shape-outside

尝试一下

shape-outside: circle(50%);

shape-outside: ellipse(130px 140px at 20% 20%);

shape-outside: url("/proxy/developer.mozilla.org/shared-assets/images/examples/round-balloon.png");

shape-outside: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);

<section class="default-example" id="default-example">
  <div class="example-container">
    <img
      class="transition-all"
      id="example-element"
      src="/proxy/developer.mozilla.org/shared-assets/images/examples/round-balloon.png"
      width="150" />
    We had agreed, my companion and I, that I should call for him at his house,
    after dinner, not later than eleven o’clock. This athletic young Frenchman
    belongs to a small set of Parisian sportsmen, who have taken up “ballooning”
    as a pastime. After having exhausted all the sensations that are to be found
    in ordinary sports, even those of “automobiling” at a breakneck speed, the
    members of the “Aéro Club” now seek in the air, where they indulge in all
    kinds of daring feats, the nerve-racking excitement that they have ceased to
    find on earth.
  </div>
</section>

.example-container {
  text-align: left;
  padding: 20px;
}

#example-element {
  float: left;
  width: 150px;
  margin: 20px;
}

语法

/* 关键字值 */
shape-outside: none;
shape-outside: margin-box;
shape-outside: content-box;
shape-outside: border-box;
shape-outside: padding-box;

/* 函数值 */
shape-outside: circle();
shape-outside: ellipse();
shape-outside: inset(10px 10px 10px 10px);
shape-outside: polygon(10px 10px, 20px 20px, 30px 30px);

/* <url> 值 */
shape-outside: url(image.png);

/* 渐变值 */
shape-outside: linear-gradient(45deg, rgba(255, 255, 255, 0) 150px, red 150px);

/* 全局值 */
shape-outside: initial;
shape-outside: inherit;
shape-outside: unset;

shape-outside 属性指定使用下面列表的值来定义浮动元素的浮动区域。这个浮动区域决定了行内内容（浮动元素）所包裹的形状。

值

none

该浮动区域不产生影响，行内元素以默认的方式包裹着该元素的 margin box。

<shape-box>

根据浮动元素的边缘（通过 CSS box model 来定义）形状计算出浮动的区域。可能是 margin-box, border-box, padding-box, 或者 content-box。这个形状包括了由 border-radius 属性制造出来的弧度（与 background-clip 的表现类似）。

margin-box

定义一个由外边距的外边缘封闭形成的形状。这个形状的角的半径由相应的border-radius 和margin 的值决定。如果 border-radius / margin 的比率大于等于 1 , 那么这个 margin box 的角的弧度就是 border-radius + margin ；如果比率小于 1，那么这个 margin box 的角的弧度就是 border-radius + (margin * (1 + (ratio-1)^3)) 。

border-box

定义一个由边界的外边缘封闭形成的形状。这个形状遵循正常的边界外部圆角的形成规则。

padding-box

定义一个由内边距的外边缘封闭形成的形状。这个形状遵循正常的边界内部圆角的形成规则。

content-box

定义一个由内容区域的外边缘封闭形成的形状（译者：表述的不太好，就是被 padding 包裹的区域，在 chrome 控制台中的盒子模型图中的蓝色区域。）。每一个角的弧度取 0 或 border-radius - border-width - padding 中的较大值。

<basic-shape>

基于 inset()、circle()、ellipse() 或 polygon() 其中一个创造出来的形状计算出浮动区域。如果同时存在 <shape-box>，那么会为 <basic-shape> 方法定义一个参考盒，这个参考盒默认为 margin-box。

<image>

提取并且计算指定 <image> 的 alpha 通道得出浮动区域（译者：即根据图片的非透明区域进行包裹）。就跟通过 shape-image-threshold来定义一样。

备注：用户代理 必须使用由 HTML5 规范定义的 CORS-enabled fetch 方法来处理 shape-outside 的值中的所有 URL。当捕获的时候，用户代理必须使用“匿名”模式来设置层叠样式表的 URL 的 referrer source 和设置所在文档的 URL 的 origin。如果这导致出现没有有效的备份图像这样的网络错误，产生的影响就跟指定了值 none 一样。

正式语法

shape-outside = 
  none                              |
  [ <basic-shape> || <shape-box> ]  |
  <image>                           

<basic-shape> = 
  <basic-shape-rect>  |
  <circle()>          |
  <ellipse()>         |
  <polygon()>         |
  <path()>            |
  <shape()>           

<shape-box> = 
  <visual-box>     |
  margin-box       |
  half-border-box  

<image> = 
  <url>           |
  <image()>       |
  <image-set()>   |
  <cross-fade()>  |
  <element()>     |
  <gradient>      

<basic-shape-rect> = 
  <inset()>  |
  <rect()>   |
  <xywh()>   

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

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

<polygon()> = 
  polygon( <'fill-rule'>? [ round <length> ]? , [ <length-percentage> <length-percentage> ]# )  

<path()> = 
  path( <'fill-rule'>? , <string> )  

<shape()> = 
  shape( <'fill-rule'>? from <position> , <shape-command># )  

