<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta name="generator" content=
"HTML Tidy for Linux/x86 (vers 1st March 2005), see www.w3.org" />
<title>RMagick 1.15.6: RVG Reference: Shapes</title>
<meta http-equiv="Content-Type" content=
"text/html; charset=us-ascii" />
<meta name="GENERATOR" content="Quanta Plus" />
<meta name="Copyright" content=
"Copyright (C) 2006 by Timothy P. Hunter" />
<link rel="stylesheet" type="text/css" href="css/doc.css" />
<link rel="stylesheet" type="text/css" href="css/ref.css" />
<script type="text/javascript" src="scripts/doc.js">
</script>
<script type="text/javascript">
//<![CDATA[
//]]>
</script>
<style type="text/css">
/*<![CDATA[*/
}
/*]]>*/
</style>
</head>
<body>
<h6 id="header">RMagick 1.15.6 User's Guide and Reference</h6>
<div class="nav">
« <a href="rvgstyle.html">Prev</a> | <a href=
"index.html">Contents</a> | <a href=
"rvgxform.html">Next</a> »
</div>
<h1>The shape methods</h1>
<div id="toc">
<h2>Table of Contents</h2>
<h3>About the shape methods</h3>
<h3>Shape methods</h3>
<div class="toccol">
<ul>
<li><a href="#circle">circle</a></li>
<li><a href="#ellipse">ellipse</a></li>
<li><a href="#line">line</a></li>
<li><a href="#path">path</a></li>
<li><a href="#polygon">polygon</a></li>
<li><a href="#polyline">polyline</a></li>
<li><a href="#rect">rect</a></li>
</ul>
</div>
</div>
<div class="subhd">
<h2>About the shape methods</h2>
</div>
<div class="intro">
<p>The shape methods listed below are defined in the <a href=
"rvg.html">RVG</a>, <a href="rvgclip.html">RVG::ClipPath</a>,
<a href="rvggroup.html">RVG::Group</a>, and <a href=
"rvgpattern.html">RVG::Pattern</a> classes. You can chain the
<a href="rvgstyle.html">styles</a> method and the <a href=
"rvgxform.html">transform methods</a> to the shape methods.</p>
</div>
<div class="subhd">
<h2>shape</h2>
</div>
<div class="sig">
<h4 id='circle'>circle</h4>
<p><span class="arg">obj</span>.circle(<span class=
"arg">radius</span>, <span class="arg">cx</span>=0,
<span class="arg">cy</span>=0) -> <span class=
"arg">aCircle</span></p>
</div>
<div class='desc'>
<h5>Description</h5>
<p>Adds a circle to the target object. The arc of a circle
begins at the "3 o'clock" point on the radius and progresses
towards the "9 o'clock" point. The starting point and direction
of the arc are affected by the user space transform in the same
manner as the geometry of the object.</p>
<h5>Arguments</h5>
<dl>
<dt>radius</dt>
<dd>The radius of the circle</dd>
<dt>cx, cy</dt>
<dd>The center of the circle</dd>
</dl>
<h5>Example</h5>
<p><a href="javascript:popup('circle01.rb.html')"><img src=
"ex/circle01.gif" title="Click to see the example script" alt=
"circle example" /></a></p>
</div>
<div class="sig">
<h4 id='ellipse'>ellipse</h4>
<p><span class="arg">obj</span>.ellipse(<span class=
"arg">rx</span>, <span class="arg">ry</span>, <span class=
"arg">cx</span>=0, <span class="arg">cy</span>=0) ->
<span class="arg">anEllipse</span></p>
</div>
<div class='desc'>
<h5>Description</h5>
<p>Adds an ellipse to the target object. The arc of an ellipse
begins at the "3 o'clock" point on the radius and progresses
towards the "9 o'clock" point. The starting point and direction
of the arc are affected by the user space transform in the same
manner as the geometry of the object.</p>
<h5>Arguments</h5>
<dl>
<dt>rx, ry</dt>
<dd>The <em>x</em>- and <em>y</em>-radii of the ellipse</dd>
<dt>cx, cy</dt>
<dd>The center of the ellipse</dd>
</dl>
<h5>Example</h5>
<p><a href="javascript:popup('ellipse01.rb.html')"><img src=
"ex/ellipse01.gif" title="Click to see the example script" alt=
