Name: offset-path
Value: none | <> || <>
Initial: none
Applies to: [=transformable elements=]
Inherited: no
Percentages: n/a
Computed value: as specified
Media: visual
Animation type: by computed value

<offset-path> = <> | <> | <>

: none :: The element does not have an [=offset transform=]. : <> || <> :: The element has an [=offset transform=], defined by some [=offset path=]. See [[#transform]] for details on how to calculate the [=offset transform=]. All the usual effects of having a 'transform' apply (such as creating a [=stacking context=], etc.) See [[css-transforms-1#transform-rendering]] for details. If <> is omitted, it defaults to inset(0 round X), where X is the value of 'border-radius' on the element that establishes the [=containing block=] for this element. If <> is omitted, it defaults to ''/border-box''. See the specific values (below) for the interpretation of each component. : <> :: The [=offset path=] is a line extending from the [=ray()/origin=] at some angle. See [[#ray-function]] for details. The <> provides the [=/reference box=] for the ray. : <> :: A URL reference to an SVG [=shape element=]. The [=offset path=] is the referenced element's [=equivalent path=]. [[!SVG2]] If the URL does not reference a [=shape element=] (because it references a different element, or resolves to a non-SVG document, or doesn't resolve at all, etc) this behaves as ''path("m 0 0")'' (a <>) instead. The <> defines the viewport and user coordinate system for the [=shape element=], with the origin (the 0,0 point) at the top left corner, and units being ''1px'' in size. : <> :: The [=offset path=] is the [=/equivalent path=] of the <> function. For all <>s, if they accept an ''at <>'' argument but that argument is omitted, and the element defines an [=offset starting position=] via 'offset-position', it uses the specified [=offset starting position=] for that argument. Otherwise it defaults as specified for each function. The <> provides the [=/reference box=] for the <>. : <> :: Defines the box that the <> sizes into. In CSS contexts, the boxes being referenced are from the element that establishes the [=containing block=] for this element. In SVG contexts, all values behave as ''/view-box''.

The ''ray()'' Function

ray() = ray( <> && <>? && contain? && [at <>]? )

<ray-size> = <> | sides

: <> :: The offset path is a single line segment that starts from the [=offset starting position=] and proceeds in the direction defined by the specified <>. (Its length is determined by the other arguments.) As with [=gradient functions=], <> values are interpreted as bearing angles, with ''0deg'' pointing up and positive angles representing clockwise rotation. : <ray-size> :: Specifies the length of the [=offset path=] (the distance between the ''offset-distance: 0%'' and ''offset-distance: 100%'' points) relative to the containing box. If no <> is specified it defaults to ''closest-side''. Note: For ''sides'', the distance depends on the <> specified; for all other values, the distance is constant regardless of the <>. Individual keywords are:

: closest-side :: The distance from the ray's starting point to whichever side of the [=containing block=] is closest. : closest-corner :: The distance from the ray's starting point to whichever corner of the [=containing block=] is closest. : farthest-side :: The distance from the ray's starting point to whichever side of the [=containing block=] is farthest. : farthest-corner :: The distance from the ray's starting point to whichever corner of the [=containing block=] is farthest. : sides :: The distance from the ray's starting point to the point where the [=offset path=] intersects the [=containing block's=] boundary. If the ray's starting point is on the [=containing block's=] boundary, or outside its bounds entirely, the distance is zero.

Note: For ''closest-side'' and ''closest-corner'', if the ray's starting point is on an edge/corner, that's the closest one. (In other words, the distance is zero.) Note: For ''closest-side'' and ''farthest-side'', if the ray's starting point is outside the [=containing block=] entirely, the edges of the [=containing block=] are considered to extend out to infinity. : contain :: The length of the [=offset path=] is reduced so that the element stays within the [=containing block=] even at ''offset-distance: 100%''. Specifically, the path's length is reduced by half the width or half the height of the element's border box, whichever is larger, and floored at zero.

