diff options
Diffstat (limited to 'examples/corelib/threads/mandelbrot/renderthread.cpp')
| -rw-r--r-- | examples/corelib/threads/mandelbrot/renderthread.cpp | 117 |
1 files changed, 45 insertions, 72 deletions
diff --git a/examples/corelib/threads/mandelbrot/renderthread.cpp b/examples/corelib/threads/mandelbrot/renderthread.cpp index eee44c7242..77a14a6ac1 100644 --- a/examples/corelib/threads/mandelbrot/renderthread.cpp +++ b/examples/corelib/threads/mandelbrot/renderthread.cpp @@ -1,65 +1,20 @@ -/**************************************************************************** -** -** 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." -** -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2021 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause #include "renderthread.h" #include <QImage> +#include <QElapsedTimer> +#include <QTextStream> + #include <cmath> +int RenderThread::numPasses = 8; + //! [0] RenderThread::RenderThread(QObject *parent) : QThread(parent) { - restart = false; - abort = false; - for (int i = 0; i < ColormapSize; ++i) colormap[i] = rgbFromWaveLength(380.0 + (i * 400.0 / ColormapSize)); } @@ -79,13 +34,14 @@ RenderThread::~RenderThread() //! [2] void RenderThread::render(double centerX, double centerY, double scaleFactor, - QSize resultSize) + QSize resultSize, double devicePixelRatio) { QMutexLocker locker(&mutex); this->centerX = centerX; this->centerY = centerY; this->scaleFactor = scaleFactor; + this->devicePixelRatio = devicePixelRatio; this->resultSize = resultSize; if (!isRunning()) { @@ -100,48 +56,53 @@ void RenderThread::render(double centerX, double centerY, double scaleFactor, //! [3] void RenderThread::run() { + QElapsedTimer timer; forever { mutex.lock(); - QSize resultSize = this->resultSize; - double scaleFactor = this->scaleFactor; - double centerX = this->centerX; - double centerY = this->centerY; + const double devicePixelRatio = this->devicePixelRatio; + const QSize resultSize = this->resultSize * devicePixelRatio; + const double requestedScaleFactor = this->scaleFactor; + const double scaleFactor = requestedScaleFactor / devicePixelRatio; + const double centerX = this->centerX; + const double centerY = this->centerY; mutex.unlock(); //! [3] //! [4] - int halfWidth = resultSize.width() / 2; + const int halfWidth = resultSize.width() / 2; //! [4] //! [5] - int halfHeight = resultSize.height() / 2; + const int halfHeight = resultSize.height() / 2; QImage image(resultSize, QImage::Format_RGB32); + image.setDevicePixelRatio(devicePixelRatio); - const int NumPasses = 8; int pass = 0; - while (pass < NumPasses) { + while (pass < numPasses) { const int MaxIterations = (1 << (2 * pass + 6)) + 32; - const int Limit = 4; + constexpr int Limit = 4; bool allBlack = true; + timer.restart(); + for (int y = -halfHeight; y < halfHeight; ++y) { if (restart) break; if (abort) return; - uint *scanLine = + auto scanLine = reinterpret_cast<uint *>(image.scanLine(y + halfHeight)); - double ay = centerY + (y * scaleFactor); + const double ay = centerY + (y * scaleFactor); for (int x = -halfWidth; x < halfWidth; ++x) { - double ax = centerX + (x * scaleFactor); + const double ax = centerX + (x * scaleFactor); double a1 = ax; double b1 = ay; int numIterations = 0; do { ++numIterations; - double a2 = (a1 * a1) - (b1 * b1) + ax; - double b2 = (2 * a1 * b1) + ay; + const double a2 = (a1 * a1) - (b1 * b1) + ax; + const double b2 = (2 * a1 * b1) + ay; if ((a2 * a2) + (b2 * b2) > Limit) break; @@ -164,8 +125,20 @@ void RenderThread::run() if (allBlack && pass == 0) { pass = 4; } else { - if (!restart) - emit renderedImage(image, scaleFactor); + if (!restart) { + QString message; + QTextStream str(&message); + str << " Pass " << (pass + 1) << '/' << numPasses + << ", max iterations: " << MaxIterations << ", time: "; + const auto elapsed = timer.elapsed(); + if (elapsed > 2000) + str << (elapsed / 1000) << 's'; + else + str << elapsed << "ms"; + image.setText(infoKey(), message); + + emit renderedImage(image, requestedScaleFactor); + } //! [5] //! [6] ++pass; } @@ -187,9 +160,9 @@ void RenderThread::run() //! [10] uint RenderThread::rgbFromWaveLength(double wave) { - double r = 0.0; - double g = 0.0; - double b = 0.0; + double r = 0; + double g = 0; + double b = 0; if (wave >= 380.0 && wave <= 440.0) { r = -1.0 * (wave - 440.0) / (440.0 - 380.0); |