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    <title>RMagick 6.1.1: RVG Reference: RVG::Pattern Class</title>
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    <h6 id="header">RMagick 6.1.1 User's Guide and Reference</h6>

    <div class="nav">&laquo;&nbsp;<a href="rvgimage.html">Prev</a> | <a href="index.html">Contents</a> | <a href="rvgclip.html">Next</a>&nbsp;&raquo;</div>

    <h1>class RVG::Pattern <span class="superclass">&lt; Object</span></h1>

    <div id="toc">
      <h2>Table of Contents</h2>

      <h3>class methods</h3>

      <ul>
        <li><a href="#new">new</a></li>
      </ul>

      <h3>instance methods</h3>

      <div>
        <div class="toccol">
          <ul>
            <li><a href="#g">g</a></li>

            <li><a href="#image">image</a></li>

            <li><a href="#preserve_aspect_ratio">preserve_aspect_ratio</a></li>
          </ul>
        </div>

        <div class="toccol">
          <ul>
            <li><a href="#rvg">rvg</a></li>

            <li><a href="#RVG_text">text</a></li>
          </ul>
        </div>

        <div class="toccol">
          <ul>
            <li><a href="#RVG_use">use</a></li>

            <li><a href="#viewbox">viewbox</a></li>
          </ul>
        </div>
      </div>

      <h3>shared methods</h3>

      <p>
        In addition to the methods listed above, this class also implements the
        <a href="rvgstyle.html">styles</a> method, the <a href="rvgshape.html">shape methods</a> and the <a href="rvgxform.html">transform methods</a>.
      </p>
    </div>

    <h2 class="methods">class methods</h2>

    <div class="sig">
      <h3 id="new">new</h3>

      <p>
        RVG::Pattern.new(<span class="arg">width</span>=0, <span class="arg">height</span>=0, <span class="arg">x</span>=0, <span class="arg">y</span>=0) [
        <span class="arg">{ |pattern| drawing method calls }</span> ] -&gt;
        <em>pattern</em>
      </p>
    </div>

    <div class="desc">
      <h4>Description</h4>

      <p>Creates a pattern that can be used with the <code>:fill</code> and <code>:stroke</code> styles.</p>

      <p>
        Define the pattern in the associated block. The pattern can be composed of <a href="rvgshape.html">shapes</a>, <a href="rvgtext.html#new">text</a>,
        <a href="rvgimage.html#new">raster images</a>, <a href="rvggroup.html#new">groups</a>, and <a href="rvg.html#RVG_new">RVG objects</a>. You can use the
        <a href="rvguse.html#new">use</a> method to include graphic objects in the pattern.
      </p>

      <h4>Arguments</h4>

      <dl>
        <dt>width, height</dt>

        <dd>These arguments define the pattern viewport.</dd>

        <dt>x, y</dt>

        <dd>
          Specify the starting offset of the pattern. The pattern will be repeated at <span class="arg">x</span><code>+m*width</code> and
          <span class="arg">y</span><code>+n*height</code> offsets.
        </dd>
      </dl>

      <h4>Example</h4>

      <p>
        <a href="javascript:popup('rvg_pattern.rb.html')"><img src="ex/rvg_pattern.gif" title="Click to see the example script" alt="pattern example" /></a>
      </p>
    </div>

    <h2 class="methods">instance methods</h2>

    <div class="sig">
      <h3 id="g">g</h3>

      <p><span class="arg">pattern.</span>g [{|<span class="arg">grp</span>| ...}] -&gt; <em>group</em></p>
    </div>

    <div class="desc">
      <h4>Description</h4>

      <p>
        Calls <a href="rvggroup.html#new">RVG::Group.new</a> to construct a group and adds it to the pattern. Yields to a block if one is present, passing the
        new group as an argument.
      </p>

      <h4>Returns</h4>

      <p>Returns the new group, so <code>RVG::Group</code> methods can be chained to this method.</p>
    </div>

    <div class="sig">
      <h3 id="image">image</h3>

      <p>
        <span class="arg">pattern.</span>image(<span class="arg">raster_image</span>, <span class="arg">width</span>=nil, <span class="arg">height</span>=nil,
        <span class="arg">x</span>=0, <span class="arg">y</span>=0) -&gt; <em>image</em>
      </p>
    </div>

    <div class="desc">
      <h4>Description</h4>

      <p>Calls <a href="rvgimage.html#new">RVG::Image.new</a> to construct an image and adds it to the pattern.</p>