"ellipse example" /></a></p>
</div>
<div class="sig">
<h4 id='line'>line</h4>
<p><span class="arg">obj</span>.line(<span class=
"arg">x1</span>=0, y1=0, <span class="arg">x2</span>=0,
<span class="arg">y2</span>=0) -> <span class=
"arg">aLine</span></p>
</div>
<div class='desc'>
<h5>Description</h5>
<p>Adds a line to the target object. Lines are never
filled.</p>
<h5>Arguments</h5>
<dl>
<dt>x1, y1</dt>
<dd>The starting point of the line</dd>
<dt>x2, y2</dt>
<dd>The ending point of the line</dd>
</dl>
<h5>Example</h5>
<p><a href="javascript:popup('line01.rb.html')"><img src=
"ex/line01.gif" title="Click to see the example script" alt=
"line example" /></a></p>
</div>
<div class="sig">
<h4 id='path'>path</h4>
<p><span class="arg">obj</span>.path(<span class=
"arg">path_data</span>) -> <span class=
"arg">aPath</span></p>
</div>
<div class="desc">
<h5>Description</h5>
<p>Adds a path to the target object.</p>
<h5>Arguments</h5>
<p>A path string. The path string has the same syntax as the
<strong>d=</strong> attribute on SVG's path element. See the
<a href="http://www.w3.org/TR/SVG11/paths.html">SVG
standard</a> for a complete description of the syntax.</p>
<h5>Examples</h5>
<p>moveto, lineto, and closepath commands<a href=
"javascript:popup('triangle01.rb.html')"><img src=
"ex/triangle01.gif" title="Click to see the example script"
alt="triangle example" /></a></p>
<p>simple uses of cubic Bézier commands within a
path<a href="javascript:popup('cubic01.rb.html')"><img src=
"ex/cubic01.gif" title="Click to see the example script" alt=
"cubic Bezier commands example" /></a></p>
<p>cubic Bézier commands change their shape according to
the position of the control points<a href=
"javascript:popup('cubic02.rb.html')"><img src="ex/cubic02.gif"
title="Click to see the example script" alt=
"cubic Bezier commands example" /></a></p>
<p>simple uses of quadratic Bézier commands within a
path <a href="javascript:popup('quad01.rb.html')"><img src=
"ex/quad01.gif" title="Click to see the example script" alt=
"quadratic Bezier commands example" /></a></p>
<p>simple uses of arc commands within a path<a href=
"javascript:popup('arcs01.rb.html')"><img src="ex/arcs01.gif"
title="Click to see the example script" alt=
"arc commands example" /></a></p>
<p>Elliptical arcs: The following illustrates the four
combinations of large-arc-flag and sweep-flag and the four
different arcs that will be drawn based on the values of these
flags. <a href="javascript:popup('arcs02.rb.html')"><img src=
"ex/arcs02.gif" title="Click to see the example script" alt=
"elliptical arc example" /></a></p>
</div>
<div class="sig">
<h4 id='polygon'>polygon</h4>
<p><span class="arg">obj</span>.polygon(<span class=
"arg">x1</span>, y1, <span class="arg">x2</span>, <span class=
"arg">y2</span>...) -> <span class=
"arg">aPolygon</span><br />
<span class="arg">obj</span>.polygon(<span class=
"arg">array</span>) -> <span class=
"arg">aPolygon</span><br />
<span class="arg">obj</span>.polygon(<span class=
"arg">array1</span>, <span class="arg">array2</span>) ->
<span class="arg">aPolygon</span></p>
</div>
<div class="desc">
<h5>Description</h5>
<p>Adds a closed shape consisting of a series of connected line
segments to the target object.</p>
<h5>Arguments</h5>
<p>The arguments to <code>polygon</code> and <a href=
"#polyline">polyline</a> can be</p>
<ol>
<li>At least 4 numbers that describe the [x, y] coordinates
of the points of the polygon/polyline.</li>
<li>One array containing at least 4 numbers.</li>
<li>Two arrays. The first array is a list of x-coordinates.
