angle in radian between the two vectors

basically times fps(e.g. divide by 0.016 = time 60), this is because angular velocity is a per second unit, engine subsequently will integrate this value by times delta again.

a vector that will be the rotation axis, perpendicular to both vectors, and since they are unit vectors, this is sin(a). this means it will rotate to target direction faster if their angle are larger.

a vector point to target_position globally

transform forward_local_axis to point to the global x direction.

very profound statement.

does "transformations" here mean, for example, loading some files into the game?

but backward solution is also not "perfect", right? using the previous example, this time hapless peasant will indeed have a chance to update, but after heroine update, foul beast gets deleted, loop decrements, heroine update twice?

This is saying why (2.55).toFixed(1) evaluates to 2.5, cuz, internally, 2.55 is actually, 2.5499999999..., which evals to 2.5 indeed.

• the 'cleanup function' is the return of setup .
• 'cleanup函数'是setup返回的。

because, before, it was depending on only 'roomId' and 'serverUrl', if they didn't change, it will not re-connect. but now, when 'onReceiveMessage' function is included in the dependency array, it will re-connect when re-rendered, because it's a new function every time.

possible typo: 'or' should be 'of'.

"read" here means decode it to inspect its content.

wow. so if the grantType is authorization code flow type, this parseFromUrl() function actually automatically does an entire extra step which is the POST to get the token.

here's the key difference to implicit flow. the token and other info properties are return as the response of the POST request.

according to the next paragraph, at least in this example case of okta, we don't need manual access to the random secret generated by frontend code.

• types of these fields must also match, e.g., it will be removed if you provide a number to the code field.
• 这些属性的类型也必须匹配，如果你给的code是一个number类型，它也会被筛掉。

@github.com/mj2068

• so, because of Immer, we can 'mutate' states directly. but we can also return state as well.
• 有了Immer，可以直接在reducer里改state，也可以return state。

• this is why extraReducers exists.
• 为什么extraReducers存在的原因。