a719c630f1
Create the pixmap with a device pixel ratio set. Change-Id: I7f7e90aec4d117304852f050be70e14a0c6bf69d Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
226 lines
7.2 KiB
C++
226 lines
7.2 KiB
C++
/****************************************************************************
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**
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** Copyright (C) 2016 The Qt Company Ltd.
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** Contact: https://www.qt.io/licensing/
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**
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** This file is part of the examples of the Qt Toolkit.
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**
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** $QT_BEGIN_LICENSE:BSD$
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** Commercial License Usage
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** Licensees holding valid commercial Qt licenses may use this file in
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** accordance with the commercial license agreement provided with the
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** Software or, alternatively, in accordance with the terms contained in
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** a written agreement between you and The Qt Company. For licensing terms
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** and conditions see https://www.qt.io/terms-conditions. For further
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** information use the contact form at https://www.qt.io/contact-us.
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**
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** BSD License Usage
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** Alternatively, you may use this file under the terms of the BSD license
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** as follows:
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**
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** "Redistribution and use in source and binary forms, with or without
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** modification, are permitted provided that the following conditions are
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** met:
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** * Redistributions of source code must retain the above copyright
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** notice, this list of conditions and the following disclaimer.
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** * Redistributions in binary form must reproduce the above copyright
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** notice, this list of conditions and the following disclaimer in
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** the documentation and/or other materials provided with the
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** distribution.
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** * Neither the name of The Qt Company Ltd nor the names of its
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** contributors may be used to endorse or promote products derived
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** from this software without specific prior written permission.
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**
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**
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** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
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**
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** $QT_END_LICENSE$
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**
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****************************************************************************/
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#include "renderthread.h"
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#include <QImage>
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#include <cmath>
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//! [0]
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RenderThread::RenderThread(QObject *parent)
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: QThread(parent)
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{
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for (int i = 0; i < ColormapSize; ++i)
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colormap[i] = rgbFromWaveLength(380.0 + (i * 400.0 / ColormapSize));
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}
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//! [0]
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//! [1]
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RenderThread::~RenderThread()
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{
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mutex.lock();
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abort = true;
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condition.wakeOne();
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mutex.unlock();
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wait();
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}
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//! [1]
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//! [2]
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void RenderThread::render(double centerX, double centerY, double scaleFactor,
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QSize resultSize, double devicePixelRatio)
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{
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QMutexLocker locker(&mutex);
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this->centerX = centerX;
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this->centerY = centerY;
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this->scaleFactor = scaleFactor;
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this->devicePixelRatio = devicePixelRatio;
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this->resultSize = resultSize;
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if (!isRunning()) {
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start(LowPriority);
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} else {
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restart = true;
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condition.wakeOne();
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}
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}
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//! [2]
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//! [3]
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void RenderThread::run()
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{
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forever {
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mutex.lock();
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const double devicePixelRatio = this->devicePixelRatio;
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const QSize resultSize = this->resultSize * devicePixelRatio;
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const double requestedScaleFactor = this->scaleFactor;
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const double scaleFactor = requestedScaleFactor / devicePixelRatio;
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const double centerX = this->centerX;
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const double centerY = this->centerY;
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mutex.unlock();
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//! [3]
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//! [4]
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int halfWidth = resultSize.width() / 2;
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//! [4] //! [5]
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int halfHeight = resultSize.height() / 2;
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QImage image(resultSize, QImage::Format_RGB32);
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image.setDevicePixelRatio(devicePixelRatio);
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const int NumPasses = 8;
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int pass = 0;
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while (pass < NumPasses) {
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const int MaxIterations = (1 << (2 * pass + 6)) + 32;
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const int Limit = 4;
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bool allBlack = true;
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for (int y = -halfHeight; y < halfHeight; ++y) {
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if (restart)
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break;
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if (abort)
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return;
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auto scanLine =
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reinterpret_cast<uint *>(image.scanLine(y + halfHeight));
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const double ay = centerY + (y * scaleFactor);
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for (int x = -halfWidth; x < halfWidth; ++x) {
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const double ax = centerX + (x * scaleFactor);
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double a1 = ax;
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double b1 = ay;
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int numIterations = 0;
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do {
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++numIterations;
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const double a2 = (a1 * a1) - (b1 * b1) + ax;
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const double b2 = (2 * a1 * b1) + ay;
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if ((a2 * a2) + (b2 * b2) > Limit)
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break;
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++numIterations;
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a1 = (a2 * a2) - (b2 * b2) + ax;
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b1 = (2 * a2 * b2) + ay;
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if ((a1 * a1) + (b1 * b1) > Limit)
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break;
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} while (numIterations < MaxIterations);
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if (numIterations < MaxIterations) {
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*scanLine++ = colormap[numIterations % ColormapSize];
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allBlack = false;
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} else {
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*scanLine++ = qRgb(0, 0, 0);
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}
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}
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}
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if (allBlack && pass == 0) {
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pass = 4;
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} else {
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if (!restart)
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emit renderedImage(image, requestedScaleFactor);
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//! [5] //! [6]
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++pass;
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}
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//! [6] //! [7]
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}
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//! [7]
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//! [8]
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mutex.lock();
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//! [8] //! [9]
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if (!restart)
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condition.wait(&mutex);
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restart = false;
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mutex.unlock();
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}
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}
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//! [9]
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//! [10]
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uint RenderThread::rgbFromWaveLength(double wave)
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{
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double r = 0;
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double g = 0;
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double b = 0;
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if (wave >= 380.0 && wave <= 440.0) {
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r = -1.0 * (wave - 440.0) / (440.0 - 380.0);
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b = 1.0;
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} else if (wave >= 440.0 && wave <= 490.0) {
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g = (wave - 440.0) / (490.0 - 440.0);
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b = 1.0;
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} else if (wave >= 490.0 && wave <= 510.0) {
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g = 1.0;
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b = -1.0 * (wave - 510.0) / (510.0 - 490.0);
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} else if (wave >= 510.0 && wave <= 580.0) {
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r = (wave - 510.0) / (580.0 - 510.0);
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g = 1.0;
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} else if (wave >= 580.0 && wave <= 645.0) {
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r = 1.0;
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g = -1.0 * (wave - 645.0) / (645.0 - 580.0);
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} else if (wave >= 645.0 && wave <= 780.0) {
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r = 1.0;
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}
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double s = 1.0;
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if (wave > 700.0)
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s = 0.3 + 0.7 * (780.0 - wave) / (780.0 - 700.0);
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else if (wave < 420.0)
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s = 0.3 + 0.7 * (wave - 380.0) / (420.0 - 380.0);
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r = std::pow(r * s, 0.8);
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g = std::pow(g * s, 0.8);
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b = std::pow(b * s, 0.8);
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return qRgb(int(r * 255), int(g * 255), int(b * 255));
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}
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//! [10]
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