spiro_vinnymidterm

// SPIROGRAPH

// http://en.wikipedia.org/wiki/Spirograph

// also (for inspiration):

// http://ensign.editme.com/t43dances

//

// this p5 sketch uses simple transformations to create a

// Spirograph-like effect with interlocking circles (called sines).  

// press the spacebar to switch between tracing and

// showing the underlying geometry.

//

// your tasks:

// (1) tweak the code to change the simulation so that it draws something you like.

// hint: you can change the underlying system, the way it gets traced when you hit the space bar,

// or both.  try to change *both*.  :)

// (2) use p5.sound or tone.js to make the simulation MAKE SOUND.

// hint: the websites for p5.sound and tone.js have lots of examples.

// try and adapt them.

// another hint: javascript isn't super efficient with a large number of audio playing at once.

// see if there's a simple way to get an effective sound, or limit the number of shapes

// you're working with.

​

var NUMSINES = 10; // how many of these things can we do at once?

var sines = new Array(NUMSINES); // an array to hold all the current angles

var rad; // an initial radius value for the central sine

var i; // a counter variable

var oscs = new Array(NUMSINES);

​

// play with these to get a sense of what's going on:

var fund = 0.050; // the speed of the central sine

var ratio = 2; // what multiplier for speed is each additional sine?

var alpha = 100; // how opaque is the tracing system

​

var trace = false; // are we tracing?

​

function setup()

{

  createCanvas(windowWidth, windowHeight);

​

  rad = height/2; // compute radius for central circle

  background(255); // clear the screen

​

  for (i = 0; i<sines.length; i++)

  {

    sines[i] = PI; // start EVERYBODY facing NORTH

    oscs[i] = new p5.Oscillator('sine');

    oscs[i].amp(0.05);

    oscs[i].freq(50*0.7*(i+2));

    oscs[i].start();

  }

}

​

function draw()

{

  if (!trace) {

    background(255); // clear screen if showing geometry

    stroke(0, 255); // black pen

  } 

​

  // MAIN ACTION

  push(); // start a transformation matrix

  translate(width/2, height/2); // move to middle of screen

​

  for (i = 0; i<sines.length; i++) // go through all the sines

  {

    var erad = 50; // radius for small "point" within circle... this is the 'pen' when tracing

    // setup for tracing

    if (trace) {

      stroke(102, 0, 51*(float(i)/sines.length), alpha); // blue

      fill(102, 0, 51, alpha/2); // also, um, blue

      erad = 2.0*(0.5+float(i)/sines.length); // pen width will be related to which sine

    }

    var radius = rad/(i+1); // radius for circle itself

    rotate(sines[i]); // rotate circle

    if (!trace) ellipse(0,0, radius*2, radius*2); // if we're simulating, draw the sine

    push(); // go up one level

    translate(0, radius); // move to sine edge

    if (!trace) rect(0, 0, 5, 50); // draw a little circle

    if (trace) rect(50, 5, erad, erad); // draw with erad if tracing

    pop(); // go down one level

    translate(0, radius); // move into position for next sine

    sines[i] = (sines[i]+(fund+(fund*i*ratio)))%TWO_PI; // update angle based on fundamental

  }

  pop(); // pop down final transformation

}

​

function keyReleased()

{

  if (key==' ') {

    trace = !trace; 

    background("black");

  }

}