This behavior is optimized for a particular case-- the element's width and height are equal or nearly so; the element is either completely rounded by 'border-radius' or the corners aren't relevant to its appearance; the ''ray()'' uses ''closest-side'' positioning; and 'offset-anchor' is set to ''offset-anchor/center''. Under these conditions, which are common for situations like positioning elements around the edge of a round clock face, this ensures that each element is positioned fairly snugly against the inner edge of the clock face at ''offset-distance: 100%''. In other conditions this will act similarly but might not give quite as optimal a result.

: at <> :: Specifies the origin of the ray, where the ray's line begins (the 0% position). It's resolved by using the <> to position a 0x0 object area within the box's [=containing block=]. If omitted, it uses the [=offset starting position=] of the element, given by 'offset-position'. If the element doesn't have an [=offset starting position=] either, it behaves as ''at center''. Note: ''ray()'' is currently only usable as an [=offset path=]. If it ever gets extended to other uses, its usage of 'offset-position' will be limited solely to when it's an [=offset path=], similar to other <> functions.

Here are some examples. The first example shows that some parts of boxes are outside of the offset path.

    <style>
        body {
            transform-style: preserve-3d;
            width: 200px;
            height: 200px;
        }
        .box {
            width: 50px;
            height: 50px;
            offset-position: 50% 50%;
            offset-distance: 100%;
            offset-rotate: 0deg;
        }
        #redBox {
            background-color: red;
            offset-path: ray(45deg closest-side);
        }
        #blueBox {
            background-color: blue;
            offset-path: ray(180deg closest-side);
        }
    </style>
    <body>
        <div class="box" id="redBox"></div>
        <div class="box" id="blueBox"></div>
    </body>
    

In the second example, 'contain' is given to the 'offset-path' value of each box to avoid overflowing.

    <style>
        body {
            transform-style: preserve-3d;
            width: 200px;
            height: 200px;
        }
        .box {
            width: 50px;
            height: 50px;
            offset-position: 50% 50%;
            offset-distance: 100%;
            offset-rotate: 0deg;
        }
        #redBox {
            background-color: red;
            offset-path: ray(45deg closest-side contain);
        }
        #blueBox {
            background-color: blue;
            offset-path: ray(180deg closest-side contain);
        }
    </style>
    <body>
        <div class="box" id="redBox"></div>
        <div class="box" id="blueBox"></div>
    </body>
    

In the third example, the path size is increased so that the box can be contained. The used offset distance is negative.

    <style>
        body {
            transform-style: preserve-3d;
            width: 250px;
            height: 250px;
        }
        .box {
            width: 60%;
            height: 10%;

            offset-position: 20% 20%;
            offset-distance: 0%;
            offset-rotate: 0deg;
            offset-anchor: 200% -300%;
        }
        #blueBox {
            background-color: blue;
            offset-path: ray(-90deg closest-side contain);
        }
    </style>
    <body>
        <div class="box" id="blueBox"></div>
    </body>
    

In the fourth example, the initial position is outside the containing block.

    <style>
        #container {
            transform-style: preserve-3d;
            width: 200px;
            height: 200px;
        }
        .box {
            width: 20%;
            height: 20%;
            offset-position: 140% 70%;
            offset-distance: 100%;
        }
        #redBox {
            background-color: red;
            offset-path: ray(-90deg sides);
        }
        #blueBox {
            background-color: blue;
            offset-path: ray(180deg closest-side);
        }
    </style>
    <div id="container">
        <div class="box" id="redBox"></div>
        <div class="box" id="blueBox"></div>
    </div>
    

> Positioning ### {#example-shape}

This example uses a circle with implicit center position.

