offset-path

The offset-path CSS property specifies the offset path where the element gets positioned. The exact element’s position on the offset path is determined by the offset-distance property. An offset path is either a specified path with one or multiple sub-paths or the geometry of a not-styled basic shape. Each shape or path must define an initial position for the computed value of "0" for offset-distance and an initial direction which specifies the rotation of the object to the initial position.

In this specification, a direction (or rotation) of 0 degrees is equivalent to the direction of the positive x-axis in the object’s local coordinate system. In other words, a rotation of 0 degree points to the right side of the UA if the object and its ancestors have no transformation applied.

Syntax

TBD

Formal syntax

none | ray( [ <angle> && <size>? && contain? ] ) | <path()> | <url> | [ <basic-shape> || <geometry-box> ]
where 
<size> = closest-side | farthest-side | closest-corner | farthest-corner | <length> | <length-percentage>{2}
<basic-shape> = <inset()> | <circle()> | <ellipse()> | <polygon()>
<geometry-box> = <shape-box> | fill-box | stroke-box | view-box
where 
<length-percentage> = <length> | <percentage>
<inset()> = inset( <length-percentage>{1,4} [ round <border-radius> ]? )
<circle()> = circle( [ <shape-radius> ]? [ at <position> ]? )
<ellipse()> = ellipse( [ <shape-radius>{2} ]? [ at <position> ]? )
<polygon()> = polygon( <fill-rule>? , [ <length-percentage> <length-percentage> ]# )
<shape-box> = <box> | margin-box
where 
<shape-radius> = <length-percentage> | closest-side | farthest-side
<position> = [[ left | center | right | top | bottom | <length-percentage> ] | [ left | center | right | <length-percentage> ] [ top | center | bottom | <length-percentage> ] | [ center | [ left | right ] <length-percentage>? ] && [ center | [ top | bottom ] <length-percentage>? ]]
<fill-rule> = nonzero | evenodd
<box> = border-box | padding-box | content-box

Examples

The following example is excerpted from a sample that may be viewed live on GitHub in a supporting browser. The SVG in the second code sample is a simple drawing of a house with a chimney. The offset-path properties in the first code sample move a pair of scissors along the outside border of the house. Notice the :path() pseudo class in the offset-path property and the <path> element in the SVG. If you compare them, you'll find they are identical.

#firstScissorHalf {
  offset-path: path('M900,190  L993,245 V201  A11,11 0 0,1 1004,190  H1075  A11,11 0 0,1 1086,201  V300  L1294,423 H1216  A11,11 0 0,0 1205,434  V789  A11,11 0 0,1 1194,800  H606  A11,11 0 0,1 595,789  V434  A11,11 0 0,0 584,423  H506 L900,190');
}

#secondScissorHalf {
  offset-path: path('M900,190  L993,245 V201  A11,11 0 0,1 1004,190  H1075  A11,11 0 0,1 1086,201  V300  L1294,423 H1216  A11,11 0 0,0 1205,434  V789  A11,11 0 0,1 1194,800  H606  A11,11 0 0,1 595,789  V434  A11,11 0 0,0 584,423  H506 L900,190');
}

<svg xmlns="http://www.w3.org/2000/svg"
     width="700"
     height="450"
     viewBox="350 0 1400 900">
  <rect x="595"
        y="423"
        width="610"
        height="377"
        fill="blue" />
  <polygon points="506,423 900,190 1294,423"
           fill="yellow" />
  <polygon points="993,245 993,190 1086,190 1086,300"
           fill="red" />
  <path id="house" d="M900,190 L993,245 V201 A11,11 0 0,1 1004,190 H1075 A11,11 0 0,1 1086,201 V300 L1294,423 H1216 A11,11 0 0,0 1205,434 V789 A11,11 0 0,1 1194,800 H606 A11,11 0 0,1 595,789 V434 A11,11 0 0,0 584,423 H506 L900,190"
        fill="none"
        stroke="black"
        stroke-width="13"
        stroke-linejoin="round"
        stroke-linecap="round" />
  <path id="firstScissorHalf"
        d="M30,0 H-10 A10,10 0 0,0 -20,10 A20,20 0 1,1 -40,-10 H20 A10,10 0 0,1 30,0 M-40,20 A10,10 1 0,0 -40,0 A10,10 1 0,0 -40,20 M0,0"
        transform="translate(0,0)"
        fill="green"
        stroke="black"
        stroke-width="5"
        stroke-linejoin="round"
        stroke-linecap="round"
        fill-rule="evenodd" />
  <path id="secondScissorHalf"
        d="M30,0 H-10 A10,10 0 0,1 -20,-10 A20,20 0 1,0 -40,10 H20 A10,10 0 0,0 30,0 M-40,-20 A10,10 1 0,0 -40,0 A10,10 1 0,0 -40,-20 M0,0"
        transform="translate(0,0)"
        fill="forestgreen"
        stroke="black"
        stroke-width="5"
        stroke-linejoin="round"
        stroke-linecap="round"
        fill-rule="evenodd" />
</svg>

Specifications

Browser compatibility