org.lwjgl.egl

Class KHRContextFlushControl

java.lang.Object

org.lwjgl.egl.KHRContextFlushControl

public final class KHRContextFlushControl
extends java.lang.Object

Native bindings to the KHR_context_flush_control extension.

OpenGL and OpenGL ES have long supported multiple contexts. The semantics of switching contexts is generally left to window system binding APIs such as WGL, GLX and EGL. Most of these APIs (if not all) specify that when the current context for a thread is changed, the outgoing context performs an implicit flush of any commands that have been issued to that point. OpenGL and OpenGL ES define a flush as sending any pending commands for execution and that this action will result in their completion in finite time.

This behavior has subtle consequences. For example, if an application is rendering to the front buffer and switches contexts, it may assume that any rendering performed thus far will eventually be visible to the user. With recent introduction of shared memory buffers, there become inumerable ways in which applications may observe side effects of an implicit flush (or lack thereof).

In general, a full flush is not the desired behavior of the application. Nonetheless, applications that switch contexts frequently suffer the performance consequences of this unless implementations make special considerations for them, which is generally untenable.

The EGL, GLX, and WGL extensions add new context creation parameters that allow an application to specify the behavior that is desired when a context is made non-current, and specifically to opt out of the implicit flush behavior. The GL extension allows querying the context flush behavior.

Field Summary

Fields

Modifier and Type	Field and Description
static int	EGL_CONTEXT_RELEASE_BEHAVIOR_FLUSH_KHR Accepted as an attribute value for CONTEXT_RELEASE_BEHAVIOR_KHR in the *attrib_list argument to CreateContext.
static int	EGL_CONTEXT_RELEASE_BEHAVIOR_KHR Accepted as an attribute name in the *attrib_list argument to CreateContext.
static int	EGL_CONTEXT_RELEASE_BEHAVIOR_NONE_KHR Accepted as an attribute value for CONTEXT_RELEASE_BEHAVIOR_KHR in the *attrib_list argument to CreateContext.

Method Summary

Methods inherited from class java.lang.Object

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

Field Detail

EGL_CONTEXT_RELEASE_BEHAVIOR_KHR

public static final int EGL_CONTEXT_RELEASE_BEHAVIOR_KHR

Accepted as an attribute name in the *attrib_list argument to CreateContext.

See Also:

Constant Field Values

EGL_CONTEXT_RELEASE_BEHAVIOR_NONE_KHR

public static final int EGL_CONTEXT_RELEASE_BEHAVIOR_NONE_KHR

Accepted as an attribute value for CONTEXT_RELEASE_BEHAVIOR_KHR in the *attrib_list argument to CreateContext.

See Also:

Constant Field Values

EGL_CONTEXT_RELEASE_BEHAVIOR_FLUSH_KHR

public static final int EGL_CONTEXT_RELEASE_BEHAVIOR_FLUSH_KHR

Accepted as an attribute value for CONTEXT_RELEASE_BEHAVIOR_KHR in the *attrib_list argument to CreateContext.

See Also:

Constant Field Values