2003-2014
The Khronos Group Inc.
eglSwapBuffers
3G
eglSwapBuffers
post EGL surface color buffer to a native window
C Specification
EGLBoolean eglSwapBuffers
EGLDisplay display
EGLSurface surface
Parameters
display
Specifies the EGL display connection.
surface
Specifies the EGL drawing surface whose buffers are to be swapped.
Description
If surface is a window surface,
eglSwapBuffers posts its color buffer
to the associated native window.
The contents of ancillary buffers are always undefined after
calling eglSwapBuffers. The contents of
the color buffer are left unchanged if the value of the
EGL_SWAP_BEHAVIOR attribute of
surface is
EGL_BUFFER_PRESERVED, and are undefined
if the value is EGL_BUFFER_DESTROYED.
The value of EGL_SWAP_BEHAVIOR can be
set for some surfaces using
eglSurfaceAttrib.
eglSwapBuffers performs an implicit
flush operation on the context (glFlush
for an OpenGL ES or OpenGL context,
vgFlush for an OpenVG context) bound to
surface before swapping. Subsequent
client API commands may be issued on that context
immediately after calling
eglSwapBuffers, but are not executed
until the buffer exchange is completed.
If surface is a pixel buffer or a pixmap,
eglSwapBuffers
has no effect, and no error is generated.
Notes
Attribute EGL_SWAP_BEHAVIOR is
supported only if the EGL version is 1.2 or greater. In
earlier versions, behavior is as though the attribute
exists, and always has the value
EGL_BUFFER_DESTROYED.
The EGL 1.4 specification was updated to acknowledge that
ancillary buffers are not necessarily preserved after a
swap, and that the EGL_SWAP_BEHAVIOR
attribute applies only to the color buffer. This change in
the specification acknowledged the behavior of many shipping
implementations, and is not intended to result in behavior
changes in any existing implementation. Applications which
require preservation of ancillary buffers across a swap
should be aware that not all implementations can preserve
them, and that EGL 1.4 has no way to query whether or not
they are preserved.
Errors
EGL_FALSE is returned if swapping of the
surface buffers fails, EGL_TRUE otherwise.
EGL_BAD_DISPLAY is generated if
display is not an EGL display connection.
EGL_NOT_INITIALIZED is generated if
display has not been initialized.
EGL_BAD_SURFACE is generated if
surface is not an EGL drawing surface.
EGL_CONTEXT_LOST is generated if a power management
event has occurred. The application must destroy all contexts and
reinitialise OpenGL ES state and objects to continue rendering.
See Also
glFlush,
eglCopyBuffers