Physics body jumping and landing - Help with logic

cocos2d-x C++
1

I would like to jump up once and then land even when the jump button is pressed continuously.
Currently I am doing something like this.

When the jump button is pressed a flag is set indicating that the player needs to jump . The update loop then makes the character jump.When the jump button is released the character lands back down.Here is the code

void Player_Controls::onTouchesBegan(const std::vector<cocos2d::Touch*>& touch , cocos2d::Event* event)
{
     ....
        else if(JumpButton->boundingBox().containsPoint(pA))
        {
            CCLOG("JumpButton Pressed");
            //Tell the update loop to make this sprite jump
            this->sprite_motion.motionDirection=SpriteMotion::MotionDirection::EnumJump;
        }
}


   //Set a flag when player releases the button 
   void Player_Controls::onTouchesEnded(const std::vector<cocos2d::Touch*>& touch , cocos2d::Event* event)
    {
            ....
            ....
            if(JumpButton->boundingBox().containsPoint(pA))
            {
                CCLOG("FireButton Released");
                this->sprite_motion.motionDirection=SpriteMotion::MotionDirection::EnumFall; //Tell the loop to make character fall down
            }
    }

This is what goes in the update loop

 if( this->sprite_motion.motionDirection == SpriteMotion::MotionDirection::EnumJump)
    {

               eagle->getPhysicsBody()->setVelocity(Vec2(0,400));
               this->sprite_motion.motionDirection=SpriteMotion::MotionDirection::EnumNone;
    }
    if( this->sprite_motion.motionDirection == SpriteMotion::MotionDirection::EnumFall)
    {
        CCLOG("Falling Down");
        eagle->getPhysicsBody()->setVelocity(Vec2(0,-400));
        this->sprite_motion.motionDirection=SpriteMotion::MotionDirection::EnumNone;
    }

Now the problem with this approach occurs if the jump button is continuously pressed and not released. The character keeps on going higher and higher. I wanted to know how to emulate a single jump even if the jump button is pressed continuously.

2

implementing some kind of state machine early into your control logic will help in the long run as well, this is a good reference point to start http://gameprogrammingpatterns.com/state.html

3

I think you forgot to post the link to the url

4

lol, thanks for pointing that out it has been fixed.
here u go direct link seems like linker problem Arrrrgggghhhhh…

5

Not really :smile:

6

Instead of a boolean flag, set a float with the number of seconds you want the jump to take.
Then, in your update(float dt); method …

if (jumpTimer > 0)
{
  jumpTimer -= dt;
  if (jumpTimer <= 0)
  {
    stopJumping(); // implement this to start falling
  }
}
1 Like
7

You can also use function pointers/jump maps and get rid of those nasty branches.

8

I am not sure which branches are you talking about.

9

I’m talking about your if/else constructs.

It was just a suggestion, that there are possibilities to get rid of them. It’s just that I don’t like them :smile:

Performance depends on how often your branches are taken. If they are taken every frame, if could harm performance.

10

I totally agree. I will definitely be refactoring my code. I am currently in a prototyping phase and the code is all messy. Thanks for the suggestion though.