QQuickFramebufferObject ¶

概要 ¶

详细描述 ¶

On most platforms, the rendering will occur on a dedicated thread . For this reason, the QQuickFramebufferObject class enforces a strict separation between the item implementation and the FBO rendering. All item logic, such as properties and UI-related helper functions needed by QML should be located in a QQuickFramebufferObject class subclass. Everything that relates to rendering must be located in the Renderer 类。

警告

This class is only functional when Qt Quick is rendering via OpenGL, either directly or through the RHI-based rendering path . It is not compatible with other RHI backends, such as, Vulkan or Metal.

To avoid race conditions and read/write issues from two threads it is important that the renderer and the item never read or write shared variables. Communication between the item and the renderer should primarily happen via the synchronize() function. This function will be called on the render thread while the GUI thread is blocked.

Using queued connections or events for communication between item and renderer is also possible.

Both the Renderer and the FBO are memory managed internally.

To render into the FBO, the user should subclass the Renderer class and reimplement its render() function. The Renderer subclass is returned from createRenderer() .

The size of the FBO will by default adapt to the size of the item. If a fixed size is preferred, set textureFollowsItemSize to false and return a texture of your choosing from createFramebufferObject() .

Starting Qt 5.4, the QQuickFramebufferObject class is a texture provider and can be used directly in ShaderEffects and other classes that consume texture providers.

另请参阅

场景图形 - 渲染 FBO (帧缓冲对象) 场景图形和渲染

class QQuickFramebufferObject ( [ parent=None ] ) ¶

param parent

QQuickItem

构造新 QQuickFramebufferObject 采用父级 parent .

PySide2.QtQuick.QQuickFramebufferObject. createRenderer ( ) ¶

返回类型

Renderer

Reimplement this function to create a renderer used to render into the FBO.

This function will be called on the rendering thread while the GUI thread is blocked.

PySide2.QtQuick.QQuickFramebufferObject. mirrorVertically ( ) ¶

返回类型

bool

另请参阅

setMirrorVertically()

PySide2.QtQuick.QQuickFramebufferObject. mirrorVerticallyChanged ( arg__1 ) ¶

参数

arg__1 – bool

PySide2.QtQuick.QQuickFramebufferObject. setMirrorVertically ( enable ) ¶

参数

enable – bool

另请参阅

mirrorVertically()

PySide2.QtQuick.QQuickFramebufferObject. setTextureFollowsItemSize ( follows ) ¶

参数

follows – bool

另请参阅

textureFollowsItemSize()

PySide2.QtQuick.QQuickFramebufferObject. textureFollowsItemSize ( ) ¶

返回类型

bool

另请参阅

setTextureFollowsItemSize()

PySide2.QtQuick.QQuickFramebufferObject. textureFollowsItemSizeChanged ( arg__1 ) ¶

参数

arg__1 – bool