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Diffstat (limited to 'static/source/qt5-mandelbrot/mandelbrotwidget.cxx')
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1 files changed, 228 insertions, 0 deletions
diff --git a/static/source/qt5-mandelbrot/mandelbrotwidget.cxx b/static/source/qt5-mandelbrot/mandelbrotwidget.cxx new file mode 100644 index 0000000000..5886dd2664 --- /dev/null +++ b/static/source/qt5-mandelbrot/mandelbrotwidget.cxx @@ -0,0 +1,228 @@ +/**************************************************************************** +** +** Copyright (C) 2016 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** BSD License Usage +** Alternatively, 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 "mandelbrotwidget.h" +#include "mandelbrotwidget.moc" + +#include <QtGui/QPainter> +#include <QtGui/QKeyEvent> + +#include <math.h> + +const double DefaultCenterX = -0.637011; +const double DefaultCenterY = -0.0395159; +const double DefaultScale = 0.00403897; + +const double ZoomInFactor = 0.8; +const double ZoomOutFactor = 1 / ZoomInFactor; +const int ScrollStep = 20; + +MandelbrotWidget::MandelbrotWidget(QWidget* parent) + : QWidget(parent) + , centerX(DefaultCenterX) + , centerY(DefaultCenterY) + , pixmapScale(DefaultScale) + , curScale(DefaultScale) +{ + connect(&thread, &RenderThread::renderedImage, this, &MandelbrotWidget::updatePixmap); + + setWindowTitle(tr("Mandelbrot")); +#if QT_CONFIG(cursor) + setCursor(Qt::CrossCursor); +#endif + resize(550, 400); +} + +void MandelbrotWidget::paintEvent(QPaintEvent* /* event */) +{ + QPainter painter(this); + painter.fillRect(rect(), Qt::black); + + if (pixmap.isNull()) + { + painter.setPen(Qt::white); + painter.drawText(rect(), Qt::AlignCenter, tr("Rendering initial image, please wait...")); + return; + } + + if (qFuzzyCompare(curScale, pixmapScale)) + { + painter.drawPixmap(pixmapOffset, pixmap); + } + else + { + auto previewPixmap = qFuzzyCompare(pixmap.devicePixelRatioF(), qreal(1)) + ? pixmap + : pixmap.scaled(pixmap.size() / pixmap.devicePixelRatioF(), + Qt::KeepAspectRatio, Qt::SmoothTransformation); + double scaleFactor = pixmapScale / curScale; + int newWidth = int(previewPixmap.width() * scaleFactor); + int newHeight = int(previewPixmap.height() * scaleFactor); + int newX = pixmapOffset.x() + (previewPixmap.width() - newWidth) / 2; + int newY = pixmapOffset.y() + (previewPixmap.height() - newHeight) / 2; + + painter.save(); + painter.translate(newX, newY); + painter.scale(scaleFactor, scaleFactor); + + QRectF exposed = painter.transform().inverted().mapRect(rect()).adjusted(-1, -1, 1, 1); + painter.drawPixmap(exposed, previewPixmap, exposed); + painter.restore(); + } + + QString text = tr("Use mouse wheel or the '+' and '-' keys to zoom. " + "Press and hold left mouse button to scroll."); + QFontMetrics metrics = painter.fontMetrics(); + int textWidth = metrics.horizontalAdvance(text); + + painter.setPen(Qt::NoPen); + painter.setBrush(QColor(0, 0, 0, 127)); + painter.drawRect((width() - textWidth) / 2 - 5, 0, textWidth + 10, metrics.lineSpacing() + 5); + painter.setPen(Qt::white); + painter.drawText((width() - textWidth) / 2, metrics.leading() + metrics.ascent(), text); +} + +void MandelbrotWidget::resizeEvent(QResizeEvent* /* event */) +{ + thread.render(centerX, centerY, curScale, size(), devicePixelRatioF()); +} + +void MandelbrotWidget::keyPressEvent(QKeyEvent* event) +{ + switch (event->key()) + { + case Qt::Key_Plus: + zoom(ZoomInFactor); + break; + case Qt::Key_Minus: + zoom(ZoomOutFactor); + break; + case Qt::Key_Left: + scroll(-ScrollStep, 0); + break; + case Qt::Key_Right: + scroll(+ScrollStep, 0); + break; + case Qt::Key_Down: + scroll(0, -ScrollStep); + break; + case Qt::Key_Up: + scroll(0, +ScrollStep); + break; + default: + QWidget::keyPressEvent(event); + } +} + +#if QT_CONFIG(wheelevent) +void MandelbrotWidget::wheelEvent(QWheelEvent* event) +{ + const int numDegrees = event->angleDelta().y() / 8; + const double numSteps = numDegrees / double(15); + zoom(pow(ZoomInFactor, numSteps)); +} +#endif + +void MandelbrotWidget::mousePressEvent(QMouseEvent* event) +{ + if (event->button() == Qt::LeftButton) + lastDragPos = event->pos(); +} + +void MandelbrotWidget::mouseMoveEvent(QMouseEvent* event) +{ + if (event->buttons() & Qt::LeftButton) + { + pixmapOffset += event->pos() - lastDragPos; + lastDragPos = event->pos(); + update(); + } +} + +void MandelbrotWidget::mouseReleaseEvent(QMouseEvent* event) +{ + if (event->button() == Qt::LeftButton) + { + pixmapOffset += event->pos() - lastDragPos; + lastDragPos = QPoint(); + + const auto pixmapSize = pixmap.size() / pixmap.devicePixelRatioF(); + int deltaX = (width() - pixmapSize.width()) / 2 - pixmapOffset.x(); + int deltaY = (height() - pixmapSize.height()) / 2 - pixmapOffset.y(); + scroll(deltaX, deltaY); + } +} + +void MandelbrotWidget::updatePixmap(const QImage& image, double scaleFactor) +{ + if (!lastDragPos.isNull()) + return; + + pixmap = QPixmap::fromImage(image); + pixmapOffset = QPoint(); + lastDragPos = QPoint(); + pixmapScale = scaleFactor; + update(); +} + +void MandelbrotWidget::zoom(double zoomFactor) +{ + curScale *= zoomFactor; + update(); + thread.render(centerX, centerY, curScale, size(), devicePixelRatioF()); +} + +void MandelbrotWidget::scroll(int deltaX, int deltaY) +{ + centerX += deltaX * curScale; + centerY += deltaY * curScale; + update(); + thread.render(centerX, centerY, curScale, size(), devicePixelRatioF()); +} |