glXMakeCurrent(3G) OpenGL Reference - GLX glXMakeCurrent(3G)
NAME
glXMakeCurrent - attach a GLX context to a window or a GLX pixmap
C SPECIFICATION
Bool glXMakeCurrent( Display *dpy,
GLXDrawable drawable,
GLXContext ctx )
PARAMETERS
dpy Specifies the connection to the X server.
drawable Specifies a GLX drawable. Must be either an X window ID or a
GLX pixmap ID.
ctx Specifies a GLX rendering context that is to be attached to
drawable.
DESCRIPTION
glXMakeCurrent does two things: It makes ctx the current GLX rendering
context of the calling thread, replacing the previously current context
if there was one, and it attaches ctx to a GLX drawable, either a window
or a GLX pixmap. As a result of these two actions, subsequent OpenGL
rendering calls use rendering context ctx to modify GLX drawable
drawable. Because glXMakeCurrent always replaces the current rendering
context with ctx, there can be only one current context per thread.
Pending commands to the previous context, if any, are flushed before it
is released.
The first time ctx is made current to any thread, its viewport is set to
the full size of drawable. Subsequent calls by any thread to
glXMakeCurrent with ctx have no effect on its viewport.
To release the current context without assigning a new one, call
glXMakeCurrent with drawable set to None and ctx set to NULL.
glXMakeCurrent returns True if it is successful, False otherwise. If
False is returned, the previously current rendering context and drawable
(if any) remain unchanged.
NOTES
A process is a single-execution environment, implemented in a single
address space, consisting of one or more threads.
A thread 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.
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glXMakeCurrent(3G) OpenGL Reference - GLX glXMakeCurrent(3G)
ERRORS
BadMatch is generated if drawable was not created with the same X screen
and visual as ctx. It is also generated if drawable is None and ctx is
not NULL.
BadAccess is generated if ctx was current to another thread at the time
glXMakeCurrent was called.
GLXBadDrawable is generated if drawable is not a valid GLX drawable.
GLXBadContext is generated if ctx is not a valid GLX context.
GLXBadContextState is generated if glXMakeCurrent is called between the
execution of glBegin and the corresponding execution of glEnd.
GLXBadContextState is also generated if the rendering context current to
the calling thread has OpenGL renderer state GLFEEDBACK or GLSELECT.
GLXBadCurrentWindow is generated if there are pending OpenGL commands for
the previous context and the current drawable is a window that is no
longer valid.
BadAlloc may be generated if the server has delayed allocation of
ancillary buffers until glXMakeCurrent is called, only to find that it
has insufficient resources to complete the allocation.
MACHINE DEPENDENCIES
On RealityEngine, RealityEngine2, and VTX, on InfiniteReality, on High
Impact and Maximum Impact, on Solid Impact systems, and on O2 systems, it
is not possible to use a context for rendering to both windows and
pixmaps.
SEE ALSO
glXCreateContext, glXCreateGLXPixmap glXGetCurrentContext,
glXGetCurrentDisplay, glXGetCurrentDrawable
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