cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   marchold
   Member

   I have been using the stuff from this post about using UIGestureRecognizer to work with cocos2d
   http://www.cocos2d-iphone.org/forum/topic/8929

   I am really stuck on determining the exact direction and velocity of the swipe gesture. The idea is the swipe gesture will throw a ball. I can get the point where the gesture started, but I also need the end point and time delay to determine a velocity. Anyone have any idea how to get the velocity of a swipe gesture, or just the end point.

   Thanks

   Posted 1 year ago #
2. 

   Birkemose
   Moderator

   You could use gettimeofday to calculate the timing when touch began, moved and ended. That way it should be possible to calculate direction and velocity the moment your finger leaves the screen.

   If that is the way the big guys do it, I dont know.

   Posted 1 year ago #
3. 

   neophit
   Member

   You could use UIPanGestureRecognizer which provides velocity via velocityInView:. You can use it in your callback like this:
   

   - (void)handlePan:(UIGestureRecognizer*)recognizer node:(CCNode*)node {
   	UIPanGestureRecognizer *pan = (UIPanGestureRecognizer*)recognizer;
   	if ([pan state] == UIGestureRecognizerStateBegan || [pan state] == UIGestureRecognizerStateChanged) {
   		// Drag the ball
   		CGPoint delta = [pan translationInView:pan.view.superview];
   		ball.position = ccpAdd(ball.position, delta);
   		[pan setTranslation:CGPointZero inView:pan.view.superview];
   	} else if ([pan state] == UIGestureRecognizerStateEnded) {
   		CGPoint velocity = [pan velocityInView:pan.view.superview];
   		velocity.x; // Horizontal velocity
   		velocity.y; // Vertical velocity
   
   		// Add momentum to the ball. Maybe apply force in box2d or chipmunk?
   	}
   }

   This should get you going in the right direction.

   Posted 1 year ago #
4. 

   marchold
   Member

   Thanks for that, the pan gesture is the way to go.

   Posted 1 year ago #

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