ImFusion::GL::Context Class Reference

#include <ImFusion/Core/GL/Context.h>

Base class for low-level OpenGL context handling within the ImFusion SDK. More...

Inheritance diagram for ImFusion::GL::Context:

Detailed Description

Base class for low-level OpenGL context handling within the ImFusion SDK.

The child classes implement the concrete platform-specific code (based on WGL, GLX, etc.).

For very barebone applications, you can use the static create() factory function to create a GL::Context instance matching your local platform:

GL::Context::CreateInfo createInfo;
createInfo.requestedVersion = {4, 2};   // request at least OpenGL 4.2
createInfo.useDebugContext = true;      // request a debug context if available
 
// will create an offscreen context with the given specifications
std::unique_ptr<GL::Context> ctx = GL::Context::create(createInfo);

See also

ContextManager for a more high-level interface to manage OpenGL contexts

Classes
struct	CreateInfo

Public Member Functions
virtual bool	makeCurrent () const =0
	Make context current.
virtual bool	doneCurrent () const =0
	Disable context.
virtual void *	internalHandle () const =0
	Returns the native handle of this OpenGL context that can be used with CreateInfo::shareContext.
virtual std::unique_ptr< Context >	clone ()=0
	Instantiates a new OpenGL context that is shared with this one.
virtual void	detachFromCurrentThread ()
	Removes the binding of the OpenGL context to the current (i.e., calling) thread.
virtual void	moveToCurrentThread ()
	Moves the OpenGL context to the current (i.e., calling) thread.

Static Public Member Functions
static std::unique_ptr< Context >	create (CreateInfo createInfo)
	Factory function for creating a new offscreen OpenGL context.
static bool	hasCurrent ()
	Returns whether the calling thread has a current OpenGL context.
static void *	currentContextId ()
	Returns a platform-specific handle to the currently active OpenGL context.

Protected Member Functions
virtual void	deinitialize ()
	Clean up internal resources attached to this context.

Static Protected Member Functions
static int	defaultPixelBufferSize ()
	Default width and height of the pixel buffer of newly created offscreen contexts.
static void	installDefaultDebugMessageHandler ()
	Sets up the Debug::defaultMessageCallback handler.

Member Function Documentation

create()

std::unique_ptr< Context > ImFusion::GL::Context::create ( CreateInfo createInfo )

static

Factory function for creating a new offscreen OpenGL context.

The freshly created context will be made current. The derived class of the returned object is platform dependent.

On Linux, multiple backends are supported which can be changed by setting the IMFUSION_GL_BACKEND environment variable. Possible values are 'glx' and 'egl'. If the variable is empty, 'glx' is used by default.

See also

There is ContextManager::createContext() as convenience function to automatically create an OpenGL context that is compatible and shared with the main OpenGL context used by the ImFusion SDK.

currentContextId()

void * ImFusion::GL::Context::currentContextId ( )

static

Returns a platform-specific handle to the currently active OpenGL context.

Note

There is a 1-to-1 mapping of existing OpenGL contexts to the pointers returned. If there is no context current, this function will return 0. Apart from this you can not make any assumptions on the underlying type of the return value.

makeCurrent()

virtual bool ImFusion::GL::Context::makeCurrent ( ) const

pure virtual

Make context current.

Implemented in ImFusion::GlContextQt.

doneCurrent()

virtual bool ImFusion::GL::Context::doneCurrent ( ) const

pure virtual

Disable context.

Implemented in ImFusion::GlContextQt.

internalHandle()

virtual void * ImFusion::GL::Context::internalHandle ( ) const

pure virtual

Returns the native handle of this OpenGL context that can be used with CreateInfo::shareContext.

Implemented in ImFusion::GlContextQt.

clone()

virtual std::unique_ptr< Context > ImFusion::GL::Context::clone ( )

pure virtual

Instantiates a new OpenGL context that is shared with this one.

The freshly created context will be made current. This method will throw if the context could not be initialized.

Note

If you plan to use this context in a different thread, you will need to call moveToCurrentThread() on the returned context before.

Implemented in ImFusion::GlContextQt.

detachFromCurrentThread()

virtual void ImFusion::GL::Context::detachFromCurrentThread ( )

virtual

Removes the binding of the OpenGL context to the current (i.e., calling) thread.

Note

Before calling this method, make sure to release the context from the source thread (i.e. call doneCurrent()). After calling this method, move the context to the new thread and make it current there.

Reimplemented in ImFusion::GlContextQt.

moveToCurrentThread()

virtual void ImFusion::GL::Context::moveToCurrentThread ( )

virtual

Moves the OpenGL context to the current (i.e., calling) thread.

Note

Before calling this method, make sure to release the context from the source thread (i.e. call doneCurrent()). After calling this method, make the context current in the new thread.

Reimplemented in ImFusion::GlContextQt.

deinitialize()

virtual void ImFusion::GL::Context::deinitialize ( )

protectedvirtual

Clean up internal resources attached to this context.

Derived classes must call this function in their destructor before destroying the GL context.

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The documentation for this class was generated from the following file:

• ImFusion/Core/GL/Context.h