CopperSpice API  1.7.2
QSurfaceFormat Class Reference

The QSurfaceFormat class represents the format of a QSurface. More...

Public Typedefs

using FormatOptions = QFlags< FormatOption >
 

Public Types

enum  FormatOption
 
enum  OpenGLContextProfile
 
enum  RenderableType
 
enum  SwapBehavior
 

Public Methods

 QSurfaceFormat (const QSurfaceFormat &other)
 
 QSurfaceFormat (FormatOptions options)
 
 ~QSurfaceFormat ()
 
int alphaBufferSize () const
 
int blueBufferSize () const
 
int depthBufferSize () const
 
int greenBufferSize () const
 
bool hasAlpha () const
 
int majorVersion () const
 
int minorVersion () const
 
QSurfaceFormat & operator= (const QSurfaceFormat &other)
 
QSurfaceFormat::FormatOptions options () const
 
OpenGLContextProfile profile () const
 
int redBufferSize () const
 
RenderableType renderableType () const
 
int samples () const
 
void setAlphaBufferSize (int size)
 
void setBlueBufferSize (int size)
 
void setDepthBufferSize (int size)
 
void setGreenBufferSize (int size)
 
void setMajorVersion (int majorVersion)
 
void setOption (FormatOption option, bool on=true)
 
void setOptions (QSurfaceFormat::FormatOptions options)
 
void setProfile (OpenGLContextProfile profile)
 
void setRedBufferSize (int size)
 
void setRenderableType (RenderableType type)
 
void setSamples (int numSamples)
 
void setStencilBufferSize (int size)
 
void setStereo (bool enable)
 
void setSwapBehavior (SwapBehavior behavior)
 
void setSwapInterval (int interval)
 
void setVersion (int major, int minor)
 
int stencilBufferSize () const
 
bool stereo () const
 
SwapBehavior swapBehavior () const
 
int swapInterval () const
 
bool testOption (FormatOption option) const
 
QPair< int, int > version () const
 

Static Public Methods

static QSurfaceFormat defaultFormat ()
 
static void setDefaultFormat (const QSurfaceFormat &format)
 

Friends

bool operator!= (const QSurfaceFormat &, const QSurfaceFormat &)
 
bool operator== (const QSurfaceFormat &, const QSurfaceFormat &)
 

Detailed Description

The format includes the size of the color buffers, red, green, and blue; the size of the alpha buffer, the size of the depth and stencil buffers; and number of samples per pixel for multisampling. In addition, the format contains surface configuration parameters such as OpenGL profile and version for rendering, whether or not to enable stereo buffers, and swap behavior.

Member Typedef Documentation

Member Enumeration Documentation

This enum contains format options for use with QSurfaceFormat.

ConstantValueDescription
QSurfaceFormat::StereoBuffers 0x0001 Used to request stereo buffers in the surface format.
QSurfaceFormat::DebugContext 0x0002 Used to request a debug context with extra debugging information.
QSurfaceFormat::DeprecatedFunctions 0x0004 Used to request that deprecated functions be included in the OpenGL context profile. If not specified, you should get a forward compatible context without support functionality marked as deprecated. This requires OpenGL version 3.0 or higher.
QSurfaceFormat::ResetNotification 0x0008 Enables notifications about resets of the OpenGL context. The status is then queryable via the context's isValid() function. Note that not setting this flag does not guarantee that context state loss never occurs. Additionally, some implementations may choose to report context loss regardless of this flag. Platforms that support dynamically enabling the monitoring of the loss of context, such as, Windows with WGL, or Linux/X11 (xcb) with GLX, will monitor the status in every call to makeCurrent(). See isValid() for more information on this.

This enum is used to specify the OpenGL context profile in conjunction with QSurfaceFormat::setMajorVersion() and QSurfaceFormat::setMinorVersion().

Profiles are a feature added in OpenGL 3.2 and used in all newer versions. They are used to choose between a restricted core profile and a compatibility profile, which might contain deprecated functionality. For access to the deprecated functionality in the core profile use the QSurfaceFormat format option QSurfaceFormat::DeprecatedFunctions.

ConstantValueDescription
QSurfaceFormat::NoProfile 0 OpenGL version is lower than 3.2. For version 3.2 and newer this is same as CoreProfile
QSurfaceFormat::CoreProfile 1 Functionality deprecated in OpenGL version 3.0 is not available
QSurfaceFormat::CompatibilityProfile 2 Functionality from earlier OpenGL versions is available

This enum specifies the rendering backend for the surface.

