QSGRendererInterface

An interface providing access to some of the graphics API specific internals of the scenegraph. More…

Inheritance diagram of PySide2.QtQuick.QSGRendererInterface

Synopsis

Virtual functions

Static functions

Detailed Description

Renderer interfaces allow accessing graphics API specific functionality in the scenegraph. Such internals are not typically exposed. However, when integrating custom rendering via QSGRenderNode for example, it may become necessary to query certain values, for instance the graphics device (e.g. the Direct3D or Vulkan device) that is used by the scenegraph.

QSGRendererInterface ‘s functions have varying availability. API and language queries, such as, graphicsApi() or shaderType() are always available, meaning it is sufficient to construct a QQuickWindow or QQuickView , and the graphics API or shading language in use can be queried right after via rendererInterface() . This guarantees that utilities like the GraphicsInfo QML type are able to report the correct values as early as possible, without having conditional property values - depending on for instance shaderType() - evaluate to unexpected values.

Engine-specific accessors, like getResource() , are however available only after the scenegraph is initialized. Additionally, there may be backend-specific limitations on when such functions can be called. The only way that is guaranteed to succeed is calling them when the rendering of a node (i.e. the preparation of the command list for the next frame) is active. In practice this typically means render() .

class PySide2.QtQuick.QSGRendererInterface
PySide2.QtQuick.QSGRendererInterface.GraphicsApi

Constant

Description

QSGRendererInterface.Unknown

An unknown graphics API is in use

QSGRendererInterface.Software

The Qt Quick 2D Renderer is in use

QSGRendererInterface.OpenGL

OpenGL ES 2.0 or higher

QSGRendererInterface.Direct3D12

Direct3D 12

QSGRendererInterface.OpenVG

OpenVG via EGL

QSGRendererInterface.OpenGLRhi

OpenGL ES 2.0 or higher via a graphics abstraction layer. This value was introduced in Qt 5.14.

QSGRendererInterface.Direct3D11Rhi

Direct3D 11 via a graphics abstraction layer. This value was introduced in Qt 5.14.

QSGRendererInterface.VulkanRhi

Vulkan 1.0 via a graphics abstraction layer. This value was introduced in Qt 5.14.

QSGRendererInterface.MetalRhi

Metal via a graphics abstraction layer. This value was introduced in Qt 5.14.

QSGRendererInterface.NullRhi

Null (no output) via a graphics abstraction layer. This value was introduced in Qt 5.14.
PySide2.QtQuick.QSGRendererInterface.Resource

Constant

Description

QSGRendererInterface.DeviceResource

The resource is a pointer to the graphics device, when applicable. For example, a VkDevice *, MTLDevice * or ID3D11Device *. Note that with Vulkan the returned value is a pointer to the VkDevice, not the handle itself. This is because Vulkan handles may not be pointers, and may use a different size from the architecture’s pointer size so merely casting to/from void * is wrong.

QSGRendererInterface.CommandQueueResource

The resource is a pointer to the graphics command queue used by the scenegraph, when applicable. For example, a VkQueue * or MTLCommandQueue *. Note that with Vulkan the returned value is a pointer to the VkQueue, not the handle itself.

QSGRendererInterface.CommandListResource

The resource is a pointer to the command list or buffer used by the scenegraph, when applicable. For example, a VkCommandBuffer * or MTLCommandBuffer *. This object has limited validity, and is only valid while the scene graph is preparing the next frame. Note that with Vulkan the returned value is a pointer to the VkCommandBuffer, not the handle itself.

QSGRendererInterface.PainterResource

The resource is a pointer to the active QPainter used by the scenegraph, when running with the software backend.

QSGRendererInterface.RhiResource

The resource is a pointer to the QRhi instance used by the scenegraph, when applicable. This value was introduced in Qt 5.14.

QSGRendererInterface.PhysicalDeviceResource

The resource is a pointer to the pysical device object used by the scenegraph, when applicable. For example, a VkPhysicalDevice *. Note that with Vulkan the returned value is a pointer to the VkPhysicalDevice, not the handle itself. This value was introduced in Qt 5.14.

QSGRendererInterface.OpenGLContextResource

The resource is a pointer to the QOpenGLContext used by the scenegraph (on the render thread), when applicable. This value was introduced in Qt 5.14.