    <style>
        body {
            width: 323px;
            height: 131px;
            margin: 0px;
            border: 2px solid black;
            padding: 8px;
            transform-style: preserve-3d;
        }
        .item {
            width:  90px;
            height: 40px;
            background-color: violet;
        }
        #middle {
            offset-position: auto;
            offset-path: circle(60%) margin-box;
            offset-distance: 25%;
            offset-anchor: left top;
        }
    </style>
    <body>
        <div class="item"></div>
        <div class="item" id="middle"></div>
        <div class="item"></div>
    </body>
    

### Examples of <> Positioning ### {#example-coord}

This example shows how <> offset path works in combination with 'border-radius'.

    <style>
        body {
            width: 500px;
            height: 300px;
            border-radius: 80px;
            border: dashed aqua;
            margin: 0;
        }
        #blueBox {
            width: 40px;
            height: 20px;
            background-color: blue;
            offset-path: margin-box;
        }
    </style>
    <body>
        <div id="blueBox"></div>
    </body>
    

Position On The Path: the 'offset-distance' property {#offset-distance-property} --------------------------------------------------------------------------------

Name: offset-distance
Value: <>
Initial: 0
Applies to: [=transformable elements=]
Inherited: no
Percentages: relative to the [=offset path=] length
Computed value: a computed <> value
Media: visual
Animation type: by computed value

Specifies where along the [=offset path=] the [=offset position=] is.

: <> :: The [=offset position=] is the point that is the specified distance along the element's [=offset path=]. See [[#path-distance]] for details about how to calculate distances along a path. Percentages are relative to the total length of the [=offset path=].

animation/offset-distance-composition.html animation/offset-distance-interpolation.html animation/reftests/offset-distance-interpolation-001.html offset-distance-001.html offset-distance-002.html offset-distance-003.html offset-distance-004.html offset-distance-005.html offset-distance-006.html offset-distance-007.html offset-distance-008.html offset-distance-009.html parsing/offset-distance-computed.html parsing/offset-distance-parsing-invalid.html parsing/offset-distance-parsing-valid.html Note: By animating the 'offset-distance', an element can easily trace out a complex path. If the element does not have an [=offset path=], this property does nothing. ### Calculating the computed distance along a path ### {#path-distance} Processing the distance along an offset path operates differently depending upon the nature of the offset path: * References to <> offset paths with contain are unclosed intervals. * References to <> offset paths without contain are unbounded rays. * All basic CSS shapes are closed loops. * Offset paths (including references to SVG Paths) are closed loops only if the final command in the path list is a closepath command ("z" or "Z"), otherwise they are unclosed intervals. * References to SVG circles, ellipses, images, polygons and rects are closed loops. * References to SVG lines and polylines are unclosed intervals. To determine the used offset distance for a given offset path and offset distance: 1. Let the total length be the total length of offset path with all sub-paths. 2. Convert offset distance to pixels, with 100% being converted to total length. 3.

: If offset path is an unbounded ray: :: Let used offset distance be equal to offset distance. : Otherwise if offset path is an <> path with contain: :: Let used offset distance be equal to offset distance, clamped so that the box lies entirely within the path. : If offset path is any other unclosed interval: :: Let used offset distance be equal to offset distance clamped by 0 and the total length of the path. : Otherwise offset path is a closed loop: :: Let used offset distance be equal to offset distance modulo the total length of the path. If the total length of the path is 0, used offset distance is also 0. Note: “Modulo” here uses the traditional mathematical definition, where the output is always non-negative.

This example shows boxes placed along an unclosed interval.

<style>
    .item {
        width: 100px;
        height: 40px;
        offset-position: 0% 0%;
        offset-path: path('m 0 0 h 200 v 150');
    }
    #box1 {
        background-color: red;
        offset-distance: -280%;
    }
    #box2 {
        background-color: green;
        offset-distance: 190%;
    }
</style>
<body>
    <div class="item" id="box1"></div>
    <div class="item" id="box2"></div>
</body>

This example shows boxes placed along a closed interval.