The second array is a list of y-coordinates. Both arrays must
have at least one element. If one array is shorter than the
other, the shorter array is extended by duplicating its
elements as necessary. The combined arrays must describe at
least 2 pairs of [x,y] coordinates. For example
<pre>
x = [1, 3, 5, 7, 9]
y = [2,4]
canvas.polygon(x, y)
# is equivalent to canvas.polygon(1,2, 3,4, 5,2, 7,4, 9,2)
</pre>
</li>
</ol>
<p>It is an error to specify an odd number of coordinates.
Array arguments can be any objects that can be converted to
arrays by the Kernel#Array method.</p>
<h5>Example</h5>
<p><a href="javascript:popup('polygon01.rb.html')"><img src=
"ex/polygon01.gif" title="Click to see the example script" alt=
"polygon example" /></a></p>
</div>
<div class="sig">
<h4 id='polyline'>polyline</h4>
<p><span class="arg">obj</span>.polyline(<span class=
"arg">x1</span>, y1, <span class="arg">x2</span>, <span class=
"arg">y2</span>...) -> <span class=
"arg">aPolyline</span><br />
<span class="arg">obj</span>.polyline(<span class=
"arg">array</span>) -> <span class=
"arg">aPolyline</span><br />
<span class="arg">obj</span>.polyline(<span class=
"arg">array1</span>, <span class="arg">array2</span>) ->
<span class="arg">aPolyline</span></p>
</div>
<div class="desc">
<h5>Description</h5>
<p>Adds a set of connected lines segments to the target object.
Typically a polyline defines an open shape.</p>
<h5>Arguments</h5>
<p>See <a href="#polygon">polygon</a></p>
<h5>Example</h5>
<p><a href="javascript:popup('polyline01.rb.html')"><img src=
"ex/polyline01.gif" title="Click to see the example script"
alt="polyline example" /></a></p>
</div>
<div class="sig">
<h4 id='rect'>rect</h4>
<p><span class="arg">obj</span>.rect(<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">aRect</span></p>
</div>
<div class="desc">
<h5>Description</h5>
<p>Adds a rectangle to the target object.</p>
<h5>Arguments</h5>
<dl>
<dt>width, height</dt>
<dd>The width and height of the rectangle</dd>
<dt>x, y</dt>
<dd>The <em>x</em>- and <em>y</em>-axis coordinates of the
upper-left corner</dd>
</dl>
<h5>Example</h5>
<p><a href="javascript:popup('rect01.rb.html')"><img src=
"ex/rect01.gif" title="Click to see the example script" alt=
"rect example" /></a></p>
<h5>Rounded rectangles</h5>
<p>You can define a rounded rectangle by chaining the
<code>round</code> method to <code>rect</code>:</p>
<p><span class="arg">obj</span>.rect(<span class=
"arg">width</span>, <span class="arg">height</span>,
<span class="arg">x</span>=0, <span class=
"arg">y</span>=0).round(<code>rx</code>[, <code>ry</code>])</p>
<p>The round method accepts two arguments.</p>
<dl>
<dt>rx</dt>
<dd>The x-axis radius of the ellipse used to round off the
corners of the rectangle</dd>
<dt>ry</dt>
<dd>The y-axis radius of the ellipse used to round off the
corners of the rectangle</dd>
</dl>
<p>If the second argument is omitted it defaults to the value
of the first argument.</p>
<h5>Example</h5>
<p><a href="javascript:popup('rect02.rb.html')"><img src=
"ex/rect02.gif" title="Click to see the example script" alt=
"rect example" /></a></p>
</div>
<p class="spacer"> </p>
<div class="nav">
« <a href="rvgstyle.html">Prev</a> | <a href=
"index.html">Contents</a> | <a href="rvgxform.html">Next</a>
»
</div>
</body>
</html>