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| |
| #include "trackball.h" |
| #include "scene.h" |
| |
| //============================================================================// |
| // TrackBall // |
| //============================================================================// |
| |
| TrackBall::TrackBall(TrackMode mode) |
| : TrackBall(0, QVector3D(0, 1, 0), mode) |
| { |
| } |
| |
| TrackBall::TrackBall(float angularVelocity, const QVector3D& axis, TrackMode mode) |
| : m_axis(axis) |
| , m_angularVelocity(angularVelocity) |
| , m_mode(mode) |
| {} |
| |
| 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); |
| const float angleDelta = qRadiansToDegrees(float(delta.length())); |
| m_angularVelocity = angleDelta / msecs; |
| m_axis = QVector3D(-delta.dy(), delta.dx(), 0.0f).normalized(); |
| m_axis = transformation.rotatedVector(m_axis); |
| m_rotation = QQuaternion::fromAxisAndAngle(m_axis, angleDelta) * 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(std::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(std::sqrt(sqrZ)); |
| else |
| currentPos3D.normalize(); |
| |
| m_axis = QVector3D::crossProduct(lastPos3D, currentPos3D); |
| float angle = qRadiansToDegrees(std::asin(m_axis.length())); |
| |
| 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; |
| } |
| |