QtDisplayWidget Class Reference

#include <ImFusion/GUI/QtDisplayWidget.h>

Specialization of a QOpenGLWidget that allows for rendering the contents of a Display into a QtWidget-based application. More...

Inheritance diagram for QtDisplayWidget:

Detailed Description

Specialization of a QOpenGLWidget that allows for rendering the contents of a Display into a QtWidget-based application.

Warning

Make sure you understand and follow the constraints/expected class invariants regarding the used OpenGL contexts by both the ImFusion SDK and by QOpenGLWidget described below. In any case you must make sure that OpenGL context sharing is enabled between the ImFusion context and the used Qt context!

The underlying QOpenGLWidget will always create its own OpenGL context and expect all rendering happen in there. This complicates integration to some extent because the ImFusion SDK also maintains its own context for the main thread in which it expects the main OpenGL objects to reside and the rendering to happen. Therefore, QtDisplayWidget provides two different RenderModes:

• UseImFusionContext (recommended as default):
  This mode will conduct the rendering in the main context of the ImFusion SDK and therefore temporarily switch away from the Qt context in paintGL(). This simplifies the initialization of OpenGL resources since you can simply instantiate the Display and all Views in the main thread on that main context.
• UseQOpenGLWidgetContext:
  This mode will conduct the rendering in the context created internally by the QOpenGLWidget as it is designed/intended by Qt. However, it has the drawback that this context is only created after construction of QtDisplayWidget. Therefore you must create all OpenGL resources used by the Display (i.e. its views) only in initializeGL() or in the signalGLContextInitialized callback.

Either way, you must make sure that OpenGL context sharing is enabled between the ImFusion context and the Qt context(s). We recommend the following approach for this:

// enable GL context sharing across all contexts managed by Qt
QGuiApplication::setAttribute(Qt::AA_ShareOpenGLContexts);
QSurfaceFormat::setDefaultFormat(...); // use a format that is compatible with `glCreateInfo` below
QApplication app(argc, argv);
[...]
 
// initialize the ImFusion SDK with the shared OpenGL context from above
Framework::InitConfig sdkInitConfig;
sdkInitConfig.glContext = std::make_unique<GlContextQt>(0, 0, false, QOpenGLContext::globalShareContext());
Framekwork::init(std::move(sdkInitConfig));

Once the context sharing is configured correctly, the creation of QtDisplayWidget is straight-forward:

// create and configure the Display
GUI::Display display;
[...]
 
// create the QtDisplayWidget wrapper and add it to your window:
GUI::QtDisplayWidget* displayQt = new GUI::QtDisplayWidget(display);
myQLayout->addWidget(displayQt);

See also

QtDisplayWindow

Public Types
enum class	RenderMode { UseImFusionContext , UseQOpenGLWidgetContext }
	Enumeration to define in which OpenGL context to conduct the rendering of the display (see class docstring for details). More...

Public Member Functions
	QtDisplayWidget (Display &display, QWidget *parent=nullptr, RenderMode renderContext=RenderMode::UseImFusionContext)
	Create a new QtDisplayWidget showing the given display.
bool	event (QEvent *event) override
bool	eventFilter (QObject *obj, QEvent *event) override
QPointF	mapToGlobal (const QPointF &pos) const final override
	Implementations shall forward to Qt's mapToGlobal() function of the wrapper class.
Public Member Functions inherited from QtDisplayWrapperBase
	QtDisplayWrapperBase (Display &display)
	Constructor will subscribe to the Display::signalUpdateRequested signal.
Display &	display ()
	Returns the Display shown by this widget.
QPointF	mapFromOpenGL (const vec2 &point) const
	Converts point from ImFusion::GUI's bottom-left-origin coordinates to Qt's top-left-origin coordinates.
vec2	mapToOpenGL (const QPointF &point) const
	Converts point from Qt's top-left-origin coordinates to ImFusion::GUI's bottom-left-origin coordinates.
Public Member Functions inherited from SignalReceiver
	SignalReceiver ()=default
	Default constructor.
	SignalReceiver (const SignalReceiver &other)
	Copy constructor, does not copy any existing signal connections from other.
SignalReceiver &	operator= (SignalReceiver rhs)
	Assignment operator, disconnects all existing connections, does not copy any existing signal connections from rhs.
virtual	~SignalReceiver ()
	Virtual destructor disconnects from all connected signals.

Public Attributes
Signal	signalGLContextInitialized
	Signal emitted during initializeGL() to allow for the initialization of GL resources without subclassing.

Protected Member Functions
void	initializeGL () override
void	resizeGL (int w, int h) override
void	paintGL () override
void	onDisplayUpdateRequested () final override
	Implementations shall make Qt rerender the display.
double	getDevicePixelRatio () const final override
	Return the device pixel ratio of the screen the display is shown on.
int	getHeight () const final override
	Return the height of the display wrapper in pixels.
void	setCursor (const QCursor &cursor) final override
	Implementations shall forward to Qt's setCursor() function of the wrapper class.
Protected Member Functions inherited from QtDisplayWrapperBase
bool	handleInputEvent (QEvent *event)
Protected Member Functions inherited from SignalReceiver
void	disconnectAll ()
	Disconnects all existing connections.

Additional Inherited Members
Protected Attributes inherited from QtDisplayWrapperBase
Display *	m_display

Member Enumeration Documentation

RenderMode

enum class RenderMode

strong

Enumeration to define in which OpenGL context to conduct the rendering of the display (see class docstring for details).

Enumerator
UseImFusionContext	Perform rendering in the ImFusion main context.
UseQOpenGLWidgetContext	Perform rendering in the context created by the underlying QOpenGLWidget.

Member Function Documentation

mapToGlobal()

QPointF mapToGlobal ( const QPointF & pos ) const

finaloverridevirtual

Implementations shall forward to Qt's mapToGlobal() function of the wrapper class.

Implements QtDisplayWrapperBase.

onDisplayUpdateRequested()

void onDisplayUpdateRequested ( )

finaloverrideprotectedvirtual

Implementations shall make Qt rerender the display.

Implements QtDisplayWrapperBase.

getDevicePixelRatio()

double getDevicePixelRatio ( ) const

finaloverrideprotectedvirtual

Return the device pixel ratio of the screen the display is shown on.

Implements QtDisplayWrapperBase.

getHeight()

int getHeight ( ) const

finaloverrideprotectedvirtual

Return the height of the display wrapper in pixels.

Implements QtDisplayWrapperBase.

setCursor()

void setCursor ( const QCursor & cursor )

finaloverrideprotectedvirtual

Implementations shall forward to Qt's setCursor() function of the wrapper class.

Implements QtDisplayWrapperBase.

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The documentation for this class was generated from the following file:

• ImFusion/GUI/QtDisplayWidget.h