int ballX, ballY, ballVelocityX, ballVelocityY;
int padX, padY, padVelocity, padWidth = 100, padHeight = 10;
int score;
boolean ballAlive;

void setup() {
  size(480, 600);
  ballX=10; 
  ballY=10; 
  ballVelocityX=12; 
  ballVelocityY=8; 
  ballAlive=true;
  padX=100; 
  padY=height-padHeight;
  padVelocity=10;
  score=0;
}

void draw() {
  //球の跳ね返し
  if (ballAlive) {
    //壁との衝突
    if (ballX<0 || width<ballX) ballVelocityX*=-1;
    if (ballY<0) ballVelocityY*=-1;
    //棒との衝突
    if (padX<ballX && ballX<padX+padWidth && ballY>padY-10) {
      ballVelocityY*=-1;
      score++;
    }
    //地面との接触
    if (height<ballY) {
      ballAlive=false;
      score=0;
    }
  }

  //球と棒の位置の更新
  ballX+=ballVelocityX;
  ballY+=ballVelocityY;
  padX=mouseX-50;

  //棒の動ける範囲
  if (padX<0)padX=0;
  if (padX+padWidth>width) padX=width-padWidth;

  //球と棒の描画
  background(0);
  fill(255);
  if (ballAlive) ellipse(ballX, ballY, 20, 20);
  rect(padX, padY, padWidth, padHeight);
  textSize(30);
  textAlign(LEFT);
  text("SCORE:" + score, 10, 30);

  //ゲームオーバー
  if (ballAlive==false) {
    textSize(30); 
    textAlign(CENTER);
    text("CLICK HERE", width/2, height/2);
  }

  //リスタート
  if (ballAlive==false && mousePressed) {
    ballAlive=true;
    ballX=10;
    ballY=10;
  }
}