Struct qt_3d_render::QBufferDataGenerator

#[repr(C)]pub struct QBufferDataGenerator { /* fields omitted */ }

Provides a mechanism to generate buffer data from a job.

C++ class: Qt3DRender::QBufferDataGenerator.

C++ documentation:

Provides a mechanism to generate buffer data from a job.

The Qt3DRender::QBufferDataGenerator should be subclassed to provide a way to fill the data of a Qt3DRender::QBuffer. Such functors are executed at runtime in a Qt 3D job (likely in parallel with many other jobs). When providing a functor you must implement the operator() which will be called to generate the actual data. You must make sure that you have stored copies of anything you might need for it to execute properly. You should also implement the operator==. It will be used to compare with other functors and based on that allow the renderer to decide if a new functor should be executed or not.

Note: functors are useful when you can build data from a few set of attributes (e.g: building a sphere from a radius property). If you already have access to the buffer data, using Qt3DRender::QBuffer::setData() is likely more efficient.

QByteArray createSphereMeshVertexData(float radius, int rings, int slices)
{
      ...
}
class SphereVertexDataFunctor : public QBufferDataGenerator
{
public:
      SphereVertexDataFunctor(int rings, int slices, float radius)
          : m_rings(rings)
          , m_slices(slices)
          , m_radius(radius)
      {}
      QByteArray operator ()() Q_DECL_OVERRIDE
      {
          return createSphereMeshVertexData(m_radius, m_rings, m_slices);
      }
      bool operator ==(const QBufferDataGenerator &other) const Q_DECL_OVERRIDE
      {
          const SphereVertexDataFunctor *otherFunctor = functor_cast<SphereVertexDataFunctor>(&other);
          if (otherFunctor != nullptr)
              return (otherFunctor->m_rings == m_rings &&
                      otherFunctor->m_slices == m_slices &&
                      otherFunctor->m_radius == m_radius);
          return false;
      }
      QT3D_FUNCTOR(SphereVertexDataFunctor)
private:
      int m_rings;
      int m_slices;
      float m_radius;
};

The QT3D_FUNCTOR macro should be added when subclassing. This allows you to use functor_cast in your comparison operator to make sure that the other functor is of the same type as the one your are trying to compare against.

Methods

impl QBufferDataGenerator

pub unsafe fn call(&self) -> CppBox<QByteArray>

Should be implemented to return the buffer data as a QByteArray when called.

Calls C++ function: pure virtual QByteArray Qt3DRender::QBufferDataGenerator::operator()().

C++ documentation:

Should be implemented to return the buffer data as a QByteArray when called.

Methods from Deref<Target = QAbstractFunctor>

pub unsafe fn id(&self) -> isize

Returns a pointer to the id of the functor.

Calls C++ function: pure virtual qintptr Qt3DRender::QAbstractFunctor::id() const.

C++ documentation:

Returns a pointer to the id of the functor.

Trait Implementations

impl CppDeletable for QBufferDataGenerator

unsafe fn delete(&self)

Destroys the instance of QBufferDataGenerator. The destructor is virtual.

Calls C++ function: virtual [destructor] void Qt3DRender::QBufferDataGenerator::~QBufferDataGenerator().

C++ documentation:

Destroys the instance of QBufferDataGenerator. The destructor is virtual.

impl Deref for QBufferDataGenerator

type Target = QAbstractFunctor

The resulting type after dereferencing.

fn deref(&self) -> &QAbstractFunctor

Calls C++ function: Qt3DRender::QAbstractFunctor* static_cast<Qt3DRender::QAbstractFunctor*>(Qt3DRender::QBufferDataGenerator* ptr).

impl DynamicCast<QBufferDataGenerator> for QAbstractFunctor

unsafe fn dynamic_cast(ptr: Ptr<QAbstractFunctor>) -> Ptr<QBufferDataGenerator>

Calls C++ function: Qt3DRender::QBufferDataGenerator* dynamic_cast<Qt3DRender::QBufferDataGenerator*>(Qt3DRender::QAbstractFunctor* ptr).

impl PartialEq<Ref<QBufferDataGenerator>> for QBufferDataGenerator

fn eq(&self, other: &Ref<QBufferDataGenerator>) -> bool

Should be reimplemented to return true when two generators (the one you are comparing against and the other generator) are identical, false otherwise.

Calls C++ function: pure virtual bool Qt3DRender::QBufferDataGenerator::operator==(const Qt3DRender::QBufferDataGenerator& other) const.

C++ documentation:

Should be reimplemented to return true when two generators (the one you are comparing against and the other generator) are identical, false otherwise.

Note: The renderer uses this comparison to decide whether data for a buffer needs to be reuploaded or not when the functor on a Qt3DRender::QBuffer changes.

#[must_use]fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl StaticDowncast<QBufferDataGenerator> for QAbstractFunctor

unsafe fn static_downcast(
    ptr: Ptr<QAbstractFunctor>
) -> Ptr<QBufferDataGenerator>

Calls C++ function: Qt3DRender::QBufferDataGenerator* static_cast<Qt3DRender::QBufferDataGenerator*>(Qt3DRender::QAbstractFunctor* ptr).

impl StaticUpcast<QAbstractFunctor> for QBufferDataGenerator

unsafe fn static_upcast(ptr: Ptr<QBufferDataGenerator>) -> Ptr<QAbstractFunctor>

Calls C++ function: Qt3DRender::QAbstractFunctor* static_cast<Qt3DRender::QAbstractFunctor*>(Qt3DRender::QBufferDataGenerator* ptr).