<style>
    .item {
        width: 100px;
        height: 40px;
        offset-position: 0% 0%;
        offset-path: path('m 0 0 h 200 v 150 z');
    }
    #box1 {
        background-color: red;
        offset-distance: -280%;
    }
    #box2 {
        background-color: green;
        offset-distance: 190%;
    }
</style>
<body>
    <div class="item" id="box1"></div>
    <div class="item" id="box2"></div>
</body>

This example shows a way to align boxes within the polar coordinate system using 'offset-path', 'offset-distance'.

    <style>
        body {
            transform-style: preserve-3d;
            width: 300px;
            height: 300px;
            border: dashed gray;
            border-radius: 50%;
        }
        .circleBox {
            position: absolute;
            left: 50%;
            top: 50%;
            width: 40px;
            height: 40px;
            background-color: red;
            border-radius: 50%;
        }
        #circle1 {
            offset-path: ray(0deg farthest-side);
            offset-distance: 50%;
        }
        #circle2 {
            offset-path: ray(90deg farthest-side);
            offset-distance: 20%;
        }
        #circle3 {
            offset-path: ray(225deg farthest-side);
            offset-distance: 100%;
        }
    </style>
    <body>
        <div class="circleBox" id="circle1"></div>
        <div class="circleBox" id="circle2"></div>
        <div class="circleBox" id="circle3"></div>
    </body>
    

Starting Point Of The Path: the 'offset-position' property {#offset-position-property} -------------------------------------------------------------------------------------------------

Name: offset-position
Value: normal | auto | <>
Initial: normal
Media: visual
Inherited: no
Applies to: [=transformable elements=]
Percentages: Refer to the size of containing block
Computed value: The ''offset-position/normal'' or ''offset-position/auto'' keywords, or a computed <>
Animation type: by computed value

Specifies the offset starting position that is used by the <> functions if they don't specify their own starting position. Values are defined as follows:

: normal :: The element does not have an [=offset starting position=]. : auto :: The [=offset starting position=] is the top-left corner of the box. Note: This is the top-left corner of the element's own box, not that of its [=containing block=]! It's completely different from specifiying ''top left''. It's meant, for example, to allow a ''path()'' to start relative to the element's own position. : <> :: The [=offset starting position=] is the result of using the <> to position a 0x0 object area within the box's [=containing block=].

parsing/offset-position-computed.html parsing/offset-position-parsing-invalid.html parsing/offset-position-parsing-valid.html

This example shows positioning a box with 'offset-position'.

    <style>
        #wrap {
            position: relative;
            width: 300px;
            height: 300px;
            border: 1px solid black;
        }

        #box {
            width: 100px;
            height: 100px;
            background-color: green;
            position: absolute;
            top: 100px;
            left: 80px;
            offset-position: auto;
            offset-anchor: center;
            offset-path: ray(45deg);
        }
    </style>
    <body>
        <div id="wrap">
            <div id="box"></div>
        </div>
    </body>
    

This example shows the interaction with the 'transform' property, and with an individual transform property ('rotate'). The motion path transform is a vertical translation moving ('left', 'top') to 'offset-position'.

<style>
    #wrap {
        transform-style: preserve-3d;
        width: 400px;
        height: 350px;
    }
    .item {
        position: absolute;
        left: 200px;
        top: 0px;
        offset-position: 200px 100px; /* translates by 0px,100px */
        offset-anchor: left top;
        transform-origin: left top;
        width: 130px;
        height: 80px;
        border-top-right-radius: 23px;
    }
    #box1 {
        background-color: tomato;
        offset-position: auto;
    }
    #box2 {
        background-color: green;
    }
    #box3 {
        background-color: navy;
        rotate: 90deg; /* applied before motion path transform */
    }
    #box4 {
        background-color: gold;
        transform: rotate(90deg); /* applied after motion path transform */
    }
</style>
<body>
    <div id="wrap">
        <div class="item" id="box1"></div>
        <div class="item" id="box2"></div>
        <div class="item" id="box3"></div>
        <div class="item" id="box4"></div>
    </div>
</body>

This example uses 'position' ''static'', so 'offset-position' generates translations from the normal flow positions. By amplifying these translations using 'scale', the normal flow is rotated 180 degrees around the 'offset-position', and the boxes are exploded away from each other.

