// By Chris Orban for Physics 1251 at OSU Marion

float x;
float y;

float vx=10.0;
float vy;

float deltaVx;
float deltaVy;

float mass = 1.0; // Atomic mass unit
float dt = 0.1;

float x_plate_left = 200;
float x_plate_right = 500;

float q = 1; // elementary charge
float E = 5; // Natural units

//For drawing the image of the proton
PImage img;

void setup() {
  size(750,500);
  smooth();

  x = 0.05*width;
  y = height/2;
  img = loadImage("http://www.physics.ohio-state.edu/~orban/physics1251lab/proton.png");
}

// For people with C and C++ experience, draw() is
// very similar to main(), except that draw() 
// is run over and over again 
void draw() {
  
  // Update velocities
  vx += deltaVx;

  // Update location
  x += vx*dt;

  // Set deltaV to zero (thrust off unless user turns it on)
  deltaVx = 0;

  if ( ( x > x_plate_left) & (x < x_plate_right))
  {
  deltaVx = (q*E/mass)*dt;
  }

  // Draw ship and other stuff
  display();

  if ( (x > width) | (x < 0) ) {
  drawText("Final Velocity = ",width/2-125,height/2);
  drawText(vx,width/2+25,height/2);
  noLoop();
  }


} // end draw()