Constructs an OpenGL widget with a parent widget. The default format is used. The widget will be invalid if the system has no OpenGL support. The value for parent and flags are passed to the QWidget constructor.

If shareWidget is a valid QGLWidget, this widget will share OpenGL display lists and texture objects with shareWidget. But if shareWidget and this widget have different formats, sharing might not be possible. You can check whether sharing is in effect by calling isSharing().

The initialization of OpenGL rendering state, etc. should be done by overriding initializeGL() rather than in the constructor of your QGLWidget subclass.

See also

QGLFormat::defaultFormat()

Constructs an OpenGL widget with the given parent. The context argument is a pointer to the QGLContext that you wish to be bound to this widget. This allows you to pass in your own QGLContext sub-classes. The widget will be invalid if the system has no OpenGL support.

The value for parent and flags are passed to the QWidget constructor.

If shareWidget is a valid QGLWidget, this widget will share OpenGL display lists and texture objects with shareWidget. But if shareWidget and this widget have different formats, sharing might not be possible. You can check whether sharing is in effect by calling isSharing().

The initialization of OpenGL rendering state, etc. should be done by overriding the initializeGL() function, rather than in the constructor of your QGLWidget subclass.

See also

QGLFormat::defaultFormat(), isValid()

Constructs an OpenGL widget with the given parent.

The value for parent and flags are passed to the QWidget constructor.

The format argument specifies the desired rendering options. If the underlying OpenGL/Window system can not satisfy all the features requested in format, the nearest subset of features will be used. After creation, the format() method will return the actual format obtained. The widget will be invalid if the system has no OpenGL support.

If shareWidget is a valid QGLWidget, this widget will share OpenGL display lists and texture objects with shareWidget. But if shareWidget and this widget have different formats, sharing might not be possible. You can check whether sharing is in effect by calling isSharing().

The initialization of OpenGL rendering state, etc. should be done by overriding the initializeGL() function, rather than in the constructor of your QGLWidget subclass.

See also

QGLFormat::defaultFormat(), isValid()

Destroys the widget.

Returns true if the widget is doing automatic GL buffer swapping, otherwise returns false.

See also

setAutoBufferSwap()

The binding options are a set of options used to decide how to bind the texture to the context.

Calls QGLContext::bindTexture(image, target, format) on the currently set context.

See also

deleteTexture()

Generates and binds a 2D GL texture to the current context, based on pixmap. The binding options are a set of options used to decide how to bind the texture to the context. The generated texture id is returned and can be used in any OpenGL texture call.

Calls QGLContext::bindTexture(pixmap, target, format) on the currently set context.

See also

deleteTexture()

Calls QGLContext::bindTexture(fileName) on the currently set context.

See also

deleteTexture()

Returns the colormap for this widget. Usually it is only top-level widgets that can have different colormaps installed. Asking for the colormap of a child widget will return the colormap for the child's top-level widget. If no colormap has been set for this widget, the QGLColormap returned will be empty.

See also

setColormap(), QGLColormap::isEmpty()

Returns the context of this widget. It is possible that the context is not valid (see isValid()), for example, if the underlying hardware does not support the format attributes that were requested.

Converts the image img into the unnamed format expected by OpenGL functions such as glTexImage2D(). The returned image is not usable as a QImage, but QImage::width(), QImage::height() and QImage::bits() may be used with OpenGL. The GL format used is GL_RGBA.

Equivalent to calling QGLContext::deleteTexture(texture_id) on the currently set context.

See also

bindTexture()

Makes no GL context the current context. Normally, you do not need to call this function; QGLContext calls it as necessary. However, it may be useful in multithreaded environments.

Returns true if the contained GL rendering context has double buffering, otherwise returns false.

See also

QGLFormat::doubleBuffer()

Calls the corresponding QGLContext::drawTexture() with point, texture_id, and textureTarget for this widget's context.

Calls the corresponding QGLContext::drawTexture() with target, texture_id, and textureTarget for this widget's context.

Reimplemented from QWidget::event()

Returns the format of the contained GL rendering context.

See also

setFormat()

Calls the virtual function paintGL(). The widget's rendering context will become the current context and initializeGL() will be called if it has not already been called.

Initializes OpenGL for this widget's context. Calls the virtual function initializeGL().

Returns an image of the frame buffer. If withAlpha is true the alpha channel is included. Depending on your hardware, you can explicitly select which color buffer to grab with a glReadBuffer() call before calling this function.

This method is called once before the first call to paintGL() or resizeGL() and then again whenever the widget is assigned a new QGLContext.

The method should be reimplemented in a subclass. The implementation is responsible for setting up any required OpenGL context rendering flags, defining display lists, etc. There is no need to call makeCurrent() because this has already been done when this method is called.

This method is used in the same manner as initializeGL() except that it operates on the widget's overlay context instead of the widget's main context. This means that initializeOverlayGL() is called once before the first call to paintOverlayGL() or resizeOverlayGL().

The method should be reimplemented in a subclass. The implementation is responsible for setting up any required OpenGL context rendering flags, defining display lists, etc. for the overlay context. There is no need to call makeOverlayCurrent() because this has already been done when this function is called.

Returns true if this widget's GL context is shared with another GL context, otherwise false is returned. Context sharing might not be possible if the widgets use different formats.

See also

format()

Returns true if the widget has a valid GL rendering context, otherwise returns false. A widget will be invalid if the system has no OpenGL support.

Makes this widget the current widget for OpenGL operations, i.e. makes the widget's rendering context the current OpenGL rendering context.

Makes the overlay context of this widget current. Use this if you need to issue OpenGL commands to the overlay context outside of initializeOverlayGL(), resizeOverlayGL(), and paintOverlayGL().

Does nothing if this widget has no overlay.

