use built-in portal functionality for Hackman scenario (#1651)

Previously, the logic to wrap horizontally was hand-coded, both for the player (using a dedicated monitor robot) and for ghosts (who, as system robots, implemented the teleportation themselves).

Now that we can use built-in portal functionality (#1356), no custom logic is needed to handle the teleportation.  A (much-simplified) monitor robot still observes the base robot to award the hidden "World wrap" goal.

## Demo

    scripts/play.sh -i data/scenarios/Challenges/hackman.yaml --autoplay --speed 6

data/scenarios/Challenges/_hackman/ghost.sw

@@ -117,19 +117,6 @@ def chooseDirection : cmd dir =
     }
     end;
 
-// Ghosts must implement teleporting logic themselves.
-// Hard-codes location of the teleporter.
-def checkNeedsTeleport = \offset.
-    currentLoc <- whereami;
-    if (fst currentLoc < -offset) {
-        teleport self (offset, snd currentLoc)
-    } {
-        if (fst currentLoc > offset) {
-            teleport self (-offset, snd currentLoc)
-        } {}
-    }
-    end;
-
 startPos <- whereami;
 
 def go =
@@ -138,7 +125,6 @@ def go =
         teleport self startPos;
     } {
         move;
-        checkNeedsTeleport 11;
         newDirection <- chooseDirection;
         turn newDirection;
         go;

data/scenarios/Challenges/_hackman/solution.sw

@@ -126,7 +126,7 @@ def returnToCenter =
     end;
 
 def invadeDen =
-    doN 14 move;
+    doN 13 move;
     turn right;
     doN 2 move;
     turn left;

data/scenarios/Challenges/_hackman/teleport_monitor.sw

@@ -0,0 +1,22 @@
+/* Algorithm:
+If, at any point, the base is more than two cells from its previous location,
+it must have teleported.
+*/
+
+def abs = \n. if (n<0) {-n} {n} end;
+
+def getBasePos =
+    as base {whereami};
+    end;
+
+def go = \lastBasePos.
+    wait 1;
+    curBasePos <- getBasePos;
+    let deltaX = abs(fst curBasePos - fst lastBasePos) in
+    if (deltaX > 1) {
+        create "bit (0)";
+    } {go curBasePos};
+    end;
+
+curBasePos <- getBasePos;
+go curBasePos;

data/scenarios/Challenges/hackman.yaml

@@ -76,7 +76,7 @@ objectives:
       - |
         Be teleported
     condition: |
-      r <- robotnamed "teleporter";
+      r <- robotnamed "teleport_monitor";
       loc <- as r {
         has "bit (0)"
       };
@@ -149,14 +149,14 @@ robots:
       - strange loop
       - treads
       - workbench
-  - name: teleporter
+  - name: teleport_monitor
     dir: [0, 1]
     system: true
     display:
       invisible: true
       char: 'T'
     program: |
-      run "scenarios/Challenges/_hackman/teleporter.sw"
+      run "scenarios/Challenges/_hackman/teleport_monitor.sw"
   - name: ghost1
     dir: [0, 1]
     system: true
@@ -272,38 +272,61 @@ world:
     'b': [blank, null, ghost2]
     'c': [blank, null, ghost3]
     'd': [blank, null, ghost4]
-    'T': [blank, null, teleporter]
     '.': [blank, pellet]
     '*': [blank, donut]
     'x': [blank, wall]
+    'T': [blank, null, teleport_monitor]
     '=': [blank, gate]
     '┌': [stone, upper left corner]
     '┐': [stone, upper right corner]
     '└': [stone, lower left corner]
     '┘': [stone, lower right corner]
     '─': [stone, horizontal wall]
     '│': [stone, vertical wall]
-  upperleft: [-11, 10]
+    'W':
+      cell: [blank]
+      waypoint:
+        name: western_exit
+    'X':
+      cell: [blank]
+      waypoint:
+        name: western_entrance
+    'Y':
+      cell: [blank]
+      waypoint:
+        name: eastern_exit
+    'Z':
+      cell: [blank]
+      waypoint:
+        name: eastern_entrance
+  portals:
+    - entrance: eastern_entrance
+      exitInfo:
+        exit: western_exit
+    - entrance: western_entrance
+      exitInfo:
+        exit: eastern_exit
+  upperleft: [-12, 10]
   map: |-
-    xxxxxxxxxxxxxxxxxxxxxxx
-    x..........x..........x
-    x*xxx.xxxx.x.xxxx.xxx*x
-    x.xxx.xxxx.x.xxxx.xxx.x
-    x.....................x
-    x.xxx.x.xxxxxxx.x.xxx.x
-    x.....x....x....x.....x
-    xxxxx.xxxxBxBxxxx.xxxxx
-    BBBBx.xBBBBBBBBBx.xBBBB
-    xxxxx.xB┌──=──┐Bx.xxxxx
-    TBBBB.BB│abBcd│BB.BBBBT
-    xxxxx.xB└─────┘Bx.xxxxx
-    BBBBx.xBBBfΩBBBBx.xBBBB
-    xxxxx.xBxxxxxxxBx.xxxxx
-    x..........x..........x
-    x.xxx.xxxx.x.xxxx.xxx.x
-    x*..x.............x..*x
-    xxx.x.x.xxxxxxx.x.x.xxx
-    x.....x....x....x.....x
-    x.xxxxxxxx.x.xxxxxxxx.x
-    x.....................x
-    xxxxxxxxxxxxxxxxxxxxxxx
+    BxxxxxxxxxxxxxxxxxxxxxxxT
+    Bx..........x..........xB
+    Bx*xxx.xxxx.x.xxxx.xxx*xB
+    Bx.xxx.xxxx.x.xxxx.xxx.xB
+    Bx.....................xB
+    Bx.xxx.x.xxxxxxx.x.xxx.xB
+    Bx.....x....x....x.....xB
+    Bxxxxx.xxxxBxBxxxx.xxxxxB
+    BBBBBx.xBBBBBBBBBx.xBBBBB
+    Bxxxxx.xB┌──=──┐Bx.xxxxxB
+    ZYBBBB.BB│abBcd│BB.BBBBWX
+    Bxxxxx.xB└─────┘Bx.xxxxxB
+    BBBBBx.xBBBfΩBBBBx.xBBBBB
+    Bxxxxx.xBxxxxxxxBx.xxxxxB
+    Bx..........x..........xB
+    Bx.xxx.xxxx.x.xxxx.xxx.xB
+    Bx*..x.............x..*xB
+    Bxxx.x.x.xxxxxxx.x.x.xxxB
+    Bx.....x....x....x.....xB
+    Bx.xxxxxxxx.x.xxxxxxxx.xB
+    Bx.....................xB
+    BxxxxxxxxxxxxxxxxxxxxxxxB