<visual-box> = 
  content-box  |
  padding-box  |
  border-box   

<image()> = 
  image( <image-tags>? [ <image-src>? , <color>? ]! )  

<image-set()> = 
  image-set( <image-set-option># )  

<cross-fade()> = 
  cross-fade( <cf-image># )  

<element()> = 
  element( <id-selector> )  

<inset()> = 
  inset( <length-percentage>{1,4} [ round <'border-radius'> ]? )  

<rect()> = 
  rect( <top> , <right> , <bottom> , <left> )  

<xywh()> = 
  xywh( <length-percentage>{2} <length-percentage [0,∞]>{2} [ round <'border-radius'> ]? )  

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

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

<fill-rule> = 
  nonzero  |
  evenodd  

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

<shape-command> = 
  <move-command>             |
  <line-command>             |
  close                      |
  <horizontal-line-command>  |
  <vertical-line-command>    |
  <curve-command>            |
  <smooth-command>           |
  <arc-command>              

<image-tags> = 
  ltr  |
  rtl  

<image-src> = 
  <url>     |
  <string>  

<image-set-option> = 
  [ <image> | <string> ] [ <resolution> || type( <string> ) ]?  

<cf-image> = 
  [ <image> | <color> ]  &&
  <percentage [0,100]>?  

<id-selector> = 
  <hash-token>  

<border-radius> = 
  <length-percentage [0,∞]>{1,4} [ / <length-percentage [0,∞]>{1,4} ]?  

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

<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}          

<move-command> = 
  move <command-end-point>  

<line-command> = 
  line <command-end-point>  

<horizontal-line-command> = 
  hline [ to [ <length-percentage> | left | center | right | x-start | x-end ] | by <length-percentage> ]  

<vertical-line-command> = 
  vline [ to [ <length-percentage> | top | center | bottom | y-start | y-end ] | by <length-percentage> ]  

<curve-command> = 
  curve [ [ to <position> with <control-point> [ / <control-point> ]? ] | [ by <coordinate-pair> with <relative-control-point> [ / <relative-control-point> ]? ] ]  

<smooth-command> = 
  smooth [ [ to <position> [ with <control-point> ]? ] | [ by <coordinate-pair> [ with <relative-control-point> ]? ] ]  

<arc-command> = 
  arc <command-end-point> [ [ of <length-percentage>{1,2} ] && <arc-sweep>? && <arc-size>? && [ rotate <angle> ]? ]  

<command-end-point> = 
  to <position>         |
  by <coordinate-pair>  

<control-point> = 
  <position>                |
  <relative-control-point>  

<coordinate-pair> = 
  <length-percentage>{2}  

<relative-control-point> = 
  <coordinate-pair> [ from [ start | end | origin ] ]?  

<arc-sweep> = 
  cw   |
  ccw  

<arc-size> = 
  large  |
  small  

插值

当在两个 <basic-shape> 之间产生动画时，将会应用以下规则。shape 里的值将会被当成一个简单列表插入。插入列表的值的类型可能是 <length>，<percentage>，或 calc()。如果列表的值不是以上的几种类型，但是都相同的话（如在两个列表的相同位置找到了 nonzero ），那些值会插入到列表中。

• 两个形状必须使用同样的参考盒。
• 如果两个形状都是 ellipse() 或 circle()类型，并且它们的 radii 都没有使用 closest-side 或 farthest-side 关键字，则将两个形状对应值之间的值插入到 shape 方法中。
• 如果两个形状的类型都是 inset()，则将两个形状对应值之间的值插入到 shape 方法中。
• 如果两个形状都是 polygon()，两个多边形之间有相同的定点数量并且 <fill-rule> 相同，则将两个形状对应值之间的值插入到 shape 方法中。
• 其余所有情况都不会发生插入。

示例

HTML

<div class="main">
  <div class="left"></div>
  <div class="right"></div>
  <p>
    Sometimes a web page's text content appears to be funneling your attention
    towards a spot on the page to drive you to follow a particular link.
    Sometimes you don't notice.
  </p>
</div>

CSS

.main {
  width: 500px;
}

.left,
.right {
  width: 40%;
  height: 12ex;
  background-color: lightgray;
}

.left {
  -webkit-shape-outside: polygon(0 0, 100% 100%, 0 100%);
  shape-outside: polygon(0 0, 100% 100%, 0 100%);
  float: left;
  -webkit-clip-path: polygon(0 0, 100% 100%, 0 100%);
  clip-path: polygon(0 0, 100% 100%, 0 100%);
}

.right {
  -webkit-shape-outside: polygon(100% 0, 100% 100%, 0 100%);
  shape-outside: polygon(100% 0, 100% 100%, 0 100%);
  float: right;
  -webkit-clip-path: polygon(100% 0, 100% 100%, 0 100%);
  clip-path: polygon(100% 0, 100% 100%, 0 100%);
}

p {
  text-align: center;
}

Result

规范

浏览器兼容性

参见

• CSS Shapes
• Overview of CSS Shapes
• Shapes from Box Values
• Basic Shapes
• Shapes from Images
• <basic-shape>
• shape-margin
• shape-image-threshold