<style>
    #wrap {
        transform-style: preserve-3d;
        width: 500px;
        height: 250px;
        line-height: 0px;
    }
    span {
        position: static;
        display: inline-block;
        width: 100px;
        height: 50px;
        border-top-right-radius: 23px;
        scale: 2.5 2.5; /* applied before motion path transform */
        offset-position: center;
        transform: scale(0.4); /* applied after motion path transform */
    }
    #box1 {
        background-color: tomato;
    }
    #box2 {
        background-color: green;
    }
    #box3 {
        background-color: navy;
    }
    #box4 {
        background-color: gold;
    }
</style>
<body>
    <div id="wrap">
        <div>
            <span id="box1"></span><span id="box2"></span>
        </div>
        <div>
            <span id="box3"></span><span id="box4"></span>
        </div>
    </div>
</body>

In this example, each 'offset-position' value is ignored as 'offset-path' is a <>, but the other offset properties combine to have an effect equivalent to that for 'offset-position' 'right bottom'.

<style>
    #wrap {
        transform-style: preserve-3d;
        width: 540px;
        height: 420px;
    }
    .item {
        position: absolute;
        width: 90px;
        height: 70px;
        border-top-right-radius: 23px;
        scale: 0.8 0.8; /* applied before motion path transform */
        offset-path: padding-box;
        offset-distance: 50%;
        offset-rotate: 0deg;
        offset-anchor: right bottom;
        transform: scale(1.25); /* applied after motion path transform */
    }
    #box1 {
        background-color: tomato;
        position: static;
        offset-position: auto; /* ignored */
    }
    #box2 {
        background-color: green;
        right: 0px;
        top: 0px;
        offset-position: 23% 45%; /* ignored */
    }
    #box3 {
        background-color: navy;
        left: 0px;
        bottom: 0px;
        offset-position: 34% 56px; /* ignored */
    }
    #box4 {
        background-color: gold;
        right: 0px;
        bottom: 0px;
        offset-position: 45px 67px; /* ignored */
    }
</style>
<body>
    <div id="wrap">
        <div class="item" id="box1"></div>
        <div class="item" id="box2"></div>
        <div class="item" id="box3"></div>
        <div class="item" id="box4"></div>
    </div>
</body>

The Element's Anchor Point: the 'offset-anchor' property {#offset-anchor-property} ------------------------------------------------------------------------------

Name: offset-anchor
Applies to: [=transformable elements=]
Value: auto | <>
Initial: auto
Media: visual
Inherited: no
Percentages: relative to the width and the height of the element's [=reference box=]
Computed value: the ''offset-anchor/auto'' keyword or a computed <>
Animation type: by computed value

Defines the element's offset anchor point-- the point that is aligned with the [=offset position=] along the [=offset path=]. Values have the following meanings:

: auto :: The [=anchor point=] is the same as the point indicated by 'transform-origin'. Specifically, the [=computed value=] of 'transform-origin' is resolved as a <> against the element's [=reference box=]. : <> :: The [=anchor point=] is the result of resolving the <> against the element's [=reference box=].

animation/offset-anchor-composition.html animation/offset-anchor-interpolation.html offset-anchor-transform-box-fill-box-001.html offset-anchor-transform-box-fill-box-002.html offset-anchor-transform-box-fill-box-003.html parsing/offset-anchor-computed.html parsing/offset-anchor-parsing-invalid.html parsing/offset-anchor-parsing-valid.html Issue: Which box this is resolved against is being discussed in Issue 503.

The following explains how to set the anchor point of the box.

#plane {
    offset-anchor: center;
}

The red dot in the middle of the shape indicates the anchor point of the shape.

This example shows an alignment of four boxes with different anchor points.

