GLXCOPYCONTEXT() MachTen Programmer’s Manual GLXCOPYCONTEXT()

NAME
glXCopyContext - copy state from one rendering context to
another

C SPECIFICATION
void glXCopyContext( Display *dpy,
GLXContext src,
GLXContext dst,
unsigned long mask )

delim $$

PARAMETERS
dpy Specifies the connection to the X server.

src Specifies the source context.

dst Specifies the destination context.

mask Specifies which portions of src state are to be
copied to dst.

DESCRIPTION
glXCopyContext copies selected groups of state variables
from src to dst. mask indicates which groups of state
variables are to be copied. mask contains the bitwise OR
of the same symbolic names that are passed to the GL com-
mand glPushAttrib. The single symbolic constant
GL_ALL_ATTRIB_BITS can be used to copy the maximum possi-
ble portion of rendering state.

The copy can be done only if the renderers named by src
and dst share an 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 neces-
sary for the calling threads to share an address space,
only for their related rendering contexts to share an
address space.

Not all values for GL state can be copied. For example,
pixel pack and unpack state, render mode state, and select
and feedback state are not copied. The state that can be
copied is exactly the state that is manipulated by the GL
command
glPushAttrib.

An implicit glFlush is done by glXCopyContext if src is
the current context for the calling thread.

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 sin-
gle 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.

ERRORS
BadMatch is generated if rendering contexts src and dst do
not share an address space or were not created with
respect to the same screen.

BadAccess is generated if dst is current to any thread
(including the calling thread) at the time glXCopyContext
is called.

GLXBadCurrentWindow is generated if src is the current
context and the current drawable is a window that is no
longer valid.

GLXBadContext is generated if either src or dst is not a
valid GLX context.

SEE ALSO
glPushAttrib, glXCreateContext, glXIsDirect

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