f, 466.16f,
            493.88f, 523.25f, 554.37f, 554.37f, 587.33f, 622.25f, 622.25f,
            659.26f, 698.46f, 739.99f, 739.99f, 783.99f, 830.61f, 830.61f,
            880.0f, 932.33f, 932.33f, 987.77f, 1046.5f };
    /**
     * method uses playTone method
     * @param note is a String representation of the musical note in range C3-C6. See notes[] for allowed values
     * @param duration is note duration in ms
     */
    public void musicTone(String note, int duration) {
        for (int i = 0; i < notes.length; i++) {
            if(note.equals(notes[i])) {
                Sound.playTone((int)frequency[i], duration);
                Sound.pause(duration);
            }
        }
    }
    /**
     * method uses playNote method with Sound.XYLOPHONE as instrument argument
     * @param note is a String representation of the musical note in range C3-C6. See notes[] for allowed values
     * @param duration
     */
    public void musicXylo(String note, int duration) {
        for (int i = 0; i < notes.length; i++) {
            if(note.equals(notes[i])) {
                Sound.playNote(Sound.XYLOPHONE,(int)frequency[i], duration);
            }
        }
    }
    /**
     * method uses playNote method with Sound.PIANO as instrument argument
     * @param note is a String representation of the musical note in range C3-C6. See notes[] for allowed values
     * @param duration
     */    
    public void musicPiano(String note, int duration) {
        for (int i = 0; i < notes.length; i++) {
            if(note.equals(notes[i])) {
                Sound.playNote(Sound.PIANO,(int)frequency[i], duration);
            }
        }
    }
    /**
     * method uses playNote method with Sound.FLUTE as instrument argument
     * @param note is a String representation of the musical note in range C3-C6. See notes[] for allowed values
     * @param duration
     */        
    public void musicFlute(String note, int duration) {
        for (int i = 0; i < notes.length; i++) {
            if(note.equals(notes[i])) {
                Sound.playNote(Sound.FLUTE,(int)frequency[i], duration);
            }
        }
    }
}
Here is an example implementation of the class:

import lejos.nxt.Sound;

public class MusicTest {
    private static String[] melody = { "C4", "D4", "E4", "C4", 
        "E4", "C4",    "E4"};

    public static void main(String[] args) {
        Music music = new Music();
        for (int i = 0; i < melody.length; i++) {
            music.musicPiano(melody[i], 300);
            System.out.println(melody[i]);
        }
        Sound.pause(300);
        for (int i = 0; i < melody.length; i++) {
            music.musicTone(melody[i], 300);
            System.out.println(melody[i]);
        }
    }
}

Sunday, October 06, 2013

Processing.js Save Part of Sketch Window

I'm working on a save feature for a web app for drawing musical compositions. I want to make sure you can save your drawn composition and reload them instead of having to recreate them. Processing.js  has a save() method but I was thinking it was a dead end because it saves either the whole sketch window or a loaded image in the sketch, of which the drawn composition is neither. But this tip from the forum saved the day. Use get() to capture the region where the composition is drawn and define that as an image, then call save on that!
void trySaveImage() {
  if(mouseX > width-40 && mouseY < 40) {
    PImage drawWindow = get(20, top, width-20, height-top);
    drawWindow.save("drawing.png");
  }
}

Now I just have to figure out how to load the saved image...