See also

makeCurrent()

Returns the overlay context of this widget or a nullptr if this widget has no overlay.

See also

context()

Returns the widget's paint engine.

This method should not be called explicitly by the user, since it is meant for reimplementation purposes only. The method is called by CopperSpice internally, and the default implementation may not always return a valid pointer.

Reimplemented from QWidget::paintEngine()

Handles paint events passed in the event parameter. Will cause the virtual paintGL() function to be called. The widget's rendering context will become the current context and initializeGL() will be called if it has not already been called.

Reimplemented from QWidget::paintEvent()

This method is called whenever the widget needs to be painted. The method should be reimplemented in a subclass. There is no need to call makeCurrent() because this has already been done when this function is called.

This method is used in the same manner as paintGL() except that it operates on the widget's overlay context instead of the widget's main context. This means that paintOverlayGL() is called whenever the widget's overlay needs to be painted.

The method should be reimplemented in a subclass. There is no need to call makeOverlayCurrent() because this has already been done when this method is called.

Specifies the clearing color to OpenGL. Calls glClearColor (in RGBA mode) or glClearIndex (in color-index mode) with the color c. Applies to this widgets GL context.

See also

qglColor(), QGLContext::currentContext(), QColor

Specifies a drawing color to OpenGL. Calls glColor4 (in RGBA mode) or glIndex (in color-index mode) with the color c. Applies to this widgets GL context.

Note

This method is not supported on OpenGL/ES 2.0 systems.

See also

qglClearColor(), QGLContext::currentContext(), QColor

Renders the current scene on a pixmap and returns the pixmap. You can use this method on both visible and invisible QGLWidget objects. This method will create a pixmap and a temporary QGLContext to render on the pixmap. It will then call initializeGL(), resizeGL(), and paintGL() on this context. Finally, the widget's original GL context is restored.

The size of the pixmap will be w pixels wide and h pixels high unless one of these parameters is 0, in which case the pixmap will have the same size as the widget.

If useContext is true, this method will try to be more efficient by using the existing GL context to render the pixmap. The default is false. Only use true if you understand the risks. On Windows a temporary context has to be created and usage of the useContext parameter is not supported.

Overlays are not rendered onto the pixmap. If the GL rendering context and the desktop have different bit depths, the result will most likely look surprising.

The creation of display lists, modifications of the view frustum etc. should be done from within initializeGL(). If this is not done the temporary QGLContext will not be initialized properly and the rendered pixmap may be incomplete or corrupted.

The values for x, y and z are specified in scene or object coordinates relative to the currently set projection and model matrices. This can be useful if you want to annotate models with text labels and have the labels move with the model as it is rotated etc.

This method is not supported on OpenGL/ES systems. If depth testing is enabled before this method is called, then the drawn text will be depth-tested against the models that have already been drawn in the scene. Use glDisable(GL_DEPTH_TEST) before calling this function to annotate the models without depth-testing the text.

Renders the string str into the GL context of this widget. The values for x and y are specified in window coordinates, with the origin in the upper left-hand corner of the window. If font is not specified the currently set application font will be used to render the string. To change the color of the rendered text call glColor() or the qglColor() methods just before calling renderText().

This method clears the stencil buffer and is not supported on OpenGL/ES systems. It will also temporarily disable depth-testing when the text is drawn.

This method can only be used inside a QPainter::beginNativePainting() / QPainter::endNativePainting() block if the default OpenGL paint engine is QPaintEngine::OpenGL. To make QPaintEngine::OpenGL the default GL engine, call QGL::setPreferredPaintEngine(QPaintEngine::OpenGL) before the QApplication constructor.

Handles resize events that are passed in the event parameter. Calls the virtual function resizeGL().

Reimplemented from QWidget::resizeEvent()

This method is called whenever the widget has been resized. The new size is passed in width and height.

The method should be reimplemented in a subclass. There is no need to call makeCurrent() because this has already been done when this function is called.

This virtual function is used in the same manner as paintGL() except that it operates on the widget's overlay context instead of the widget's main context. This means that resizeOverlayGL() is called whenever the widget has been resized. The new size is passed in width and height.

The method should be reimplemented in a subclass. There is no need to call makeOverlayCurrent() because this has already been done when this function is called.

If on is true automatic GL buffer swapping is switched on, otherwise it is switched off. If the parameter on is true and the widget is using a double-buffered format, the background and foreground GL buffers will automatically be swapped after each paintGL() call.

The buffer auto-swapping is on by default.

See also

autoBufferSwap(), doubleBuffer(), swapBuffers()

Set the colormap for this widget to map. Usually it is only top-level widgets that can have colormaps installed.

See also

colormap()

Deprecated:

Sets a new format for this widget.

If the underlying OpenGL/Window system can not satisfy all the features requested in format, the nearest subset of features will be used. After creation, the format() method will return the actual rendering context format obtained.

The widget will be assigned a new QGLContext, and the initializeGL() function will be executed for this new context before the first resizeGL() or paintGL().

This method will try to keep display list and texture object sharing in effect with other QGLWidget objects, but changing the format might make sharing impossible. Use isSharing() to see if sharing is still in effect.

See also

format(), isSharing(), isValid()

Swaps the screen contents with an off-screen buffer. This only works if the widget's format specifies double buffer mode.

Normally, there is no need to explicitly call this function because it is done automatically after each widget repaint, i.e. each time after paintGL() has been executed.

See also

doubleBuffer(), setAutoBufferSwap(), QGLFormat::setDoubleBuffer()

Updates the widget by calling glDraw().

Updates the widget's overlay (if any). Will cause the virtual function paintOverlayGL() to be executed.

The widget's rendering context will become the current context and initializeGL() will be called if it has not already been called.