Package com.jogamp.opengl

Class GLDrawableFactory

java.lang.Object

com.jogamp.opengl.GLDrawableFactory

public abstract class GLDrawableFactory
extends Object

Provides a virtual machine- and operating system-independent mechanism for creating GLDrawables.

The GLCapabilities objects passed in to the various factory methods are used as a hint for the properties of the returned drawable. The default capabilities selection algorithm (equivalent to passing in a null GLCapabilitiesChooser) is described in DefaultGLCapabilitiesChooser. Sophisticated applications needing to change the selection algorithm may pass in their own GLCapabilitiesChooser which can select from the available pixel formats. The GLCapabilitiesChooser mechanism may not be supported by all implementations or on all platforms, in which case any passed GLCapabilitiesChooser will be ignored.

Because of the multithreaded nature of the Java platform's Abstract Window Toolkit, it is typically not possible to immediately reject a given GLCapabilities as being unsupportable by either returning null from the creation routines or raising a GLException. The semantics of the rejection process are (unfortunately) left unspecified for now. The current implementation will cause a GLException to be raised during the first repaint of the GLCanvas or GLJPanel if the capabilities can not be met.
GLOffscreenAutoDrawable are created lazily, see createOffscreenAutoDrawable(..).

The concrete GLDrawableFactory subclass instantiated by getFactory can be changed by setting the system property opengl.factory.class.name to the fully-qualified name of the desired class.

Method Summary

Modifier and Type	Method	Description
abstract boolean	canCreateExternalGLDrawable(AbstractGraphicsDevice device)	Returns true if it is possible to create an external GLDrawable object via createExternalGLDrawable().
abstract boolean	canCreateFBO(AbstractGraphicsDevice device, GLProfile glp)	Returns true if it is possible to create an framebuffer object (FBO).
abstract boolean	canCreateGLPbuffer(AbstractGraphicsDevice device, GLProfile glp)	Returns true if it is possible to create an pbuffer surface.
abstract GLAutoDrawable	createDummyAutoDrawable(AbstractGraphicsDevice deviceReq, boolean createNewDevice, GLCapabilitiesImmutable capsRequested, GLCapabilitiesChooser chooser)	Creates a realized dummy GLAutoDrawable incl it's dummy, invisible NativeSurface as created with createDummyDrawable(AbstractGraphicsDevice, boolean, GLCapabilitiesImmutable, GLCapabilitiesChooser).
abstract GLDrawable	createDummyDrawable(AbstractGraphicsDevice deviceReq, boolean createNewDevice, GLCapabilitiesImmutable capsRequested, GLCapabilitiesChooser chooser)	Creates an unrealized dummy GLDrawable.
abstract GLContext	createExternalGLContext()	Creates a GLContext object representing an existing OpenGL context in an external (third-party) OpenGL-based library.
abstract GLDrawable	createExternalGLDrawable()	Creates a GLDrawable object representing an existing OpenGL drawable in an external (third-party) OpenGL-based library.
abstract GLDrawable	createGLDrawable(NativeSurface target)	Returns an unrealized GLDrawable according to it's chosen GLCapabilitiesImmutable, which determines pixel format, on- and offscreen incl.
abstract GLOffscreenAutoDrawable	createOffscreenAutoDrawable(AbstractGraphicsDevice device, GLCapabilitiesImmutable caps, GLCapabilitiesChooser chooser, int width, int height)	Creates a realized GLOffscreenAutoDrawable incl it's offscreen NativeSurface with the given capabilities and dimensions.
abstract GLDrawable	createOffscreenDrawable(AbstractGraphicsDevice device, GLCapabilitiesImmutable caps, GLCapabilitiesChooser chooser, int width, int height)	Creates an unrealized offscreen GLDrawable incl it's offscreen NativeSurface with the given capabilities and dimensions.
abstract ProxySurface	createProxySurface(AbstractGraphicsDevice device, int screenIdx, long windowHandle, GLCapabilitiesImmutable caps, GLCapabilitiesChooser chooser, UpstreamSurfaceHook upstream)	Creates a proxy NativeSurface w/ defined surface handle, i.e.
List<GLCapabilitiesImmutable>	getAvailableCapabilities(AbstractGraphicsDevice device)	Returns an array of available GLCapabilities for the device. The list is sorted by the native ID, ascending. The chosen GLProfile statement in the result may not refer to the maximum available profile due to implementation constraints, ie using the shared resource.
abstract AbstractGraphicsDevice	getDefaultDevice()	Retrieve the default device connection, unit ID and unique ID name.
static GLDrawableFactory	getDesktopFactory()	Returns the sole GLDrawableFactory instance for the desktop (X11, WGL, ..) if exist or null
static GLDrawableFactory	getEGLFactory()	Returns the sole GLDrawableFactory instance for EGL if exist or null.
static GLDrawableFactory	getFactory(boolean useNativeGLES)	Returns the sole GLDrawableFactory instance, either for mobile if usesNativeGLES is true, or for desktop otherwise.
static GLDrawableFactory	getFactory(AbstractGraphicsDevice device)	Returns the sole GLDrawableFactory matching the given AbstractGraphicsDevice instance, which will be suitable either for native mobile or native desktop.
static GLDrawableFactory	getFactory(GLProfile glProfile)	Returns the sole GLDrawableFactory instance.
abstract boolean	getIsDeviceCompatible(AbstractGraphicsDevice device)
abstract GLRendererQuirks	getRendererQuirks(AbstractGraphicsDevice device, GLProfile glp)	Returns the shared resource's context GLRendererQuirks.
abstract boolean	hasOpenGLDesktopSupport()	Method returns true if underlying implementation may support native desktop OpenGL, otherwise false.
abstract boolean	hasOpenGLESSupport()	Method returns true if underlying implementation may support native embedded OpenGL ES, otherwise false.
boolean	hasRendererQuirk(AbstractGraphicsDevice device, GLProfile glp, int quirk)	Returns true if the quirk exist in the shared resource's context GLRendererQuirks.
static void	initSingleton()	Instantiate singleton factories if available, EGLES1, EGLES2 and the OS native ones.
abstract void	resetAllDisplayGamma()	Resets the gamma, brightness and contrast values of all modified displays to their original values before setDisplayGamma was called the first time.
abstract void	resetDisplayGamma(NativeSurface surface)	Resets the gamma, brightness and contrast values of the display associated with the given surface to its original values before setDisplayGamma was called the first time.
abstract boolean	setDisplayGamma(NativeSurface surface, float gamma, float brightness, float contrast)	Sets the gamma, brightness, and contrast of the display associated with the given surface.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

