Processing_01_Basics.pde

/* 
 * A simple example of how to use
 * Processing as a demo platform.
 * 
 * Features:
 *  - Setup for rendering resolution-independent
 *    2D graphics
 *  - Music playback with Minim
 *  - Simple play/pause/seek-functionality
 */
 
// Minim is needed for the music playback.
import ddf.minim.spi.*;
import ddf.minim.signals.*;
import ddf.minim.*;
import ddf.minim.analysis.*;
import ddf.minim.ugens.*;
import ddf.minim.effects.*;

// All these you can (must) change!
// These control how big the opened window is.
// Before you release your demo, set these to 
// full HD resolution (1920x1080).
final int CANVAS_WIDTH = 1920;
final int CANVAS_HEIGHT = 1080;

// You can skip backwards/forwards in your demo by using the 
// arrow keys; this controls how many milliseconds you skip
// with one keypress.
int SONG_SKIP_MILLISECONDS = 2000;

// Don't change this – needed for resolution independent rendering
float ASPECT_RATIO = (float)CANVAS_WIDTH/CANVAS_HEIGHT;

// Needed for audio
Minim minim;
AudioPlayer song;


/*
 * Sets up audio playing: call this last in setup()
 * so that the song doesn't start to play too early.
 *
 * By default, playback doesn't start automatically –
 * you must press spacebar to start it.
 */
void setupAudio() {
  minim = new Minim(this);
  song = minim.loadFile("../common/tekno_127bpm.mp3");
  // Uncomment this if you want the demo to start instantly
  // song.play();
}

/*
 * Function settings must be used when calling size with variable height and width
 * New in processing 3
 */
void settings() {
  // Set up the drawing area size and renderer (usually P2D or P3D,
  // respectively for accelerated 2D/3D graphics).
  size(CANVAS_WIDTH, CANVAS_HEIGHT, P2D);
}

/*
 * Processing's setup method.
 *
 * Do all your one-time setup routines in here.
 */
void setup() {
  // Drawing options that don't change, modify as you wish
  frameRate(60);
  noStroke();
  fill(255);

  setupAudio();
}

/*
 * Your drawing code ends up in here!
 *
 */
void drawDemo(int time) {
// TODO: implement some example drawing
  // and time-based sync done in code
  
  // Draw centered unit circle
  ellipse(0., 0., 1.0, 1.0);
  
  // The following lines draw a full-screen quad.
  // Params for rect: x, y, width, height
  // rect(-ASPECT_RATIO, -1, 2*ASPECT_RATIO, 2);
}

/*
 * Draws coordinate axes (for reference).
 * You can remove this method if you don't 
 * need to see the axes.
 */
void drawAxes() {
  // Drawing options for axes
  stroke(255);
  strokeWeight(0.004);
  fill(255);

  // X-axis
  line(-ASPECT_RATIO, 0, ASPECT_RATIO, 0); 
  pushMatrix();
  resetMatrix();
  text(String.format("%.3f", -ASPECT_RATIO), 12, CANVAS_HEIGHT/2);
  text(String.format("%.3f", ASPECT_RATIO), CANVAS_WIDTH-42, CANVAS_HEIGHT/2);
  popMatrix();
  
  // Y-axis
  line(0, -1, 0, 1);
  pushMatrix();
  resetMatrix();
  text("1", CANVAS_WIDTH/2+12, 12);
  text("-1", CANVAS_WIDTH/2+12, CANVAS_HEIGHT - 12);
  popMatrix();
}

/*
 * Processing's drawing method – all
 * rendering should be done here!
 */
void draw() {
  // Reset all transformations.
  resetMatrix();

  // The following lines map coordinates so that we can
  // draw in a resolution independent coordinate system. 
  //
  // After this line coordinate axes are as follows:
  //   x: -ASPECT_RATIO ... ASPECT_RATION
  //   y: -1 ... 1  
  // Negative x is at left, y at bottom, origo at the center of 
  // the screen.
  // This is the coordinate system you're probably used to
  // already!
  translate(CANVAS_WIDTH/2.0, CANVAS_HEIGHT/2.0);
  scale(CANVAS_WIDTH/2.0/ASPECT_RATIO, -CANVAS_HEIGHT/2.0);
  
  // Clear the screen after previous frame.
  // If you comment this line, you always draw on top the last frame,
  // which can lead to something interesting.
  background(0);

  // Draw coordinate axes for reference.
  drawAxes();
  // Draw demo at the current song position.
  drawDemo(song.position());
}

void keyPressed() {
  if (key == CODED) {
    // Left/right arrow keys: seek song
    if (keyCode == LEFT) {
      song.skip(-SONG_SKIP_MILLISECONDS);
    } 
    else if (keyCode == RIGHT) {
      song.skip(SONG_SKIP_MILLISECONDS);
    }
  }
  // Space bar: play/payse
  else if (key == ' ') {
    if (song.isPlaying())
      song.pause();
    else
      song.play();
  }
  // Enter: spit out the current position
  // (for syncing)
  else if (key == ENTER) {
    print(song.position() + ", ");
  }
}