<style>
    body {
        transform-style: preserve-3d;
        width: 300px;
        height: 300px;
        border: 2px solid gray;
        border-radius: 50%;
    }
    .box {
        width: 50px;
        height: 50px;
        background-color: orange;
        offset-position: 50% 50%;
        offset-distance: 100%;
        offset-rotate: 0deg;
    }
    #item1 {
        offset-path: ray(45deg closest-side);
        offset-anchor: right top;
    }
    #item2 {
        offset-path: ray(135deg closest-side);
        offset-anchor: right bottom;
    }
    #item3 {
        offset-path: ray(225deg closest-side);
        offset-anchor: left bottom;
    }
    #item4 {
        offset-path: ray(315deg closest-side);
        offset-anchor: left top;
    }
</style>
<body>
    <div class="box" id="item1"></div>
    <div class="box" id="item2"></div>
    <div class="box" id="item3"></div>
    <div class="box" id="item4"></div>
</body>

This example shows boxes centered at their offset-position.

<style>
    body {
        width: 500px;
        height: 500px;
    }
    .box {
        background-color: mediumpurple;
        offset-path: none;
        offset-anchor: center;
    }
    #item1 {
        offset-position: 90% 20%;
        width: 60%;
        height: 20%;
    }
    #item2 {
        offset-position: 100% 100%;
        width: 30%;
        height: 10%;
    }
    #item3 {
        offset-position: 50% 100%;
        width: 20%;
        height: 60%;
    }
    #item4 {
        offset-position: 0% 100%;
        width: 30%;
        height: 90%;
    }
</style>
<body>
    <div class="box" id="item1"></div>
    <div class="box" id="item2"></div>
    <div class="box" id="item3"></div>
    <div class="box" id="item4"></div>
</body>

This example shows how offset-anchor computes to their offset-position.

<style>
    body {
        width: 500px;
        height: 500px;
    }
    .box {
        background-color: mediumpurple;
        offset-path: none;
        offset-anchor: auto;
    }
    #item1 {
        offset-position: 90% 20%;
        width: 60%;
        height: 20%;
    }
    #item2 {
        offset-position: 100% 100%;
        width: 30%;
        height: 10%;
    }
    #item3 {
        offset-position: 50% 100%;
        width: 20%;
        height: 60%;
    }
    #item4 {
        offset-position: 0% 100%;
        width: 30%;
        height: 90%;
    }
</style>
<body>
    <div class="box" id="item1"></div>
    <div class="box" id="item2"></div>
    <div class="box" id="item3"></div>
    <div class="box" id="item4"></div>
</body>

Rotating To Match The Path: the 'offset-rotate' property {#offset-rotate-property} -------------------------------------------------------------------------

Name: offset-rotate
Value: [ auto | reverse ] || <>
Initial: auto
Applies to: transformable elements
Inherited: no
Percentages: n/a
Computed value: computed <> value, optionally preceded by auto
Media: visual
Animation type: by computed value

Defines a rotation component of the [=offset transform=], possibly based on the direction of the [=offset path=] at the [=offset position=]. Values have the following meanings:

: auto <>? :: The [=offset transform=] will have a rotation component equal to the difference between the [=offset path's=] direction at the [=offset position=] and the direction of the positive X axis (that is, a line going toward the right). See SVG's [=direction of a path=] for details on how to calculate this. If specified with an <>, the angle is added to the rotation component. Note: In other words, if the [=offset path=] is moving to the right, ''offset-rotate/auto'' doesn't add any rotation. As it diverges from straight rightward, the rotation matches. By combining ''offset-rotate/auto'' with an <>, you can adjust the "starting" rotation. : reverse <>? :: Identical to ''offset-rotate/auto'', but adds an additional ''180deg'' to the rotation. : <> :: When specified on its own, adds a rotation component to the [=offset transform=] of the specified angle. (That is, ''offset-rotate: 45deg;'' is similar to ''transform: rotate(45deg)''; it's just ordered to be part of the [=offset transform=].)

animation/offset-rotate-composition.html animation/offset-rotate-interpolation-math-functions.html animation/offset-rotate-interpolation.html animation/reftests/offset-rotate-interpolation-001.html offset-rotate-001.html offset-rotate-002.html offset-rotate-003.html offset-rotate-004.html offset-rotate-005.html parsing/offset-rotate-computed.html parsing/offset-rotate-parsing-invalid.html parsing/offset-rotate-parsing-valid.html

The following examples use the shape of a plane. The red dot in the middle of the shape indicates the anchor point of the shape. When no offset properties are set, the shape is not translated or rotated along the path.

