SKLinearAlgebra

This library allows common vector operations using SceneKit's native types: SCNVector3, SCNVector4, and SCNMatrix4. It also provides useful linear algebra functions for 3D graphics.

It has been written in the style of Swift, intending to enhance and complete Scenekit's existing functions.

Features

Tests are complete for all implemented features.

Operations

• equality (==)
• inequality (!=)
• equivalence (~=)
  • Returns true if the components are close to equal to each other.
• inequivalence (!~=)
• addition (+, +=)
• subtraction (-, -=)
• dot product (*)
• scalar multiplication (*, *=)
• scalar division (/, /=)
• cross product (×)
• subscript access (v[0], m[1, 2])
  • Zero based indexing
  • Access by [row, column]

Functions

• cross product (cross(a: Vector, b: Vector))
• magnitude (magnitude(v: Vector))
• normalize (normalize(v: Vector))
• angle between (angle(a: Vector, b: Vector))
• component (component(a: Vector, b: Vector)) - comp_{b} a
  • Read this as "the component of a onto b", it would be written comp_{b} a.
• projection (projection(a: Vector, b: Vector))
  • Read this as "the projection of a onto b", it would be written proj_{b} a
• determinate (det(m: Matrix))
• transpose (transpose(m: Matrix))
• inverse (inverse(m: Matrix))

Usage

The documentation for using a custom Swift library is lacking at the moment, but my process has been as follows:

1. Clone [email protected]:apexskier/SKLinearAlgebra.git into your project directory.
2. Drag SKLinearAlgebra.xcodeproj into your Xcode project.
3. Select your project, select your target, under General find "Linked Frameworks and Libraries".
4. Add SKLinearAlgebra.framework, either from the + button or by dragging in SKLinearAlgebra/Products/SKLinearAlgebra.framework from the project navigator.

// Example import statements

import SceneKit
import SKLinearAlgebra

let vector = SCNVector4(x: 1, y: 2, z: 3, w: 4)
vector *= 4
println(vector)

Future Plans

• Some kind of support for bases (origin + 3 vectors)
  • Conversion between basis
• Use specific type aliases
  • Vectors for colors, locations, directions, rotations
• Rotation utilities
• Torque and Force utilities
• Utilize Accelerate or Surge

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