PVector location;
PVector velocity;
float a = 0;
float b = 0;
float c = 0;
int size = 16;
boolean down = true;
boolean gravity = true;
boolean symmetrical = false;

void setup() {
  size(600,600);
  smooth();
  background(255);
  location = new PVector(350,300);
  velocity = new PVector(2.5,0);
}

void draw() {
  noStroke();
  fill(255,10);
  rect(0,0,width,height);

  location.add(velocity);//moves the ball
  if(gravity)//if gravity is true or "on"...
  {
    if(down == true)//...and down is true...
    {
      velocity.add(0,.2);//...gravity pulls ball down
    }
    if(down == false)//...and down is false
    {
      velocity.add(0,-.2);//...gravity pulls ball up
    }
  }
  if (((location.y > height) || (location.y < 0)) && (down == true)) {
    velocity.y = (velocity.y - .4) * -1;//makes ball lose some momentum when it bounces off of the floor or ceiling
    a = random(0,255);//sets a b and c variables to random floats between 0 and 255
    b = random(0,255);
    c = random(0,255);
  }
  if(((location.y > height) || (location.y < 0)) && (down == false))
  {
    velocity.y = (velocity.y + .4) * -1;//makes ball lose some momentum when it bounces off of the floor or ceiling
    a = random(0,255);//sets a b and c variables to random floats between 0 and 255
    b = random(0,255);
    c = random(0,255);
  }

  if(symmetrical == false)//if symmetrical is false...
  {
    if ((location.x > width) || (location.x < 0)) {//...then the ball can move across the entire width of the rectangle
      velocity.x = velocity.x * -1;//makes ball bounce off of walls
      a = random(0,255);
      b = random(0,255);
      c = random(0,255);
    }
    stroke(0);
    fill(a,b,c);
    ellipse(location.x,location.y,size,size);//shows the path of the object
  }

  if(symmetrical == true)//if symmetrical is true...
  {
    if ((location.x < (width/2 + size/2)) || (location.x > width)) {//...then makes ball bounce off of the middle line
      velocity.x = velocity.x * -1;
      a = random(0,255);
      b = random(0,255);
      c = random(0,255);
    }
   stroke(0);
  fill(a,b,c); // makes ball the color of random floats
  ellipse(location.x,location.y,size,size);//shows the path of the object
  scale(-1,1);
  ellipse(location.x-600,location.y,size,size);//shows a second object (that isn't there) on the other side of the line of symmetry, because i wanted to do it with only one PVector
  }
}

void keyPressed()
{
  if(key == 's' || key == 'S')//s for size
  {
    size = (int)random(2,30);//randomly changes the size of the ball
  }
  if(key == 'd' || key == 'D')//d for down
  {
    down = !down;//reverses gravity(goes up or down)
  }
  if(key == 'a' || key == 'A')//a for acceleration (sometimes, the ball goes out of bounds)
  {
    velocity.y = 0;//stops the ball from falling momentarily
  }
  if(key == 'g'|| key == 'G')//g for gravity
  {
    gravity = !gravity;//turns off gravity
  }
}
void mouseClicked()
{
  setup();
  symmetrical = !symmetrical;//makes the symmetrical version run
}