Bounce code

Game Development
1

so i’ve got this ball that i’d like to bounce off a paddle however the ball isnt effected at all by the paddle upon collision, I think it may have to do with pointers but i could be something else

ball class:

bool CBall::mCollision(CPaddle* other)
{
	if((mY >= other->mGetY() +other->mGetH()) && (mX >= other->mGetX() + other->mGetW()) &&
		(mY + mH <= other->mGetY()) && (mX + mW <= other->mGetX()))
		return true;
}

void CBall::mBounce(CPaddle* other)
{
	if(CBall::mCollision(other))
	{
	if(mDirection>=0 && mDirection<90)
	{
		if(mY + mH <= other->mGetY())
			mDirection = 270 + ((270 - mDirection) * 2);
		if(mX + mW <= other->mGetX())
			mDirection = 180 - ((0 + mDirection) * 2);
	}
	if(mDirection>=90 && mDirection<180)
	{
		if(mY + mH <= other->mGetY())
			mDirection = 270 + ((270 - mDirection) * 2);
		if(mX >= other->mGetX() + other->mGetW())
			mDirection = 0 - ((0 + mDirection) * 2);
	}
	if(mDirection>=180 && mDirection<270)
	{
		if(mY >= other->mGetY() + other->mGetH())
			mDirection = 90 + ((270 - mDirection)*2);
		if(mX >= other->mGetX() + other->mGetW())
			mDirection = 0 - ((mDirection - 180)*2);
	}
	if(mDirection>=270 && mDirection<360)
	{
		if(mY >= other->mGetY() + other->mGetH())
			mDirection = 90 - ((mDirection - 270)*2);
		if(mX + mW <= other->mGetX())
			mDirection = 180 + ((360 - mDirection)*2);
	}
	}
}

paddle class:

int CPaddle::mGetX()
{
	return mX;
}
int CPaddle::mGetY()
{
	return mY;
}

int CPaddle::mGetW()
{
	return mW;
}
int CPaddle::mGetH()
{
	return mH;
}

main:

// instantiate objects
CPaddle  mPlayer(10, (SCREEN_HEIGHT/2) - 30, 20, 60, 0xff, 0xff, 0xff, 5);
CBall	mBall;

// logic
mBall.mBounce(&mPlayer);

this is all the code related to the bounce function i believe, everything else works besides this bounce function(IDK why?), I’m able to get the ball to bounce off the screen borders so I know the bounce math is good just getting the ball to react to a collision with an object with changable x and y seems to be the problem

2

Passing a pointer to a class into another class is a bad idea. You would do better to pass a constant reference to the class:

bool CBall::mCollision(const CPaddle& other)

and then redefine the paddle’s accessor as a const accessor:

int CPaddle::mGetX() const
{
   return mX;
}

Passing a pointer to a class like that, or as I used to do, passing a non-const reference, will mangle your data sooner or later. Especially if there is a pointer inside the class.