transform - SVG: Scalable Vector Graphics 编辑

The transform attribute defines a list of transform definitions that are applied to an element and the element's children.

html,body,svg { height:100% }

<svg viewBox="-40 0 150 100" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
  <g fill="grey"
     transform="rotate(-10 50 100)
                translate(-36 45.5)
                skewX(40)
                scale(1 0.5)">
    <path id="heart" d="M 10,30 A 20,20 0,0,1 50,30 A 20,20 0,0,1 90,30 Q 90,60 50,90 Q 10,60 10,30 z" />
  </g>

  <use xlink:href="#heart" fill="none" stroke="red"/>
</svg>

Note: As of SVG2, transform is a presentation attribute, meaning it can be used as a CSS property. However, be aware that there are some difference in syntax between the CSS property and the attribute. See the documentation for the CSS property transform for the specific syntax to use in that case.

As a presentation attribute, transform can be used by any element (in SVG 1.1, only these 16 elements were allowed to use it: <a>, <circle>, <clipPath>, <defs>, <ellipse>, <foreignObject>, <g>, <image>, <line>, <path>, <polygon>, <polyline>, <rect>, <switch>, <text>, and <use>).

Also, as a legacy from SVG 1.1, <linearGradient> and <radialGradient> support the gradientTransform attribute, and <pattern> supports the patternTransform attribute, both of which act exactly like the transform attribute.

Transform functions

The following transform functions can be used by the transform attribute <transform-list>

Warning: As per the spec, you should be able to also use CSS transform functions. However, the compatibility isn't guaranteed.

Matrix

The matrix(<a> <b> <c> <d> <e> <f>) transform function specifies a transformation in the form of a transformation matrix of six values. matrix(a,b,c,d,e,f) is equivalent to applying the transformation matrix:$$\begin{pmatrix} a & c & e \\ b & d & f \\ 0 & 0 & 1 \end{pmatrix}$$ which maps coordinates from a previous coordinate system into a new coordinate system by the following matrix equalities:$$\begin{pmatrix} x_{\mathrm{newCoordSys}} \\ y_{\mathrm{newCoordSys}} \\ 1 \end{pmatrix} = \begin{pmatrix} a & c & e \\ b & d & f \\ 0 & 0 & 1 \end{pmatrix} \begin{pmatrix} x_{\mathrm{prevCoordSys}} \\ y_{\mathrm{prevCoordSys}} \\ 1 \end{pmatrix} = \begin{pmatrix} a x_{\mathrm{prevCoordSys}} + c y_{\mathrm{prevCoordSys}} + e \\ b x_{\mathrm{prevCoordSys}} + d y_{\mathrm{prevCoordSys}} + f \\ 1 \end{pmatrix}$$

Example

html,body,svg { height:100% }

<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg">
  <rect x="10" y="10" width="30" height="20" fill="green" />

  <!--
  In the following example we are applying the matrix:
  [a c e]    [3 -1 30]
  [b d f] => [1  3 40]
  [0 0 1]    [0  0  1]

  which transform the rectangle as such:

  top left corner: oldX=10 oldY=10
  newX = a * oldX + c * oldY + e = 3 * 10 - 1 * 10 + 30 = 50
  newY = b * oldX + d * oldY + f = 1 * 10 + 3 * 10 + 40 = 80

  top right corner: oldX=40 oldY=10
  newX = a * oldX + c * oldY + e = 3 * 40 - 1 * 10 + 30 = 140
  newY = b * oldX + d * oldY + f = 1 * 40 + 3 * 10 + 40 = 110

  bottom left corner: oldX=10 oldY=30
  newX = a * oldX + c * oldY + e = 3 * 10 - 1 * 30 + 30 = 30
  newY = b * oldX + d * oldY + f = 1 * 10 + 3 * 30 + 40 = 140

  bottom right corner: oldX=40 oldY=30
  newX = a * oldX + c * oldY + e = 3 * 40 - 1 * 30 + 30 = 120
  newY = b * oldX + d * oldY + f = 1 * 40 + 3 * 30 + 40 = 170
  -->
  <rect x="10" y="10" width="30" height="20" fill="red"
        transform="matrix(3 1 -1 3 30 40)" />
</svg>

Translate

The translate(<x> [<y>]) transform function moves the object by x and y. If y is not provided, it is assumed to be 0.

In other words:

    xnew = xold + <x>
    ynew = yold + <y>

Example

html,body,svg { height:100% }

<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
  <!-- No translation -->
  <rect x="5" y="5" width="40" height="40" fill="green" />

  <!-- Horizontal translation -->
  <rect x="5" y="5" width="40" height="40" fill="blue"
        transform="translate(50)" />

  <!-- Vertical translation -->
  <rect x="5" y="5" width="40" height="40" fill="red"
        transform="translate(0 50)" />

  <!-- Both horizontal and vertical translation -->
  <rect x="5" y="5" width="40" height="40" fill="yellow"
         transform="translate(50,50)" />
</svg>

Scale

The scale(<x> [<y>]) transform function specifies a scale operation by x and y. If y is not provided, it is assumed to be equal to x.

Example

html,body,svg { height:100% }

<svg viewBox="-50 -50 100 100" xmlns="http://www.w3.org/2000/svg">
  <!-- uniform scale -->
  <circle cx="0" cy="0" r="10" fill="red"
          transform="scale(4)" />

  <!-- vertical scale -->
  <circle cx="0" cy="0" r="10" fill="yellow"
          transform="scale(1,4)" />

  <!-- horizontal scale -->
  <circle cx="0" cy="0" r="10" fill="pink"
          transform="scale(4,1)" />

  <!-- No scale -->
  <circle cx="0" cy="0" r="10" fill="black" />
</svg>

Rotate

The rotate(<a> [<x> <y>]) transform function specifies a rotation by a degrees about a given point. If optional parameters x and y are not supplied, the rotation is about the origin of the current user coordinate system. If optional parameters x and y are supplied, the rotation is about the point (x, y).

Example

html,body,svg { height:100% }

<svg viewBox="-12 -2 34 14" xmlns="http://www.w3.org/2000/svg">
  <rect x="0" y="0" width="10" height="10" />

  <!-- rotation is done around the point 0,0 -->
  <rect x="0" y="0" width="10" height="10" fill="red"
        transform="rotate(100)" />

  <!-- rotation is done around the point 10,10 -->
  <rect x="0" y="0" width="10" height="10" fill="green"
        transform="rotate(100,10,10)" />
</svg>

SkewX

The skewX(<a>) transform function specifies a skew transformation along the x axis by a degrees.

Example

html,body,svg { height:100% }

<svg viewBox="-5 -5 10 10" xmlns="http://www.w3.org/2000/svg">
  <rect x="-3" y="-3" width="6" height="6" />

  <rect x="-3" y="-3" width="6" height="6" fill="red"
        transform="skewX(30)" />
</svg>

SkewY

The skewY(<a>) transform function specifies a skew transformation along the y axis by a degrees.

Example

html,body,svg { height:100% }

<svg viewBox="-5 -5 10 10" xmlns="http://www.w3.org/2000/svg">
  <rect x="-3" y="-3" width="6" height="6" />

  <rect x="-3" y="-3" width="6" height="6" fill="red"
        transform="skewY(30)" />
</svg>

Specifications