How to Make a Jump Function in TGB/iTGB/TGE

Jumping seems to be a common question. It is a common function to have but on the outside it seems rather baffling. In the following tutorial I am going to teach you how to make one for yourself.

The basic idea of it a jump function is as follows:

1. When the level loads define a variable(we'll call it isJumping) the tells if the character is on the ground.
2. When the character collides with the ground isJumping is set to false
3. If player taps then make character jump. Set isJumping to true
4. When character collides again set isJumping to false
5. loop ...

So the first step is to define the variable and enable collision callback:

character::onLevelLoaded(%this, %scenegraph)
{
   //This allows collision callback(true/false)
   %this.setCollisionCallback(true);
   // Make our global isJumping variable
   $isJumping = false;
   //We call the character later
   $character = %this;
}

Then we check to see if character is colliding with the ground:

character::onCollision(%srcObj, %dstObj, %this)
{
  //checks to see what the character is colliding with(so you can jump only when you touch the ground)
  if(%dstObj.class $= "ground_class")
	{
		$isJumping = false;
	}
}

Finally we write the jump function:

function jump()
{
	if ($isJumping == false)
	{
	  	$isJumping = true;
	  	$character.setLinearVelocityY( -200 );
	}
}

Now you have to implement this in this function in the game(this function is different per product, I'm using iTorque)(game.cs):

function touchesDown(%touchIDs, %touchesX, %touchesY)
{
   echo("Entered touch down function");

   // How many fingers are down
   %numTouches = getWordCount( %touchIDs );

   // Loop through each finger and print its coordinates
   for(%count = 0; %count < %numTouches; %count++)
   {
		if ($gameOver == false){
			jump();
		} else if ($gameOver == true){
			restart();
		}
      // Finger ID
      %curTouch = getWord( %touchIDs, %count );
      
      // X screen coordinate
      %curX = getWord( %touchesX, %count );
      
      // Y screen coordinate
      %curY = getWord( %touchesY , %count );

      // World position
      %worldPos = sceneWindow2D.getWorldPoint(%curX, %curY);

      // Print results
      echo("Scanning touch " @ curTouch @ " at " @ %worldPos);
   }
}

Hope it helps! Please comment below for help if you need it :)