      <h4>Returns</h4>

      <p>Returns the new image, so <code>RVG::Image</code> methods can be chained to this method.</p>
    </div>

    <div class="sig">
      <h3 id="preserve_aspect_ratio">preserve_aspect_ratio</h3>

      <p>
        <span class="arg">pattern</span>.preserve_aspect_ratio(<span class="arg">align</span>, <span class="arg">meet_or_slice</span>='meet') [{|<span
          class="arg"
          >self</span
        >| ...}] -&gt; <em>self</em>
      </p>
    </div>

    <div class="desc">
      <h4>Description</h4>

      <p>
        If you use the <a href="#viewbox">viewbox</a> method and the user coordinate system does not scale uniformly to the default coordinate system, use the
        <code>preserve_aspect_ratio</code> method to specify whether or not the content is stretched to fit. If not, you can specify how to fit the content into
        the space.
      </p>

      <p><code>Preserve_aspect_ratio</code> yields to a block if one is present, passing <span class="arg">self</span> as an argument.</p>

      <h4>Arguments</h4>

      <dl>
        <dt>align</dt>

        <dd>
          When the value of the <code>meet_or_slice</code> argument is 'meet' or 'slice', this argument controls the placement of the content within the
          viewport. The <code>align</code> argument is the concatenation of an <em>x</em>-alignment and a <em>y</em>-alignment. The values are shown in these
          lists:

          <h6><em>x</em>-alignment</h6>

          <dl>
            <dt>xMin</dt>

            <dd>align the minimum <em>x</em> value of the content with the left corner of the viewport.</dd>

            <dt>xMid</dt>

            <dd>vertically center the content within the viewport.</dd>

            <dt>xMax</dt>

            <dd>align the maximum <em>x</em> value of the content with the right corner of the viewport.</dd>
          </dl>

          <h6><em>y</em>-alignment</h6>

          <dl>
            <dt>YMin</dt>

            <dd>align the minimum <em>y</em> value of the content with the top of the viewport.</dd>

            <dt>YMid</dt>

            <dd>horizontally center the content within the viewport.</dd>

            <dt>YMax</dt>

            <dd>align the maximum <em>y</em> value of the content with the bottom of the viewport</dd>
          </dl>
        </dd>

        <dt>meet_or_slice</dt>

        <dd>
          This argument can have one of these three values:

          <dl>
            <dt>'none'</dt>

            <dd>The content is scaled as necessary so that it fits exactly within the viewport. The aspect ratio is <em>not</em> maintained.</dd>

            <dt>'meet'</dt>

            <dd>
              The content is scaled as necessary so that the larger dimension exactly fits the viewport. There may be some unused space in the viewport. The
              aspect ratio is maintained.
            </dd>

            <dt>'slice'</dt>

            <dd>
              The content is scaled as necessary so that the smaller dimension exactly fits the viewport. Some of the content in the larger dimension may be cut
              off. The aspect ratio is maintained.
            </dd>
          </dl>
        </dd>
      </dl>

      <h4>Example</h4>

      <p>
        See the RVG class
        <a href="rvg.html#RVG_preserve_aspect_ratio">example</a>.
      </p>

      <h4>Returns</h4>

      <p><span class="arg">Self</span>, so other <code>RVG::Pattern</code> methods can be chained to this method.</p>

      <h4>See Also</h4>

      <p><a href="#viewbox">viewbox</a></p>
    </div>

    <div class="sig">
      <h3 id="rvg">rvg</h3>

      <p>
        <span class="arg">pattern</span>.rvg(<span class="arg">width</span>, <span class="arg">height</span>, <span class="arg">x</span>=0,
        <span class="arg">y</span>=0) [{|<span class="arg">new_rvg</span>| ...}] -&gt; <em>pattern</em>
      </p>
    </div>

    <div class="desc">
      <h4>Description</h4>

      <p>
        This method constructs a new RVG object and adds it to the pattern. Each nested RVG object can use the
        <a href="rvg.html#RVG_viewbox">viewbox</a> method to define its own coordinate system. The <code>rvg</code> method yields to a block, passing the nested
        RVG object as an argument. Within the block, any drawing objects added to the nested RVG object are rendered within the nested RVG object's viewport.
      </p>

      <h4>Arguments</h4>

      <dl>
        <dt>width, height</dt>

        <dd>Specifies the viewport width and height. The units are in the user coordinate system of the parent container.</dd>

