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Diffstat (limited to 'examples/corelib/threads/mandelbrot/renderthread.cpp')
| -rw-r--r-- | examples/corelib/threads/mandelbrot/renderthread.cpp | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/examples/corelib/threads/mandelbrot/renderthread.cpp b/examples/corelib/threads/mandelbrot/renderthread.cpp new file mode 100644 index 0000000000..5779c65c9c --- /dev/null +++ b/examples/corelib/threads/mandelbrot/renderthread.cpp @@ -0,0 +1,215 @@ +/**************************************************************************** +** +** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/legal +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** 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 Digia Plc and its Subsidiary(-ies) 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." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "renderthread.h" + +#include <QtWidgets> + +#include <math.h> + +//! [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)); +} +//! [0] + +//! [1] +RenderThread::~RenderThread() +{ + mutex.lock(); + abort = true; + condition.wakeOne(); + mutex.unlock(); + + wait(); +} +//! [1] + +//! [2] +void RenderThread::render(double centerX, double centerY, double scaleFactor, + QSize resultSize) +{ + QMutexLocker locker(&mutex); + + this->centerX = centerX; + this->centerY = centerY; + this->scaleFactor = scaleFactor; + this->resultSize = resultSize; + + if (!isRunning()) { + start(LowPriority); + } else { + restart = true; + condition.wakeOne(); + } +} +//! [2] + +//! [3] +void RenderThread::run() +{ + forever { + mutex.lock(); + QSize resultSize = this->resultSize; + double scaleFactor = this->scaleFactor; + double centerX = this->centerX; + double centerY = this->centerY; + mutex.unlock(); +//! [3] + +//! [4] + int halfWidth = resultSize.width() / 2; +//! [4] //! [5] + int halfHeight = resultSize.height() / 2; + QImage image(resultSize, QImage::Format_RGB32); + + const int NumPasses = 8; + int pass = 0; + while (pass < NumPasses) { + const int MaxIterations = (1 << (2 * pass + 6)) + 32; + const int Limit = 4; + bool allBlack = true; + + for (int y = -halfHeight; y < halfHeight; ++y) { + if (restart) + break; + if (abort) + return; + + uint *scanLine = + reinterpret_cast<uint *>(image.scanLine(y + halfHeight)); + double ay = centerY + (y * scaleFactor); + + for (int x = -halfWidth; x < halfWidth; ++x) { + 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; + if ((a2 * a2) + (b2 * b2) > Limit) + break; + + ++numIterations; + a1 = (a2 * a2) - (b2 * b2) + ax; + b1 = (2 * a2 * b2) + ay; + if ((a1 * a1) + (b1 * b1) > Limit) + break; + } while (numIterations < MaxIterations); + + if (numIterations < MaxIterations) { + *scanLine++ = colormap[numIterations % ColormapSize]; + allBlack = false; + } else { + *scanLine++ = qRgb(0, 0, 0); + } + } + } + + if (allBlack && pass == 0) { + pass = 4; + } else { + if (!restart) + emit renderedImage(image, scaleFactor); +//! [5] //! [6] + ++pass; + } +//! [6] //! [7] + } +//! [7] + +//! [8] + mutex.lock(); +//! [8] //! [9] + if (!restart) + condition.wait(&mutex); + restart = false; + mutex.unlock(); + } +} +//! [9] + +//! [10] +uint RenderThread::rgbFromWaveLength(double wave) +{ + double r = 0.0; + double g = 0.0; + double b = 0.0; + + if (wave >= 380.0 && wave <= 440.0) { + r = -1.0 * (wave - 440.0) / (440.0 - 380.0); + b = 1.0; + } else if (wave >= 440.0 && wave <= 490.0) { + g = (wave - 440.0) / (490.0 - 440.0); + b = 1.0; + } else if (wave >= 490.0 && wave <= 510.0) { + g = 1.0; + b = -1.0 * (wave - 510.0) / (510.0 - 490.0); + } else if (wave >= 510.0 && wave <= 580.0) { + r = (wave - 510.0) / (580.0 - 510.0); + g = 1.0; + } else if (wave >= 580.0 && wave <= 645.0) { + r = 1.0; + g = -1.0 * (wave - 645.0) / (645.0 - 580.0); + } else if (wave >= 645.0 && wave <= 780.0) { + r = 1.0; + } + + double s = 1.0; + if (wave > 700.0) + s = 0.3 + 0.7 * (780.0 - wave) / (780.0 - 700.0); + else if (wave < 420.0) + s = 0.3 + 0.7 * (wave - 380.0) / (420.0 - 380.0); + + r = pow(r * s, 0.8); + g = pow(g * s, 0.8); + b = pow(b * s, 0.8); + return qRgb(int(r * 255), int(g * 255), int(b * 255)); +} +//! [10] |