renderthread.cpp Example File | Qt Core 5.6

Qt 5.6 | Qt Core | Queued Custom Type Example | renderthread.cpp Example File

Qt 5.6.2 Reference Documentation

# renderthread.cpp Example File

threads/queuedcustomtype/renderthread.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2015 The Qt Company Ltd.
      ** Contact: http://www.qt.io/licensing/
      **
      ** 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 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."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #include "renderthread.h"

      RenderThread::RenderThread(QObject *parent)
          : QThread(parent)
      {
          m_abort = false;
      }

      RenderThread::~RenderThread()
      {
          mutex.lock();
          m_abort = true;
          mutex.unlock();

          wait();
      }

      void RenderThread::processImage(const QImage &image)
      {
          if (image.isNull())
              return;

          m_image = image;
          m_abort = false;
          start();
      }

      void RenderThread::run()
      {
          int size = qMax(m_image.width()/20, m_image.height()/20);
          for (int s = size; s > 0; --s) {
              for (int c = 0; c < 400; ++c) {
                  int x1 = qMax(0, (qrand() % m_image.width()) - s/2);
                  int x2 = qMin(x1 + s/2 + 1, m_image.width());
                  int y1 = qMax(0, (qrand() % m_image.height()) - s/2);
                  int y2 = qMin(y1 + s/2 + 1, m_image.height());
                  int n = 0;
                  int red = 0;
                  int green = 0;
                  int blue = 0;
                  for (int i = y1; i < y2; ++i) {
                      for (int j = x1; j < x2; ++j) {
                          QRgb pixel = m_image.pixel(j, i);
                          red += qRed(pixel);
                          green += qGreen(pixel);
                          blue += qBlue(pixel);
                          n += 1;
                      }
                  }
                  Block block(QRect(x1, y1, x2 - x1 + 1, y2 - y1 + 1),
                              QColor(red/n, green/n, blue/n));
                  emit sendBlock(block);
                  if (m_abort)
                      return;
                  msleep(10);
              }
          }
      }

      void RenderThread::stopProcess()
      {
          mutex.lock();
          m_abort = true;
          mutex.unlock();
      }