swarm logo animation (#1018)

./scripts/play.sh --scenario data/scenarios/Fun/logo-burst.yaml

![image](https://user-images.githubusercontent.com/261693/213022706-9ef7f8dc-03ef-4e84-8772-6ccd5645268f.png)

data/scenarios/Fun/00-ORDER.txt

@@ -1 +1,2 @@
 GoL.yaml
+logo-burst.yaml

data/scenarios/Fun/_logo-burst/coordinator.sw

@@ -0,0 +1,12 @@
+def forever : cmd unit -> cmd unit = \c. c ; forever c end
+
+def alternate =
+  wait 50;
+  say "Green light";
+  make "bit (1)";
+  wait 100;
+  say "Red light";
+  make "bit (0)";
+  end;
+
+forever alternate;

data/scenarios/Fun/_logo-burst/drone.sw

@@ -0,0 +1,67 @@
+
+def repeat : int -> cmd unit -> cmd unit =
+  \n. \c. if (n == 0) {} {c ; repeat (n-1) c}
+end
+def abs = \n. if (n < 0) {-n} {n} end
+def elif = \t. \then. \else. {if t then else} end
+def else = \t. t end
+
+def randdir : cmd dir =
+  d <- random 4;
+  return (
+    if (d == 0) {north}
+    $ elif (d == 1) {east}
+    $ elif (d == 2) {south}
+    $ else {west}
+  )
+end;
+
+def wander =
+  d <- randdir;
+  turn d;
+  dist <- random 4;
+  try {repeat dist move} {};
+end;
+
+def disperse =
+  r <- robotnamed "stoplight";
+  greenLight <- as r {has "bit (1)"};
+  if greenLight {
+    wander;
+    disperse;
+  } {};
+  end;
+
+def converge = \loc. \currentLoc.
+
+  let xDist = fst currentLoc - fst loc in
+  let yDist = snd currentLoc - snd loc in
+
+  if (xDist < 0) {
+    turn east;
+  } {
+    if (xDist > 0) {
+      turn west;
+    } {};
+  };
+  repeat (abs xDist) move;
+
+  if (yDist < 0) {
+    turn north;
+  } {
+    if (yDist > 0) {
+      turn south;
+    } {};
+  };
+  repeat (abs yDist) move;
+  end;
+
+def go = \loc.
+  disperse;
+  currentLoc <- whereami;
+  converge loc currentLoc;
+  go loc;
+  end;
+
+loc <- whereami;
+go loc;

data/scenarios/Fun/logo-burst.yaml

@@ -0,0 +1,84 @@
+version: 1
+name: Logo burst
+author: Karl Ostmo
+description: |
+  Animate the Swarm logo
+creative: false
+seed: 0
+robots:
+  # We include a base robot to stabilize the screen at a fixed position.
+  - name: base
+    display:
+      invisible: true
+    dir: [1, 0]
+    devices:
+      - logger
+      - hearing aid
+  - name: botRight
+    system: true
+    display:
+      invisible: false
+    dir: [1, 0]
+    program: |
+      run "scenarios/Fun/_logo-burst/drone.sw"
+  - name: botUp
+    system: true
+    display:
+      invisible: false
+    dir: [0, 1]
+    program: |
+      run "scenarios/Fun/_logo-burst/drone.sw"
+  - name: botLeft
+    system: true
+    display:
+      invisible: false
+    dir: [-1, 0]
+    program: |
+      run "scenarios/Fun/_logo-burst/drone.sw"
+  - name: botDown
+    system: true
+    display:
+      invisible: false
+    dir: [0, -1]
+    program: |
+      run "scenarios/Fun/_logo-burst/drone.sw"
+  - name: stoplight
+    system: true
+    display:
+      invisible: false
+    dir: [0, 1]
+    devices:
+      - lodestone
+    inventory:
+      - [1, bit (0)]
+    program: |
+      run "scenarios/Fun/_logo-burst/coordinator.sw"
+  
+known: [boulder, tree, water, wavy water]
+world:
+  default: [blank]
+  upperleft: [0, 0]
+  offset: false
+  palette:
+    'Ω': [blank, null, base]
+    's': [blank, null, stoplight]
+    '.': [blank]
+    ' ': [blank]
+    '@': [blank, boulder]
+    'T': [blank, tree]
+    '▒': [blank, water]
+    '~': [blank, wavy water]
+    '>': [blank, null, botRight]
+    '^': [blank, null, botUp]
+    '<': [blank, null, botLeft]
+    'v': [blank, null, botDown]
+  map: |
+    s                   v                                     .
+    .                                                         . 
+    . v<^vv<<@   ^^     vv    >^v^T    ^^^v<     <><      v   >
+    T  ^<        >^  <  >>   v>   v<   >T   <v>  <<▒^  @><>   .
+    .   <@v^^>>   @v  >  <T  <v<T<Ω^>   v><v<     << <<T^ v<  . 
+    . >     >>   v@ @@> <<   ~v   <    >~  ^~    >>  @^  >v   .
+    .   >>^v^^^    < ~ T~v    v<   <~   >>T  <v   vv      ▒>  . 
+    .                             ▒                           . 
+    .                   ^      ^     v       >      >         .