int currentindex = 0;
int numx = 1;
int numy = 1;
int dirx = 1;
int diry = 1;
int oldmouseX = -1;
int oldmouseY = -1;
int[] beginX = new int[200];
int[] endX = new int[200];
int[] beginY = new int[200];
int[] endY = new int[200];
int oldKeyCode = -1;

void setup() {
  size(500, 500);
  background(255);
  int i = 0;
  while(i < 200){
	beginX[i] = -1;
	beginY[i] = -1;
	endX[i] = -1;
	endY[i] = -1;
	i+= 1;
  }
}

// redraw all lines recorded in the vectors
void redrawlines() {
  int j = 0;
  while(j < currentindex){
    line(beginX[j], beginY[j], endX[j], endY[j]);
    j+= 1;
  }
}

void keyPressed() {
  if ((key == CODED) && (keyCode != oldKeyCode)) {
    if (keyCode == UP) {
      print(" Just pressed key up ");
    } else if (keyCode == DOWN) {
      print(" Just pressed key down ");
    } else if (keyCode == LEFT) {
      print(" Just pressed key left ");
    } else if (keyCode == RIGHT) {
      print(" Just pressed key right ");
    } 
    oldKeyCode = keyCode;
  } 
}

void draw() {
  stroke(0);
  keyPressed();
  if(mousePressed) {
    if(oldmouseX != - 1) {
      if(abs(oldmouseX - mouseX) > abs(oldmouseY - mouseY)) {
       if(currentindex < 200) {
           line(mouseX, oldmouseY, oldmouseX, oldmouseY);
           beginX[currentindex] = mouseX;
           beginY[currentindex] = oldmouseY;
           endX[currentindex] = oldmouseX;
           endY[currentindex] = oldmouseY;
           currentindex+= 1; 
       }
      }
      else { // y difference greater than x difference
      if(currentindex < 200){
        if(mouseY != oldmouseY){
        line(oldmouseX, mouseY, oldmouseX, oldmouseY);
         beginX[currentindex] = oldmouseX;
         beginY[currentindex] = mouseY;
         endX[currentindex] = oldmouseX;
         endY[currentindex] = oldmouseY;
         currentindex+= 1; }}
        // and then what? TYLER
      }
    }
    //print(" jacked " + mouseX);
    //print(" oldmouseX is " +oldmouseX);
    oldmouseX = mouseX;
    oldmouseY = mouseY;
  }  { //  advance ball and then check whether we hit a line
     numx+= dirx;
     numy+= diry;
     background(255); // refreshes the screen
     int i = 1;
     set(numx, (int) ((numy)), color(i));
     set(numx, (int) (1+(numy)), color(i));
     set(numx, (int) ((-1)+(numy)), color(i));
     set(numx+1, (int) ((numy)), color(i));
     set(numx-1, (int) ((numy)), color(i));
     set(numx+1, (int) (1+(numy)), color(i));
     set(numx-1, (int) ((-1)+(numy)), color(i));
     set(numx+1, (int) ((numy)-1), color(i));
     set(numx-1, (int) ((numy)+1), color(i));
     // now determine whether we hit a line and if so, change direction
     int j = 0;
     while(j < currentindex) {
     if(((beginX[j] == endX[j]) && (numx == beginX[j])) 
     && (((((endY[j]) >= beginY[j]) && ((endY[j] >= numy) && (beginY[j] <= numy)))) || 
     (((endY[j]) <= beginY[j]) && ((endY[j] <= numy) && (beginY[j] >= numy))))) {dirx = - dirx;}
     if(((beginY[j] == endY[j]) && (numy == beginY[j])) 
     && (((((endX[j]) >= beginX[j]) && ((endX[j] >= numx) && (beginX[j] <= numx)))) || 
     (((endX[j]) <= beginX[j]) && ((endX[j] <= numx) && (beginX[j] >= numx))))) {diry = - diry;}
     j+= 1;}
     if((numx > 501) || (numx < -1)) dirx = - dirx;
     if((numy > 501) || (numy < -1)) diry = - diry;
   
     redrawlines();
  
  // print(" currentindex is " + currentindex);
}
}