## Angles Done With Integers Docs: https://docs.rs/integer_angles/ ```rust use integer_angles::Angle; assert_eq!(Angle::pi_2().cos::(), 0.0f64); ``` Here we go, down the rabbit hole of floating-point instability and all sorts of crazy problems that come with representing angles within computers. The goal of this library is to solve the following problems: * If you have multiple angles, and you add them together, the result you get should be exactly correct. * If you add multiple angles together and end up with a full circle, that should be exactly a full circle. * If you do trigonometry of some multiple of `pi` radians, you should end up with the exact answer. * Keep track of the difference between a `0` radian angle, and a `2 pi` radians angle. * Keep track of if the angle is going clockwise or counter-clockwise starting at the positive x axis. * Do not allow the user to represent an angle outside the range [`-2 pi` to `2 pi`] The way this library does it's magic is the following: * Stores the angle in units of `[0..2**64)` where each unit is `1/(2**64)`th of a circle. * This means that adding and subtracting angles (with wrapping) will always be correct, and always within the specified range. (No more range reduction!) * This also means that you can (inside the library) *cast* an angle from `u64` to `i64` and end up with the same angle. * Set a flag for a full circle, and allow units to be `0` for a `0` degree angle. * This also means, for example, `pi` radians is exactly equal to `1<<63` units in this library. * Keep track of the clockwise/counterclockwise-ness of the angle using a separate flag. * Solves the Chebyshev to compute the sin/cos/tan using the new units (with more precision than the standard library). * Uses a binary search (at the moment) to compute asin/acos/atan/atan2. Caveats: * This library is slower than using an f64 (about 10 times slower to compute `cos`. You've gotta wait a whole 80 ns to get the result!). * ... Probably other things. License: MIT