# Squircle CSS Houdini
A tiny CSS Houdini module that allows adding a squircle shape to HTML elements.
---
### 🎻 [Demo on GitHub Pages](https://pavellaptev.github.io/squircle-houdini-css/)
### 👾 [Codepen examples](https://codepen.io/collection/XjgQqp)
### 📦 [NPM package](https://www.npmjs.com/package/css-houdini-squircle)
### 🗞 [Medium article](https://pavellaptev.medium.com/squircles-on-the-web-houdini-to-the-rescue-5ef11f646b72)
---
# 🚀 Usage
## Add the script
In order to use the module, you need to add the script to your HTML file. But it's not a usual JS module that you can import.
```js
// Vanilla JS and Create React App
// Add the script to the index.html file
```
```tsx
// NextJS for TSX files
// Add the script to the _app.js file (or any other file that is loaded on every page)
React.useEffect(() => {
(CSS as any).paintWorklet.addModule("squircle.min.js");
}, []);
```
## Add the styles
```css
/* use mask */
.squircle {
width: 200px;
height: 200px;
background: linear-gradient(45deg, yellow, blue);
--squircle-smooth: 1;
--squircle-radius: 10px;
mask-image: paint(squircle);
}
```
```css
/* use background */
.squircle {
width: 200px;
height: 200px;
background: paint(squircle);
--squircle-smooth: 1;
--squircle-radius: 10px;
--squircle-fill: #f45;
}
```
## 👉 [codepen example](https://codepen.io/PavelLaptev/pen/PoWjzyB)
---
# 🎛 Custom CSS Properties
## --squircle-radius property
The property controls the roundness of the corners.
You can provide 1, 2, 3 or 4 values, similar to padding/margin in CSS.
The order is clockwise: top left, top right, bottom right, bottom left
- Syntax: **``** OR **``** OR **``** OR **``**
- Defaul value: **`8px`** (if no radius at all is defined) OR: **`0`** (if only some radii are defined)
- Min/Max values: **`—`** (the radii are capped at half of the shorter side of width/ height)
#### --squircle-radius-top-left, --squircle-radius-top-right, --squircle-radius-bottom-right, --squircle-radius-bottom-left
Set radii for the corners individually
```css
/* Usage */
.squircle {
/* other properties */
width: 200px;
height: 200px;
background: paint(squircle);
/* the property */
--squircle-radius: 20px;
}
```
---
## individual border radius
The property controls the roundness of the corners individually.
```css
/* Usage */
.squircle {
/* other properties */
width: 200px;
height: 200px;
background: paint(squircle);
/* the property */
--squircle-radius-top-left: 0px;
--squircle-radius-top-right: 15px;
--squircle-radius-bottom-right: 30px;
--squircle-radius-bottom-left: 40px;
}
```
---
## --squircle-smooth property
The property controls the length of bezier guide lines. Could be defined by `--squircle-ratio`.
- Syntax: **``**
- Defaul value: **`1`**
- Min/Max values: **`0.1 / 1`**
```css
/* Usage */
.squircle {
/* other properties */
width: 200px;
height: 200px;
background: paint(squircle);
--squircle-radius: 20px;
/* the property */
--squircle-smooth: 0.5;
}
```
---
## --squircle-outline property
The property controls squircle outline. There are two methods how too use it with `background-mask` and `mask`+`:pseudo-element`. to find out more check [codepen examples](https://codepen.io/collection/XjgQqp).
- Syntax: **``**
- Defaul value: **`—`**
- Min/Max values: **`—`**
```css
/* Usage */
.squircle {
/* other properties */
width: 200px;
height: 200px;
background: paint(squircle);
--squircle-radius: 20px;
/* the property */
--squircle-outline: 5px;
}
```
---
## --squircle-fill property
The property accepts any color, including variables.
⚠️ Work only with `background: paint(squircle);`. For `mask-image: paint(squircle);` use `background` property.
- Syntax: **``**
- Defaul value: **`#f45`**
- Min/Max values: **`—`**
```css
/* Usage */
.squircle {
/* other properties */
width: 200px;
height: 200px;
background: paint(squircle);
--squircle-radius: 20px;
/* the property */
--squircle-fill: #f45;
}
```
---
## 🕹 How to install particular version
```js
// latest version
// or particular version
```
#### Install via NPM
```
npm i css-houdini-squircle
```
#### Download
You can download the min version of the module [from UNPKG](https://www.unpkg.com/browse/css-houdini-squircle/squircle.min.js)
```
// latest version
https://www.unpkg.com/browse/css-houdini-squircle/squircle.min.js
```
---
## ✨ Use `css-paint-polyfill`
In order to get the module work on other browsers, you can use [Paint Worklets polyfill](https://github.com/GoogleChromeLabs/css-paint-polyfill).
⚠️ Check for artefacts before deploying.
```js
// use with polifill example
```
---
## Contributing and testing
If you have any ideas, just [open an issue](https://github.com/PavelLaptev/squircle-houdini-css/issues) and tell what you think.
If you'd like to contribute, please fork the repository. Pull requests are warmly welcome.
The project structure is separated into `nextJS` app and `lib` folder. The `lib` folder contains the script itself. The `nextJS` app is used for the demo. The `lib` folder is a separate NPM package.
```
📁 root
📁 lib
- package.json
- squircle.js
📁 … other nextJS folders
```
In order to test the script locally:
1. you need to run `npm run dev` in the root folder. It will start the NextJS app.
2. Then you need to run `npm run watch:build` in the `lib` folder. It will start the watcher for the script. It will build the script every time you change it and create `squircle.min.js` file in the `lib` folder and in the `public` folder of the NextJS app.
3. In the `index.tsx` file of the NextJS app, you can uncomment the line with [test section](https://github.com/PavelLaptev/squircle-houdini-css/blob/70f81510d45185e3946ec2cbec3cd4ab6495224b/src/pages/index.tsx#L57) un comment other in order to ease the development process.
---
## Change log (v0.3.0)
- Removed `--squircle-ratio` property. It's now fixed to `1.8`. It's still possible to change the ratio by changing `--squircle-smooth` property.
- Moved the demo to NextJS
- Added `--squircle-radius-top-left`, `--squircle-radius-top-right`, `--squircle-radius-bottom-right`, `--squircle-radius-bottom-left` properties
- Added separate `lib` folder only for the script