initSingleton

public static final void initSingleton()

Instantiate singleton factories if available, EGLES1, EGLES2 and the OS native ones.

setDisplayGamma

public abstract boolean setDisplayGamma(NativeSurface surface,
                                        float gamma,
                                        float brightness,
                                        float contrast)
                                 throws IllegalArgumentException

Sets the gamma, brightness, and contrast of the display associated with the given surface.

This functionality is not available on all platforms and graphics hardware. Returns true if the settings were successfully changed, false if not. This method may return false for some values of the incoming arguments even on hardware which does support the underlying functionality.

If this method returns true, the display settings will automatically be reset to their original values upon JVM exit (assuming the JVM does not crash); if the user wishes to change the display settings back to normal ahead of time, use resetDisplayGamma(NativeSurface) or resetAllDisplayGamma().

It is recommended to call resetDisplayGamma(NativeSurface) or resetAllDisplayGamma() before calling e.g. System.exit() from the application rather than rely on the shutdown hook functionality due to inevitable race conditions and unspecified behavior during JVM teardown.

This method may be called multiple times during the application's execution, but calling resetDisplayGamma(NativeSurface) will only reset the settings to the values before the first call to this method.

Parameters:

surface - denominates the display device

gamma - The gamma value, typically > 1.0 (default values vary, but typically roughly 1.0)

brightness - The brightness value between -1.0 and 1.0, inclusive (default values vary, but typically 0)

contrast - The contrast, greater than 0.0 (default values vary, but typically 1)

Returns:

true if gamma settings were successfully changed, false if not

Throws:

IllegalArgumentException - if any of the parameters were out-of-bounds

See Also:

resetDisplayGamma(NativeSurface), resetAllDisplayGamma()

resetDisplayGamma

public abstract void resetDisplayGamma(NativeSurface surface)

Resets the gamma, brightness and contrast values of the display associated with the given surface to its original values before setDisplayGamma was called the first time.

While it is not explicitly required that this method be called before exiting manually, calling it is recommended because of the inevitable unspecified behavior during JVM teardown.

resetAllDisplayGamma

public abstract void resetAllDisplayGamma()

Resets the gamma, brightness and contrast values of all modified displays to their original values before setDisplayGamma was called the first time.

