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<h1 class="title">QGLColormap Class Reference</h1>
<!-- $$$QGLColormap-brief -->
<p>The QGLColormap class is used for installing custom colormaps into a <a href="qglwidget.html">QGLWidget</a>. <a href="#details">More...</a></p>
<!-- @@@QGLColormap -->
<pre class="cpp"> <span class="preprocessor">#include <QGLColormap></span></pre><ul>
<li><a href="qglcolormap-members.html">List of all members, including inherited members</a></li>
</ul>
<a name="public-functions"></a>
<h2>Public Functions</h2>
<table class="alignedsummary">
<tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#QGLColormap">QGLColormap</a></b> ()</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#QGLColormap-2">QGLColormap</a></b> ( const QGLColormap & <i>map</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#dtor.QGLColormap">~QGLColormap</a></b> ()</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> QColor </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#entryColor">entryColor</a></b> ( int <i>idx</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> QRgb </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#entryRgb">entryRgb</a></b> ( int <i>idx</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#find">find</a></b> ( QRgb <i>color</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#findNearest">findNearest</a></b> ( QRgb <i>color</i> ) const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#isEmpty">isEmpty</a></b> () const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#setEntries">setEntries</a></b> ( int <i>count</i>, const QRgb * <i>colors</i>, int <i>base</i> = 0 )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#setEntry">setEntry</a></b> ( int <i>idx</i>, QRgb <i>color</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#setEntry-2">setEntry</a></b> ( int <i>idx</i>, const QColor & <i>color</i> )</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#size">size</a></b> () const</td></tr>
<tr><td class="memItemLeft rightAlign topAlign"> QGLColormap & </td><td class="memItemRight bottomAlign"><b><a href="qglcolormap.html#operator-eq">operator=</a></b> ( const QGLColormap & <i>map</i> )</td></tr>
</table>
<a name="details"></a>
<!-- $$$QGLColormap-description -->
<div class="descr">
<h2>Detailed Description</h2>
<p>The QGLColormap class is used for installing custom colormaps into a <a href="qglwidget.html">QGLWidget</a>.</p>
<p>QGLColormap provides a platform independent way of specifying and installing indexed colormaps for a <a href="qglwidget.html">QGLWidget</a>. QGLColormap is especially useful when using the OpenGL color-index mode.</p>
<p>Under X11 you must use an X server that supports either a <tt>PseudoColor</tt> or <tt>DirectColor</tt> visual class. If your X server currently only provides a <tt>GrayScale</tt>, <tt>TrueColor</tt>, <tt>StaticColor</tt> or <tt>StaticGray</tt> visual, you will not be able to allocate colorcells for writing. If this is the case, try setting your X server to 8 bit mode. It should then provide you with at least a <tt>PseudoColor</tt> visual. Note that you may experience colormap flashing if your X server is running in 8 bit mode.</p>
<p>The <a href="qglcolormap.html#size">size</a>() of the colormap is always set to 256 colors. Note that under Windows you can also install colormaps in child widgets.</p>
<p>This class uses <a href="implicit-sharing.html">implicit sharing</a> as a memory and speed optimization.</p>
<p>Example of use:</p>
<pre class="cpp"> <span class="preprocessor">#include <QApplication></span>
<span class="preprocessor">#include <QGLColormap></span>
<span class="type">int</span> main(<span class="type">int</span> argc<span class="operator">,</span> <span class="type">char</span> <span class="operator">*</span>argv<span class="operator">[</span><span class="operator">]</span>)
{
<span class="type"><a href="qapplication.html">QApplication</a></span> app(argc<span class="operator">,</span> argv);
MySuperGLWidget widget; <span class="comment">// a QGLWidget in color-index mode</span>
<span class="type">QGLColormap</span> colormap;
<span class="comment">// This will fill the colormap with colors ranging from</span>
<span class="comment">// black to white.</span>
<span class="keyword">const</span> <span class="type">int</span> size <span class="operator">=</span> <span class="number">256</span>;
<span class="keyword">for</span> (<span class="type">int</span> i <span class="operator">=</span> <span class="number">0</span>; i <span class="operator"><</span> size; <span class="operator">+</span><span class="operator">+</span>i)
colormap<span class="operator">.</span>setEntry(i<span class="operator">,</span> <a href="qcolor.html#qRgb">qRgb</a>(i<span class="operator">,</span> i<span class="operator">,</span> i));
widget<span class="operator">.</span>setColormap(colormap);
widget<span class="operator">.</span>show();
<span class="keyword">return</span> app<span class="operator">.</span>exec();
}</pre>
</div>
<p><b>See also </b><a href="qglwidget.html#setColormap">QGLWidget::setColormap</a>() and <a href="qglwidget.html#colormap">QGLWidget::colormap</a>().</p>
<!-- @@@QGLColormap -->
<div class="func">
<h2>Member Function Documentation</h2>
<!-- $$$QGLColormap[overload1]$$$QGLColormap -->