When the shape's anchor point is placed at different positions along the path and 'offset-rotate' is ''0deg'', the shape is not rotated.

If the 'offset-rotate' property is set to ''offset-rotate/auto'', and the shape's anchor point is placed at different positions along the path, the shape is rotated based on the gradient at the current position and faces the direction of the path at this position.

In this example, the 'offset-rotate' property is set to ''reverse''. The plane faces the opposite direction of the path at each position on the path.

The last example sets the 'offset-rotate' property to ''-45deg''. The shape is rotated anticlockwise by 45 degree once and keeps the rotation at each position on the path.

This example shows how ''offset-rotate/auto'' or ''offset-rotate/reverse'' work when specified in combination with <>. The computed value of <> is added to the computed value of ''offset-rotate/auto'' or ''offset-rotate/reverse''.

    <style>
        body {
            width: 300px;
            height: 300px;
            margin: 0px;
            border: solid gray;
            border-radius: 50%;
        }
        .circle {
            offset-position: 150px 150px;
            offset-distance: 86%;
            width: 42px;
            height: 42px;
            background-color: mediumpurple;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        #item1 {
            offset-path: ray(0deg closest-side);
            offset-rotate: auto 90deg;
        }
        #item2 {
            offset-path: ray(45deg closest-side);
            offset-rotate: auto 90deg;
        }
        #item3 {
            offset-path: ray(135deg closest-side);
            offset-rotate: auto -90deg;
        }
        #item4 {
            offset-path: ray(180deg closest-side);
            offset-rotate: auto -90deg;
        }
        #item5 {
            offset-path: ray(225deg closest-side);
            offset-rotate: reverse 90deg;
        }
        #item6 {
            offset-path: ray(-45deg closest-side);
            offset-rotate: reverse -90deg;
        }
    </style>
    <body>
        <div class="circle" id="item1">1</div>
        <div class="circle" id="item2">2</div>
        <div class="circle" id="item3">3</div>
        <div class="circle" id="item4">4</div>
        <div class="circle" id="item5">5</div>
        <div class="circle" id="item6">6</div>
    </body>
    

The 'offset' Shorthand {#offset-shorthand} ------------------------------------------

Name: offset
Value: [ <<'offset-position'>>? [ <<'offset-path'>> [ <<'offset-distance'>> || <<'offset-rotate'>> ]? ]? ]! [ / <<'offset-anchor'>> ]?
Applies to: transformable elements

animation/offset-interpolation.html animation/offset-position-composition.html animation/offset-position-interpolation.html parsing/offset-parsing-invalid.html parsing/offset-parsing-valid.html parsing/offset-shorthand.html inheritance.html offset-supports-calc.html This is a shorthand property for setting 'offset-position', 'offset-path', 'offset-distance', 'offset-rotate' and 'offset-anchor'. Omitted values are set to their initial values. Calculating The Offset Transform {#transform} ---------------------------------------------------- The [=offset transform=] is a 2d transform, a translation followed by a rotation: * Translate the element by the (X, Y) that aligns its [=anchor point=] with its [=offset position=]. * Rotate the element by the angle specified by 'offset-rotate'. Equivalent Paths For <> {#paths} ==================================== The <> definition given by [[css-shapes]] defines each function as producing a shape-- a 2-dimensional figure with an outline, an inside, and an outside. This specification instead uses <> as producing a path-- a line with a starting point, ending point, and direction, that happens to trace out a particular shape's outline. The details of what makes up a path are defined by SVG. [[SVG2]] The equivalent path for all the <> values are:

