ok i wrote the code. im trying to make it so that i havve a tank and i want it to move so i have the picture i think but whenever i try to run it i get a white screen. help?
 
final static int NORTH = 1;
final static int EAST = 2;
final static int SOUTH = 4;
final static int WEST = 8;
int result;
float x,y;//x and y for tank

int speed=5;//speed of tank

class Hero{
 
  void display(){
    background(255);
   
  }
}
   
 

void setup(){
  PImage tankup;
  tankup=loadImage("Tank Up.png");
  image(tankup,x,y);
  size(600,600);
  result=0;
  x=0;
  y=0;
}
void draw(){
 
  Hero hero;
  hero= new Hero();
  hero.display();
 
 
   
 
 
  switch(result) {
    case NORTH: y=y-speed; break;
    case EAST: x=x+speed; break;
    case SOUTH: y=y+speed; break;
    case WEST: x=x-speed; break;
  }
 
 
 
}
void keyPressed(){
  switch(key) {
    case('w'):case('W'):result |=NORTH;speed=5;break;
    case('d'):case('D'):result |=EAST;speed=5;break;
    case('s'):case('S'):result |=SOUTH;speed=5;break;
    case('a'):case('A'):result |=WEST;speed=5;break;
  }
}
 
void keyReleased(){ 
  switch(key) {
    case('w'):case('W'):result ^=NORTH;break;
    case('d'):case('D'):result ^=EAST;break;
    case('s'):case('S'):result ^=SOUTH;break;
    case('a'):case('A'):result ^=WEST;break;
  }
}