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Diffstat (limited to 'src/imports/threed/qgraphicslookattransform.cpp')
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diff --git a/src/imports/threed/qgraphicslookattransform.cpp b/src/imports/threed/qgraphicslookattransform.cpp deleted file mode 100644 index e3772b94..00000000 --- a/src/imports/threed/qgraphicslookattransform.cpp +++ /dev/null @@ -1,517 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). -** All rights reserved. -** Contact: Nokia Corporation ([email protected]) -** -** This file is part of the QtQuick3D module 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 "qgraphicslookattransform.h" -#include "qgraphicsrotation3d.h" -#include <QtCore/qmath.h> - -QT_BEGIN_NAMESPACE - -/*! - \class QGraphicsLookAtTransform - \brief The QGraphicsLookAtTransform class implements a transformation - that causes an Item3D to orient to face another Item3D. - \since 4.8 - \ingroup qt3d - \ingroup qt3d::graphicsview - - Sometimes it can be useful to make an object face towards another object, - wherever it might be located. This is useful for objects like cameras, - lights, arrows, faces etc. - - Another common use is called "billboarding", where a quad is always - oriented to face the camera. -*/ - -/*! - \qmlclass LookAtTransform QGraphicsLookAtTransform - \brief The LookAtTransform item implements a transformation that causes objects to face the camera. - \since 4.8 - \ingroup qt3d::qml3d - - Sometimes it can be useful to make an object face towards another object, - wherever it might be located. This is useful for objects like cameras, - lights, arrows, faces etc. - - Another common use is called "billboarding", where a quad is always - oriented to face the camera. In QML, this can be achieved as follows: - - \code - Camera3D camera - Item3D { - mesh: Mesh { source: "pane.obj" } - position: Qt.vector3d(2, 0, -20) - transform: LookAtTransform { worldPosition - camera.worldPosition } - effect: Effect { texture: "picture.jpg" } - } - \endcode - - Because the lookAt transformation will override many other transformations - ont the matrix, it will usually be the last element in the \c transform - list (transformations are applied to the matrix in reverse order of their - appearance in \c transform): - - \code - Item3D { - mesh: Mesh { source: "pane.obj" } - position: Qt.vector3d(2, 0, -20) - transform: [ - Scale3D { scale: 0.5 }, - Rotation3D { angle: 30 }, - LookAtTransform { worldPosition - camera.worldPosition } - ] - effect: Effect { texture: "picture.jpg" } - } - \endcode - - Typically, orientation as well as facing is important. For example, a face - that does not remain basically upright will look very odd indeed as it - tracks a subject. The lookAt transform will always rotate first around the - local y axis, and secondarily around the local x axis, around an origin of - (0,0,0). - - If rotation around a different axis or origin is desired, place the - Item3D to be rotated inside a new parent Item3D. Apply rotations the - and translations to the original Item3D such that the desired "front" - matches the new parent Item3d's positive z direction and the left to right - matches the parent's x-axis, and then apply the LookAt transform to the - new parent item. - - \code - Item3D { - position: Qt.vector3d(0,0,4) - transform: LookAt { subject: subjectPenguin } - - Item3D { - id: lookAwayMonkey - mesh: Mesh { source: "meshes/monkey.3ds" } - transform: Rotation3D { axis: Qt.vector3d(0,1,0); angle: 180 } - } - } - \endcode - - By default the LookAt transform will cause the object to - face directly at the subject no matter how the world co-ordinate - system is rotated. Sometimes it is useful to limit the lookAt to only - one axis of rotation - for example, a tank with a turret and barrel that - each have only one degree of freedom. - This is achieved by