内容

• 公共类型
• 公共函数
• 详细描述

QSGEngine Class

QSGEngine class allows low level rendering of a scene graph. 更多...

头：	#include <QSGEngine>
qmake:	QT += quick
Since:	Qt 5.4
继承：	QObject

• 所有成员列表，包括继承成员

公共类型

enum	CreateTextureOption { TextureHasAlphaChannel, TextureOwnsGLTexture, TextureCanUseAtlas, TextureIsOpaque }
flags	CreateTextureOptions

公共函数

	QSGEngine (QObject * parent = Q_NULLPTR)
	~QSGEngine ()
QSGImageNode *	createImageNode () const
QSGNinePatchNode *	createNinePatchNode () const
QSGRectangleNode *	createRectangleNode () const
QSGAbstractRenderer *	createRenderer () const
QSGTexture *	createTextureFromId (uint id , const QSize & size , CreateTextureOptions options = CreateTextureOption()) const
QSGTexture *	createTextureFromImage (const QImage & image , CreateTextureOptions options = CreateTextureOption()) const
void	initialize (QOpenGLContext * context )
void	invalidate ()
QSGRendererInterface *	rendererInterface () const

• 32 公共函数继承自 QObject

额外继承成员

• 1 特性继承自 QObject
• 1 公共槽继承自 QObject
• 2 信号继承自 QObject
• 11 静态公共成员继承自 QObject
• 9 保护函数继承自 QObject

详细描述

QSGEngine class allows low level rendering of a scene graph.

A QSGEngine can be used to render a tree of QSGNode directly on a QWindow or QOpenGLFramebufferObject without any integration with QML, QQuickWindow or QQuickItem and the convenience that they provide.

This means that you must handle event propagation, animation timing, and node lifetime yourself.

注意： This class is for very low level access to an independent scene graph. Most of the time you will instead want to subclass QQuickItem and insert your QSGNode in a normal QtQuick scene by overriding QQuickItem::updatePaintNode ().

另请参阅 QSGAbstractRenderer .

成员类型文档编制

enum QSGEngine:: CreateTextureOption
flags QSGEngine:: CreateTextureOptions

The CreateTextureOption enums are used to customize how a texture is wrapped.

常量	值	描述
QSGEngine::TextureHasAlphaChannel	0x0001	The texture has an alpha channel and should be drawn using blending.
QSGEngine::TextureOwnsGLTexture	0x0004	The texture object owns the texture id and will delete the GL texture when the texture object is deleted.
QSGEngine::TextureCanUseAtlas	0x0008	The image can be uploaded into a texture atlas.
QSGEngine::TextureIsOpaque	0x0010	The texture object is opaque.

The CreateTextureOptions type is a typedef for QFlags <CreateTextureOption>. It stores an OR combination of CreateTextureOption values.

成员函数文档编制

QSGEngine:: QSGEngine ( QObject * parent = Q_NULLPTR)

构造新的 QSGEngine with its parent

QSGEngine:: ~QSGEngine ()

Destroys the engine

QSGImageNode *QSGEngine:: createImageNode () const

Creates a simple image node. When the scenegraph is not initialized, the return value is null.

This is cross-backend alternative to constructing a QSGSimpleTextureNode directly.

该函数在 Qt 5.8 引入。

另请参阅 QSGImageNode .

QSGNinePatchNode *QSGEngine:: createNinePatchNode () const

Creates a nine patch node. When the scenegraph is not initialized, the return value is null.

该函数在 Qt 5.8 引入。

QSGRectangleNode *QSGEngine:: createRectangleNode () const

Creates a simple rectangle node. When the scenegraph is not initialized, the return value is null.

This is cross-backend alternative to constructing a QSGSimpleRectNode directly.

该函数在 Qt 5.8 引入。

另请参阅 QSGRectangleNode .

QSGAbstractRenderer *QSGEngine:: createRenderer () const

Returns a renderer that can be used to render a QSGNode tree

You call initialize () first with the QOpenGLContext that you want to use with this renderer. This will return a null renderer otherwise.

QSGTexture *QSGEngine:: createTextureFromId ( uint id , const QSize & size , CreateTextureOptions options = CreateTextureOption()) const

Creates a texture object that wraps the GL texture id uploaded with size

Valid options are TextureHasAlphaChannel and TextureOwnsGLTexture

The caller takes ownership of the texture object and the texture should only be used with this engine.

另请参阅 createTextureFromImage (), QSGSimpleTextureNode::setOwnsTexture ()，和 QQuickWindow::createTextureFromId ().

QSGTexture *QSGEngine:: createTextureFromImage (const QImage & image , CreateTextureOptions options = CreateTextureOption()) const

Creates a texture using the data of image

Valid options are TextureCanUseAtlas and TextureIsOpaque .

The caller takes ownership of the texture and the texture should only be used with this engine.

另请参阅 createTextureFromId (), QSGSimpleTextureNode::setOwnsTexture ()，和 QQuickWindow::createTextureFromImage ().

void QSGEngine:: initialize ( QOpenGLContext * context )

Initialize the engine with context .

警告： You have to make sure that you call QOpenGLContext::makeCurrent () 在 context before calling this.

void QSGEngine:: invalidate ()

Invalidate the engine releasing its resources

You will have to call initialize () 和 createRenderer () if you want to use it again.

QSGRendererInterface *QSGEngine:: rendererInterface () const

Returns the current renderer interface if there is one. Otherwise null is returned.

该函数在 Qt 5.8 引入。

另请参阅 QSGRenderNode and QSGRendererInterface .