QSGRendererInterface.DeviceContextResource

The resource is a pointer to the device context used by the scenegraph, when applicable. For example, a ID3D11DeviceContext *. This value was introduced in Qt 5.14.

QSGRendererInterface.CommandEncoderResource

The resource is a pointer to the currently active render command encoder object used by the scenegraph, when applicable. For example, a MTLRenderCommandEncoder *. This object has limited validity, and is only valid while the scene graph is recording a render pass for the next frame. This value was introduced in Qt 5.14.

QSGRendererInterface.VulkanInstanceResource

The resource is a pointer to the QVulkanInstance used by the scenegraph, when applicable. This value was introduced in Qt 5.14.

QSGRendererInterface.RenderPassResource

The resource is a pointer to the render pass used by the scenegraph, describing the color and depth/stecil attachments and how they are used. For example, a VkRenderPass *. This value was introduced in Qt 5.14.
PySide2.QtQuick.QSGRendererInterface.ShaderType

Constant

Description

QSGRendererInterface.UnknownShadingLanguage

Not yet known due to no window and scenegraph associated

QSGRendererInterface.GLSL

GLSL or GLSL ES

QSGRendererInterface.HLSL

HLSL

QSGRendererInterface.RhiShader

Consumes QShader instances containing shader variants for multiple target languages and intermediate formats. This value was introduced in Qt 5.14.
PySide2.QtQuick.QSGRendererInterface.ShaderCompilationType

Constant

Description

QSGRendererInterface.RuntimeCompilation

Runtime compilation of shader source code is supported

QSGRendererInterface.OfflineCompilation

Pre-compiled bytecode supported
PySide2.QtQuick.QSGRendererInterface.ShaderSourceType

Constant

Description

QSGRendererInterface.ShaderSourceString

Shader source can be provided as a string in the corresponding properties of ShaderEffect

QSGRendererInterface.ShaderSourceFile

Local or resource files containing shader source code are supported

QSGRendererInterface.ShaderByteCode

Local or resource files containing shader bytecode are supported
PySide2.QtQuick.QSGRendererInterface.getResource(window, resource)
Parameters:
Return type:

void

Queries a graphics resource in window . Returns null when the resource in question is not supported or not available.

When successful, the returned pointer is either a direct pointer to an interface (and can be cast, for example, to ID3D12Device * ) or a pointer to an opaque handle that needs to be dereferenced first (for example, VkDevice dev = *static_cast<VkDevice *>(result) ). The latter is necessary since such handles may have sizes different from a pointer.

Note

The ownership of the returned pointer is never transferred to the caller.

Note

This function must only be called on the render thread.

PySide2.QtQuick.QSGRendererInterface.getResource(window, resource)
Parameters:
Return type:

void

Queries a graphics resource. resource is a backend-specific key. This allows supporting any future resources that are not listed in the Resource enum.

Note

The ownership of the returned pointer is never transferred to the caller.

Note

This function must only be called on the render thread.

PySide2.QtQuick.QSGRendererInterface.graphicsApi()
Return type:

GraphicsApi

Returns the graphics API that is in use by the Qt Quick scenegraph.

Note

This function can be called on any thread.

static PySide2.QtQuick.QSGRendererInterface.isApiRhiBased(api)
Parameters:

api – GraphicsApi

Return type:

bool

Returns true if api is based on a graphics abstraction layer (QRhi) instead of directly calling the native graphics API.

Note

This function can be called on any thread.

PySide2.QtQuick.QSGRendererInterface.shaderCompilationType()
Return type:

ShaderCompilationTypes

Returns a bitmask of the shader compilation approaches supported by the Qt Quick backend the application is using.

Note

This function can be called on any thread.

See also

QtQuick::GraphicsInfo

PySide2.QtQuick.QSGRendererInterface.shaderSourceType()
Return type:

ShaderSourceTypes

Returns a bitmask of the supported ways of providing shader sources in ShaderEffect items.

Note

This function can be called on any thread.

See also

QtQuick::GraphicsInfo

PySide2.QtQuick.QSGRendererInterface.shaderType()
Return type:

ShaderType

Returns the shading language supported by the Qt Quick backend the application is using.

Note

This function can be called on any thread.

See also

QtQuick::GraphicsInfo