ConstantValueDescription
QSurfaceFormat::DefaultRenderableType 0x0 Default, unspecified rendering method
QSurfaceFormat::OpenGL 0x1 Desktop OpenGL rendering
QSurfaceFormat::OpenGLES 0x2 OpenGL ES 2.0 rendering

This enum is used by QSurfaceFormat to specify the swap behavior of a surface. The swap behavior is mostly transparent to the application, but it affects factors such as rendering latency and throughput.

ConstantValueDescription
QSurfaceFormat::DefaultSwapBehavior 0 The default, unspecified swap behavior of the platform.
QSurfaceFormat::SingleBuffer 1 Used to request single buffering, which might result in flickering when OpenGL rendering is done directly to screen without an intermediate offscreen buffer.
QSurfaceFormat::DoubleBuffer 2 This is typically the default swap behavior on desktop platforms, consisting of one back buffer and one front buffer. Rendering is done to the back buffer, and then the back buffer and front buffer are swapped, or the contents of the back buffer are copied to the front buffer, depending on the implementation.
QSurfaceFormat::TripleBuffer 3 This swap behavior is sometimes used in order to decrease the risk of skipping a frame when the rendering rate is just barely keeping up with the screen refresh rate. Depending on the platform it might also lead to slightly more efficient use of the GPU due to improved pipelining behavior. Triple buffering comes at the cost of an extra frame of memory usage and latency, and might not be supported depending on the underlying platform.

Constructor & Destructor Documentation

QSurfaceFormat::QSurfaceFormat ( FormatOptions  options)

Constructs a QSurfaceFormat with the given format options.

QSurfaceFormat::QSurfaceFormat ( const QSurfaceFormat &  other)

Constructs a copy of other.

QSurfaceFormat::~QSurfaceFormat ( )

Destroys the QSurfaceFormat.

Method Documentation

int QSurfaceFormat::alphaBufferSize ( ) const

Get the size in bits of the alpha channel of the color buffer.

int QSurfaceFormat::blueBufferSize ( ) const

Get the size in bits of the blue channel of the color buffer.

QSurfaceFormat QSurfaceFormat::defaultFormat ( )
static

Returns the global default surface format. When setDefaultFormat() is not called, this is a default-constructed QSurfaceFormat.

See also
setDefaultFormat()
int QSurfaceFormat::depthBufferSize ( ) const

Returns the depth buffer size.

See also
setDepthBufferSize()
int QSurfaceFormat::greenBufferSize ( ) const

Get the size in bits of the green channel of the color buffer.

bool QSurfaceFormat::hasAlpha ( ) const

Returns true if the alpha buffer size is greater than zero. This means that the surface might be used with per pixel translucency effects.

int QSurfaceFormat::majorVersion ( ) const

Returns the major OpenGL version. The default version is 2.0.

int QSurfaceFormat::minorVersion ( ) const

Returns the minnor OpenGL version.

QSurfaceFormat & QSurfaceFormat::operator= ( const QSurfaceFormat &  other)

Assigns other to this object.

QSurfaceFormat::FormatOptions QSurfaceFormat::options ( ) const

Returns the currently set format options.

See also
setOption(), setOptions(), testOption()
QSurfaceFormat::OpenGLContextProfile QSurfaceFormat::profile ( ) const

Get the configured OpenGL context profile. This setting is ignored if the requested OpenGL version is less than 3.2.

int QSurfaceFormat::redBufferSize ( ) const

Get the size in bits of the red channel of the color buffer.

QSurfaceFormat::RenderableType QSurfaceFormat::renderableType ( ) const

Returns the renderable type which will be desktop OpenGL or OpenGL ES.

int QSurfaceFormat::samples ( ) const

Returns the number of samples per pixel when multisampling is enabled. By default multisampling is disabled.

See also
setSamples()
void QSurfaceFormat::setAlphaBufferSize ( int  size)

Set the desired size in bits of the alpha channel of the color buffer.

void QSurfaceFormat::setBlueBufferSize ( int  size)

Set the desired size in bits of the blue channel of the color buffer.

Note
On Mac OSX, be sure to set the buffer size of all color channels, otherwise this setting will have no effect. If one of the buffer sizes is not set, the current bit-depth of the screen is used.
void QSurfaceFormat::setDefaultFormat ( const QSurfaceFormat &  format)
static

Sets the global default surface format. This format is used by default in QOpenGLContext, QWindow, QOpenGLWidget and similar classes.

It can always be overridden on a per-instance basis by using the class in question's own setFormat() function. However, it is often more convenient to set the format for all windows once at the start of the application. It also guarantees proper behavior in cases where shared contexts are required, because setting the format via this function guarantees that all contexts and surfaces, even the ones created internally will use the same format.

