2d-point 中文文档教程

Question

2D Point

Create and manipulate 2d point object.

Installation

作为节点包提供。 安装使用

$ npm install 2d-point

Methods

以下方法可用。

• create
• add
• multiply
• subtract
• fitWithin
• fitOnce

Use

create Point.create(x, y)

创建冻结的 2D 点。 如果没有给出参数，则默认为原点坐标。

var Point = require('2d-point');

var pt = Point.create(2, 4);
// => {x: 2, y: 4}

var origin = Point.create();
// => {x: 0, y: 0}

add Point.add(p, q)

矢量添加两个点返回一个新点。

var p = Point.create(2, 3);
var q = Point.create(4, 5);

Point.add(p, q);
// => {x: 6, y: 8}

subtract Point.subtract(p, q)

向量减去两个点返回一个新点。

var p = Point.create(2, 3);
var q = Point.create(4, 5);

Point.subtract(p, q);
// => {x: -2, y: -2}

multiply Point.multiply(a, p)

向量标量乘以一个点返回一个新点。

var a = 3;
var p = Point.create(2, 3);

Point.multiply(a, p);
// => {x: 6, y: 9}

fitWithin Point.fitWithin(container, vector)

缩放矢量以适合容器点的边界框。

var container = Point.create(2, 2);
var landscape = Point.create(8, 4);
var portrait = Point.create(0.5, 1);

Point.fitWithin(container, landscape);
// => {x: 2, y: 1}

Point.fitWithin(container, portrait);
// => {x: 1, y: 2}

fitOnce Point.fitWithin(container, vector)

缩放矢量以恰好适合容器点边界框的维度。

var container = Point.create(2, 2);
var landscape = Point.create(8, 4);
var portrait = Point.create(0.5, 1);

Point.fitWithin(container, landscape);
// => {x: 4, y: 2}

Point.fitWithin(container, portrait);
// => {x: 2, y: 4}

Considered extensions

• fit within to deal with zeros ?
• negate ?
• Curry methods ?
• comparison methods ?
• conditionally make svg point if available ? No
• tests in browser ? No
• dot product ?
• convert to radial ? No
• furthest ?
• nearest ?