lighting.cpp Example File

effects/lighting/lighting.cpp
/**************************************************************************** ** ** 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 "lighting.h" #include <QtWidgets> #include <QtCore/qmath.h> #ifndef M_PI #define M_PI 3.14159265358979323846 #endif Lighting::Lighting(QWidget *parent): QGraphicsView(parent), angle(0.0) { setScene(&m_scene); setupScene(); QTimer *timer = new QTimer(this); connect(timer, SIGNAL(timeout()), SLOT(animate())); timer->setInterval(30); timer->start(); setRenderHint(QPainter::Antialiasing, true); setFrameStyle(QFrame::NoFrame); } void Lighting::setupScene() { m_scene.setSceneRect(-300, -200, 600, 460); QLinearGradient linearGrad(QPointF(-100, -100), QPointF(100, 100)); linearGrad.setColorAt(0, QColor(255, 255, 255)); linearGrad.setColorAt(1, QColor(192, 192, 255)); setBackgroundBrush(linearGrad); QRadialGradient radialGrad(30, 30, 30); radialGrad.setColorAt(0, Qt::yellow); radialGrad.setColorAt(0.2, Qt::yellow); radialGrad.setColorAt(1, Qt::transparent); QPixmap pixmap(60, 60); pixmap.fill(Qt::transparent); QPainter painter(&pixmap); painter.setPen(Qt::NoPen); painter.setBrush(radialGrad); painter.drawEllipse(0, 0, 60, 60); painter.end(); m_lightSource = m_scene.addPixmap(pixmap); m_lightSource->setZValue(2); for (int i = -2; i < 3; ++i) for (int j = -2; j < 3; ++j) { QAbstractGraphicsShapeItem *item; if ((i + j) & 1) item = new QGraphicsEllipseItem(0, 0, 50, 50); else item = new QGraphicsRectItem(0, 0, 50, 50); item->setPen(QPen(Qt::black, 1)); item->setBrush(QBrush(Qt::white)); QGraphicsDropShadowEffect *effect = new QGraphicsDropShadowEffect; effect->setBlurRadius(8); item->setGraphicsEffect(effect); item->setZValue(1); item->setPos(i * 80, j * 80); m_scene.addItem(item); m_items << item; } } void Lighting::animate() { angle += (M_PI / 30); qreal xs = 200 * qSin(angle) - 40 + 25; qreal ys = 200 * qCos(angle) - 40 + 25; m_lightSource->setPos(xs, ys); for (int i = 0; i < m_items.size(); ++i) { QGraphicsItem *item = m_items.at(i); Q_ASSERT(item); QGraphicsDropShadowEffect *effect = static_cast<QGraphicsDropShadowEffect *>(item->graphicsEffect()); Q_ASSERT(effect); QPointF delta(item->x() - xs, item->y() - ys); effect->setOffset(delta.toPoint() / 30); qreal dx = delta.x(); qreal dy = delta.y(); qreal dd = qSqrt(dx * dx + dy * dy); QColor color = effect->color(); color.setAlphaF(qBound(0.4, 1 - dd / 200.0, 0.7)); effect->setColor(color); } m_scene.update(); } void Lighting::resizeEvent(QResizeEvent * /* event */) { }