[nacltoons] Add compound shapes.

nacltoons/data/res/sample_game/level1.def

 # Level description file.  This file describes a single level.  It
 # is designed to be referenced from the game.def file.
 # It should not pollute the global namespace and should return a
 # single value which is the table describing the level.
 # vi: filetype=yaml
 
 num_stars: 3
 
 sprites:
   - { pos: [ 100, 500 ], image: ball_image, script: ball.lua, tag: BALL }
   - { pos: [ 700, 40  ], image: goal_image, tag: GOAL, sensor: true }
   - { pos: [ 200, 480 ], image: star_image, tag: STAR1, sensor: true }
   - { pos: [ 200, 240 ], image: star_image, tag: STAR2, sensor: true }
   - { pos: [ 420, 90  ], image: star_image, tag: STAR3, sensor: true }
+  - { pos: [ 550, 250  ], image: star_image, sensor: true }
 
 shapes:
   # create three ramps for the ball to roll down
   - { type: line, color: [ 50, 230, 0 ], start: [ 20, 450 ], finish: [ 550, 400 ] }
 
   - { type: line, color: [ 230, 50, 0 ], start: [ 200, 200], finish: [ 780, 380 ] }
 
   - { type: line, color: [ 0, 50, 230 ], start: [ 20, 240 ], finish: [ 200, 50  ] }
 
-  # create a box
-  - { type: line, start: [ 500, 200 ], finish: [ 500, 300 ] }
-  - { type: line, start: [ 500, 300 ], finish: [ 600, 300 ] }
-  - { type: line, start: [ 600, 300 ], finish: [ 600, 200 ] }
-  - { type: line, start: [ 600, 200 ], finish: [ 500, 200 ] }
+  # Create a box made of 4 lines.
+  - { type: compound, pos: [ 500, 200 ],
+      children: [
+        { type: line, start: [   0,   0 ], finish: [   0, 100 ] },
+        { type: line, start: [   0, 100 ], finish: [ 100, 100 ] },
+        { type: line, start: [ 100, 100 ], finish: [ 100,   0 ] },
+        { type: line, start: [ 100,   0 ], finish: [   0,   0 ] },
+      ]
+    }
 
   # create a dynamic line anchored to the world at a fixed point.
   - { type: line, start: [ 220, 50 ], finish: [ 620, 50 ], dynamic: true, anchor: [ 420, 50 ] }
 
   # create a 'floor' object using the 'edge' type
   - { type: edge, start: [ 0, 0 ], finish: [ 800, 0 ], tag: FLOOR }