qt-everywhere-src-5.15.1/qtquick3d/src/quick3d/qquick3dcustomcamera.cpp

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#include "qquick3dcustomcamera_p.h"

#include <QtQuick3DRuntimeRender/private/qssgrendercamera_p.h>

#include <QtMath>
#include <QtQuick3DUtils/private/qssgutils_p.h>

#include "qquick3dutils_p.h"

QT_BEGIN_NAMESPACE

/*!
    \qmltype CustomCamera
    \inherits Camera
    \inqmlmodule QtQuick3D
    \brief Defines a Custom Camera for viewing the content of a 3D scene.

    A Camera is always necessary to view the content of a 3D scene. A camera
    defines how to project the content of a 3D scene into a 2D coordinate space,
    which can then be used on a 2D surface. When a camera is present in the scene
    it can be used to direct what is displayed in a View3D.

    To determine the projection of this camera a high level API is provided.
    First it is possible to position this Camera like any other spatial Node in
    the scene. This determines where the Camera is in the scene, and what
    direction it is facing. The default direction of the camera is such that the
    forward vector is looking up the +Z axis, and the up direction vector is up
    the +Y axis. With this in mind any transformation applied to the camera as
    well as the transformations inherited from it's parent Nodes you can define
    exactly where and in what direction your camera is facing.

    If you need full-control over how the projection matrix is created, this is the camera
    to use.

    \sa PerspectiveCamera, OrthographicCamera, FrustumCamera
*/

/*!
 * \internal
 */
QQuick3DCustomCamera::QQuick3DCustomCamera() {}

/*!
    \qmlproperty matrix4x4 CustomCamera::projection

    This property defines a custom projection matrix.
*/
QMatrix4x4 QQuick3DCustomCamera::projection() const
{
    return m_projection;
}

void QQuick3DCustomCamera::setProjection(const QMatrix4x4 &projection)
{
    if (m_projection == projection)
        return;

    m_projection = projection;
    emit projectionChanged();
    update();
}

bool QQuick3DCustomCamera::checkSpatialNode(QSSGRenderCamera *camera)
{
    camera->flags.setFlag(QSSGRenderNode::Flag::CameraCustomProjection, true);

    bool changed = false;
    changed |= qUpdateIfNeeded(camera->projection, m_projection);
    changed |= qUpdateIfNeeded(camera->enableFrustumClipping, frustumCullingEnabled());

    return changed;
}

QT_END_NAMESPACE