Maths: struct representing an Angle

Summary of feature

In geometry, I work with angles quite often, so I ended having an Angle structure which has proven a lot more useful than I imagined, because it handles stuff like:

• Radian/Degree conversion
• Angle between vectors
• radial arithmetics (an angle can represent a direction, but also the number of turns)
• Equality (which is tricky; is 0° == 360° ? it depends on the context)

Once you think about it, angles have their own mathematical domain that has always been very underrated.

Taken from my code, it would be something like this:

struct Angle
{
    public float Radians;

    public float Degrees => Radians * 180 / Math.Pi;

    public static implicit operator float(Angle angle) => angle.Radians;

    public static Angle InDegrees(float degrees) ... 
    public static Angle InRadians(float radians) ... 
    public static Angle InClockTime(int hour, int min, int second) ... 
    public static Angle Between(Vector2 a, Vector2 b) ...
    public static Angle Between(Vector3 a, Vector3 b) ...
    public static Angle ArcTan(float y, float x) ...
    public static Angle ArcCos(float cos) ...
    public static Angle ArcSin(float sin) ...
    public static Angle Round(Angle angle) ... rounds any angle to 0°-360° range
    public static operator Angle +(Angle a, Angle b)....
}

Comments

The biggest advantage I had by using such a structure is that it greatly reduces the extremely common case of using radians in place of degrees or the other way around, in other words: it makes the concept of an angle value strong typed.

And it makes the code a lot more pleasant:

var angle = Angle.InDegrees(90) + Angle.Between( vector1, vector2 );

Does this have a proposal?

Check the documentation/proposals folder. If it doesn’t have one, you may need to create one if you’re making massive breaking changes.

[Perksey]

FYI here’s the discussion recording, the notes probably don’t go into all of the details of our discussion: https://youtu.be/gjneerMeRVU?t=3720

[HurricanKai]

readonly struct Radians { public readonly float Value } is preferable IMO. For maths it’d be on theme to make it take <T>, but I don’t really mind either option.