Simple Math and Geometry convenience improvements

Summary

The following suggestions were gathered while using the engine for a number of projects. The intention is to make one’s life easier by providing shortcuts for common calculations.

List of suggestions

1. Vector component properties for Vector2 and Vector3 types. Obtaining the X, Y and Z vector components quickly. Names are arguable. Implementation example:

struct Vector3 {
    Vector3 XVector { get { return new Vector3 (this.X, 0f, 0f); } }
    Vector3 YVector { get { return new Vector3 (0f, this.Y, 0f); } }
    Vector3 ZVector { get { return new Vector3 (0f, 0f, this.Z); } }
}

1. More coordinate selector properties for Rect. Convenient access for: TopMiddle, RightMiddle, BottomMiddle and LeftMiddle coordinates.

2. A saturation function to the MathF class. Similar to Sign, but accepts an epsilon value too. Implementation example:

float Saturate (float val, float eps)
{
    if (Abs (val) <= eps) return 0f;
    return Sign (val);
}

1. Clamp is quite often used with 0f and 1f as boundaries. Let’s create a function for that: Clamp01.

2. Inverse linear interpolation to MathF, and possibly to Vector2 and Vector3. Implementation example:

float InvLerp (float value, float min, float max)
{
    return (value - min) / (max - min);
}

1. Inverse linear interpolation with 0f and 1f as boundaries.

2. Introduce the well known smoothstep function to MathF. The formula is x * x * (3 - 2 * x).

[deanljohnson]

Yup, I saw that mentioned previously in the thread. I believe I’ve got it right, I just haven’t had a chance to ensure it is so.

If you wanted to go the extra mile you could add unit tests for this to the DualityTests project. That’d also give you a chance to test every case without needing to setup a game project. You’ll need to install the NUnit test adapter in order or run the unit tests.

[deanljohnson]

@helle253 Yep, nothing on that Todo list has been done yet. Have at it.