New Language Features

• Cube and custom marker orientation discrimination: we can now test whether a cube or custom marker is upright, sideways, inverted, or at some other angle (called "tilted"). In addition, for custom markers we can distinguish "left" from "right" when the marker is sideways.
  
  
• The custom marker graphics in the PDF file (for printing on adhesive labels) have been modified to indicate which way is "up". Download the file from https://www.cs.cmu.edu/~dst/Calypso/Curriculum/extra/custom-marker-labels.pdf.
  
  
• Better path planning: we can now pick up cubes whose orientation is "sideways" by planning a path to the correct side. Also, we now consider alternative paths to a cube if the path to the closest side is obstructed.

• Cozmo can now track your face: use "WHEN see face in-frame DO turn toward it".
  
  
• Improved sequencing: the "look" and "lift" actions now accept the "and then" modifier tile. If this tile is used, any indented rules appearing below them will only be performed after the look or lift action has completed.
  
  
• Further simplified syntax for regular expressions in "hear" tiles. Anything outside of parentheses is treated as literal text and all punctuation is removed. Inside parentheses you can use syntax such as (word1|word2) for alternation, (word|) for an optional word, and (.*) for a wildcard that will match anything. Spaces between words and regular expressions are automatically handled correctly. Also, you can once again have multiple lines of text in a "hear" tile; the test will succeed if at least one line matches the input.
  
  
• The "drop" action now works whenever the lift is raised, even if Cozmo doesn't think he's carrying a cube. This is useful if the user put the cube on the lift instead of having Cozmo pick it up himself.

User Interface Improvements

• Better rule display: we now draw a line connecting an "it" tile to the WHEN condition that binds the "it". This may be the rule's own "WHEN", or a parent rule if the rule is indented.
  
  
• Cube orientation is now displayed in the world map: upright, sideways, inverted, or tilted. Each uses a different icon.
  
  
• Custom marker orientation is now displayed on the world map by rotating the marker icon.
  
  
• On Macs, control-left click can now substitute for right-click to call up context menus. Try control-left clicking on a cube in the world map, or on a "WHEN" tile in the rule editor.