Tracking and ordering multi-touches...

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Tracking and ordering multi-touches...

(4 posts) (3 voices)

Started 1 year ago by Sam
Latest reply from Sam

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Sam
Member

What would be the best way to track each individual multitouch and give each touch an assigned number?

What I'd like to accomplish is have 5 individual sprites appear at the tips of your fingers as you touch the screen with them. So if you have 4 fingers touching the screen, sprites 1-4 will be appearing at the tips of your fingers. If you remove a finger, 1-3.

How would I make it so order matters, which finger was picked up/released?
How would I make it so order doesn't matter?

I hope I'm making sense. I want to know which touch was the 1st touch on the screen, which was the 2nd, 3rd, 4th, or 5th, and if I pick up the 2nd or 3rd finger, I want the numbers to be re-assigned to the remaining fingers on the screen...

Thanks for the help!!

Posted 1 year ago #
bazcocos
Member

I just track them using the UITouch pointer that Cocos passes in.
So, when the first touch appears in ccTouchesBegan, asign it finger1touch = touch. Then, if a new one appears (whilst finger1touch is still active), asign it finger2touch etc. ccTouchesEnded tells you when the touch is released. Simples :)

Posted 1 year ago #

Each touch has a hash you can use to identify each touch. The logic may vary but once you have a hash for a touch you can pretty much order them anyway you like. The hash is unique so if you have 5 touches they will all have a unique hash.

In my joystick code I use this sometimes...

- (void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

	UITouch *touch = [touches anyObject];
	CGPoint point = [touch locationInView: [touch view]];
	point = convertCoordinate(point);

	// Start only if the first touch is within the pad's boundaries.
	// Allow touches to be tracked outside of the pad as long as the
	// screen continues to be pressed.
	if (isPointInCircle(point, kCenter, JOYSTICK_RADIUS)) {
		isPressed = YES;
		joypadTouchHash = [touch hash];
		[self updateVelocity:point];
	}

}

Then from another method I can query that hash to see what touch we are dealing with. I am not sure if that helps or not.

Posted 1 year ago #

Sam
Member

That actually does help. Question, though.. of what data type is joypadTouchHash?

Posted 1 year ago #

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