Angles are provided as absolute values that wrap at 360 degrees

[mdgriffith]

This is to allow something like this to work as expected.

Animation.loop [Animation.rotate (turn 1)]

Comparing this strategy to Absolute and Relative angles

Relative angles:

[ rotate (turn 2)
, rotate (turn 0.25)
, rotate (turn 2.5)
]

would result in 4.75 turns forward.

We can describe this approach as you specify how far you want to go and in what direction. But you don't get to specify exactly where you want to end up without knowing every previous rotation.

Absolute angles:

[ rotate (turn 2)
, rotate (turn 0.25)
, rotate (turn 2.5)
]

Would result in

• 2 turns forward
• reverse for 1.75 turns
• 2.25 turns forward to arrive at 2.5

I believe the "reverse for 1.75 turns" is the counter intuitive step. If that rotation command rotate (turn 0.25) is given at some other point in the code other than right next to rotate (turn 2), and it turns in reverse for 1.75 turns...I think that would most likely be unexpected.

We can describe this approach as you specify where you want to end up. But you don't get to specify how long it takes to get there.

Our compromise (absolutely specified angles that wrap at full rotations)

[ rotate (turn 2)
, rotate (turn 0.25)
, rotate (turn 2.5)
]

Wrapping at every whole number this results in the following:

• two turns forward
• 0.25 turn forward
• Then 2.25 turns forward to arrive at the equivalent of 2.5

Resulting in 4.5 turns

We are also able to achieve the same result as absolute units by doing the following:

[ rotate (turn 2)
, rotate (turn -1.75)
, rotate (turn 2.5)
]

Which results in

• two turns forward
• 1.75 turn in reverse to arrive at an angle of 0.25 turns
• Then 2.25 turns forward to arrive at the equivalent of 2.5

Advantages

• Angles are given as absolute values. This is way easier to think about vs relative values because you don't need to know current state.
• You get to think of even less state than absolute-non-wrapping values because of the unexpected-reverse-1.75-turns case mentioned previously
• You basically just specify what angle in the 0-360 range that you want to end up at and how many turns you want to make to get there.