@kdh/tsm

tsm: A Typescript vector and matrix math library

tsm is a a collection of vector, matrix and quaternion classes written in Typescript.

The library's design is influenced by both gl-matrix and glm.

What's special about tsm?

• tsm makes use of Typescript's type annotations to reduce the number of possible bugs.

• tsm makes use of Javascript's new property definitions to enable GLSL-style swizzle operators:

    let v1 = new vec2();
    let q1 = new quat();
  
    v1.xy = [0, 1];
    q1.w = 1.0;
  

• tsm offers both non-static and static methods for many operations:

    let v1 = new vec3([1, 2, 3]);
    let v2 = new vec3([4, 5, 6]);
  
    let v3 = vec3.sum(v1, v2);
    let v4 = v1.copy().add(v2);
  
    console.log(v3.equals(v4)); // output: "true"
  

General design notes

Swizzle operators return numeric arrays, not vector instances:

let v = new vec4([1, 2, 3, 4]);
let n = v.xyz; // n = [1, 2, 3]

If, instead, you want to create a new instance of a vector or a matrix, use the copy() method:

let v1 = new vec4([1, 2, 3, 4]);
let v2 = v1.copy();

You can also initialize a new vector with the values of another:

let v1 = new vec4([1, 2, 3, 4]);
let v2 = new vec4(v1.xyzw);

Or copy the values of one vector to another using the swizzle operators or the copy() method:

v2.xyzw = v1.xyzw; // same as v1.copy(v2)

The four basic arithmetic operations can be performed on vector instances or using static methods:

let v1 = new vec4([1, 2, 3, 4]);
let v2 = new vec4([5, 6, 7, 8]);

let v3 = vec4.product(v1, v2); // returns a new vec4 instance

v1.multiply(v2); // writes the result of the multiplication into v1
v2.multiply(v1); // writes the result of the multiplication into v2

The reason for all of these different ways of doing the same thing is that object allocation in Javascript is slow and dynamic allocation shoud therefore be reduced to a minimum.

For this reason, static methods offer an optional destination parameter:

let v3 = vec3.cross(v1, v2) // allocates a new instance of vec3

is the same as:

let v3 = new vec3();
vec3.cross(v1, v2, v3) // writes into the existing instance

Matrices do not have swizzle operators. Instead, they provide the all(), row() and col() methods:

let m = new mat2([1, 2, 3, 4]);

let all = m.all();  // [1, 2, 3, 4]  
let row = m.row(0); // [1, 2]
let col = m.col(0); // [1, 3]