Event Polling!

Goals:

Pencil Code gives direct access to the most-recently-generated mouse event objects with variables lastclick, lastmouseup, lastmousedown, and lastmousemove.
The pressed function can be used to check whether a specific key has been pressed (as shown in the example) or to list all currently-pressed keys by calling pressed().

Pencil Code maintains records of the most recent event object for several mouse-related events, as well as a list of all currently pressed keys. It does this, behind the scenes, using event listeners.
Referencing these records of events in a frequent, repeated manner—i.e., within the body of a callback to a timing event—is called polling.
Polling allows us to write code that responds more fluidly to events, owing to the fact that the timer dictates the timing interval of the execution of our callback, rather than the timing of the mouse or keyboard event.

Save each of the following in a folder called EventPolling.

MouseMover : Code a script that directs a sprite to move around the screen using the arrow keys and the turnto and moveto methods. Make the movements smooth and fluid by using event polling rather than explicit use of mouse event bindings.

KeyboardMover : Program a script that lets you maneuver a sprite around a fixed area of the screen using the arrow keys (or, if you prefer, a,w,s,d). Experiment with different turn angles and forward distances to come up with an algorithm that makes smooth movements and (as an extra challenge) also prevents the sprite from crossing the boundary. Access event objects using event polling, not keybinding functions!

CopsAndRobbers : Make a chase game, in which the player controls a police-car sprite in hot pursuit of a randomly-moving getaway-car sprite. Add features, such as hazards or roads, that make the game more challenging and/or interesting. As an extension, add a button to let the player choose which role to play—or perhaps turn it into a two-player, head-to-head game?