I am trying to learn box2d in cocos2d. I have searched for online tutorials and ray Wenderlich's seem to be the best ones!I am learning in a slow but steady pace! I am currently developing an app in which I will include a ball in the screen, and every time I touch/tap this ball, it is going to move like someone is flicking a soccer ball. I have coded the part for the upward movement(y axis) of the ball, when touching/tapping it. The problem that I encounter is that I can not find a way to give the ball the appropriate angle in order to rotate and move on the x axis. Let me give you an example. Imagine you are flicking a soccer ball, you kick the ball upwards but also there is a spinning force on the ball. I am trying to develop the spinning and moving across the x axis part. I would like to touch the ball, in its lower right "corner" for example and spin and move in a realistic way. Touching it in the lower right "corner" while the ball is in the air, means that the ball will move and spin to the left side of the screen. I hope I clarified the situation! I would be grateful if someone could help me to understand that kind of movement! If you still haven't understand the concept of my game, search for "parksoccer" and you will understand what I am trying to develop.
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1 Answers
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I did this yesterday only. In this case what you can do is when you touch or tap a screen , you take that point in ccTouchesBegan and then find the position of the ball by GetPostion() method on body. Than you have to calculate the angle between these two points and find in which direction ball will go from these two points. now you have angle and direction in which ball will go so apply linearForce on that by ApplyLinearForce(b2vec2 forceangle, body->GetPosition()). Thats it.
Enjoy.
