Vec2D

a * b # where a is instance of Vec2D and b is a scalar
a + b # where both a and b are both instances of Vec2D
a - b # where both a and b are both instances of Vec2D
a / b # where a is instance of Vec2D and b is a scalar
a == b # where both a and b are both instances of Vec2D
a ^ b # formerly cross product where both a and b are both instances of Vec2D
a.angle_between(b) # where both a and b are both instances of Vec2D
a.copy # where a is instance of Vec2D returns a deep copy
a.dist(b) # where both a and b are both instances of Vec2D
a.dot(b) # where both a and b are both instances of Vec2D
a.heading # where a is instance of Vec2D
a.lerp(b) # where both a and b are both instances of Vec2D
a.lerp!(b) # where both a and b are both instances of Vec2D
a.mag # where a is instance of Vec2D
a.normalize # where a is instance of Vec2D
a.normalize! # where a is instance of Vec2D
a.normalize!(b) # where both a and b are both instances of Vec2D
a.rotate(b) # where both a is an instance of Vec2D and b is scalar radians
a.rotate!(b) # where both a is an instance of Vec2D and b is scalar radians
a.set_mag(b) # where both a is instance of Vec2D and b is scalar
a.set_mag(b) &block # a conditional variantwhere &block evaluates to a boolean
a.to_a # returns an array [x, y] where a is instance of Vec2D
a.to_s # returns a string where a is instance of Vec2D
a.to_vertex(b) # where b is a instance of Render sends vector a to PApplet.vertex
a.x returns x as a float # where a is instance of Vec2D
a.x=b # sets the x value of Vec2D a to the float b
a.y # returns y as a float # where a is instance of Vec2D
a.y=b # sets the y value of Vec2D a to the float b

Vec2D.from_angle(a) # returns a new Vec2D object # where a is a float radians
Vec2D.random # returns a new random Vec2D object # with mag 1.0
Vec2D.new # returns new instance where x, y are both zero.
Vec2D.new(a, b) # where a and b are both float or numeric (NB: stored as float)
Vec2D.new(vec) # where vec has methods `:x` and `:y` that return float or numeric