Cartoon Studio IV

Review — Cartoon Studio III 5 min

• Every actor stands at (my x) - (camera x) and hides when far away.
• A pan worked out from the timer, eased with cos.
• A follow camera closes a tenth of the gap each frame.
• Zoom multiplies distances, sizes and Pip’s offsets — up to 1.4.

Quick-fire

Pip’s mouth read a list of times and a list of mouths. What would you need to add to that idea so the same loop could make anyone do anything?

Today’s Topic 3 min

• A cue sheet: three lists — time, actor, action
• A director that reads it against the timer
• Dispatchers: short cue scripts that start the long actions
• A title card, The End, and credits that roll

Learning outcome

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

1. Drive a whole project from data in lists.
2. Send one message that only the right sprite acts on.
3. Change a film by changing rows, not scripts.

Learnt — the director’s chair 28 min

1 · The cue sheet

Three lists that stay in step. Row 3 says: at 2.5 seconds, the foley desk plays Boing.

2 · The director

The Stage reads the sheet. For each row it waits for the time, puts the actor and the action into two variables, and sends one message: cue.

when flag clicked
set [start v] to (timer)
set [i v] to (1)
repeat until <(i) > (length of [cue time v])>
  wait until <((timer) - (start)) > (item (i) of [cue time v])>
  set [actor v] to (item (i) of [cue actor v])
  set [action v] to (item (i) of [cue action v])
  broadcast (cue v) and wait
  change [i v] by (1)
end
            

Every actor hears cue, checks whether it is for them, and acts:

when I receive [cue v]
if <(actor) = [Pip]> then
  if <(action) = [wave]> then
    broadcast (pip wave v)
  end
  if <(action) = [jump]> then
    broadcast (pip jump v)
  end
  if <(action) = [bow]> then
    broadcast (pip bow v)
  end
end
              

when I receive [cue v]
if <(actor) = [foley]> then
  set [sfx v] to (action)
  broadcast (foley play v)
end

when I receive [foley play v]
start sound (sfx)
              

3 · Why a dispatcher?

Why not put the wave straight into Pip’s cue script? Because a broadcast restarts every script that answers it. The next cue — even one for the Speaker — would start Pip’s cue script again from the top, and the wave would be cut off halfway.

So the cue script only dispatches: it sends a second message, such as pip wave, and finishes at once. The long action lives under when I receive [pip wave v], where no other cue can reach it.

The dispatchers finish at once, so broadcast (cue v) and wait costs just one frame. That frame matters: two rows with the same time are read one after the other, and neither is lost.

4 · Title, The End, credits

A film opens on a title card and closes with credits — and, as in Boss Tower, the credits name everything you borrowed. Ours is a tall costume that glides up the Stage.

when I receive [credits roll v]
go to x: (0) y: (-460)
go to [front v] layer
show
glide (8) secs to x: (0) y: (450)
hide
broadcast (credits done v)
            

Basic — Pip’s Big Day 25 min

Open last lesson’s road, with the zooming camera. Everything you have built this arc goes into one short film.

Step 1 — the cast

1. Upload a Title sprite with two costumes: title card and the end, and a Credits sprite.
2. Add the Cake sprite at size 40, standing in the world at x 1240 between Pip and Kitty. It stays hidden until its cue.
3. Give the Mouth the song from Lesson 26 (with a song start clock), and a Speaker sprite the Cheer sound. The Speaker can be hidden — a hidden sprite still plays sounds.

Step 2 — the sheet

1. Make the lists cue time, cue actor and cue action, and import film-cue-time.txt, film-cue-actor.txt and film-cue-action.txt. That is these 14 rows:

Step 3 — direct

1. Build the director from Learnt part 2 on the Stage.
2. Give every actor a dispatcher for its rows. The Stage is an actor too: for camera it switches the follow loop on, or plays a shot (1240, 1.4) for the close-up and (1240, 1) for the wide shot.
3. Pip walks 39 steps of 5, as in Lesson 27. Kitty jumps twice by changing a cat y that the draw adds on.

A new scene, without a new script

Add a moment to the short sheet from Learnt part 1.

• At 1.5 seconds, Pip trips: a little hop, and “Whoa!”
• At the same moment, the Speaker plays “Slide Whistle”.
• The two rows go in at row 2, so the sheet stays in time order.

insert (1.5) at (2) of [cue time v]
insert [Pip] at (2) of [cue actor v]
insert [trip] at (2) of [cue action v]
insert (1.5) at (3) of [cue time v]
insert [foley] at (3) of [cue actor v]
insert [Slide Whistle] at (3) of [cue action v]
            

Skip to the next scene

A film has scenes. Let the viewer jump ahead.

• Rows with actor director and action scene mark where each scene starts.
• Pressing → jumps the film to the next scene row.
• Every cue after the jump still plays, at its right place in the scene.

when [right arrow v] key pressed
repeat until <<(i) > (length of [cue time v])> or <(item (i) of [cue action v]) = [scene]>>
  change [i v] by (1)
end
if <not <(i) > (length of [cue time v])>> then
  set [start v] to ((timer) - (item (i) of [cue time v]))
end
            

Rehearsal speed

Directors watch rehearsals fast. Add a speed control.

• A speed variable: 1 is normal, 2 is double speed.
• At speed 2, the cues come twice as fast.
• The cue sheet is not changed at all.

wait until <(((timer) - (start)) * (speed)) > (item (i) of [cue time v])>
            

Recast a role

Kitty is busy today. The Dog will play the friend — and no script may change.

• The sheet’s actor column names roles: hero and friend.
• Two more lists: roles (hero, friend) and cast (Pip, Dog).
• The director turns each role into a sprite name before it sends the cue.
• Only the friend who is cast is on the Stage.

set [actor v] to (item (item # of (item (i) of [cue actor v]) in [roles v]) of [cast v])
            

when flag clicked
if <(item (2) of [cast v]) = [Cat]> then
  show
else
  hide
end
            

Summary 5 min

• A cue sheet is three lists in step: time, actor, action.
• The director waits for each time and sends one cue; each actor checks if it is for them.
• A cue script only dispatches. A broadcast restarts its answers, so long actions live under their own message.
• Change the film by changing rows: insert, skip, speed up, recast.

Cue sheet

The plan of a show: when, who, and what.

Director

The script that reads the plan and calls each cue.

Dispatcher

A short script that only passes a job on to the right place.

Credits

The list of who and what made the film.

Hand in

Save Pip’s Big Day — the Cartoon Studio arc is finished, and you have made a film. Next lesson the games come back: an old arcade classic, Brick Breaker.