Wizt::GLContextChecker Class Reference

This is a convenience class to check if an OpenGL context is currently active and available. More...

#include <ocean/GLvish/MetaGLViewerCreator.hpp>

Inheritance diagram for Wizt::GLContextChecker:

Classes
struct	ContextAvailable

Public Member Functions
virtual const void *	CurrentGLContextID () const =0
	Get a an OpenGL context ID, which is useful to check if at this point of the code calling OpenGL functions is allowed.
Public Member Functions inherited from MemCore::ReferenceBase< GLContextChecker >
auto	getObjectCountID () const noexcept
	Get a unique ID for this object in the given domain.
bool	isIdentical (const WeakPtr< GLContextChecker, GLContextChecker > &PossibleSelf) const noexcept
	Check if this object is identical to the one used by the given pointer.
void	mkAutoDestructive ()
	Marks this object as being automatically destructed, e.g.
refcount_t	refcount () const noexcept
	The strong reference count.
	ReferenceBase (GLContextChecker *that) noexcept
	Constructor, initializes reference counter to zero.
const auto &	self () const
	Return weak pointer to the object self.
refcount_t	wrefcount () const noexcept
	The weak reference count.

Static Public Member Functions
static int	invalidContext ()

Additional Inherited Members
Public Types inherited from MemCore::ReferenceBase< GLContextChecker >
using	reference_domain_t = GLContextChecker
	The type of the base class.
using	SelfPtr_t = WeakPtr< GLContextChecker, GLContextChecker >
	Type for a pointer to this object itself.
Protected Member Functions inherited from MemCore::ReferenceBase< GLContextChecker >
virtual void	extremeUnction ()
	A virtual function that will be called just before the object is destroyed.
ReferenceBase &	operator= (const ReferenceBase &R)
	Protected assignment operator (should not be called).
void	suicide ()
	Delete this.
virtual	~ReferenceBase ()
	Virtual destructor.

Detailed Description

This is a convenience class to check if an OpenGL context is currently active and available.

if (GLContextChecker::invalidContext() )
{
        not good... no OpenGL context...
}

Member Function Documentation

CurrentGLContextID()

virtual const void * Wizt::GLContextChecker::CurrentGLContextID ( ) const

pure virtual

Get a an OpenGL context ID, which is useful to check if at this point of the code calling OpenGL functions is allowed.

This is especcially useful for destructors of objects that clean up OpenGL objects. No explicit OpenGL context object is available then, but this function allows to check for validity. Such object may only be destroyed if there is a current OpenGL context, otherwise it will lead to runtime errors.

invalidContext()

int Wizt::GLContextChecker::invalidContext ( )

static

Returns

Positive: There is no context. Zero: An OpenGL context is available and active. Negative: Context information could not be determined.

Referenced by Wizt::VBOCreator::release(), Wizt::GLTextureID::selectActiveTextureUnit(), Wizt::BufferArray::~BufferArray(), Wizt::GLTextureBase::~GLTextureBase(), Wizt::GLTextureID::~GLTextureID(), and Wizt::VBO::~VBO().