<?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>renderthread.cpp Example File | Qt Core 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="qtcore-index.html">Qt Core</a></td><td ><a href="qtcore-threads-mandelbrot-example.html">Mandelbrot Example</a></td><td >renderthread.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtcore-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">renderthread.cpp Example File</h1> <span class="subtitle">threads/mandelbrot/renderthread.cpp</span> <!-- $$$threads/mandelbrot/renderthread.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 examples 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 "renderthread.h"</span> <span class="preprocessor">#include <QtWidgets></span> <span class="preprocessor">#include <cmath></span> RenderThread<span class="operator">::</span>RenderThread(<span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>parent) : <span class="type"><a href="qthread.html">QThread</a></span>(parent) { restart <span class="operator">=</span> <span class="keyword">false</span>; abort <span class="operator">=</span> <span class="keyword">false</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> ColormapSize; <span class="operator">+</span><span class="operator">+</span>i) colormap<span class="operator">[</span>i<span class="operator">]</span> <span class="operator">=</span> rgbFromWaveLength(<span class="number">380.0</span> <span class="operator">+</span> (i <span class="operator">*</span> <span class="number">400.0</span> <span class="operator">/</span> ColormapSize)); } RenderThread<span class="operator">::</span><span class="operator">~</span>RenderThread() { mutex<span class="operator">.</span>lock(); abort <span class="operator">=</span> <span class="keyword">true</span>; condition<span class="operator">.</span>wakeOne(); mutex<span class="operator">.</span>unlock(); wait(); } <span class="type">void</span> RenderThread<span class="operator">::</span>render(<span class="type">double</span> centerX<span class="operator">,</span> <span class="type">double</span> centerY<span class="operator">,</span> <span class="type">double</span> scaleFactor<span class="operator">,</span> <span class="type"><a href="qsize.html">QSize</a></span> resultSize) { <span class="type"><a href="qmutexlocker.html">QMutexLocker</a></span> locker(<span class="operator">&</span>mutex); <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>centerX <span class="operator">=</span> centerX; <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>centerY <span class="operator">=</span> centerY; <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>scaleFactor <span class="operator">=</span> scaleFactor; <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>resultSize <span class="operator">=</span> resultSize; <span class="keyword">if</span> (<span class="operator">!</span>isRunning()) { start(LowPriority); } <span class="keyword">else</span> { restart <span class="operator">=</span> <span class="keyword">true</span>; condition<span class="operator">.</span>wakeOne(); } } <span class="type">void</span> RenderThread<span class="operator">::</span>run() { forever { mutex<span class="operator">.</span>lock(); <span class="type"><a href="qsize.html">QSize</a></span> resultSize <span class="operator">=</span> <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>resultSize; <span class="type">double</span> scaleFactor <span class="operator">=</span> <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>scaleFactor; <span class="type">double</span> centerX <span class="operator">=</span> <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>centerX; <span class="type">double</span> centerY <span class="operator">=</span> <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>centerY; mutex<span class="operator">.</span>unlock(); <span class="type">int</span> halfWidth <span class="operator">=</span> resultSize<span class="operator">.</span>width() <span class="operator">/</span> <span class="number">2</span>; <span class="type">int</span> halfHeight <span class="operator">=</span> resultSize<span class="operator">.</span>height() <span class="operator">/</span> <span class="number">2</span>; <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> image(resultSize<span class="operator">,</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span><span class="operator">::</span>Format_RGB32); <span class="keyword">const</span> <span class="type">int</span> NumPasses <span class="operator">=</span> <span class="number">8</span>; <span class="type">int</span> pass <span class="operator">=</span> <span class="number">0</span>; <span class="keyword">while</span> (pass <span class="operator"><</span> NumPasses) { <span class="keyword">const</span> <span class="type">int</span> MaxIterations <span class="operator">=</span> (<span class="number">1</span> <span class="operator"><</span><span class="operator"><</span> (<span class="number">2</span> <span class="operator">*</span> pass <span class="operator">+</span> <span class="number">6</span>)) <span class="operator">+</span> <span class="number">32</span>; <span class="keyword">const</span> <span class="type">int</span> Limit <span class="operator">=</span> <span class="number">4</span>; bool allBlack <span class="operator">=</span> <span class="keyword">true</span>; <span class="keyword">for</span> (<span class="type">int</span> y <span class="operator">=</span> <span class="operator">-</span>halfHeight; y <span class="operator"><</span> halfHeight; <span class="operator">+</span><span class="operator">+</span>y) { <span class="keyword">if</span> (restart) <span class="keyword">break</span>; <span class="keyword">if</span> (abort) <span class="keyword">return</span>; <span class="type"><a href="qtglobal.html#uint-typedef">uint</a></span> <span class="operator">*</span>scanLine <span class="operator">=</span> <span class="keyword">reinterpret_cast</span><span class="operator"><</span><span class="type"><a href="qtglobal.html#uint-typedef">uint</a></span> <span class="operator">*</span><span class="operator">></span>(image<span class="operator">.