Note
When setting Qt::AA_ShareOpenGLContexts it is strongly recommended to place the call to this method before the construction of the QApplication. Otherwise format will not be applied to the global share context and therefore issues may arise with context sharing afterwards.
See also
defaultFormat()
void QSurfaceFormat::setDepthBufferSize ( int  size)

Set the minimum depth buffer size to size.

See also
depthBufferSize()
void QSurfaceFormat::setGreenBufferSize ( int  size)

Set the desired size in bits of the green channel of the color buffer.

Note
On Mac OSX, be sure to set the buffer size of all color channels, otherwise this setting will have no effect. If one of the buffer sizes is not set, the current bit-depth of the screen is used.
void QSurfaceFormat::setMajorVersion ( int  majorVersion)

Sets the major OpenGL version to majorVersion.

void QSurfaceFormat::setOption ( QSurfaceFormat::FormatOption  option,
bool  on = true 
)

void QSurfaceFormat::setMinorVersion(int minorVersion)

Sets the minor OpenGL version to minorVersoin.

Sets the format option option if on is true, otherwise clears the option.

See also
setOptions(), options(), testOption()
void QSurfaceFormat::setOptions ( QSurfaceFormat::FormatOptions  options)

Sets the format options to options.

See also
options(), testOption()
void QSurfaceFormat::setProfile ( OpenGLContextProfile  profile)

Sets the desired OpenGL context profile. This setting is ignored if the requested OpenGL version is less than 3.2.

void QSurfaceFormat::setRedBufferSize ( int  size)

Set the desired size in bits of the red channel of the color buffer.

Note
On Mac OSX, be sure to set the buffer size of all color channels, otherwise this setting will have no effect. If one of the buffer sizes is not set, the current bit-depth of the screen is used.
void QSurfaceFormat::setRenderableType ( RenderableType  type)

Sets the desired renderable to type.

void QSurfaceFormat::setSamples ( int  numSamples)

Set the preferred number of samples per pixel when multisampling is enabled to numSamples. By default, multisampling is disabled.

See also
samples()
void QSurfaceFormat::setStencilBufferSize ( int  size)

Set the preferred stencil buffer size to size bits.

See also
stencilBufferSize()
void QSurfaceFormat::setStereo ( bool  enable)

If enable is true enables stereo buffering, otherwise disables stereo buffering. Stereo buffering is disabled by default.

Stereo buffering provides extra color buffers to generate left-eye and right-eye images.

See also
stereo()
void QSurfaceFormat::setSwapBehavior ( SwapBehavior  behavior)

Set the swap behavior of the surface.

The swap behavior specifies whether single, double, or triple buffering is desired. The default, DefaultSwapBehavior, gives the default swap behavior of the platform.

void QSurfaceFormat::setSwapInterval ( int  interval)

Sets the preferred swap interval to the passed value of interval. The swap interval specifies the minimum number of video frames that are displayed before a buffer swap occurs. This can be used to sync the GL drawing into a window to the vertical refresh of the screen.

Setting an interval value of 0 will turn the vertical refresh syncing off, any value higher than 0 will turn the vertical syncing on. Setting interval to a higher value, for example 10, results in having 10 vertical retraces between every buffer swap. The default interval is 1.

Changing the swap interval may not be supported by the underlying platform. If it is not then the request will be silently ignored.

See also
swapInterval()
void QSurfaceFormat::setVersion ( int  major,
int  minor 
)

Sets the desired major and minor OpenGL versions. The default version is 2.0.

int QSurfaceFormat::stencilBufferSize ( ) const

Returns the stencil buffer size in bits.

See also
setStencilBufferSize()
bool QSurfaceFormat::stereo ( ) const
inline

Returns true if stereo buffering is enabled, otherwise returns false. Stereo buffering is disabled by default.

See also
setStereo()
QSurfaceFormat::SwapBehavior QSurfaceFormat::swapBehavior ( ) const

Returns the configured swap behavior.

See also
setSwapBehavior()
int QSurfaceFormat::swapInterval ( ) const

Returns the swap interval.

See also
setSwapInterval()
bool QSurfaceFormat::testOption ( QSurfaceFormat::FormatOption  option) const

Returns true if the format option option is set, otherwise returns false.

See also
options()
QPair< int, int > QSurfaceFormat::version ( ) const

Returns a QPair<int, int> representing the OpenGL version. This is useful for version checks. For example format.version() >= qMakePair(3, 2).

Friends And Related Function Documentation

bool operator!= ( const QSurfaceFormat &  a,
const QSurfaceFormat &  b 
)
friend

Returns false if all the options of the two QSurfaceFormat objects a and b are equal, otherwise returns true.

bool operator== ( const QSurfaceFormat &  a,
const QSurfaceFormat &  b 
)
friend

Returns true if all the options of the two QSurfaceFormat objects a and b are equal.