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Index › Programming Questions & Help › Syntax Questions › Collision syntax
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Collision syntax (Read 376 times)
adzer2
Collision syntax
Mar 30th, 2006, 12:40pm  
I am now looking to create a cascade effect of balls hitting off one another, this is the final piece of my program, but i am looking for an adjustment to my collision detection method below so that when a collision is detected the ball moves from a stationary position to go somewhere else depending on how much speed there is hitting the ball and the ball emitting the force moves slower and in the direction it should when hitting another ball
Code:

void collide() 
{ 
  ballHit = 0;
  correctBall = false;

  for (int i = 0; i <= 15; i++) 
  { 
    for (int j = 0; j <= 15; j++) 
    { 
	if ( i != j ) 
	{
	  distX = b[j].getXPos() - b[i].getXPos(); 
	  distY = b[j].getYPos() - b[i].getYPos(); 
	  d = dist(b[j].getXPos(), b[j].getYPos(), b[i].getXPos(), b[i].getYPos()); 

	  if ( d < 30) 
	  { 
	    if (i == 15)
	    {
		ballHit++;
		//doesnt need to be used in this problem
		//correctBall = checkHit(ballHit, j);
		theta = atan2(distY, distX);
		//set the direction of the X and Y axis depending on where the ball was hit (theta)
		b[i].directionX = -1 * cos(theta); 
		b[i].directionY = -1 * sin(theta);
		//my attempts at the problem
		//b[j].setSpeed(b[i].getSpeed() / 2); 
		//b[i].setSpeed(b[i].getSpeed() / 2);  
	    }  
	  } 
	}
    } 
  } 
}
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adzer2
Re: Collision syntax
Reply #1 - Mar 30th, 2006, 8:39pm  
A revision of the code here, I have the balls moving after they are hit but they keep overlapping each other now and never slow down (I have a getSpeed = getSpeed -2 in the main method when the speed isnt 0)

Code:

void collide() 
{ 
  ballHit = 0;
  correctBall = false;

  for (int i = 0; i <= 15; i++) 
  { 
    for (int j = 0; j <= 15; j++) 
    { 
	if ( i != j ) 
	{
	  distX = b[j].getXPos() - b[i].getXPos(); 
	  distY = b[j].getYPos() - b[i].getYPos(); 
	  d = dist(b[j].getXPos(), b[j].getYPos(), b[i].getXPos(), b[i].getYPos()); 

	  if ( d < 30) 
	  { 
	    if (i == 15)
	    {
		ballHit++;
		correctBall = checkHit(ballHit, j);
	    }
	    theta = atan2(distY, distX);
	    if ((b[i].getSpeedX() > b[j].getSpeedX()) || (b[i].getSpeedY() > b[j].getSpeedY()))
	    {
		b[i].setDirectionX(-1 * cos(theta));
		b[i].setDirectionY(-1 * sin(theta));
	    }
	    else
	    {
		b[j].setDirectionX(-1 * cos(theta));
		b[j].setDirectionY(-1 * sin(theta));
	    }
	    b[i].setSpeedX ((b[i].getSpeedX() + b[j].getSpeedX()) / 2);
	    b[i].setSpeedY ((b[i].getSpeedY() + b[j].getSpeedX()) / 2);
	  } 
	}
    } 
  } 
}
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