        <dt>x, y</dt>

        <dd>The x- and y-axis offsets of the viewport upper-left corner. The units are in the user coordinate system of the parent container.</dd>
      </dl>

      <h4>Example</h4>

      <p>
        See the example for
        <a href="#preserve_aspect_ratio">preserve_aspect_ratio</a> in <code>class RVG</code>.
      </p>

      <h4>Returns</h4>

      <p>The <code>RVG</code> object, so other <code>RVG</code> methods can be chained to this method.</p>
    </div>

    <div class="sig">
      <h3 id="RVG_text">text</h3>

      <p>
        <span class="arg">pattern.</span>text(<span class="arg">x</span>=0, <span class="arg">y</span>=0, <span class="arg">text</span>=nil) [{|<span
          class="arg"
          >text</span
        >| ...}] -&gt; <em>text</em>
      </p>
    </div>

    <div class="desc">
      <h4>Description</h4>

      <p>
        Calls <a href="rvgtext.html#new">RVG::Text.new</a> to construct a text object and adds it to the pattern. Yields to a block if one is present, passing
        the new text object as an argument.
      </p>

      <h4>Returns</h4>

      <p>The <code>RVG::Text</code> object, so other <code>RVG::Text</code> methods can be chained to this method.</p>
    </div>

    <div class="sig">
      <h3 id="RVG_use">use</h3>

      <p>
        <span class="arg">pattern</span>.use(<span class="arg">obj</span>, <span class="arg">x</span>=0, <span class="arg">y</span>=0,
        <span class="arg">width</span>=nil, <span class="arg">height</span>=nil) -&gt; <em>use</em>
      </p>
    </div>

    <div class="desc">
      <h4>Description</h4>

      <p>Calls <a href="rvguse.html#new">RVG::Use.new</a> to constructs a <code>use</code> object and adds it to the pattern.</p>

      <p>
        When the referenced argument is an RVG object,
        <span class="arg">width</span> and <span class="arg">height</span> can be used to specify the width and height of the viewport. If present and non-nil,
        these arguments override any width and height specified when the RVG object was created. You must specify the viewport size either when creating the RVG
        object or when referencing it with <code>use</code>.
      </p>

      <h4>Examples</h4>

      <p>See <a href="rvguse.html#new">RVG::Use.new</a></p>

      <h4>Returns</h4>

      <p>The <code>RVG::Use</code> object, so other <code>RVG::Use</code> methods can be chained to this method.</p>
    </div>

    <div class="sig">
      <h3 id="viewbox">viewbox</h3>

      <p>
        <span class="arg">pattern</span>.viewbox(<span class="arg">min_x</span>, <span class="arg">min_y</span>, <span class="arg">width</span>,
        <span class="arg">height</span>) [{|<span class="arg">self</span>| ...}] -&gt; <em>self</em>
      </p>
    </div>

    <div class="desc">
      <h4>Description</h4>

      <p>
        The area of the pattern is called the <em>viewport</em>. By default the origin of the coordinate system for an pattern is (0,0). The user coordinates
        are pixels and the width and height are established by the <span class="arg">width</span> and <span class="arg">height</span> arguments to
        <code>RVG::Pattern.new</code>.
      </p>

      <p>
        Use the <code>viewbox</code> method to superimpose a user coordinate system on the viewport. The <code>viewbox</code> method lets you set up a
        coordinate system using the units of your choice.
      </p>

      <p>The <code>viewbox</code> method yields to a block if one is present, passing <code>self</code> as an argument.</p>

      <h4>Arguments</h4>

      <dl>
        <dt>min_x, min_y</dt>

        <dd>The minimum <em>x</em>-coordinate and <em>y</em>-coordinate of the user coordinate system.</dd>

        <dt>width, height</dt>

        <dd>The width and height of the user coordinate system.</dd>
      </dl>

      <h4>Example</h4>

      <p>See the <a href="rvg.html#RVG_viewbox">example</a> for the <code>RVG</code> class.</p>

      <h4>Returns</h4>

      <p><span class="arg">Self</span>, so other <code>RVG::Pattern</code> methods may be chained to <code>viewbox</code>.</p>

      <h4>See Also</h4>

      <p><a href="#preserve_aspect_ratio">preserve_aspect_ratio</a></p>
    </div>

    <p class="spacer">&nbsp;</p>

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