<h3 class="fn"><a name="QGLColormap"></a>QGLColormap::<span class="name">QGLColormap</span> ()</h3>
<p>Construct a <a href="qglcolormap.html">QGLColormap</a>.</p>
<!-- @@@QGLColormap -->
<!-- $$$QGLColormap$$$QGLColormapconstQGLColormap& -->
<h3 class="fn"><a name="QGLColormap-2"></a>QGLColormap::<span class="name">QGLColormap</span> ( const <span class="type">QGLColormap</span> & <i>map</i> )</h3>
<p>Construct a shallow copy of <i>map</i>.</p>
<!-- @@@QGLColormap -->
<!-- $$$~QGLColormap[overload1]$$$~QGLColormap -->
<h3 class="fn"><a name="dtor.QGLColormap"></a>QGLColormap::<span class="name">~QGLColormap</span> ()</h3>
<p>Dereferences the <a href="qglcolormap.html">QGLColormap</a> and deletes it if this was the last reference to it.</p>
<!-- @@@~QGLColormap -->
<!-- $$$entryColor[overload1]$$$entryColorint -->
<h3 class="fn"><a name="entryColor"></a><span class="type"><a href="qcolor.html">QColor</a></span> QGLColormap::<span class="name">entryColor</span> ( <span class="type">int</span> <i>idx</i> ) const</h3>
<p>Returns the <a href="qcolor.html#QRgb-typedef">QRgb</a> value in the colorcell with index <i>idx</i>.</p>
<!-- @@@entryColor -->
<!-- $$$entryRgb[overload1]$$$entryRgbint -->
<h3 class="fn"><a name="entryRgb"></a><span class="type"><a href="qcolor.html#QRgb-typedef">QRgb</a></span> QGLColormap::<span class="name">entryRgb</span> ( <span class="type">int</span> <i>idx</i> ) const</h3>
<p>Returns the <a href="qcolor.html#QRgb-typedef">QRgb</a> value in the colorcell with index <i>idx</i>.</p>
<!-- @@@entryRgb -->
<!-- $$$find[overload1]$$$findQRgb -->
<h3 class="fn"><a name="find"></a><span class="type">int</span> QGLColormap::<span class="name">find</span> ( <span class="type"><a href="qcolor.html#QRgb-typedef">QRgb</a></span> <i>color</i> ) const</h3>
<p>Returns the index of the color <i>color</i>. If <i>color</i> is not in the map, -1 is returned.</p>
<!-- @@@find -->
<!-- $$$findNearest[overload1]$$$findNearestQRgb -->
<h3 class="fn"><a name="findNearest"></a><span class="type">int</span> QGLColormap::<span class="name">findNearest</span> ( <span class="type"><a href="qcolor.html#QRgb-typedef">QRgb</a></span> <i>color</i> ) const</h3>
<p>Returns the index of the color that is the closest match to color <i>color</i>.</p>
<!-- @@@findNearest -->
<!-- $$$isEmpty[overload1]$$$isEmpty -->
<h3 class="fn"><a name="isEmpty"></a><span class="type">bool</span> QGLColormap::<span class="name">isEmpty</span> () const</h3>
<p>Returns true if the colormap is empty or it is not in use by a <a href="qglwidget.html">QGLWidget</a>; otherwise returns false.</p>
<p>A colormap with no color values set is considered to be empty. For historical reasons, a colormap that has color values set but which is not in use by a <a href="qglwidget.html">QGLWidget</a> is also considered empty.</p>
<p>Compare <a href="qglcolormap.html#size">size</a>() with zero to determine if the colormap is empty regardless of whether it is in use by a <a href="qglwidget.html">QGLWidget</a> or not.</p>
<p><b>See also </b><a href="qglcolormap.html#size">size</a>().</p>
<!-- @@@isEmpty -->
<!-- $$$setEntries[overload1]$$$setEntriesintconstQRgb*int -->
<h3 class="fn"><a name="setEntries"></a><span class="type">void</span> QGLColormap::<span class="name">setEntries</span> ( <span class="type">int</span> <i>count</i>, const <span class="type"><a href="qcolor.html#QRgb-typedef">QRgb</a></span> * <i>colors</i>, <span class="type">int</span> <i>base</i> = 0 )</h3>
<p>Set an array of cells in this colormap. <i>count</i> is the number of colors that should be set, <i>colors</i> is the array of colors, and <i>base</i> is the starting index. The first element in <i>colors</i> is set at <i>base</i> in the colormap.</p>
<!-- @@@setEntries -->
<!-- $$$setEntry[overload1]$$$setEntryintQRgb -->
<h3 class="fn"><a name="setEntry"></a><span class="type">void</span> QGLColormap::<span class="name">setEntry</span> ( <span class="type">int</span> <i>idx</i>, <span class="type"><a href="qcolor.html#QRgb-typedef">QRgb</a></span> <i>color</i> )</h3>
<p>Set cell at index <i>idx</i> in the colormap to color <i>color</i>.</p>
<!-- @@@setEntry -->
<!-- $$$setEntry$$$setEntryintconstQColor& -->
<h3 class="fn"><a name="setEntry-2"></a><span class="type">void</span> QGLColormap::<span class="name">setEntry</span> ( <span class="type">int</span> <i>idx</i>, const <span class="type"><a href="qcolor.html">QColor</a></span> & <i>color</i> )</h3>
<p>This is an overloaded function.</p>
<p>Set the cell with index <i>idx</i> in the colormap to color <i>color</i>.</p>
<!-- @@@setEntry -->
<!-- $$$size[overload1]$$$size -->
<h3 class="fn"><a name="size"></a><span class="type">int</span> QGLColormap::<span class="name">size</span> () const</h3>
<p>Returns the number of colorcells in the colormap.</p>
<!-- @@@size -->
<!-- $$$operator=[overload1]$$$operator=constQGLColormap& -->
<h3 class="fn"><a name="operator-eq"></a><span class="type">QGLColormap</span> & QGLColormap::<span class="name">operator=</span> ( const <span class="type">QGLColormap</span> & <i>map</i> )</h3>
<p>Assign a shallow copy of <i>map</i> to this <a href="qglcolormap.html">QGLColormap</a>.</p>
<!-- @@@operator= -->
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