color-hash/README.md

Generate color based on the given string (using HSL color space and SHA256).

# Color Hash

Generate color based on the given string.

## Demo

https://zenozeng.github.io/color-hash/demo/

## Usage

### Deno

```typescript
import ColorHash from "https://deno.land/x/color_hash@v2.0.0/mod.ts"
```

### Node.js

```bash
npm install color-hash
```

```typescript
import ColorHash from 'color-hash'
```

or

```javascript
const ColorHash = require('color-hash').default;
```

### <script type="module">

```html
<script type="module">
import ColorHash from '../dist/esm.js';
</script>
```

#### Basic

```javascript
var colorHash = new ColorHash();

// in HSL, Hue ∈ [0, 360), Saturation ∈ [0, 1], Lightness ∈ [0, 1]
colorHash.hsl('Hello World'); // [ 225, 0.65, 0.35 ]

// in RGB, R, G, B ∈ [0, 255]
colorHash.rgb('Hello World'); // [ 135, 150, 197 ]

// in HEX
colorHash.hex('Hello World'); // '#8796c5'
```

#### Custom Hash Function

```javascript
var customHash = function(str) {
    var hash = 0;
    for(var i = 0; i < str.length; i++) {
        hash += str.charCodeAt(i);
    }
    return hash;
};
var colorHash = new ColorHash({hash: customHash});
colorHash.hsl('Hello World!');
colorHash.rgb('Hello World!');
colorHash.hex('Hello World!');
```

#### Custom Hue

```javascript
var colorHash = new ColorHash({hue: 90});
```

```javascript
var colorHash = new ColorHash({hue: {min: 90, max: 270}});
```

```javascript
var colorHash = new ColorHash({hue: [ {min: 30, max: 90}, {min: 180, max: 210}, {min: 270, max: 285} ]});
```

#### Custom Lightness

```javascript
var colorHash = new ColorHash({lightness: 0.5});
```

```javascript
var colorHash = new ColorHash({lightness: [0.35, 0.5, 0.65]});
```

#### Custom Saturation

```javascript
var colorHash = new ColorHash({saturation: 0.5});
```

```javascript
var colorHash = new ColorHash({saturation: [0.35, 0.5, 0.65]});
```

## License

MIT.

## FAQ

### How does it work?

It uses the `hash` function (default is BKDRHash) to calculate the hash of the given string.

```
Hue = hash % 359. (Note that 359 is a prime)
Saturation = SaturationArray[hash / 360 % SaturationArray.length]
Lightness = LightnessArray[hash / 360 / SaturationArray.length % LightnessArray.length]

By default,
SaturationArray = LightnessArray = [0.35, 0.5, 0.65]
```

### Why not LAB?

Though LAB is more perceptually uniform, HSL is easier to control.
Simply sets lightness and saturation and change hue uniformly can generate uniform colors.

## Dev

### Test

```bash
deno test
```

#### Coverage Report

https://zenozeng.github.io/color-hash/coverage/lcov-report/lib/index.html


### Follow Semantic Versioning

http://semver.org/lang/zh-CN/