Question

I´m making an iphone app in objective-c with cocos2d, in the code below I try to detect a collision and then run an animation. (The box1 is moved by touch)

When the “[self getChildByTag:d]” and “box1” collide AND overlap I get the “JUMP NOW!” displayed but I don’t get the jump itself, but when the box1 is moved away from the “[self getChildByTag:d]” the jump occurs.

I understand that this probably has to do with the fact that the action is called many times, but please explain to me exactly what happens and please help me with a solution!

- (void)update:(ccTime)dt { 
    for (int d = lowestAvailableTag; d <= highestAvailableTag; d++) {
      if ([self getChildByTag:d].position.y < (box1.position.y+45)&&             
          [self getChildByTag:d].position.x > (box1.position.x-45) && 
          [self getChildByTag:d].position.x < (box1.position.x+45) ) {

          NSLog(@"JUMP NOW!");

          if ([self getChildByTag:d].position.x < 150) {
             [[self getChildByTag:d] runAction:
              [CCJumpTo actionWithDuration:1.5 
                        position:ccp(240, 140) height:110 jumps:1]];
          }
      }
   }
}

//albar

Answer 1

You can add some BOOL flag to detect if your jump occured. Smth like:

- (void) update:(ccTime)dt
{
    if( jumpOccured == false )
    {
        BOOL needToJump = // your jump condition
        if( needToJump == true )
        {
            // your jump code

            jumpOccured = true;
        }
    }
}

by the way, if you have many possible collisions, you can use box2d to detect them