Thread: breakout collision

I'm writing collision code for my breakout clone. Thanks to the people at allegro.cc I have gotten this far. Now I need more help with collision detection. I can find out if the ball is within the block and have it bounce off the left side, but that's all. anymore help?

Code:

   for(x =0; x < MAX_ROW; x++)
   {
      for(y = 0; y < MAX_COL; y++)
     {
        if (ball.x >  blocks[x][y].x && 
            ball.x <= blocks[x][y].width &&
            ball.y >  blocks[x][y].y && 
            ball.y <= blocks[x][y].height) 
       {
            if(blocks[x][y].color > 0)
                {
                    paddle.score += blocks[x][y].color*10;
                    blocks[x][y].color = 0;
                   if(ball.x > blocks[x][y].x)	
                      ball.dx = -BALL_DELTA; // bounce left
                   else if(ball.x <= blocks[x][y].width)
                           ball.dx = BALL_DELTA; // bounce right
                   else if(ball.y > blocks[x][y].y)
                           ball.dy = -BALL_DELTA; // bounce up
                   else if(ball.y <= blocks[x][y].height)
                           ball.dy = BALL_DELTA; // bounce down
                   numOfBlocks--;
                }
			}
		}
	}

Originally posted by lambs4

Code:

        if (ball.x >  blocks[x][y].x && 
            ball.x <= blocks[x][y].width &&
            ball.y >  blocks[x][y].y && 
            ball.y <= blocks[x][y].height)

should be:

Code:

        if (ball.x >  blocks[x][y].x && 
            ball.x <= blocks[x][y].x + blocks[x][y].width &&
            ball.y >  blocks[x][y].y && 
            ball.y <= blocks[x][y].y+blocks[x][y].height)

Then you shouldn't call the variable 'width' -- it is very confusing.

Code:

if(ball.x > blocks[x][y].x)

That condition will always be true. Try to follow and interpret your code.

Ok, I've gotten the collision code written for the blocks and and paddle. The new problem is that the ball gets stuck bouncing within the paddle. Any reason why this occurr?

Code:

void checkCollision(void)
{
   int x,y,i;
   // check ball and block collision
   for(x =0; x < MAX_ROW; x++)
  {
     for(y = 0; y < MAX_COL; y++)
    {
       if (ball.x > blocks[x][y].x && 
          ball.x <= blocks[x][y].x+blocks[x][y].width && 
          ball.y > blocks[x][y].y && 
          ball.y <= blocks[x][y].y+blocks[x][y].height)		
      {				
        if(blocks[x][y].color > 0)
       {
         if(ball.x+ball.width >= blocks[x][y].x+blocks[x][y].width)
           ball.dx = -ball.dx;			
         if(ball.x+ball.width <= blocks[x][y].x+blocks[x][y].width)
           ball.dx = ball.dx;		

         ball.dy = -ball.dy;				         
         
         paddle.score += blocks[x][y].color*10;
         blocks[x][y].color = 0;
         numOfBlocks--; 			
         playSound(BALLHITBLOCK);
       }
     }				
   }
}
// check ball and paddle collision
	if (ball.x > paddle.x &&
	ball.x <= paddle.x+paddle.width &&
	ball.y > paddle.y &&
	ball.y <= paddle.y+paddle.height)		
	{
		if(ball.x >= paddle.x+paddle.width)
			ball.dx = -ball.dx;			
		if(ball.x <= paddle.x+paddle.width)
			ball.dx = ball.dx;		

	  ball.dy = -ball.dy;
	  playSound(BALLHITPADDLE);
	}	
	
}