<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>squircle.cpp Example File | Qt Quick 5.11</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 ><a href="../qtdoc/index.html">Qt 5.11</a></td><td ><a href="qtquick-index.html">Qt Quick</a></td><td ><a href="qtquick-scenegraph-openglunderqml-example.html">Scene Graph - OpenGL Under QML</a></td><td >squircle.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.11.2 Reference Documentation</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">squircle.cpp Example File</h1> <span class="subtitle">scenegraph/openglunderqml/squircle.cpp</span> <!-- $$$scenegraph/openglunderqml/squircle.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the demonstration applications of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** BSD License Usage ** Alternatively, you may use this file under the terms of the BSD license ** as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include "squircle.h"</span> <span class="preprocessor">#include <QtQuick/qquickwindow.h></span> <span class="preprocessor">#include <QtGui/QOpenGLShaderProgram></span> <span class="preprocessor">#include <QtGui/QOpenGLContext></span> Squircle<span class="operator">::</span>Squircle() : m_t(<span class="number">0</span>) <span class="operator">,</span> m_renderer(nullptr) { connect(<span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qquickitem.html">QQuickItem</a></span><span class="operator">::</span>windowChanged<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Squircle<span class="operator">::</span>handleWindowChanged); } <span class="type">void</span> Squircle<span class="operator">::</span>setT(<span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> t) { <span class="keyword">if</span> (t <span class="operator">=</span><span class="operator">=</span> m_t) <span class="keyword">return</span>; m_t <span class="operator">=</span> t; <span class="keyword">emit</span> tChanged(); <span class="keyword">if</span> (window()) window()<span class="operator">-</span><span class="operator">></span>update(); } <span class="type">void</span> Squircle<span class="operator">::</span>handleWindowChanged(<span class="type"><a href="qquickwindow.html">QQuickWindow</a></span> <span class="operator">*</span>win) { <span class="keyword">if</span> (win) { connect(win<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qquickwindow.html">QQuickWindow</a></span><span class="operator">::</span>beforeSynchronizing<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Squircle<span class="operator">::</span>sync<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DirectConnection); connect(win<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qquickwindow.html">QQuickWindow</a></span><span class="operator">::</span>sceneGraphInvalidated<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>Squircle<span class="operator">::</span>cleanup<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DirectConnection); <span class="comment">// If we allow QML to do the clearing, they would clear what we paint</span> <span class="comment">// and nothing would show.</span> win<span class="operator">-</span><span class="operator">></span>setClearBeforeRendering(<span class="keyword">false</span>); } } <span class="type">void</span> Squircle<span class="operator">::</span>cleanup() { <span class="keyword">if</span> (m_renderer) { <span class="keyword">delete</span> m_renderer; m_renderer <span class="operator">=</span> nullptr; } } SquircleRenderer<span class="operator">::</span><span class="operator">~</span>SquircleRenderer() { <span class="keyword">delete</span> m_program; } <span class="type">void</span> Squircle<span class="operator">::</span>sync() { <span class="keyword">if</span> (<span class="operator">!</span>m_renderer) { m_renderer <span class="operator">=</span> <span class="keyword">new</span> SquircleRenderer(); connect(window()<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qquickwindow.html">QQuickWindow</a></span><span class="operator">::</span>beforeRendering<span class="operator">,</span> m_renderer<span class="operator">,</span> <span class="operator">&</span>SquircleRenderer<span class="operator">::</span>paint<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DirectConnection); } m_renderer<span class="operator">-</span><span class="operator">></span>setViewportSize(window()<span class="operator">-</span><span class="operator">></span>size() <span class="operator">*</span> window()<span class="operator">-</span><span class="operator">></span>devicePixelRatio()); m_renderer<span class="operator">-</span><span class="operator">></span>setT(m_t); m_renderer<span class="operator">-</span><span class="operator">></span>setWindow(window()); } <span class="type">void</span> SquircleRenderer<span class="operator">::</span>paint() { <span class="keyword">if</span> (<span class="operator">!</span>m_program) { initializeOpenGLFunctions(); m_program <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="../qtgui/qopenglshaderprogram.html">QOpenGLShaderProgram</a></span>(); m_program<span class="operator">-</span><span class="operator">></span>addCacheableShaderFromSourceCode(<span class="type"><a href="../qtgui/qopenglshader.html">QOpenGLShader</a></span><span class="operator">::</span>Vertex<span class="operator">,</span> <span class="string">"attribute highp vec4 vertices;"</span> <span class="string">"varying highp vec2 coords;"</span> <span class="string">"void main() {"</span> <span class="string">" gl_Position = vertices;"</span> <span class="string">" coords = vertices.xy;"</span> <span class="string">"}"</span>); m_program<span class="operator">-</span><span class="operator">></span>addCacheableShaderFromSourceCode(<span class="type"><a href="../qtgui/qopenglshader.html">QOpenGLShader</a></span><span class="operator">::</span>Fragment<span class="operator">,</span> <span class="string">"uniform lowp float t;"</span> <span class="string">"varying highp vec2 coords;"</span> <span class="string">"void main() {"</span> <span class="string">" lowp float i = 1. - (pow(abs(coords.x), 4.) + pow(abs(coords.y), 4.));"</span> <span class="string">" i = smoothstep(t - 0.8, t + 0.8, i);"</span> <span class="string">" i = floor(i * 20.) / 20.;"</span> <span class="string">" gl_FragColor = vec4(coords * .5 + .5, i, i);"</span> <span class="string">"}"</span>); m_program<span class="operator">-</span><span class="operator">></span>bindAttributeLocation(<span class="string">"vertices"</span><span class="operator">,</span> <span class="number">0</span>); m_program<span class="operator">-</span><span class="operator">></span>link(); } m_program<span class="operator">-</span><span class="operator">></span>bind(); m_program<span class="operator">-</span><span class="operator">></span>enableAttributeArray(<span class="number">0</span>); <span class="type">float</span> values<span class="operator">[</span><span class="operator">]</span> <span class="operator">=</span> { <span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">1</span> }; m_program<span class="operator">-</span><span class="operator">></span>setAttributeArray(<span class="number">0</span><span class="operator">,</span> GL_FLOAT<span class="operator">,</span> values<span class="operator">,</span> <span class="number">2</span>); m_program<span class="operator">-</span><span class="operator">></span>setUniformValue(<span class="string">"t"</span><span class="operator">,</span> (<span class="type">float</span>) m_t); glViewport(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> m_viewportSize<span class="operator">.</span>width()<span class="operator">,</span> m_viewportSize<span class="operator">.</span>height()); glDisable(GL_DEPTH_TEST); glClearColor(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">1</span>); glClear(GL_COLOR_BUFFER_BIT); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA<span class="operator">,</span> GL_ONE); glDrawArrays(GL_TRIANGLE_STRIP<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">4</span>); m_program<span class="operator">-</span><span class="operator">></span>disableAttributeArray(<span class="number">0</span>); m_program<span class="operator">-</span><span class="operator">></span>release(); <span class="comment">// Not strictly needed for this example, but generally useful for when</span> <span class="comment">// mixing with raw OpenGL.</span> m_window<span class="operator">-</span><span class="operator">></span>resetOpenGLState(); } </pre> </div> <!-- @@@scenegraph/openglunderqml/squircle.cpp --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2018 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>