: <> : <> :: The path is the defined path. [[!SVG11]] : <> : <> :: The path is the outline of the circle/ellipse. It starts at the rightmost point of the circle/ellipse, and then is composed of four circular arcs, each comprising a quarter of the circle/ellipse, proceeding clockwise, ending with a [=segment-completing close path=] operation. : rect() : inset() : xywh() :: The path is the outline of the (possibly-rounded) rectangle, composed of four or eight segments (depending on whether rounded corners are specified or not), and ending with a [=segment-completing close path=] operation. It starts at the left end of the top straight edge, immediately to the right of any rounded corners, and continues to the right (clockwise). : <> :: The path is the outline of the polygon, composed of straight line segments connecting each coordinate pair to the following coordinate pair, and finally connecting the last back to the first, with a [=segment-completing close path=] operation.

For all of these, the direction at any point along the path is defined by SVG; see [[svg2#PathDirectionality]]. Note: All of these are meant to match the "equivalent paths" defined for the similar SVG [=shape elements=]. Note: This list should be in sync with the full set of <> functions defined in [[css-shapes]]. If anything is missing, this should be considered a specification bug. This list might move to Shapes in the future, but for now is kept here as this spec is the only consumer of this information. Privacy Considerations {#privacy} ================================= This specification introduces no new privacy considerations. Security Considerations {#security} =================================== This specification introduces no new security considerations.

Changes

This section is non-normative.

Changes since the 18 December 2018 Working Draft

* Added offset-position:normal that doesn't override the normal position defaulting, and add an "at <position>"" to ray() #504. * Corrected offset-path to use <url> instead of <url()> #508 * Reworded the calculation of the offset transform, using terminology from CSS Transforms 1 * Clarified "offset-distance" and "offset-rotate" * Simplified and clarified the behavior of the "contain" keyword #363. * Changed the equivalent path of a circle()/ellipse() to match SVG #506. * The element being referenced by coord-box is the element establishing the containing block for the transformed element, and in an SVG context coord-box is treated as view-box #369 * Moved the definition of <basic-shape> paths to an appendix. * Allowed <coord-box> to be combined with any of the path functions #369 * Added inline links to some issues: #503, #504 * Clarified initial position * Moved path() to the <basic-shape> section. * Made <ray-size> optional, defaulting to "closest-side". * Rewrote introduction. * Moved ray() definition to its own subsection * Clarified definition of offset path #66 * Clarified that the <coord-box> tpe is defined in CSS Box 3. * Corrected <ray()> and <path()> type syntax. * Clarified that "modulo" has its mathematical, not C/JS definition #339. * Fixed directionality at sharp path boundaries to match SVG. #209. * Reorganized offset-path section for better readability. * Removed note describing the concept of polar angles. * Changed computed value of offset-distance to a computed <> value. * Replaced animatable by Animation type.

Changes since the 9 April 2015 First Public Working Draft

* Renamed motion-path to 'offset-path' for integrating with polar-angle. * Added the ''ray()'' to define an offset path as a line segment which direction is specified by <>. * Added <> and 'contain' value to ''ray()''. * Renamed motion-offset to 'offset-distance' for integrating with polar-distance. * Renamed motion-rotation to 'offset-rotate'. * Added 'offset-position' to specify the [=offset starting position=] of the path by merging polar-origin from [[CSS-ROUND-DISPLAY-1]]. * Added 'offset-anchor' to specify the origin point of the element by merging polar-anchor from [[CSS-ROUND-DISPLAY-1]]. * Renamed the shorthand property motion to 'offset'. * Made 'offset-rotate' specify the rotation transformation by ''offset-rotate/auto'' or ''offset-rotate/reverse'' in combination with <>.

Acknowledgments

Thanks to fantasai, Hyojin Song, and all the rest of the CSS WG members for their reviews, comments, and corrections.