- create a new GLX rendering context
( Display *dpy
Bool direct )
- Specifies the connection to the X server.
- Specifies the visual that defines the frame buffer resources available to
the rendering context. It is a pointer to an XVisualInfo structure,
not a visual ID or a pointer to a Visual.
- Specifies the context with which to share display lists. NULL
indicates that no sharing is to take place.
- Specifies whether rendering is to be done with a direct connection to the
graphics system if possible ( True) or through the X server (
creates a GLX rendering context and returns its handle.
This context can be used to render into both windows and GLX pixmaps. If
fails to create a rendering context, NULL
, then a direct rendering context is created if
the implementation supports direct rendering, if the connection is to an X
server that is local, and if a direct rendering context is available. (An
implementation may return an indirect context when direct
). If direct
, then a rendering context that
renders through the X server is always created. Direct rendering provides a
performance advantage in some implementations. However, direct rendering
contexts cannot be shared outside a single process, and they may be unable to
render to GLX pixmaps.
is not NULL
, then all display-list indexes and
definitions are shared by context shareList
and by the newly created
context. An arbitrary number of contexts can share a single display-list
space. However, all rendering contexts that share a single display-list space
must themselves exist in the same address space. Two rendering contexts share
an address space if both are nondirect using the same server, or if both are
direct and owned by a single process. Note that in the nondirect case, it is
not necessary for the calling threads to share an address space, only for
their related rendering contexts to share an address space.
If the GL version is 1.1 or greater, then all texture objects except object 0,
are shared by any contexts that share display lists.
is defined in Xutil.h.
It is a structure that includes
, and depth
is a single execution environment, implemented in a single
address space, consisting of one or more threads.
is one of a set of subprocesses that share a single address
space, but maintain separate program counters, stack spaces, and other related
global data. A thread
that is the only member of its subprocess group
is equivalent to a process
It may not be possible to render to a GLX pixmap with a direct rendering
is returned if execution fails on the client side.
is generated if the context to be created would not share the
address space or the screen of the context specified by shareList
is generated if vis
is not a valid visual (for example,
if a particular GLX implementation does not support it).
is generated if shareList
is not a GLX context and
is not NULL
is generated if the server does not have enough resources to
allocate the new context.