循环处理arraylist的圆形碰撞检测

Question

我试图避免在另一个圈子上创建圈子。我不能让碰撞检测工作。机器无休止地崩溃。

如何确保圆圈在创建时不会相互碰撞？

ArrayList balls;
int maxBall = 10;

void setup() {
  size(1000, 800);
  smooth();
  noStroke();

  // Create an empty ArrayList
  balls = new ArrayList();


  float radius = 100;

  balls.add(new Ball(random(50, width-50), random(50, height-50), radius, color(0, 255, 100) ));

  while (balls.size() < maxBall) { 
    Ball ball = new Ball(random(50, width-50), random(50, height-50), radius, color(0, 255, 100) );


    for (int i = 0; i < balls.size(); i++) {
      Ball currentBall = (Ball) balls.get(i);
      float distance = checkCollision(currentBall.getX(), currentBall.getY(), radius, ball.getX(), ball.getY(), radius);
      if (distance > 200) {
        balls.add(ball);
        println("Added, distance: " + distance);
      }
      println();
      //println("Distance: " + distance);

    }
  }
}


void draw() {
  background(0, 0);

  for (int i = balls.size()-1; i >= 0; i--) {
    Ball ball = (Ball) balls.get(i);

    ball.display();
  }
}

class Ball {

  float x;
  float y;
  float r;
  color colorID;


  Ball(float tempX, float tempY, float tempW, color tempColor) {
    x = tempX;
    y = tempY;
    r = tempW;
    colorID = tempColor;
  }


  void display()
  {
    fill (colorID);
    ellipse(x, y, r, r);
  }

  float getX() { 
    return x;
  }
  float getY() { 
    return y;
  }
}

float checkCollision(float x1, float y1, float r1, float x2, float y2, float r2) { 
  return dist(x1, y1, r1, x2, y2, r2);
}

Answer 1

你的代码没有多大意义。首先，您遍历ArrayList并检查它们中是否有任何碰撞。如果没有，则添加另一个Ball，但不要检查新的Ball是否与ArrayList中已有的内容发生冲突。

相反，您必须检查新Ball是否与ArrayList中已有的内容相交。像这样：

while (maxBall > balls.size()) { 

   Ball ball = new Ball(random(50, width-50), random(50, height-50), 100, color(0, 255, 100) );

   boolean foundCollision = false;

   for (Ball currentBall : balls) {

      isColliding = checkcirclecollide(currentBall.getX(), currentBall.getY(), 100, ball.getX(), ball.getY(), 100);

      if(isColliding){
         foundCollision = true;
      }     
   }

   if(!foundCollision){
      balls.add(ball);
   }
}

另外，只需使用Processing附带的dist()函数：

boolean checkcirclecollide(double x1, double y1, float r1, double x2, double y2, float r2) { 
  return dist(x1, y1, x2, y2) < (r1 + r2);
}

可以在the Processing reference找到更多信息。

Answer 2

我设法让它发挥作用。这可能对某些人有用，所以我将解释我所做的事情。

第一个问题是ellipseMode，我把它设置为：

ellipseMode(RADIUS);

其次，我不知道dist函数

dist(x1, y1, r1, x2, y2, r2);

无论如何，工作代码：

ArrayList balls;
int maxBall = 10;
boolean foundCollision;

void setup() {
  size(1000, 800);
  smooth();
  noStroke();
  ellipseMode(RADIUS);

  // Create an empty ArrayList
  balls = new ArrayList();


  float radius = 100;

  balls.add(new Ball(random(100, width-100), random(100, height-100), radius, color(0, 255, 100) ));

  int counter = 0;
  while (balls.size() < maxBall) { 
    foundCollision = false;
    Ball ball = new Ball(random(100, width-100), random(100, height-100), radius, color(0, 255, 100) );


    for (int i = 0; i < balls.size(); i++) {
      Ball currentBall = (Ball) balls.get(i);
      float distance = checkCollision(currentBall.getX(), currentBall.getY(), radius, ball.getX(), ball.getY(), radius);
      if (distance < 200) {
        foundCollision = true;
        counter = counter+1;
        println("COllision: " + counter);
        break;
      }
      distance = 0;
    }
    if (!foundCollision) {
      balls.add(ball);
    }

  }
  println("Total COllision counter: " + counter);
}


void draw() {
  background(0, 0);

  for (int i = balls.size()-1; i >= 0; i--) {
    Ball ball = (Ball) balls.get(i);

    ball.display();
  }
}

class Ball {

  float x;
  float y;
  float r;
  color colorID;


  Ball(float tempX, float tempY, float tempW, color tempColor) {
    x = tempX;
    y = tempY;
    r = tempW;
    colorID = tempColor;
  }


  void display()
  {
    fill (colorID);
    ellipseMode(RADIUS);
    ellipse(x, y, r, r);
  }

  float getX() { 
    return x;
  }
  float getY() { 
    return y;
  }
}

// Check the collision

float checkCollision(float x1, float y1, float r1, float x2, float y2, float r2) { 
  return dist(x1, y1, r1, x2, y2, r2);
}