Using the SVG clippath Element | Fundamentals of SVG Programming: Concepts to Source Code (Graphics Series)

Using SVG clippath Elements with Grid Patterns

Consider the clipped checkerboard pattern rendered in Figure 4.6.

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Figure 4.6: A clipped cherkboard pattern.

The SVG document in Listing 4.8 uses the SVG clipPath element and the SVG rect element in order to render a checkerboard inside a diamond-like pattern.

Listing 4.8 checkerBoardCP1.svg

<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20001102//EN"  "http://www.w3.org/TR/2000/CR-SVG-20001102/DTD/svg-20001102.dtd"> <svg width="800" height="500">   <defs>   <pattern             width="80" height="80"            patternUnits="userSpaceOnUse">      <rect fill="red"            stroke="white" stroke-dasharray="4 4 4 4"            stroke-width="8"            x="0"  y="0"  width="40" height="40"/>      <rect fill="blue"            stroke="green" stroke-dasharray="2 2 2 2"            stroke-width="2"            x="40" y="0"  width="40" height="40"/>      <rect fill="blue"            stroke="yellow" stroke-dasharray="1 1 1 1"            stroke-width="6"            x="0"  y="40" width="40" height="40"/>      <rect fill="red"            stroke="blue" stroke-dasharray="4 4 4 4"            stroke-width="4"            x="40" y="40" width="40" height="40"/>   </pattern>   <clipPath              clipPathUnits="userSpaceOnUse">     <path d="m0,200 l100,-100 100,100 -100,100z"/>   </clipPath>   </defs> <g transform="translate(50,10)"   clip-path="url(#clipPathDefinition)"              stroke="black" fill="none">   <rect      fill="url(#checkerPattern)"      style="stroke:white"      x="0" y="0" width="400" height="400"/> </g>                             </svg>

Remarks

The SVG defs element in Listing 4.8 contains an SVG pattern element that has an id attribute with the value checkerPattern. This pattern consists of a 2x2 grid of squares whose alternating red/blue colors form a checkerboard pattern.

The SVG g element defines a rectangle with width 400 and a height of 400. Notice how this SVG element is further qualified with a clip-path attribute that references a clip path definition in the SVG defs element. The rectangle defined inside the SVG g element has a fill attribute that refers to the pattern checkerPattern defined in the SVG defs element by using the following syntax:

 fill="url(#checkerPattern)"

If you double-click on this file, you will see a portion of a rectangular grid of blue rectangles with a red outer border that is restricted to the inside of the diamond pattern defined in the clip path.