renderthread.cpp

/****************************************************************************
**
** 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 "mandelbrotcl.h"

#include <QImage>

#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();

        QImage image(resultSize, QImage::Format_RGB32);

        MandelBrotCL mbcl;
        mbcl.setColorMap(colormap, ColormapSize);
        if (!mbcl.setDefaultDevice()) return;

        if (abort) return;
        mbcl.requestRender(resultSize.width(), resultSize.height(), scaleFactor, centerX, centerY, 500, reinterpret_cast<uint*>(image.bits()));

        if (!restart) emit renderedImage(image, scaleFactor);

        mutex.lock();
        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]