QwtPlotGLCanvas - Man Page

An alternative canvas for a QwtPlot derived from QGLWidget.

Synopsis

#include <qwt_plot_glcanvas.h>

Inherits QGLWidget, and QwtPlotAbstractGLCanvas.

QwtPlotGLCanvas (QwtPlot *=NULL)
Constructor.
QwtPlotGLCanvas (const QGLFormat &, QwtPlot *=NULL)
Constructor.
virtual ~QwtPlotGLCanvas ()
Destructor.
virtual Q_INVOKABLE void invalidateBackingStore () override
Invalidate the internal backing store.
Q_INVOKABLE QPainterPath borderPath (const QRect &) const
virtual bool event (QEvent *) override

Protected Member Functions

virtual void paintEvent (QPaintEvent *) override
virtual void initializeGL () override
No operation - reserved for some potential use in the future.
virtual void paintGL () override
Paint the plot.
virtual void resizeGL (int width, int height) override
No operation - reserved for some potential use in the future.

Additional Inherited Members

Detailed Description

An alternative canvas for a QwtPlot derived from QGLWidget.

QwtPlotGLCanvas implements the very basics to act as canvas inside of a QwtPlot widget. It might be extended to a full featured alternative to QwtPlotCanvas in a future version of Qwt.

Even if QwtPlotGLCanvas is not derived from QFrame it imitates its API. When using style sheets it supports the box model - beside backgrounds with rounded borders.

Since Qt 5.4 QOpenGLWidget is available, that is used by QwtPlotOpenGLCanvas.

See also

QwtPlot::setCanvas(), QwtPlotCanvas, QwtPlotOpenGLCanvas

Note

With Qt4 you might want to use the QPaintEngine::OpenGL paint engine ( see QGL::setPreferredPaintEngine() ). On a Linux test system QPaintEngine::OpenGL2 shows very basic problems like translated geometries.

Another way for getting hardware accelerated graphics is using an OpenGL offscreen buffer ( QwtPlotCanvas::OpenGLBuffer ) with QwtPlotCanvas. Performance is worse, than rendering straight to a QGLWidget, but is usually better integrated into a desktop application.

Definition at line 45 of file qwt_plot_glcanvas.h.