--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/threads/mandelbrot/renderthread.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,216 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtGui>
+
+#include <math.h>
+
+#include "renderthread.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]