</span>scanLine(y <span class="operator">+</span> halfHeight)); <span class="type">double</span> ay <span class="operator">=</span> centerY <span class="operator">+</span> (y <span class="operator">*</span> scaleFactor); <span class="keyword">for</span> (<span class="type">int</span> x <span class="operator">=</span> <span class="operator">-</span>halfWidth; x <span class="operator"><</span> halfWidth; <span class="operator">+</span><span class="operator">+</span>x) { <span class="type">double</span> ax <span class="operator">=</span> centerX <span class="operator">+</span> (x <span class="operator">*</span> scaleFactor); <span class="type">double</span> a1 <span class="operator">=</span> ax; <span class="type">double</span> b1 <span class="operator">=</span> ay; <span class="type">int</span> numIterations <span class="operator">=</span> <span class="number">0</span>; <span class="keyword">do</span> { <span class="operator">+</span><span class="operator">+</span>numIterations; <span class="type">double</span> a2 <span class="operator">=</span> (a1 <span class="operator">*</span> a1) <span class="operator">-</span> (b1 <span class="operator">*</span> b1) <span class="operator">+</span> ax; <span class="type">double</span> b2 <span class="operator">=</span> (<span class="number">2</span> <span class="operator">*</span> a1 <span class="operator">*</span> b1) <span class="operator">+</span> ay; <span class="keyword">if</span> ((a2 <span class="operator">*</span> a2) <span class="operator">+</span> (b2 <span class="operator">*</span> b2) <span class="operator">></span> Limit) <span class="keyword">break</span>; <span class="operator">+</span><span class="operator">+</span>numIterations; a1 <span class="operator">=</span> (a2 <span class="operator">*</span> a2) <span class="operator">-</span> (b2 <span class="operator">*</span> b2) <span class="operator">+</span> ax; b1 <span class="operator">=</span> (<span class="number">2</span> <span class="operator">*</span> a2 <span class="operator">*</span> b2) <span class="operator">+</span> ay; <span class="keyword">if</span> ((a1 <span class="operator">*</span> a1) <span class="operator">+</span> (b1 <span class="operator">*</span> b1) <span class="operator">></span> Limit) <span class="keyword">break</span>; } <span class="keyword">while</span> (numIterations <span class="operator"><</span> MaxIterations); <span class="keyword">if</span> (numIterations <span class="operator"><</span> MaxIterations) { <span class="operator">*</span>scanLine<span class="operator">+</span><span class="operator">+</span> <span class="operator">=</span> colormap<span class="operator">[</span>numIterations <span class="operator">%</span> ColormapSize<span class="operator">]</span>; allBlack <span class="operator">=</span> <span class="keyword">false</span>; } <span class="keyword">else</span> { <span class="operator">*</span>scanLine<span class="operator">+</span><span class="operator">+</span> <span class="operator">=</span> <a href="../qtgui/qcolor.html#qRgb">qRgb</a>(<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="keyword">if</span> (allBlack <span class="operator">&</span><span class="operator">&</span> pass <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>) { pass <span class="operator">=</span> <span class="number">4</span>; } <span class="keyword">else</span> { <span class="keyword">if</span> (<span class="operator">!</span>restart) <span class="keyword">emit</span> renderedImage(image<span class="operator">,</span> scaleFactor); <span class="operator">+</span><span class="operator">+</span>pass; } } mutex<span class="operator">.</span>lock(); <span class="keyword">if</span> (<span class="operator">!</span>restart) condition<span class="operator">.</span>wait(<span class="operator">&</span>mutex); restart <span class="operator">=</span> <span class="keyword">false</span>; mutex<span class="operator">.</span>unlock(); } } <span class="type"><a href="qtglobal.html#uint-typedef">uint</a></span> RenderThread<span class="operator">::</span>rgbFromWaveLength(<span class="type">double</span> wave) { <span class="type">double</span> r <span class="operator">=</span> <span class="number">0.0</span>; <span class="type">double</span> g <span class="operator">=</span> <span class="number">0.0</span>; <span class="type">double</span> b <span class="operator">=</span> <span class="number">0.0</span>; <span class="keyword">if</span> (wave <span class="operator">></span><span class="operator">=</span> <span class="number">380.0</span> <span class="operator">&</span><span class="operator">&</span> wave <span class="operator"><</span><span class="operator">=</span> <span class="number">440.0</span>) { r <span class="operator">=</span> <span class="operator">-</span><span class="number">1.0</span> <span class="operator">*</span> (wave <span class="operator">-</span> <span class="number">440.0</span>) <span