GLWindow Class Reference

A QWindow derivative capable of OpenGL drawing. More...

#include <glwindow.h>

Inheritance diagram for GLWindow:

Collaboration diagram for GLWindow:

Public Slots
void	setAnimating (bool animating)
	Enables/disables animation mode. More...
void	renderLater ()
	Queues a render request using the Qt event queue, to be executed at a later time. More...
void	renderNow ()
	Makes sure everything is correctly initialized, calls render and does buffer-swapping afterwards. More...

Signals
void	initializeFailed (const QString &error)
	This signal is sent when the context creation has failed, or the initialize function returned an error. More...

Public Member Functions
	GLWindow (QWindow *parent=nullptr)
QWidget *	createWindowContainer (QWidget *parent=nullptr, Qt::WindowFlags flags=nullptr)
	Creates a window container from this GLWindow. More...
bool	isAnimating () const
	Gets if the window is currently in animation mode. More...
QSurfaceFormat	format () const override
	Returns the currently used surface format. More...

Protected Member Functions
bool	event (QEvent *event) override
void	exposeEvent (QExposeEvent *event) override
virtual bool	initialize ()
	Provides a convenient point for subclasses to initialize. More...
virtual void	render ()
	Subclasses should implement this to render the window content. More...

Protected Attributes
bool	m_error
	Set to true if error occured making rendering impossible.
QOpenGLContext *	m_context
	The OpenGL context used for this window. More...

Private Attributes
bool	m_update_pending
bool	m_animating
bool	m_initializing

Detailed Description

A QWindow derivative capable of OpenGL drawing.

Modeled after http://qt-project.org/doc/qt-5/qtgui-openglwindow-example.html with some changes.

Before the window is first shown (before create is called), make sure to set a good surface format by calling setFormat. The window uses its own OpenGL rendering context, which uses the specified format. The window owns the context, so it is no longer available after the window is destroyed.

Can be used as a widget by using createWindowContainer. All subclasses get automatic access to OpenGL ES 2.0 functions.

See Also

http://www.khronos.org/opengles/2_X/

Member Function Documentation

QWidget * GLWindow::createWindowContainer	(	QWidget *	parent = nullptr,
		Qt::WindowFlags	flags = nullptr
	)

Creates a window container from this GLWindow.

Just calls QWidget::createWindowContainer with the specified parameters.

Parameters

parent	the parent of the returned widget.
flags	the window flags to be used

Returns

a new widget which is a container for this GLWindow

QSurfaceFormat GLWindow::format ( ) const

inlineoverride

Returns the currently used surface format.

This is the format of the QOpenGLContext if it exists, otherwise the requestedFormat is returned.

bool GLWindow::initialize ( )

protectedvirtual

Provides a convenient point for subclasses to initialize.

Is guaranteed to be called before the window is first rendered. The default implementation does nothing. Subclasses should return false on error, and also emit initializeFailed with a user-readable message. /return false if error occurred during initialization

Reimplemented in VolumeRenderWindow.

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void GLWindow::initializeFailed ( const QString &  error )

signal

This signal is sent when the context creation has failed, or the initialize function returned an error.

The window is unusable in this case.

Parameters

error

an error string suitable for user display

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bool GLWindow::isAnimating ( ) const

inline

Gets if the window is currently in animation mode.

See Also

setAnimating

void GLWindow::render ( )

protectedvirtual

Subclasses should implement this to render the window content.

The caller has to assure that the GL context is bound and everything is initialized, an easy way to do this is to call renderNow. The default implementation just draws a red background.

Reimplemented in VolumeRenderWindow.

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void GLWindow::renderLater ( )

slot

Queues a render request using the Qt event queue, to be executed at a later time.

Call this after updating drawing parameters. The request will call renderNow.

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void GLWindow::renderNow ( )

slot

Makes sure everything is correctly initialized, calls render and does buffer-swapping afterwards.

This method has no effect if the window is not exposed. Additionally, if an error occured during initialization, nothing will be done.

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void GLWindow::setAnimating ( bool  animating )

inlineslot

Enables/disables animation mode.

In animation mode, the window is continually rendering. This is done by calling renderLater after each renderNow call has finished, causing continuous rendering requests until setAnimating(false) is called. Note that this method is unsuitable for high-performance, low-delay animations like games.

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Member Data Documentation

QOpenGLContext* GLWindow::m_context

protected

The OpenGL context used for this window.

Not available until first call to renderNow.

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

• VoxelBlur/glwindow.h
• VoxelBlur/glwindow.cpp