The QQuickTextureFactory class provides an interface for loading custom textures from QML. 更多...
| 头： | #include <QQuickTextureFactory> |
| qmake: | QT += quick |
| Since: | Qt 5.0 |
| 继承： | QObject |
| QQuickTextureFactory () | |
| virtual | ~QQuickTextureFactory () override |
| virtual QSGTexture * | createTexture (QQuickWindow * window ) const = 0 |
| virtual QImage | image () const |
| virtual int | textureByteCount () const = 0 |
| virtual QSize | textureSize () const = 0 |
| const QMetaObject | staticMetaObject |
| QQuickTextureFactory * | textureFactoryForImage (const QImage & image ) |
The QQuickTextureFactory class provides an interface for loading custom textures from QML.
The purpose of the texture factory is to provide a placeholder for a image data that can be converted into an OpenGL texture.
Creating a texture directly is not possible as there is rarely an OpenGL context available in the thread that is responsible for loading the image data.
Constructs a texture factory. Since QQuickTextureFactory is abstract, it cannot be instantiated directly.
[override virtual]
QQuickTextureFactory::
~QQuickTextureFactory
()
Destroys the texture factory.
[pure virtual]
QSGTexture
*QQuickTextureFactory::
createTexture
(
QQuickWindow
*
window
) const
This function is called on the scene graph rendering thread to create a QSGTexture instance from the factory. window provides the context which this texture is created in.
QML will internally cache the returned texture as needed. Each call to this function should return a unique instance.
The OpenGL context used for rendering is bound when this function is called.
[虚拟]
QImage
QQuickTextureFactory::
image
() const
Returns an image version of this texture.
The lifespan of the returned image is unknown, so the implementation should return a self contained QImage , not make use of the QImage (uchar *, ...) constructor.
This function is not commonly used and is expected to be slow.
[pure virtual]
int
QQuickTextureFactory::
textureByteCount
() const
Returns the number of bytes of memory the texture consumes.
[static]
QQuickTextureFactory
*QQuickTextureFactory::
textureFactoryForImage
(const
QImage
&
image
)
返回 QQuickTextureFactory holding the given image .
This is typically used as a helper in QQuickImageResponse::textureFactory .
该函数在 Qt 5.6 引入。
[pure virtual]
QSize
QQuickTextureFactory::
textureSize
() const
Returns the size of the texture. This function will be called from arbitrary threads and should not rely on an OpenGL context bound.