class="operator">/</span> (<span class="number">440.0</span> <span class="operator">-</span> <span class="number">380.0</span>); b <span class="operator">=</span> <span class="number">1.0</span>; } <span class="keyword">else</span> <span class="keyword">if</span> (wave <span class="operator">></span><span class="operator">=</span> <span class="number">440.0</span> <span class="operator">&</span><span class="operator">&</span> wave <span class="operator"><</span><span class="operator">=</span> <span class="number">490.0</span>) { g <span class="operator">=</span> (wave <span class="operator">-</span> <span class="number">440.0</span>) <span class="operator">/</span> (<span class="number">490.0</span> <span class="operator">-</span> <span class="number">440.0</span>); b <span class="operator">=</span> <span class="number">1.0</span>; } <span class="keyword">else</span> <span class="keyword">if</span> (wave <span class="operator">></span><span class="operator">=</span> <span class="number">490.0</span> <span class="operator">&</span><span class="operator">&</span> wave <span class="operator"><</span><span class="operator">=</span> <span class="number">510.0</span>) { g <span class="operator">=</span> <span class="number">1.0</span>; b <span class="operator">=</span> <span class="operator">-</span><span class="number">1.0</span> <span class="operator">*</span> (wave <span class="operator">-</span> <span class="number">510.0</span>) <span class="operator">/</span> (<span class="number">510.0</span> <span class="operator">-</span> <span class="number">490.0</span>); } <span class="keyword">else</span> <span class="keyword">if</span> (wave <span class="operator">></span><span class="operator">=</span> <span class="number">510.0</span> <span class="operator">&</span><span class="operator">&</span> wave <span class="operator"><</span><span class="operator">=</span> <span class="number">580.0</span>) { r <span class="operator">=</span> (wave <span class="operator">-</span> <span class="number">510.0</span>) <span class="operator">/</span> (<span class="number">580.0</span> <span class="operator">-</span> <span class="number">510.0</span>); g <span class="operator">=</span> <span class="number">1.0</span>; } <span class="keyword">else</span> <span class="keyword">if</span> (wave <span class="operator">></span><span class="operator">=</span> <span class="number">580.0</span> <span class="operator">&</span><span class="operator">&</span> wave <span class="operator"><</span><span class="operator">=</span> <span class="number">645.0</span>) { r <span class="operator">=</span> <span class="number">1.0</span>; g <span class="operator">=</span> <span class="operator">-</span><span class="number">1.0</span> <span class="operator">*</span> (wave <span class="operator">-</span> <span class="number">645.0</span>) <span class="operator">/</span> (<span class="number">645.0</span> <span class="operator">-</span> <span class="number">580.0</span>); } <span class="keyword">else</span> <span class="keyword">if</span> (wave <span class="operator">></span><span class="operator">=</span> <span class="number">645.0</span> <span class="operator">&</span><span class="operator">&</span> wave <span class="operator"><</span><span class="operator">=</span> <span class="number">780.0</span>) { r <span class="operator">=</span> <span class="number">1.0</span>; } <span class="type">double</span> s <span class="operator">=</span> <span class="number">1.0</span>; <span class="keyword">if</span> (wave <span class="operator">></span> <span class="number">700.0</span>) s <span class="operator">=</span> <span class="number">0.3</span> <span class="operator">+</span> <span class="number">0.7</span> <span class="operator">*</span> (<span class="number">780.0</span> <span class="operator">-</span> wave) <span class="operator">/</span> (<span class="number">780.0</span> <span class="operator">-</span> <span class="number">700.0</span>); <span class="keyword">else</span> <span class="keyword">if</span> (wave <span class="operator"><</span> <span class="number">420.0</span>) s <span class="operator">=</span> <span class="number">0.3</span> <span class="operator">+</span> <span class="number">0.7</span> <span class="operator">*</span> (wave <span class="operator">-</span> <span class="number">380.0</span>) <span class="operator">/</span> (<span class="number">420.0</span> <span class="operator">-</span> <span class="number">380.0</span>); r <span class="operator">=</span> std<span class="operator">::</span>pow(r <span class="operator">*</span> s<span class="operator">,</span> <span class="number">0.8</span>); g <span class="operator">=</span> std<span class="operator">::</span>pow(g <span class="operator">*</span> s<span class="operator">,</span> <span class="number">0.8</span>); b <span class="operator">=</span> std<span class="operator">::</span>pow(b <span class="operator">*</span> s<span class="operator">,</span> <span class="number">0.8</span>); <span class="keyword">return</span> <a href="../qtgui/qcolor.html#qRgb">qRgb</a>(<span class="type">int</span>(r <span class="operator">*</span> <span class="number">255</span>)<span class="operator">,</span> <span class="type">int</span>(g <span class="operator">*</span> <span class="number">255</span>)<span class="operator">,</span> <span class="type">int</span>(b <span class="operator">*</span> <span class="number">255</span>)); } </pre> </div> <!-- @@@threads/mandelbrot/renderthread.cpp --> </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>