color cblack = color(0,0,0);

int t1_x = 135;
int t1_y = 135;
int t1_d = 2;
  
int t2_x = 365;
int t2_y = 365;
int t2_d = 4;
  
int crash = 0;

void setup(){
  size(500,500);
  background(cblack);
 
  stroke(200,200,200);
  noFill();
  rect(20,20,460,460);
  
  PFont font = loadFont("ArialMT-48.vlw");
  textFont(font, 12);
 
  loop();
  
 
}


void draw() {
  
  // Get current colour
  color t1_c = get(t1_x,t1_y);
  color t2_c = get(t2_x,t2_y);
  
  // Collision?
  if ( t1_c != cblack ) { crash = 1; crash(); }
  if ( t2_c != cblack ) { crash = 2; crash(); }
  
  // Draw next point and decide next direction
  
  stroke(20,170,220);
  point(t1_x, t1_y);
  stroke(220,170,20);
  point(t2_x, t2_y);
  
  if ( t1_d == 1 ) { t1_y--; }
  if ( t1_d == 2 ) { t1_x++; }
  if ( t1_d == 3 ) { t1_y++; }
  if ( t1_d == 4 ) { t1_x--; }
  
  if ( t2_d == 1 ) { t2_y--; }
  if ( t2_d == 2 ) { t2_x++; }
  if ( t2_d == 3 ) { t2_y++; }
  if ( t2_d == 4 ) { t2_x--; }
  
}



void keyPressed(){
  
  // Traceon 1 Controls
  switch(key){
  case 'd':
  case 'D':
    t1_d = 2;
    break;
  case 's':
  case 'S':
    t1_d = 3;
    break;
  case 'a':
  case 'A':
    t1_d = 4;
    break;
  case 'w':
  case 'W':
    t1_d = 1;
    break;
  }
 
  // Traceon 2 Controls
  switch(keyCode){
    case UP:
    t2_d = 1;
    break;
  case RIGHT:
    t2_d = 2;
    break;
  case DOWN:
    t2_d = 3;
    break;
  case LEFT:
    t2_d = 4;
    break;
  }
}


void crash() { 
  noLoop();
  text("Ow. Traceon "+crash+" has crashed and lost! Click to restart.", 50, 50);
}


// Reset
void mousePressed() {
  if ( crash != 0 ) {
    background(cblack);
    stroke(200,200,200);
    noFill();
    rect(20,20,460,460);
    
    t1_x = 135;
    t1_y = 135;
    t1_d = 2;
    
    t2_x = 365;
    t2_y = 365;
    t2_d = 4;
    
    crash = 0;
    
    loop();
  }
}