While it is not explicitly required that this method be called before exiting manually, calling it is recommended because of the inevitable unspecified behavior during JVM teardown.

getDefaultDevice

public abstract AbstractGraphicsDevice getDefaultDevice()

Retrieve the default device connection, unit ID and unique ID name. for this factory
The implementation must return a non null default device, which must not be opened, ie. it's native handle is null.

This method shall return the default device if available even if the GLDrawableFactory is not functional and hence not compatible. The latter situation may happen because no native OpenGL implementation is available for the specific implementation.

Returns:

the default shared device for this factory, eg. :0.0 on X11 desktop.

See Also:

getIsDeviceCompatible(AbstractGraphicsDevice)

getIsDeviceCompatible

public abstract boolean getIsDeviceCompatible(AbstractGraphicsDevice device)

Parameters:

device - which connection denotes the shared the target device, may be null for the platform's default device.

Returns:

true if the device is compatible with this factory, ie. if it can be used for GLDrawable creation. Otherwise false. This implies validation whether the implementation is functional.

See Also:

getDefaultDevice()

hasRendererQuirk

public final boolean hasRendererQuirk(AbstractGraphicsDevice device,
                                      GLProfile glp,
                                      int quirk)

Returns true if the quirk exist in the shared resource's context GLRendererQuirks.

Convenience method for:

      final GLRendererQuirks glrq = factory.getRendererQuirks(device);
      return null != glrq ? glrq.exist(quirk) : false;
 

Parameters:

device - which connection denotes the shared the target device, may be null for the platform's default device.

glp - GLProfile to identify the device's GLRendererQuirks, maybe null

quirk - the quirk to be tested, e.g. GLRendererQuirks.NoDoubleBufferedPBuffer.

Throws:

IllegalArgumentException - if the quirk is out of range

See Also:

getRendererQuirks(AbstractGraphicsDevice, GLProfile), GLRendererQuirks

getRendererQuirks

public abstract GLRendererQuirks getRendererQuirks(AbstractGraphicsDevice device,
                                                   GLProfile glp)

Returns the shared resource's context GLRendererQuirks.

Implementation calls GLContext.getRendererQuirks() on the shared resource context.

In case no shared device exist yet or the implementation doesn't support tracking quirks, the result is always null.

Parameters:

device - which connection denotes the shared the target device, may be null for the platform's default device.

glp - GLProfile to identify the device's GLRendererQuirks, maybe null

See Also:

GLContext.getRendererQuirks(), GLRendererQuirks

hasOpenGLDesktopSupport

public abstract boolean hasOpenGLDesktopSupport()

Method returns true if underlying implementation may support native desktop OpenGL, otherwise false.

hasOpenGLESSupport

public abstract boolean hasOpenGLESSupport()

Method returns true if underlying implementation may support native embedded OpenGL ES, otherwise false.

getDesktopFactory

public static GLDrawableFactory getDesktopFactory()

Returns the sole GLDrawableFactory instance for the desktop (X11, WGL, ..) if exist or null

To fetch the appropriate GLDrawableFactory for native desktop or mobile, use getFactory(boolean).

It is possible that the desktop GLDrawableFactory will be used for native mobile GL profiles, e.g. Platform.OSType.IOS.

Returns:

the matching GLDrawableFactory or null if none is available

getEGLFactory

public static GLDrawableFactory getEGLFactory()

Returns the sole GLDrawableFactory instance for EGL if exist or null.

To fetch the appropriate GLDrawableFactory for native desktop or mobile, use getFactory(boolean).

It is possible that a non EGL GLDrawableFactory will be used for native mobile GL profiles, e.g. Platform.OSType.IOS.

Returns:

the matching GLDrawableFactory or null if none is available

getFactory

public static GLDrawableFactory getFactory(GLProfile glProfile)
                                    throws GLException

Returns the sole GLDrawableFactory instance.

Parameters:

glProfile - GLProfile to determine the factory type, ie for native mobile GL or native desktop GL.

Returns:

the matching GLDrawableFactory

Throws:

GLException - if no matching GLDrawableFactory exists

getFactory

public static GLDrawableFactory getFactory(boolean useNativeGLES)

Returns the sole GLDrawableFactory instance, either for mobile if usesNativeGLES is true, or for desktop otherwise.

Parameters:

useNativeGLES - request native mobile GLES support if true

Returns:

the matching GLDrawableFactory or null if none is available

getFactory

public static GLDrawableFactory getFactory(AbstractGraphicsDevice device)

Returns the sole GLDrawableFactory matching the given AbstractGraphicsDevice instance, which will be suitable either for native mobile or native desktop.

