Construct a Goodie role
Optional onCode to run when a hero collects the goodie. If you do not provide a value, the default is that score[0] will increase by one.
Code to run when a hero collects the goodie. If you do not provide a value, the default is that score[0] will increase by one.
collisionRules lets us turn off collisions based on the roles of two actors. We do this with two sets. If A's second set contains an entry in B's first set, then we disable the collision. We also do this symmetrically with B and A. In essence, this means that the first set lets a Role say "here are special things about me", and the second set lets a Role say "I don't collide with things that are special in these ways."
The second set: properties that this role won't collide with
The first set: properties of this role
The code to run when the hero collects this goodie
Readonly prerenderTasks to run before every render
Optional actor: ActorThis actor ignores collisions with Heroes
Indicate that the current Role should not ignore collisions with some other role
The role that should not be ignored
Code to run when there is a collision involving this role's Actor
The goodie role is most easily thought of as a coin. When the hero collides with the coin, the default behavior is that the coin disappears and the score increases by 1.
Note that in reality, goodies are more powerful than the above description: when the hero collides with them, they disappear, and we can run whatever code we want. It's just that the default is for the score to increase. It's fine to make the score decrease, or make it increase by some unexpected amount. You could even make the hero's color change, or make the hero grow, or whatever else you want. The important points are just that the goodie disappears, and some code runs.