Qt Reference Documentation

QGL Namespace

The QGL namespace specifies miscellaneous identifiers used in the Qt OpenGL module. More...

 #include <QGL>

Types

enum FormatOption { DoubleBuffer, DepthBuffer, Rgba, AlphaChannel, ..., NoDeprecatedFunctions }
flags FormatOptions

Functions

void setPreferredPaintEngine ( QPaintEngine::Type engineType )

Detailed Description

The QGL namespace specifies miscellaneous identifiers used in the Qt OpenGL module.

Type Documentation

enum QGL::FormatOption
flags QGL::FormatOptions

This enum specifies the format options that can be used to configure an OpenGL context. These are set using QGLFormat::setOption().

ConstantValueDescription
QGL::DoubleBuffer0x0001Specifies the use of double buffering.
QGL::DepthBuffer0x0002Enables the use of a depth buffer.
QGL::Rgba0x0004Specifies that the context should use RGBA as its pixel format.
QGL::AlphaChannel0x0008Enables the use of an alpha channel.
QGL::AccumBuffer0x0010Enables the use of an accumulation buffer.
QGL::StencilBuffer0x0020Enables the use of a stencil buffer.
QGL::StereoBuffers0x0040Enables the use of a stereo buffers for use with visualization hardware.
QGL::DirectRendering0x0080Specifies that the context is used for direct rendering to a display.
QGL::HasOverlay0x0100Enables the use of an overlay.
QGL::SampleBuffers0x0200Enables the use of sample buffers.
QGL::DeprecatedFunctions0x0400Enables the use of deprecated functionality for OpenGL 3.x contexts. A context with deprecated functionality enabled is called a full context in the OpenGL specification.
QGL::SingleBufferDoubleBuffer<<16Specifies the use of a single buffer, as opposed to double buffers.
QGL::NoDepthBufferDepthBuffer<<16Disables the use of a depth buffer.
QGL::ColorIndexRgba<<16Specifies that the context should use a color index as its pixel format.
QGL::NoAlphaChannelAlphaChannel<<16Disables the use of an alpha channel.
QGL::NoAccumBufferAccumBuffer<<16Disables the use of an accumulation buffer.
QGL::NoStencilBufferStencilBuffer<<16Disables the use of a stencil buffer.
QGL::NoStereoBuffersStereoBuffers<<16Disables the use of stereo buffers.
QGL::IndirectRenderingDirectRendering<<16Specifies that the context is used for indirect rendering to a buffer.
QGL::NoOverlayHasOverlay<<16Disables the use of an overlay.
QGL::NoSampleBuffersSampleBuffers<<16Disables the use of sample buffers.
QGL::NoDeprecatedFunctionsDeprecatedFunctions<<16Disables the use of deprecated functionality for OpenGL 3.x contexts. A context with deprecated functionality disabled is called a forward compatible context in the OpenGL specification.

The FormatOptions type is a typedef for QFlags<FormatOption>. It stores an OR combination of FormatOption values.

See also Sample Buffers Example.

Function Documentation

void QGL::setPreferredPaintEngine ( QPaintEngine::Type engineType )

Sets the preferred OpenGL paint engine that is used to draw onto QGLWidget, QGLPixelBuffer and QGLFramebufferObject targets with QPainter in Qt.

The engineType parameter specifies which of the GL engines to use. Only QPaintEngine::OpenGL and QPaintEngine::OpenGL2 are valid parameters to this function. All other values are ignored.

By default, the QPaintEngine::OpenGL2 engine is used if GL/GLES version 2.0 is available, otherwise QPaintEngine::OpenGL is used.

Warning: This function must be called before the QApplication constructor is called.

This function was introduced in Qt 4.6.

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