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matrixgl

1.0.1 • Public • Published

MatrixGL

MatrixGL is yet another matrix library for WebGL.

Install without Node.js

Download the zip file from Releases page on GitHub, and unzip the file.

You will see matrixgl.min.js file in the build directory. Copy the file(matrixgl.min.js) into your directory. You can ignore all other files(These files are for Node.js).

Then add below code to your HTML file.

<script src="matrixgl.min.js"></script>
<script>
    // Write your code here.
</script> 

Install with Node.js

Run the install command.

$ npm install matrixgl --save

Then, import MatrixGL in JavaScript.

const { Vector3, Vector4, Matrix4, Quaternion } = require('matrixgl');

Basic Usage

MatrixGL has Vector, Matrix and Quaternion class.

You can use it simply. For example:

// create 4-dimensional vector.
const vec = new Vector4(1, 2, 3, 4);
 
// display elements.
console.log(vec.x); // 1
console.log(vec.y); // 2
console.log(vec.z); // 3
console.log(vec.w); // 4
 
// all values
console.log(vec.values);

Vector classes also have some operation.

const vec1 = new Vector4(1, 2, 3, 4);
const vec2 = new Vector4(5, 6, 7, 8);
const scalar = 5;
 
// calculate
const vecSum = vec1.add(vec2);
const vecDiff = vec1.sub(vec2);
const vecProd = vec1.mulByScalar(scalar);
const vecMag = vec1.magnitude;

Note: MatrixGL's API does not modify the original vector/matrix unlike ordinary OpenGL matrix libraries. So you should assign the result to variables

There are also Matrix classes.

const mat = new Matrix2(1, 2, 3, 4);
console.log(mat.values);

Matrices' values are stored in "column major order" which is the default order of WebGL. This means new Matrix(1, 2, 3, 4); represents the first row is [1, 3] and second row is [2, 4].

If you are bored with enumerating numbers 16 times to create a Matrix4, please use a spread operator.

const values = new Array(16);
values.fill(0);
 
const matrix = new Matrix4(...values);

In addition to basic methods, Matrix4 class has special methods. You can generate a model matrix easily with these methods.

const model = Matrix4.identity()
                      .translate(1, 2, 3)
                      .rotateX(Math.PI)
                      .scale(5, 5, 5);

Or you can build a model matrix manually.

const identity = Matrix4.identity();
const scaling = Matrix4.scaling(5, 5, 5);
const rotation = Matrix4.rotationX(Math.PI);
const translation = Matrix4.translation(1, 2, 3);
 
const model = identity.mulByMatrix4(translation)
                       .mulByMatrix4(rotation)
                       .mulByMatrix4(scaling);

If you want a rotation matrix about an arbitrary axis, use rotateAround(axis, radian) .

// An axis vector must be normalized.
const axis = new Vector3(1, 2, 3).normalize();
const rotation = Matrix4.identity()
                         .rotateAround(axis, Math.PI);

or use Matrix4.rotationAround(axis, radian).

const rotation = Matrix4.rotationAround(axis, Math.PI);

To build a "look at" matrix, use lookAt method.

const camera = new Vector3(1, 2, 3);
const lookAt = new Vector3(4, 5, 6);
const cameraUpDirection = new Vector3(7, 8, 9);
 
const view = Matrix4.lookAt(camera, lookAt, cameraUpDirection);

If you need a projection matrix, use Matrix4.orthographic or Matrix4.perspective method.

const orthographic = Matrix4.orthographic({
  top: 1,
  bottom: -1,
  left: -1,
  right: 1,
  near: 1,
  far: 2
});
 
const perspective = Matrix4.perspective({
  fovYRadian: 60 * Math.PI / 180,
  aspectRatio: 1,
  near: 1,
  far: 2
});

And combine all above matrices to build a ModelViewProjection matrix.

const mvp = perspective.mulByMatrix4(view)
                       .mulByMatrix4(model);

Quaternion

MatrixGL supports quaternions for rotation.

// Create a quaternion.
const q = new Quaternion(1, 2, 3, 4);

To create a rotation matrix from a quaternion, use Quaternion.rotationAround(axis, rad) and toRotationMatrix4().

// An axis must be normalized.
const axis = new Vector3(1, 2, 3).normalize();
const radian = 45 * Math.PI / 180;
 
// Create a quaternion from the axis and radian.
const q = Quaternion.rotationAround(axis, radian);
 
// Convert the rotation quaternion to a rotation matrix.
const rotation = q.toRotationMatrix4();

To interpolate between two quaternions, use slerp(other, t).

// To interpolate quaternions, they must be normalized.
const q1 = new Quaternion(1, 2, 3, 4).normalize();
const q2 = new Quaternion(5, 6, 7, 8).normalize();
 
// interpolate with t = 0.5.
// t is from 0.0 to 1.0. 
const interpolated = q1.slerp(q2, 0.5);

Usage with WebGL

You can get Float32Array from values property of vectors, matrices or quaternions.

So if you use MatrixGL with WebGL, just pass the vector's(or matrix's) values.

// Buffer
gl.bufferData(gl.ARRAY_BUFFER, vec1.values, gl.STATIC_DRAW);
 
// Uniform Variable
gl.uniformMatrix4fv(mvpLocation, false, mvp.values);

API Document

For more information, see also API Document.

How to Build from Source

Install dependencies.

$ npm install

Build.

$ npm run build

License

MIT License. See LICENSE.md.

install

npm i matrixgl

Downloadsweekly downloads

35

version

1.0.1

license

MIT

homepage

github.com

repository

Gitgithub

last publish

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