Parameters:

device - the queries AbstractGraphicsDevice seeking for its matching factory

Returns:

the matching GLDrawableFactory or null if none is available

getAvailableCapabilities

public final List<GLCapabilitiesImmutable> getAvailableCapabilities(AbstractGraphicsDevice device)

Returns an array of available GLCapabilities for the device.
The list is sorted by the native ID, ascending.
The chosen GLProfile statement in the result may not refer to the maximum available profile due to implementation constraints, ie using the shared resource.

Parameters:

device - which connection denotes the shared the target device, may be null for the platform's default device.

Returns:

A list of GLCapabilitiesImmutable's, maybe empty if none is available.

createGLDrawable

public abstract GLDrawable createGLDrawable(NativeSurface target)
                                     throws IllegalArgumentException,
                                            GLException

Returns an unrealized GLDrawable according to it's chosen GLCapabilitiesImmutable,
which determines pixel format, on- and offscreen incl. PBuffer type.

The chosen GLCapabilitiesImmutable are referenced within the target NativeSurface's AbstractGraphicsConfiguration.

An onscreen GLDrawable is created if caps.isOnscreen() is true.

A FBO drawable is created if both caps.isFBO() and canCreateFBO(device, caps.getGLProfile()) is true.

A Pbuffer drawable is created if both caps.isPBuffer() and canCreateGLPbuffer(device) is true.

If not onscreen and neither FBO nor Pbuffer is available, a simple pixmap/bitmap drawable/surface is created, which is unlikely to be hardware accelerated.

Throws:

IllegalArgumentException - if the passed target is null

GLException - if any window system-specific errors caused the creation of the GLDrawable to fail.

See Also:

canCreateGLPbuffer(AbstractGraphicsDevice, GLProfile), GLContext.isFBOAvailable(AbstractGraphicsDevice, GLProfile), Capabilities.isOnscreen(), GLCapabilities.isFBO(), GLCapabilities.isPBuffer(), GraphicsConfigurationFactory#chooseGraphicsConfiguration(CapabilitiesImmutable, CapabilitiesImmutable, CapabilitiesChooser, AbstractGraphicsScreen, int)

createOffscreenAutoDrawable

public abstract GLOffscreenAutoDrawable createOffscreenAutoDrawable(AbstractGraphicsDevice device,
                                                                    GLCapabilitiesImmutable caps,
                                                                    GLCapabilitiesChooser chooser,
                                                                    int width,
                                                                    int height)
                                                             throws GLException

Creates a realized GLOffscreenAutoDrawable incl it's offscreen NativeSurface with the given capabilities and dimensions.

The GLOffscreenAutoDrawable's GLDrawable is realized without an assigned GLContext, hence not initialized completely.
The GLContext can be assigned later manually via setContext(ctx) or it will be created lazily at the 1st display() method call.
Lazy GLContext creation will take a shared GLContext into account which has been set directly or via another GLAutoDrawable.

In case the passed GLCapabilitiesImmutable contains default values, i.e. caps.isOnscreen() == true, it is auto-configured. Auto configuration will set caps to offscreen and FBO or Pbuffer, whichever is available in that order.

A FBO based auto drawable, GLOffscreenAutoDrawable.FBO, is created if both caps.isFBO() and canCreateFBO(device, caps.getGLProfile()) is true.

A Pbuffer based auto drawable is created if both caps.isPBuffer() and canCreateGLPbuffer(device) is true.

If neither FBO nor Pbuffer is available, a simple pixmap/bitmap auto drawable is created, which is unlikely to be hardware accelerated.

The resulting GLOffscreenAutoDrawable has it's own independent device instance using device details.

Parameters:

device - which connection denotes the shared device to be used, may be null for the platform's default device.

caps - the requested GLCapabilties

chooser - the custom chooser, may be null for default

width - the requested offscreen width

height - the requested offscreen height

Returns:

the created and realized offscreen GLOffscreenAutoDrawable instance

Throws:

GLException - if any window system-specific errors caused the creation of the Offscreen to fail.

See Also:

createOffscreenDrawable(AbstractGraphicsDevice, GLCapabilitiesImmutable, GLCapabilitiesChooser, int, int)

createDummyAutoDrawable

public abstract GLAutoDrawable createDummyAutoDrawable(AbstractGraphicsDevice deviceReq,
                                                       boolean createNewDevice,
                                                       GLCapabilitiesImmutable capsRequested,
                                                       GLCapabilitiesChooser chooser)

Creates a realized dummy GLAutoDrawable incl it's dummy, invisible NativeSurface as created with createDummyDrawable(AbstractGraphicsDevice, boolean, GLCapabilitiesImmutable, GLCapabilitiesChooser).

