Paddle Bounce II

Review — where we got to 5 min

The ball bounces off all four walls and off the paddle. Nothing can go wrong yet.

• move (6) steps and if on edge, bounce, for ever.
• The paddle bounce points the ball somewhere between −45 and 45.

Quick-fire

if on edge, bounce bounces off the bottom too. So how do we stop it?

Today’s Topic 3 min

• A floor sprite that sits in front of the bottom edge
• A serve: putting the ball back in play after a miss
• A score that counts bounces, and three lives that count misses
• Why a game needs a pause between a mistake and the next chance

Learning outcome

By the end of this lesson you will be able to:

1. Take a life when the ball reaches the floor.
2. Serve the ball back into play from the middle.
3. End the game at zero lives and show the rally you managed.

Learnt — a floor, a serve, a score 27 min

1 · A floor in front of the wall

The bottom edge already bounces, and there is no Level 1 block that turns off one edge. So we never let the ball reach it.

1. Add a second Paddle sprite. Name it Floor.
2. Stretch it wide: set size to (560) %.
3. Put it low: go to x: (0) y: (-200).
4. Check the gap. The paddle sits at -140. The floor is a thick bar, so at -200 only its top edge shows, at about -158.
5. Give the floor a go to [back v] layer so the ball is always drawn on top of it.

when flag clicked
set size to (560) %
go to x: (0) y: (-200)
go to [back v] layer
show
            

2 · The serve

A miss costs a life and then puts the ball back. The pause matters: a ball that reappears instantly is a ball you lose twice.

1. In the ball’s forever loop, add if <touching [Floor v]?> then.
2. Inside it: a sound, change [lives v] by (-1).
3. Then go to x: (0) y: (0) and wait (1) seconds.
4. Then point in direction (pick random (135) to (225)).
5. Play it. Miss on purpose and watch the ball come back.

if <touching [Floor v]?> then
  start sound [Squawk v]
  change [lives v] by (-1)
  go to x: (0) y: (0)
  wait (1) seconds
  point in direction (pick random (135) to (225))
end
            

3 · Bounces are the score

The rally is the achievement in this game, so the number of paddle bounces is the score. Three misses ends it.

1. Make score and lives. Set them on the flag: 0 and 3.
2. In the paddle-touching if, add change [score v] by (1).
3. Under the life being taken, add if <(lives) = (0)> then with a broadcast in it.
4. On the paddle, receive the message, say the score, and stop all.
5. Play three whole games.

when I receive [game over v]
say (join [Longest rally: ] (score)) for (3) seconds
stop [all v]
            

Basic — build the game you can lose 25 min

Open last week’s project. The ball and paddle stay exactly as they are.

Step 1 — the floor

1. Add it, stretch it, place it below the paddle.
2. Send it to the back layer.
3. Check the ball can touch it without touching the paddle first.

Step 2 — losing a life

1. Make the lives variable and set it to 3 on the flag.
2. Add the floor-touching if to the ball.
3. Miss three times on purpose. It should cost exactly three.

Step 3 — the serve

1. Send the ball to the middle after a miss.
2. Add the wait.
3. Point it downward at a random angle.

Step 4 — the score

1. Make the score variable and set it on the flag.
2. Add the point inside the paddle-touching if.
3. Play until it reads at least ten.

Step 5 — the ending

1. Broadcast at zero lives.
2. Receive it on the paddle, say the score, stop all.
3. Play three games and write down the three scores.

Make a miss hurt

A life vanishing quietly is a life nobody noticed losing. Make the moment unmistakable.

• Something you hear.
• Something you see.
• A pause long enough to know what happened.

A serve nobody can complain about

A serve straight at the corner is not a challenge, it is a robbery. Find the range of angles that is fair, and use it.

• Every serve can be reached by a player who is paying attention.
• No serve is free.
• You have tried at least ten serves to check.

A score worth comparing

Your score has to let two games be compared honestly — yours today against yours tomorrow, or yours against anybody else’s. Decide what it measures, then prove it works.

• You can say in one sentence what the number counts.
• You play two games under exactly the same rules.
• The higher number belongs to the better game, every time.

An extra life you have to catch

Every so often a heart falls from the top. Catch it with the paddle and you get a life back — but you cannot chase it and the ball at once.

• A heart falls now and then, not constantly.
• Catching it gives a life back.
• Lives never go above three.
• Missing a heart costs nothing.

Summary 4 min

The ball can be lost now, so keeping it up is worth something.

1. The floor is a sprite in front of the bottom edge, because the edge always bounces.
2. A miss costs a life and serves the ball again from the middle.
3. The pause after a miss is what stops one mistake becoming three.
4. Bounces are the score, and three misses end the game.

Floor

A sprite across the bottom. Touching it is a miss.

Serve

Putting the ball back into play, in a new direction, after a pause.

Rally

Bounces in a row with no miss. Some games score this instead of the total.

Layer

Which sprite is drawn in front. The floor belongs at the back.

Next lesson: targets to break, a ball that gets faster, and a paddle that gets smaller.