y = 250;

​

vx = 25;

vy = 0;

​

deltaVx = 0;

deltaVy = 0;

​

theta = 0;

​

Fthrust = 30.0;

mass = 3.0;

dt = 0.1;

​

function draw() {

  // Update velocities

  vx += deltaVx;

  vy += deltaVy;

​

  // Update location

  x += vx * dt;

  y += vy * dt;

​

  // velocity is unchanged if there are no forces

  deltaVx = 0;

  deltaVy = 0;

​

  // Turn or thrust the ship depending on what key is pressed

  if (keyIsDown(LEFT_ARROW)) {

    theta += 0.1;

  }

  if (keyIsDown(RIGHT_ARROW)) {

    theta -= 0.1;

  }

  if (keyIsDown(UP_ARROW)) {

    // Rockets on!

    accelx = Fthrust * cos(theta) / mass;

    deltaVx = accelx * dt;

    accely = Fthrust * sin(theta) / mass;

    deltaVy = accely * dt;

  }

  if (keyIsDown(DOWN_ARROW)) {

    accelx = -Fthrust * cos(theta) / mass;

    deltaVx = accelx * dt;

    accely = -Fthrust * sin(theta) / mass;

    deltaVy = accely * dt;

  }

  if (keyIsPressed && key == ' ') { //spacebar

    // Do nothing!

  }

  // Draw ship and other stuff

  // This will clear the screen and re-draw it

  display();

  // Add more graphics here before the end of draw()

  for (i = 0; i < xhistory.length; i += 1) {

    drawPoint(xhistory[i], yhistory[i]);

  }

​

} // end draw()