MathUtil

Overview

• Strongly typed radian, degree and hour angle classes and conversions.
• 3x3 matrix, 4x4 matrix and quaternion support.
  • Conversion between matrix, quaternion, Euler angle, and axis and rotation.
  • Matrix, quaternion multiplication, inversion and scalar multiplication.
  • Overloaded multiplication and division operators in contexts of matrix and quaternion.
• Interpolation support for linear, quadratic and cubic curves with ease-in, ease-out, ease-in-out modes.
• Detect whether two line segments cross each other.
• Operator overloading for SCNVector3 and more.

Installation

Carthage

# Swift 4.0
github "DJBen/MathUtil" ~> 0.3.0

This version is compatible with Swift 4. To use Swift 3.x compatible version, use 0.1.x instead.

# Swift 3.x
github "DJBen/MathUtil" ~> 0.1.0

Usage

Strongly Typed Angles

Radian-degree Angle Conversion

RadianAngle(degreeAngle: DegreeAngle(30)).value // 0.523...
DegreeAngle(radianAngle: RadianAngle(Double.Pi / 2)).value  // 90

Hour Angle Conversion and Formatting

// Sirius' right ascension is 6h 45m 9s
let deg = DegreeAngle(hour: 6, minute: 45, second: 9)
deg.value // 101.2875

let hourAngle = HourAngle(value: deg)
// Use any custom number formatters for different decimal lengths
hourAngle.compoundDecimalNumberFormatter = NumberFormatter()
print(hourAngle.compoundDescription) // 6h 45m 9s

// Antares' right ascension is −26.432002 degrees
let degreeAngle = DegreeAngle(-26.432002)
print(degreeAngle.compoundDescription) // -26° 25′ 55″

Matrix, Quaternion and Vector Arithmetics

See documentation for VectorMath.

Interpolations

Linear interpolation

// Starts at 2.1; ends at 7.5; wants to know 85% value.
let interp = Easing(startValue: 2.1, endValue: 7.5)
interp.value(at: 0.85)   // 6.69

Quadratic, Cubic, Ease In, Ease Out

The following easing functions are available and here is their mathematic definitions.

public enum EasingFunction {
    case linear
    case quadraticEaseIn
    case quadraticEaseOut
    case quadraticEaseInOut
    case cubicEaseIn
    case cubicEaseOut
    case cubicEaseInOut
}

Just pass in the function when initializing Easing and take advantage of it!

Easing(easingMethod: .cubicEaseInOut, startValue: 21, endValue: -9)

Operator overloading

• Add operator arithmetics for CGVector and SCNVector3.

Remarks

MathUtil/VectorMath** are based on @nicklockwood's VectorMath. Great thanks!

• Based on 0.3 version. Not bumping up to the latest release because I adopted a different order of deriving Euler angles from Quaternion and vice versa.