The dummy GLAutoDrawable's GLDrawable is realized without an assigned GLContext, hence not initialized completely.
The GLContext can be assigned later manually via setContext(ctx) or it will be created lazily at the 1st display() method call.
Lazy GLContext creation will take a shared GLContext into account which has been set directly or via another GLAutoDrawable.

Parameters:

deviceReq - which connection denotes the shared device to be used, may be null for the platform's default device.

createNewDevice - if true a new independent device instance is created from the deviceReq, otherwise deviceReq is used as-is and must be valid!

capsRequested - the desired GLCapabilitiesImmutable, incl. it's GLProfile. For shared context, same VisualIDHolder.getVisualID(com.jogamp.nativewindow.VisualIDHolder.VIDType) across shared drawables will yield best compatibility.

chooser - the custom chooser, may be null for default

Returns:

the created and realized dummy GLAutoDrawable instance

See Also:

createDummyDrawable(AbstractGraphicsDevice, boolean, GLCapabilitiesImmutable, GLCapabilitiesChooser)

createOffscreenDrawable

public abstract GLDrawable createOffscreenDrawable(AbstractGraphicsDevice device,
                                                   GLCapabilitiesImmutable caps,
                                                   GLCapabilitiesChooser chooser,
                                                   int width,
                                                   int height)
                                            throws GLException

Creates an unrealized offscreen GLDrawable incl it's offscreen NativeSurface with the given capabilities and dimensions.

In case the passed GLCapabilitiesImmutable contains default values, i.e. caps.isOnscreen() == true, it is auto-configured. The latter will set offscreen and also FBO or Pbuffer, whichever is available in that order.

A resizeable FBO drawable, GLFBODrawable.Resizeable, is created if both caps.isFBO() and canCreateFBO(device, caps.getGLProfile()) is true.

A Pbuffer drawable is created if both caps.isPBuffer() and canCreateGLPbuffer(device) is true.

If neither FBO nor Pbuffer is available, a simple pixmap/bitmap drawable is created, which is unlikely to be hardware accelerated.

The resulting GLDrawable has it's own independent device instance using device details.

Parameters:

device - which connection denotes the shared device to be used, may be null for the platform's default device.

caps - the requested GLCapabilties

chooser - the custom chooser, may be null for default

width - the requested offscreen width

height - the requested offscreen height

Returns:

the created unrealized offscreen GLDrawable

Throws:

GLException - if any window system-specific errors caused the creation of the Offscreen to fail.

See Also:

#createOffscreenAutoDrawable(AbstractGraphicsDevice, GLCapabilitiesImmutable, GLCapabilitiesChooser, int, int, GLContext)

createDummyDrawable

public abstract GLDrawable createDummyDrawable(AbstractGraphicsDevice deviceReq,
                                               boolean createNewDevice,
                                               GLCapabilitiesImmutable capsRequested,
                                               GLCapabilitiesChooser chooser)

Creates an unrealized dummy GLDrawable. A dummy drawable is not visible on screen and will not be used to render directly to, it maybe on- or offscreen and implementation prefers creating a surfaceless drawable.

It is used to allow the creation of a GLContext to query information. It also allows creation of framebuffer objects which are used for rendering or creating a shared GLContext w/o actually rendering to this dummy drawable's framebuffer.

Parameters:

deviceReq - which connection denotes the shared device to be used, may be null for the platform's default device.

createNewDevice - if true a new independent device instance is created from the deviceReq, otherwise deviceReq is used as-is and must be valid!

capsRequested - the desired GLCapabilitiesImmutable, incl. it's GLProfile. For shared context, same visual ID or caps across shared drawables will yield best compatibility.

chooser - the custom chooser, may be null for default

Returns:

the created unrealized dummy GLDrawable

createProxySurface

public abstract ProxySurface createProxySurface(AbstractGraphicsDevice device,
                                                int screenIdx,
                                                long windowHandle,
                                                GLCapabilitiesImmutable caps,
                                                GLCapabilitiesChooser chooser,
                                                UpstreamSurfaceHook upstream)

Creates a proxy NativeSurface w/ defined surface handle, i.e. a WrappedSurface or GDISurface instance.

