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    vecn

    1.3.1 • Public • Published

    vecn

    A module for creating n-dimensional vector types that support swizzling.

    Build Status Coverage Status JavaScript Style Guide

    Allows for the creation of vectors of arbitrary dimension that are also JavaScript Arrays. These arrays are fixed-length and accept only numbers as input, though they generally decay gracefully into regular Arrays. For example, you're allowed to use map, reduce, concat, and other Array methods, and if the result is a valid vec, a vec will be returned. Otherwise, you'll get back a standard Array with the new elements. These are specifically overloaded methods, so experimental, custom, and rebound methods aren't guaranteed to work.

    Install

    $ npm install vecn

    Usage

    Since they're the most common, vec2, vec3, and vec4 are already included:

    const {vec3} = require('vecn')
     
    let v = vec3(1, 2, 3)
    console.log(v)
    [ 1, 2, 3 ]

    If you need to create your own vector type:

    const vecn = require('vecn')
     
    const vec5 = vecn.getVecType(5)
    var v = vec5(1, 2, 3, 4, 5)
    console.log(v)
    [ 1, 2, 3, 4, 5 ]

    For a more in-depth description of available vector methods, see the documentation.

    Swizzling

    Swizzling is a technique used in GLSL that allows you to access a vector's components by name and build new vectors from them. It works the same here at arbitrary length. It's easiest to see in an example:

    var v = vec4(1, 2, 3, 4)
     
    v.x                          // 1
    v.y                          // 2
    v.z                          // 3
    v.w                          // 4
     
    v.xx                         // vec2 [ 1, 1 ]
    v.zy                         // vec2 [ 3, 2 ]
    v.zywwxyyz                   // vec8 [ 3, 2, 4, 4, 1, 2, 2, 3 ]

    We can also set values with swizzling.

    var v = vec3(1, 2, 3)
     
    v.xz = [4, 5]
    console.log(v)
    [ 4, 2, 5 ]

    Swizzling only works for vec2, vec3, and vec4 (with plans to extend it with custom accessors).

    Important Nuance

    When creating a new vecType, you are generating a new class. However, this class is hidden behind a function that creates the object for you and returns a Proxy. Therefore, the function returned by vecn.getVecType is not a constructor. Since the new keyword implies a return this at the end of the function, but the function already returns, the existence of a new before the function call has no effect. The following code explains the importance:

    const vec2 = vecn.getVecType(2)
     
    var v1 = vec2(1, 2)          // Valid construction
    var v2 = new vec2(1, 2)      // Also valid, but misleading
     
    v1.constructor === vec2      // false

    Basically this allows for swizzling and lets me extend Array without letting the user mess with the length.

    Install

    npm i vecn

    DownloadsWeekly Downloads

    26

    Version

    1.3.1

    License

    MIT

    Unpacked Size

    26.9 kB

    Total Files

    4

    Last publish

    Collaborators

    • zunawe