HomeWork3-BallMotion-Zouziqu

/*

@autor Ziqu Zou, 07/31/2013, Homework3.0-Moving ball

*/

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int ballPosX; //ball's X position 

int ballPosY; //ball's Y position 

int ballW;

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int speed;//speed of ball

int backGroundColor;//backgroundcolor

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void setup() {

  size(700, 500);

  background(0);

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  ballW=30;

  ballPosX=int(random(0, width));

  ballPosY=height/2;

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  speed=5;

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  fill(255);

}

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void draw() {

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  background(backGroundColor);

​

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  ellipse(ballPosX, ballPosY, ballW, ballW);

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  ballPosX+=speed;

  //ballPosY+=speed;

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  if (ballPosX<25||ballPosX>(width-25)) //hit test

  {

    if (ballPosX<25)

    {

      backGroundColor=0;

      fill(255);

    }

    else if (ballPosX>(width-25)) {

      backGroundColor=255;

      fill(255, 0, 0);

    }

​

    speed=speed*-1;

    print("hit L&R");

  }

}

​

​

​