It's AbstractGraphicsConfiguration is properly set according to the given windowHandle's native visualID if set or the given GLCapabilitiesImmutable.

Lifecycle (creation and destruction) of the given surface handle shall be handled by the caller via ProxySurface.createNotify() and ProxySurface.destroyNotify().

Such surface can be used to instantiate a GLDrawable. With the help of GLAutoDrawableDelegate you will be able to implement a new native windowing system binding almost on-the-fly, see GLCanvas.

The resulting GLOffscreenAutoDrawable has it's own independent device instance using device details which may be blocking depending on platform and windowing-toolkit requirements.

Parameters:

device - which connection denotes the shared the target device, may be null for the platform's default device. Caller has to ensure it is compatible w/ the given windowHandle

screenIdx - matching screen index of given windowHandle

windowHandle - the native window handle

caps - the requested GLCapabilties

chooser - the custom chooser, may be null for default

upstream - optional UpstreamSurfaceHook allowing control of the ProxySurface's lifecycle and data it presents.

Returns:

the created ProxySurface instance w/ defined surface handle.

canCreateFBO

public abstract boolean canCreateFBO(AbstractGraphicsDevice device,
                                     GLProfile glp)

Returns true if it is possible to create an framebuffer object (FBO).

FBO feature is implemented in OpenGL, hence it is GLProfile dependent.

FBO support is queried as described in GLContext.hasBasicFBOSupport().

Parameters:

device - which connection denotes the shared the target device, may be null for the platform's default device.

glp - GLProfile to check for FBO capabilities

See Also:

GLContext.hasBasicFBOSupport()

canCreateGLPbuffer

public abstract boolean canCreateGLPbuffer(AbstractGraphicsDevice device,
                                           GLProfile glp)

Returns true if it is possible to create an pbuffer surface.

Some older graphics cards do not have this capability, as well as some new GL implementation, i.e. OpenGL 3 core on OSX.

Parameters:

device - which connection denotes the shared the target device, may be null for the platform's default device.

glp - GLProfile to check for FBO capabilities

createExternalGLContext

public abstract GLContext createExternalGLContext()
                                           throws GLException

Creates a GLContext object representing an existing OpenGL context in an external (third-party) OpenGL-based library. This GLContext object may be used to draw into this preexisting context using its GL and GLU objects. New contexts created through GLDrawables may share textures and display lists with this external context.

The underlying OpenGL context must be current on the current thread at the time this method is called. The user is responsible for the maintenance of the underlying OpenGL context; calls to makeCurrent and release on the returned GLContext object have no effect. If the underlying OpenGL context is destroyed, the destroy method should be called on the GLContext. A new GLContext object should be created for each newly-created underlying OpenGL context.

Throws:

GLException - if any window system-specific errors caused the creation of the external GLContext to fail.

canCreateExternalGLDrawable

public abstract boolean canCreateExternalGLDrawable(AbstractGraphicsDevice device)

Returns true if it is possible to create an external GLDrawable object via createExternalGLDrawable().

Parameters:

device - which connection denotes the shared the target device, may be null for the platform's default device.

createExternalGLDrawable

public abstract GLDrawable createExternalGLDrawable()
                                             throws GLException

Creates a GLDrawable object representing an existing OpenGL drawable in an external (third-party) OpenGL-based library. This GLDrawable object may be used to create new, fully-functional GLContexts on the OpenGL drawable. This is useful when interoperating with a third-party OpenGL-based library and it is essential to not perturb the state of the library's existing context, even to the point of not sharing textures or display lists with that context.

An underlying OpenGL context must be current on the desired drawable and the current thread at the time this method is called. The user is responsible for the maintenance of the underlying drawable. If one or more contexts are created on the drawable using GLDrawable.createContext(com.jogamp.opengl.GLContext), and the drawable is deleted by the third-party library, the user is responsible for calling GLContext.destroy() on these contexts.

Calls to setSize, getWidth and getHeight are illegal on the returned GLDrawable. If these operations are required by the user, they must be performed by the third-party library.

It is legal to create both an external GLContext and GLDrawable representing the same third-party OpenGL entities. This can be used, for example, to query current state information using the external GLContext and then create and set up new GLContexts using the external GLDrawable.

This functionality may not be available on all platforms and canCreateExternalGLDrawable(com.jogamp.nativewindow.AbstractGraphicsDevice) should be called first to see if it is present. For example, on X11 platforms, this API requires the presence of GLX 1.3 or later.

Throws:

GLException - if any window system-specific errors caused the creation of the external GLDrawable to fail.