javax.media.opengl
Class GLDrawableFactory

java.lang.Object
  extended by javax.media.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.
GLPbuffer are always created immediately and their creation will fail with a GLException if errors occur.

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
abstract  boolean canCreateExternalGLDrawable(AbstractGraphicsDevice device)
          Returns true if it is possible to create an external GLDrawable object via createExternalGLDrawable().
abstract  boolean canCreateGLPbuffer(AbstractGraphicsDevice device)
          Returns true if it is possible to create a GLPbuffer.
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 a GLDrawable according to it's chosen Capabilities,
which determines pixel format, on- and offscreen incl.
abstract  GLPbuffer createGLPbuffer(GLCapabilitiesImmutable capabilities, GLCapabilitiesChooser chooser, int initialWidth, int initialHeight, GLContext shareWith)
          Creates a GLPbuffer with the given capabilites and dimensions.
abstract  GLDrawable createGLPbufferDrawable(GLCapabilitiesImmutable capabilities, GLCapabilitiesChooser chooser, int initialWidth, int initialHeight)
          Creates a Pbuffer GLDrawable with the given capabilites and dimensions.
abstract  GLDrawable createOffscreenDrawable(GLCapabilitiesImmutable capabilities, GLCapabilitiesChooser chooser, int width, int height)
          Creates a Offscreen GLDrawable with the given capabilites and dimensions.
abstract  AbstractGraphicsDevice getDefaultDevice()
          Retrieve the default device AbstractGraphicsDevice.getConnection().
static GLDrawableFactory getFactory(GLProfile glProfile)
          Returns the sole GLDrawableFactory instance.
abstract  boolean getIsDeviceCompatible(AbstractGraphicsDevice device)
           
 boolean getIsSharedContextAvailable(AbstractGraphicsDevice device)
          Returns true if a shared context is already mapped to the device AbstractGraphicsDevice.getConnection(), or if a new shared context could be created and mapped.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

getDefaultDevice

public abstract AbstractGraphicsDevice getDefaultDevice()
Retrieve the default device AbstractGraphicsDevice.getConnection(). for this factory
The implementation must return a non null default device, which must not be opened, ie. it's native handle may be null.

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

getIsDeviceCompatible

public abstract boolean getIsDeviceCompatible(AbstractGraphicsDevice device)
Returns:
true if the device is compatible with this factory, ie. if it can be used for creation. Otherwise false.

getIsSharedContextAvailable

public final boolean getIsSharedContextAvailable(AbstractGraphicsDevice device)
Returns true if a shared context is already mapped to the device AbstractGraphicsDevice.getConnection(), or if a new shared context could be created and mapped. Otherwise return false.
Creation of the shared context is tried only once.

Parameters:
device - if null, the platform default device is being used

getFactory

public static GLDrawableFactory getFactory(GLProfile glProfile)
                                    throws GLException
Returns the sole GLDrawableFactory instance.

Parameters:
glProfile - GLProfile to determine the factory type, ie EGLDrawableFactory, or one of the native GLDrawableFactory's, ie X11/GLX, Windows/WGL or MacOSX/CGL.
Throws:
GLException

createGLDrawable

public abstract GLDrawable createGLDrawable(NativeSurface target)
                                     throws IllegalArgumentException,
                                            GLException
Returns a GLDrawable according to it's chosen Capabilities,
which determines pixel format, on- and offscreen incl. PBuffer type.

The native platform's chosen Capabilties are referenced within the target NativeSurface's AbstractGraphicsConfiguration.

In case Capabilities.isOnscreen() is true,
an onscreen GLDrawable will be realized.

In case Capabilities.isOnscreen() is false,
either a Pbuffer drawable is created if GLCapabilities.isPBuffer() is true,
or a simple offscreen drawable is creates. The latter 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:
javax.media.nativewindow.GraphicsConfigurationFactory#chooseGraphicsConfiguration(Capabilities, CapabilitiesChooser, AbstractGraphicsScreen)

createOffscreenDrawable

public abstract GLDrawable createOffscreenDrawable(GLCapabilitiesImmutable capabilities,
                                                   GLCapabilitiesChooser chooser,
                                                   int width,
                                                   int height)
                                            throws GLException
Creates a Offscreen GLDrawable with the given capabilites and dimensions.

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

canCreateGLPbuffer

public abstract boolean canCreateGLPbuffer(AbstractGraphicsDevice device)
Returns true if it is possible to create a GLPbuffer. Some older graphics cards do not have this capability.

Parameters:
passing - the device for the query, may be null

createGLPbufferDrawable

public abstract GLDrawable createGLPbufferDrawable(GLCapabilitiesImmutable capabilities,
                                                   GLCapabilitiesChooser chooser,
                                                   int initialWidth,
                                                   int initialHeight)
                                            throws GLException
Creates a Pbuffer GLDrawable with the given capabilites and dimensions.

Throws:
GLException - if any window system-specific errors caused the creation of the GLPbuffer to fail.

createGLPbuffer

public abstract GLPbuffer createGLPbuffer(GLCapabilitiesImmutable capabilities,
                                          GLCapabilitiesChooser chooser,
                                          int initialWidth,
                                          int initialHeight,
                                          GLContext shareWith)
                                   throws GLException
Creates a GLPbuffer with the given capabilites and dimensions.

See the note in the overview documentation on context sharing.

Throws:
GLException - if any window system-specific errors caused the creation of the GLPbuffer to fail.

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:
passing - the device for the query, may be null

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(javax.media.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(javax.media.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.


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