From e0d5221957bf0d7857f924f1f2ae63d490de0a0a Mon Sep 17 00:00:00 2001 From: Casper van Donderen Date: Wed, 22 Jun 2011 13:54:56 +0200 Subject: Move all other demos in qtbase to examples. Change-Id: Iab0e7364d1f6b348d0e3033ea9304139f5bd6d0d Reviewed-on: http://codereview.qt.nokia.com/617 Reviewed-by: Qt Sanity Bot Reviewed-by: David Boddie --- examples/graphicsview/boxes/trackball.cpp | 160 ++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 examples/graphicsview/boxes/trackball.cpp (limited to 'examples/graphicsview/boxes/trackball.cpp') diff --git a/examples/graphicsview/boxes/trackball.cpp b/examples/graphicsview/boxes/trackball.cpp new file mode 100644 index 0000000000..1bb864ce90 --- /dev/null +++ b/examples/graphicsview/boxes/trackball.cpp @@ -0,0 +1,160 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the demonstration applications of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** GNU Lesser General Public License Usage +** This file may be used under the terms of the GNU Lesser General Public +** License version 2.1 as published by the Free Software Foundation and +** appearing in the file LICENSE.LGPL included in the packaging of this +** file. Please review the following information to ensure the GNU Lesser +** General Public License version 2.1 requirements will be met: +** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU General +** Public License version 3.0 as published by the Free Software Foundation +** and appearing in the file LICENSE.GPL included in the packaging of this +** file. Please review the following information to ensure the GNU General +** Public License version 3.0 requirements will be met: +** http://www.gnu.org/copyleft/gpl.html. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms and +** conditions contained in a signed written agreement between you and Nokia. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "trackball.h" +#include "scene.h" + +//============================================================================// +// TrackBall // +//============================================================================// + +TrackBall::TrackBall(TrackMode mode) + : m_angularVelocity(0) + , m_paused(false) + , m_pressed(false) + , m_mode(mode) +{ + m_axis = QVector3D(0, 1, 0); + m_rotation = QQuaternion(); + m_lastTime = QTime::currentTime(); +} + +TrackBall::TrackBall(float angularVelocity, const QVector3D& axis, TrackMode mode) + : m_axis(axis) + , m_angularVelocity(angularVelocity) + , m_paused(false) + , m_pressed(false) + , m_mode(mode) +{ + m_rotation = QQuaternion(); + m_lastTime = QTime::currentTime(); +} + +void TrackBall::push(const QPointF& p, const QQuaternion &) +{ + m_rotation = rotation(); + m_pressed = true; + m_lastTime = QTime::currentTime(); + m_lastPos = p; + m_angularVelocity = 0.0f; +} + +void TrackBall::move(const QPointF& p, const QQuaternion &transformation) +{ + if (!m_pressed) + return; + + QTime currentTime = QTime::currentTime(); + int msecs = m_lastTime.msecsTo(currentTime); + if (msecs <= 20) + return; + + switch (m_mode) { + case Plane: + { + QLineF delta(m_lastPos, p); + m_angularVelocity = 180*delta.length() / (PI*msecs); + m_axis = QVector3D(-delta.dy(), delta.dx(), 0.0f).normalized(); + m_axis = transformation.rotatedVector(m_axis); + m_rotation = QQuaternion::fromAxisAndAngle(m_axis, 180 / PI * delta.length()) * m_rotation; + } + break; + case Sphere: + { + QVector3D lastPos3D = QVector3D(m_lastPos.x(), m_lastPos.y(), 0.0f); + float sqrZ = 1 - QVector3D::dotProduct(lastPos3D, lastPos3D); + if (sqrZ > 0) + lastPos3D.setZ(sqrt(sqrZ)); + else + lastPos3D.normalize(); + + QVector3D currentPos3D = QVector3D(p.x(), p.y(), 0.0f); + sqrZ = 1 - QVector3D::dotProduct(currentPos3D, currentPos3D); + if (sqrZ > 0) + currentPos3D.setZ(sqrt(sqrZ)); + else + currentPos3D.normalize(); + + m_axis = QVector3D::crossProduct(lastPos3D, currentPos3D); + float angle = 180 / PI * asin(sqrt(QVector3D::dotProduct(m_axis, m_axis))); + + m_angularVelocity = angle / msecs; + m_axis.normalize(); + m_axis = transformation.rotatedVector(m_axis); + m_rotation = QQuaternion::fromAxisAndAngle(m_axis, angle) * m_rotation; + } + break; + } + + + m_lastPos = p; + m_lastTime = currentTime; +} + +void TrackBall::release(const QPointF& p, const QQuaternion &transformation) +{ + // Calling move() caused the rotation to stop if the framerate was too low. + move(p, transformation); + m_pressed = false; +} + +void TrackBall::start() +{ + m_lastTime = QTime::currentTime(); + m_paused = false; +} + +void TrackBall::stop() +{ + m_rotation = rotation(); + m_paused = true; +} + +QQuaternion TrackBall::rotation() const +{ + if (m_paused || m_pressed) + return m_rotation; + + QTime currentTime = QTime::currentTime(); + float angle = m_angularVelocity * m_lastTime.msecsTo(currentTime); + return QQuaternion::fromAxisAndAngle(m_axis, angle) * m_rotation; +} + -- cgit v1.2.3