This add-on will show you
how to get the receivers to pass the ball
back to the starting point.
You can see in the example
that whenever the sprite receives the ball,
it immediately passes it back.
First, build the code to make the ball turn around.
Click the ball sprite to program it.
From motion, grab a turn right block
and snap it below the repeat until loop
inside the conditional
that checks if the Space key is pressed.
This turn right block
should turn the sprite all the way around
to reverse its direction.
There are 360 degrees in a circle
so half a circle is half of 360 or 180 degrees.
Enter 180 into the turn right block.
Now the ball sprite will go back to the starting point.
Drag out a second repeat until loop
and snap it below the turn right block.
Inside the loop, drag another move block
to make the sprite keep moving back
in its original direction after it turns around.
Find the condition that makes the loop stop running
at the right moment.
When the sprite touches an edge,
you know it's back at its starting point.
Go to sensing,
drag a touching block into the blank and select edge.
It's testing time.
Click the flag, then send the ball flying toward a receiver.
When it touches the receiver, it should bounce back.
Cool, test again by aiming for the edge.
The ball should bounce and come back,
but it just jumps back to the start.
This is because your new loop stops
before it can start moving the sprite.
It's still on an edge when the loop checks
so it exits immediately.
Fix this by placing an extra move block
right after the turn block.
That'll get the sprite away from the edge.
Great, test again.
If the go to block is still in the right place,
then the ball sprite will reset
after coming back to the start.
Finally, change the receiving costume
back to the kicking one for each receiver sprite.
This makes them look like they kick the ball back.
Just select the sprite in the dropdown
on the second switch costume block.
All right, here's the game plan.
Use a turn right and a second repeat until block
to make the ball sprite bounce back.
Switch the receiver costume to the kicking costume
when it touches the ball sprite.
Make the receivers disappear and regenerate each time you pass to them.
The ball will always bounce back to the starting position.
Add realistic variables with sliders that control the speed of the ball and the receiver sprites.
Count how many passes you complete.
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