Keeping the CCSprite on the screen

Question

In my cocos2d app I have a CCSprite moving on the screen but it moves off the screen. How can I prevent the CCSprite from moving off the screen?

Thanks

Answer 1

You have to make sure your sprite-rectangle is always within the screen bounds. You can ensure this by clamping the x, and y position of the sprite within the screen bounds.

Something like this (this is assuming the anchor point of the sprite is at its center, which is the default):

// move sprite using accelerometer

// get screen size
CGSize screen = [[CCDirector sharedDirector] winSize];

// get sprite size
CGSize size = sprite.contentSize;

// get sprite position
CGPoint pos = sprite.position;

// set new position constrained to screen bounds
sprite.position = ccp(
    clampf(pos.x, size.width * 0.5f, screen.width - size.width * 0.5f),
    clampf(pos.y, size.height * 0.5f, screen.height - size.height * 0.5f)
);