circle()

Baseline 已广泛支持

此特性已相当成熟,可在许多设备和浏览器版本上使用。自 ⁨2020 年 1 月⁩ 起,所有主流浏览器均已支持。

circle() CSS 函数使用半径和位置定义一个圆形。它是 <basic-shape> 数据类型之一。

试一试

clip-path: circle(50px);
clip-path: circle(6rem at right center);
clip-path: circle(10% at 2rem 90%);
clip-path: circle(closest-side at 5rem 6rem);
clip-path: circle(farthest-side);
<section class="default-example" id="default-example">
  <div class="transition-all" id="example-element"></div>
</section>
#default-example {
  background: #ffee99;
}

#example-element {
  background: linear-gradient(to bottom right, #ff5522, #0055ff);
  width: 100%;
  height: 100%;
}

语法

css
shape-outside: circle(50%);
clip-path: circle(6rem at 12rem 8rem);

<shape-radius>

这可以是一个 <length><percentage> 值,也可以是 closest-sidefarthest-side

closest-side

使用从图形中心到参考框最近一侧的长度。对于圆形,这是任何维度中最接近的一侧。

farthest-side

使用从图形中心到参考框最远一侧的长度。对于圆形,这是任何维度中最远的一侧。

<position>

移动圆心。可以是一个 <length><percentage> 值,或者像 left 这样的值。如果省略,<position> 值默认为中心。

正式语法

<circle()> = 
circle( <radial-size>? [ at <position> ]? )

<radial-size> =
<radial-extent> |
<length [0,∞]> |
<length-percentage [0,∞]>{2}

<position> =
<position-one> |
<position-two> |
<position-four>

<radial-extent> =
closest-corner |
closest-side |
farthest-corner |
farthest-side

<length-percentage> =
<length> |
<percentage>

<position-one> =
left |
center |
right |
top |
bottom |
x-start |
x-end |
y-start |
y-end |
block-start |
block-end |
inline-start |
inline-end |
<length-percentage>

<position-two> =
[ left | center | right | x-start | x-end ] && [ top | center | bottom | y-start | y-end ] |
[ left | center | right | x-start | x-end | <length-percentage> ] [ top | center | bottom | y-start | y-end | <length-percentage> ] |
[ block-start | center | block-end ] && [ inline-start | center | inline-end ] |
[ start | center | end ]{2}

<position-four> =
[ [ left | right | x-start | x-end ] <length-percentage> ] && [ [ top | bottom | y-start | y-end ] <length-percentage> ] |
[ [ block-start | block-end ] <length-percentage> ] && [ [ inline-start | inline-end ] <length-percentage> ] |
[ [ start | end ] <length-percentage> ]{2}

示例

基本圆形

在下面的示例中,shape-outside 属性的值为 circle(50%),它在一个浮动元素上定义了一个圆形,以便文本可以围绕其流动。

html
<div class="box">
  <img
    alt="A hot air balloon"
    src="https://mdn.github.io/shared-assets/images/examples/round-balloon.png" />
  <p>
    One November night in the year 1782, so the story runs, two brothers sat
    over their winter fire in the little French town of Annonay, watching the
    grey smoke-wreaths from the hearth curl up the wide chimney. Their names
    were Stephen and Joseph Montgolfier, they were papermakers by trade, and
    were noted as possessing thoughtful minds and a deep interest in all
    scientific knowledge and new discovery. Before that night—a memorable night,
    as it was to prove—hundreds of millions of people had watched the rising
    smoke-wreaths of their fires without drawing any special inspiration from
    the fact.
  </p>
</div>
css
body {
  font: 1.2em / 1.5 sans-serif;
}
img {
  float: left;
  shape-outside: circle(50%);
}

规范

规范
CSS Shapes Module Level 1
# funcdef-basic-shape-circle

浏览器兼容性

另见