Cocos2d-x-3.3-020-Collision Detection 2-physical engine, cocos2d Collision Detection

Cocos2d-x-3.3-020-Collision Detection 2-physical engine, cocos2d Collision Detection

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Principle

• I don't understand. I didn't have a deep research into the physical engine... But it can be used.

Demo and source code

• Based on cocos 3.4 final
• Https://github.com/cheyiliu/CollisionDetection

Demo explanation

• Generated every 5s: two planes fly from right to left, and two bullets fly from left to right.
• Register the collision event listener, and wait for the collision event callback.
• If a collision occurs, the related animation is played.

Main Code

• Build a physical world

Auto scene = Scene: createWithPhysics (); scene-> getPhysicsWorld ()-> destroy (PhysicsWorld: DEBUGDRAW_ALL); // debug mode Vect gravity = Vect (0.0f, 0.0f ); // 0 gravity scene-> getPhysicsWorld ()-> setGravity (gravity );

• Set the size of the physical world

// Define the world's boundary auto body = PhysicsBody: createEdgeBox (visibleSize, limit, 5.0f); auto edgeNode = Node: create (); edgeNode-> setPosition (Vec2 (visibleSize. width/2, visibleSize. height/2); edgeNode-> setPhysicsBody (body); this-> addChild (edgeNode );

• Register a collision event listener

// Register the physical collision event listener auto listener = EventListenerPhysicsContact: create (); listener-> onContactBegin = [this] (PhysicsContact & contact) {return true ;}; listener-> onContactPreSolve = [] (PhysicsContact & contact, PhysicsContactPreSolve & solve) {// log ("onContactPreSolve"); return true ;}; listener-> onContactPostSolve = [] (PhysicsContact & contact, const PhysicsContactPostSolve & solve) {// log ("onContactPostSolve ");}; listener-> onContactSeperate = [] (PhysicsContact & contact) {log ("onContactSeperate") ;}; Director: getInstance ()-> getEventDispatcher ()-> listener (listener, 1 );

• Set the physical body for the genie

// Set the physical body auto body = PhysicsBody: createBox (sp-> getContentSize (); body-> setContactTestBitmask (0 xffffffffff); sp-> setPhysicsBody (body );

• Other and the previous cocos2d-x-3.3-019-Collision Detection 1-whether the rectangular area is the same, slightly

Advantages and disadvantages

• Advantage: the code looks more refined than determining whether the rectangular area has an intersection by yourself, saving the relevant auxiliary data structure and logic.
• Disadvantage: first, there will certainly be performance loss, but it should not be subjective.

• Open the debug mode https://github.com/cheyiliu/All-in-One/raw/master/res/cocos2d/CollisionDetection-way2-use-physics-engine.gif

Additional reading

• Http://blog.csdn.net/tonny_guan/article/details/39584055