<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- composition.qdoc --> <title>Composition Modes | Qt Widgets 5.12.6</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="qtwidgets-index.html">Qt Widgets</a></td><td ><a href="examples-painting.html">Painting Examples</a></td><td >Composition Modes</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtwidgets-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="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">Composition Modes</h1> <span class="subtitle"></span> <!-- $$$painting/composition-brief --> <p>Demonstrates how Composition Modes work in <a href="../qtgui/qpainter.html">QPainter</a>.</p> <!-- @@@painting/composition --> <!-- $$$painting/composition-description --> <div class="descr"> <a name="details"></a> <p class="centerAlign"><img src="images/composition-demo.png" alt="" /></p><p>The two most common forms of composition are <b>Source</b> and <b>SourceOver</b>. <b>Source</b> is used to draw opaque objects onto a paint device. In this mode, each pixel in the source replaces the corresponding pixel in the destination. In <b>SourceOver</b> composition mode, the source object is transparent and is drawn on top of the destination.</p> <p>In addition to these standard modes, Qt defines the complete set of composition modes as defined by X. Porter and Y. Duff. See the <a href="../qtgui/qpainter.html">QPainter</a> documentation for details.</p> <p>Files:</p> <ul> <li><a href="qtwidgets-painting-composition-composition-cpp.html">painting/composition/composition.cpp</a></li> <li><a href="qtwidgets-painting-composition-composition-h.html">painting/composition/composition.h</a></li> <li><a href="qtwidgets-painting-composition-composition-pro.html">painting/composition/composition.pro</a></li> <li><a href="qtwidgets-painting-composition-composition-qrc.html">painting/composition/composition.qrc</a></li> <li><a href="qtwidgets-painting-composition-main-cpp.html">painting/composition/main.cpp</a></li> </ul> <p>Images:</p> <ul> <li><a href="images/used-in-examples/painting/composition/flower.jpg">painting/composition/flower.jpg</a></li> <li><a href="images/used-in-examples/painting/composition/flower_alpha.jpg">painting/composition/flower_alpha.jpg</a></li> </ul> </div> <!-- @@@painting/composition --> </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>