using the preserveUpVector property: - - \code - Pane { - position: Qt.vector3d(2, 0, -20) - transform: LookAtTransform { preserveUpVector: true } - effect: Effect { texture: "picture.jpg" } - } - \endcode -*/ - -/*! - \internal -*/ -static QMatrix4x4* cheatingSphericalBillboard(QMatrix4x4 *matrix) -{ - // Replace the top-left 3x3 of the matrix with the identity. - // The technique is "Cheating Spherical Billboards", described here: - // http://www.lighthouse3d.com/opengl/billboarding/index.php?billCheat - (*matrix)(0, 0) = 1.0f; - (*matrix)(0, 1) = 0.0f; - (*matrix)(0, 2) = 0.0f; - (*matrix)(1, 0) = 0.0f; - (*matrix)(1, 1) = 1.0f; - (*matrix)(1, 2) = 0.0f; - (*matrix)(2, 0) = 0.0f; - (*matrix)(2, 1) = 0.0f; - (*matrix)(2, 2) = 1.0f; - - return matrix; -}; - -/*! - \internal -*/ -static QMatrix4x4* cheatingCylindricalBillboard(QMatrix4x4 *matrix) -{ - // Replace some of the top-left 3x3 of the matrix with the identity, - // but leave the up vector component in the second column as-is. - // The technique is "Cheating Cylindrical Billboards", described here: - // http://www.lighthouse3d.com/opengl/billboarding/index.php?billCheat1 - (*matrix)(0, 0) = 1.0f; - (*matrix)(0, 2) = 0.0f; - (*matrix)(1, 0) = 0.0f; - (*matrix)(1, 2) = 0.0f; - (*matrix)(2, 0) = 0.0f; - (*matrix)(2, 2) = 1.0f; - - return matrix; -}; - -#define RADS_TO_DEGREES (180.0 / M_PI) - -struct LookAtRotationCache { - QGraphicsRotation3D primaryRotation; - QGraphicsRotation3D secondaryRotation; -}; - -class QGraphicsLookAtTransformPrivate -{ -public: - QGraphicsLookAtTransformPrivate(QGraphicsLookAtTransform* _lookAt); - QGraphicsLookAtTransform* lookAt; - void determineOriginItem(); - void calculateRotationValues() const; - QVector3D relativePosition(QDeclarativeItem3D* originItem, QDeclarativeItem3D* subject) const; - - bool preserveUpVector; - QDeclarativeItem3D* originItem; - QDeclarativeItem3D* subject; - mutable LookAtRotationCache rotationCache; - mutable bool rotationCacheDirty; - -}; - -QGraphicsLookAtTransformPrivate::QGraphicsLookAtTransformPrivate(QGraphicsLookAtTransform* _lookAt) : - lookAt(_lookAt), preserveUpVector(false), originItem(0), subject(0) -{ -} - -void QGraphicsLookAtTransformPrivate::determineOriginItem() -{ - QObject* workingObject = lookAt->parent(); - while (qobject_cast<QDeclarativeItem3D*>(workingObject) == 0 && - workingObject != 0) - { - workingObject = workingObject->parent(); - } - - originItem = qobject_cast<QDeclarativeItem3D*>(workingObject); - if (!originItem) - qWarning() << "LookAt transform requires an Item3D ancestor"; -} - -QVector3D QGraphicsLookAtTransformPrivate::relativePosition(QDeclarativeItem3D* originItem, QDeclarativeItem3D* subject) const -{ - QVector3D result = originItem->worldToLocal(subject->localToWorld()); - return result; - -} - -/*! \internal - Calculate the actual rotation values for the transform. - - Note this function has to be const to be called within applyTo(), but - modifies the mutable rotationCache and rotationCacheDirty values. -*/ -void QGraphicsLookAtTransformPrivate::calculateRotationValues() const -{ - QVector3D forwards(0, 0, 1); - rotationCache.primaryRotation.setAngle(0); - rotationCache.secondaryRotation.setAngle(0); - rotationCacheDirty = false; - - if (subject == 0 || originItem == 0) - { - if (subject == 0) - qWarning() << "LookAt transform got null subject"; - if (originItem == 0) - qWarning() << "LookAt transform got null originItem"; - rotationCache.primaryRotation.setAxis(QVector3D(0,1,0)); - rotationCache.primaryRotation.setAngle(0); - rotationCache.secondaryRotation.setAxis(QVector3D(1,0,0)); - rotationCache.secondaryRotation.setAngle(0); - return; - } - - // Calculate the lookat vector in the local frame: - QVector3D relativePositionVector = relativePosition(originItem, subject); - - // Project the relative position into the xz plane: - QVector3D subjectProjection = relativePositionVector; - subjectProjection.setY(0); - subjectProjection.normalize(); - QVector3D primaryRotationAxis; - - if (!subjectProjection.isNull()) - { - primaryRotationAxis = QVector3D::crossProduct(forwards, subjectProjection); - // Fix rotational axis for positions along z axis - if (primaryRotationAxis.length() == 0) - { - primaryRotationAxis = QVector3D(0,1,0); - } - - qreal angleCosine = - QVector3D::dotProduct(forwards, subjectProjection); - qreal angle = qAcos(angleCosine); - - rotationCache.primaryRotation.setAxis(primaryRotationAxis); - rotationCache.primaryRotation.setAngle(angle * RADS_TO_DEGREES ); - } else { - // Target is directly above or below, so zero primary rotation - rotationCache.primaryRotation.setAxis(QVector3D(0,1,0)); - rotationCache.primaryRotation.setAngle(0); - } - - relativePositionVector.normalize(); - - qreal secondaryAngleCosine = QVector3D::dotProduct( subjectProjection, - relativePositionVector); - // Sanity check in case of rounding errors - if (secondaryAngleCosine <= 1.0 && secondaryAngleCosine >= -1.0) - { - if (relativePositionVector.y() < 0) - rotationCache.secondaryRotation.setAxis(QVector3D(1,0,0)); - else - rotationCache.secondaryRotation.setAxis(QVector3D(-1,0,0)); - rotationCache.secondaryRotation.setAngle(qAcos(secondaryAngleCosine)*RADS_TO_DEGREES); - } else { - rotationCache.secondaryRotation.setAxis(QVector3D(1,0,0)); - rotationCache.secondaryRotation.setAngle(0.0); - } -} - -/*! - Construct a lookAt transform and attach it to \a parent. -*/ -QGraphicsLookAtTransform::QGraphicsLookAtTransform(QObject *parent) - : QGraphicsTransform3D(parent), d_ptr(new QGraphicsLookAtTransformPrivate(this)) -{ -} - -/*! - Destroy this lookAt transform. -*/ -QGraphicsLookAtTransform::~QGraphicsLookAtTransform() -{ -} - -/*! - \property QGraphicsLookAtTransform::preserveUpVector - \brief true to preserve the up orientation. - - This property indicates whether the transform should rotate around a second - axis to face directly at the subject (when the subject is the camera, this - is known as "spherical billboarding"). - - If the value for this property is true, then the object will have - its up vector's orientation preserved, rotating around only the y-axis and - not directly facing the subject unless it happens to fall on the correct - plane (when the subject is the camera, this is known as known as - "cylindrical billboarding"). - - The default value for this property is false. -*/ - -/*! - \qmlproperty bool LookatTransform::preserveUpVector - - This property indicates whether the transform should rotate around a second - axis to face directly at the subject (known as a "spherical look-at"). - - If the value for this property is true, then the object will have - its y-axis' orientation preserved, rotating around only this axis and - not directly facing the subject unless it happens to fall on the correct - plane (known as a "cylindrical look-at"). - - The default value for this property is false. -*/ - -bool QGraphicsLookAtTransform::preserveUpVector() const -{ - Q_D(const QGraphicsLookAtTransform); - return d->preserveUpVector; -} - -void QGraphicsLookAtTransform::setPreserveUpVector(bool value) -{ - Q_D(QGraphicsLookAtTransform); - if (d->preserveUpVector != value) { - d->preserveUpVector = value; - d->rotationCacheDirty = true; - emit preserveUpVectorChanged(); - emit transformChanged(); - } -} - -/*! - \property QGraphicsLookAtTransform::subject - \brief The local-relative coordinates that are being looked at - - This property indicates what this transform is trying to look at. After - applying the transformation. - - Forwards is always considered to be in the direction of the positive z axis - in local space, and up is always considered to be the positive y axis, and - rotation is always around the position (0,0,0) in local space (although - any values can be emulated by applying