<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qglcolormap.cpp --> <title>QGLColormap Class | Qt OpenGL</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.12</td><td ><a href="qtopengl-index.html">Qt OpenGL</a></td><td ><a href="qtopengl-module.html">C++ Classes</a></td><td >QGLColormap</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtopengl-index.html">Qt 5.12.6 Reference Documentation</a></td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#public-functions">Public Functions</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">QGLColormap Class</h1> <!-- $$$QGLColormap-brief --> <p>The <a href="qglcolormap.html">QGLColormap</a> class is used for installing custom colormaps into a <a href="qglwidget.html">QGLWidget</a>. <a href="#details">More...</a></p> <!-- @@@QGLColormap --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QGLColormap></span> </td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += opengl</td></tr></table></div><p><b>This class is obsolete.</b> It is provided to keep old source code working. We strongly advise against using it in new code.</p> <ul> <li><a href="qglcolormap-members.html">List of all members, including inherited members</a></li> </ul> <a name="public-functions"></a> <h2 id="public-functions">Public Functions</h2> <div class="table"><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-1">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-1">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></div> <a name="details"></a> <!-- $$$QGLColormap-description --> <div class="descr"> <h2 id="details">Detailed Description</h2> <p>The <a href="qglcolormap.html">QGLColormap</a> class is used for installing custom colormaps into a <a href="qglwidget.html">QGLWidget</a>.</p> <p><a href="qglcolormap.html">QGLColormap</a> provides a platform independent way of specifying and installing indexed colormaps for a <a href="qglwidget.html">QGLWidget</a>. <a href="qglcolormap.html">QGLColormap</a> is especially useful when using the OpenGL color-index mode.</p> <p>Under X11 you must use an X server that supports either a <code>PseudoColor</code> or <code>DirectColor</code> visual class. If your X server currently only provides a <code>GrayScale</code>, <code>TrueColor</code>, <code>StaticColor</code> or <code>StaticGray</code> 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 <code>PseudoColor</code> 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="../qtcore/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"><a href="../qtwidgets/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"><a href="qglcolormap.html#QGLColormap">QGLColormap</a></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">for</span> (<span class="type">int</span> i <span class="operator">=</span> <span class="number">0</span>; i <span class="operator"><</span> colormap<span class="operator">.</span>size(); i<span class="operator">+</span><span class="operator">+</span>) colormap<span class="operator">.</span>setEntry(i<span class="operator">,</span> <a href="../qtgui/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" id="QGLColormap"><a name="QGLColormap"></a>QGLColormap::<span class="name">QGLColormap</span>()</h3> <p>Construct a <a href="qglcolormap.html" class="obsolete">QGLColormap</a>.</p> <!-- @@@QGLColormap --> <!-- $$$QGLColormap$$$QGLColormapconstQGLColormap& --> <h3 class="fn" id="QGLColormap-1"><a name="QGLColormap-1"></a>QGLColormap::<span class="name">QGLColormap</span>(const <span class="type"><a href="qglcolormap.html#QGLColormap">QGLColormap</a></span> &<i>map</i>)</h3> <p>Construct a shallow copy of <i>map</i>.</p> <!-- @@@QGLColormap --> <!-- $$$~QGLColormap[overload1]$$$~QGLColormap --> <h3 class="fn" id="dtor.QGLColormap"><a name="dtor.QGLColormap"></a>QGLColormap::<span class="name">~QGLColormap</span>()</h3> <p>Dereferences the <a href="qglcolormap.html" class="obsolete">QGLColormap</a> and deletes it if this was the last reference to it.</p> <!-- @@@~QGLColormap --> <!-- $$$entryColor[overload1]$$$entryColorint --> <h3 class="fn" id="entryColor"><a name="entryColor"></a><span class="type"><a href="../qtgui/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="../qtgui/qcolor.html#QRgb-typedef">QRgb</a> value in the colorcell with index <i>idx</i>.</p> <!-- @@@entryColor --> <!-- $$$entryRgb[overload1]$$$entryRgbint --> <h3 class="fn" id="entryRgb"><a name="entryRgb"></a><span class="type"><a href="../qtgui/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="../qtgui/qcolor.html#QRgb-typedef">QRgb</a> value in the colorcell with index <i>idx</i>.</p> <!-- @@@entryRgb --> <!-- $$$find[overload1]$$$findQRgb --> <h3 class="fn" id="find"><a name="find"></a><span class="type">int</span> QGLColormap::<span class="name">find</span>(<span class="type"><a href="../qtgui/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" id="findNearest"><a name="findNearest"></a><span class="type">int</span> QGLColormap::<span class="name">findNearest</span>(<span class="type"><a href="../qtgui/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" id="isEmpty"><a name="isEmpty"></a><span class="type">bool</span> QGLColormap::<span class="name">isEmpty</span>() const</h3> <p>Returns <code>true</code> if the colormap is empty or it is not in use by a QGLWidget; otherwise returns <code>false</code>.</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 QGLWidget 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 QGLWidget or not.</p> <p><b>See also </b><a href="qglcolormap.html#size">size</a>().</p> <!-- @@@isEmpty --> <!-- $$$setEntries[overload1]$$$setEntriesintconstQRgb*int --> <h3 class="fn" id="setEntries"><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="../qtgui/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" id="setEntry"><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="../qtgui/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" id="setEntry-1"><a name="setEntry-1"></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="../qtgui/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" id="size"><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" id="operator-eq"><a name="operator-eq"></a><span class="type"><a href="qglcolormap.html#QGLColormap">QGLColormap</a></span> &QGLColormap::<span class="name">operator=</span>(const <span class="type"><a href="qglcolormap.html#QGLColormap">QGLColormap</a></span> &<i>map</i>)</h3> <p>Assign a shallow copy of <i>map</i> to this <a href="qglcolormap.html" class="obsolete">QGLColormap</a>.</p> <!-- @@@operator= --> </div> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>