the LookAt transformation to a - parent Item3D, and then applying transformations relative to that parent). - - If no subject is set, no transformation is applied. -*/ - -/*! - \qmlproperty bool LookatTransform::preserveUpVector - - This property indicates whether the transform should rotate around a second - axis to face directly at the subject (known as a "spherical look-at"). - - If the value for this property is true, then the object will have - its y-axis' orientation preserved, rotating around only this axis and - not directly facing the subject unless it happens to fall on the correct - plane (when the subject is the camera, this is known as a - "cylindrical look-at"). - - The default value for this property is false. -*/ - -/*! - \fn void QGraphicsLookAtTransform::subjectChanged() - - Signal that is emitted when subject() changes. -*/ - - -QDeclarativeItem3D* QGraphicsLookAtTransform::subject() const -{ - Q_D(const QGraphicsLookAtTransform); - return d->subject; -} - -void QGraphicsLookAtTransform::setSubject(QDeclarativeItem3D* value) -{ - Q_D(QGraphicsLookAtTransform); - if (d->subject != value) - { - // Listen for changes on the subject and it's ancestors that mean the - // lookAt transform needs to be recalculated - disconnect(this, SLOT(subjectPositionChanged())); - d->subject = value; - QDeclarativeItem3D* ancestorItem = d->subject; - while (ancestorItem != 0) - { - // listen for changes directly on the item, changes on it's - // transforms property, or through reparenting - connect(ancestorItem, SIGNAL(positionChanged()), this, SLOT(subjectPositionChanged())); - connect(ancestorItem, SIGNAL(rotationChanged()), this, SLOT(subjectPositionChanged())); - connect(ancestorItem, SIGNAL(scaleChanged()), this, SLOT(subjectPositionChanged())); - connect(ancestorItem, SIGNAL(parentChanged()), this, SLOT(ancestryChanged())); - QDeclarativeListProperty<QGraphicsTransform3D> transforms = - ancestorItem->transform(); - - for (int i=0; i < transforms.count(&transforms) ; i++) - { - QGraphicsTransform3D* transform = transforms.at(&transforms, i); - connect(transform, SIGNAL(transformChanged()), - this, SLOT(subjectPositionChanged())); - } - - ancestorItem = qobject_cast<QDeclarativeItem3D*> (ancestorItem->parent()); - }; - - d->rotationCacheDirty = true; - d->determineOriginItem(); - emit subjectChanged(); - emit transformChanged(); - } -}; - -void QGraphicsLookAtTransform::subjectPositionChanged() -{ - Q_D(QGraphicsLookAtTransform); - d->rotationCacheDirty = true; -} - -void QGraphicsLookAtTransform::ancestryChanged() -{ - Q_D(QGraphicsLookAtTransform); - d->determineOriginItem(); - d->rotationCacheDirty = true; -} - -/*! - \internal -*/ -void QGraphicsLookAtTransform::applyTo(QMatrix4x4 *matrix) const -{ - Q_D(const QGraphicsLookAtTransform); - bool cameraTest = false; - bool animationTest = false; - // If we're looking at the camera, and not animating, - // we can use a cheap cheat - if (cameraTest && !animationTest) - { - if (!d->preserveUpVector) - cheatingSphericalBillboard(matrix); - else - cheatingCylindricalBillboard(matrix); - matrix->optimize(); - return; - } - - if (d->rotationCacheDirty) - d->calculateRotationValues(); - - d->rotationCache.primaryRotation.applyTo(matrix); - // then, if preserveVector is not set, perform a second rotation - // around the x-axis - if (!preserveUpVector()) - d->rotationCache.secondaryRotation.applyTo(matrix); -} - -/*! - \internal -*/ -QGraphicsTransform3D *QGraphicsLookAtTransform::clone(QObject *parent) const -{ - Q_D(const QGraphicsLookAtTransform); - QGraphicsLookAtTransform *copy = new QGraphicsLookAtTransform(parent); - copy->setPreserveUpVector(d->preserveUpVector); - copy->setSubject(d->subject); - return copy; -} - -/*! - \fn void QGraphicsLookAtTransform::preserveUpVectorChanged() - - Signal that is emitted when preserveUpVector() changes. -*/ - -QT_END_NAMESPACE |