_m_a_s_k Specifies which portions of _s_r_c state are to be copied to _d_s_t.
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
ggggllllXXXXCCCCooooppppyyyyCCCCoooonnnntttteeeexxxxtttt copies selected groups of state variables from _s_r_c to _d_s_t.
_m_a_s_k indicates which groups of state variables are to be copied. _m_a_s_k
contains the bitwise OR of the same symbolic names that are passed to the
GL command ggggllllPPPPuuuusssshhhhAAAAttttttttrrrriiiibbbb. The single symbolic constant GGGGLLLL____AAAALLLLLLLL____AAAATTTTTTTTRRRRIIIIBBBB____BBBBIIIITTTTSSSS
can be used to copy the maximum possible portion of rendering state.
The copy can be done only if the renderers named by _s_r_c and _d_s_t 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 necessary 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 ggggllllPPPPuuuusssshhhhAAAAttttttttrrrriiiibbbb.
An implicit ggggllllXXXXFFFFlllluuuusssshhhh is done by ggggllllXXXXCCCCooooppppyyyyCCCCoooonnnntttteeeexxxxtttt if _s_r_c is the current
context for the calling thread.
NNNNOOOOTTTTEEEESSSS
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.
A _p_r_o_c_e_s_s is a single execution environment, implemented in a single
address space, consisting of one or more threads.
A _t_h_r_e_a_d 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 _t_h_r_e_a_d that is the only member of its subprocess
On all SGI systems, _s_r_c must be the current context and, except in the
case of direct rendering contexts on IIIInnnnffffiiiinnnniiiitttteeeeRRRReeeeaaaalllliiiittttyyyy, RRRReeeeaaaalllliiiittttyyyyEEEEnnnnggggiiiinnnneeee,
RRRReeeeaaaalllliiiittttyyyyEEEEnnnnggggiiiinnnneeee2222, and VVVVTTTTXXXX systems, _d_s_t must have been made current to some
thread prior to the copy.
On RRRReeeeaaaalllliiiittttyyyyEEEEnnnnggggiiiinnnneeee, RRRReeeeaaaalllliiiittttyyyyEEEEnnnnggggiiiinnnneeee2222, and VVVVTTTTXXXX, on IIIInnnnffffiiiinnnniiiitttteeeeRRRReeeeaaaalllliiiittttyyyy, on HHHHiiiigggghhhh
IIIImmmmppppaaaacccctttt and MMMMaaaaxxxxiiiimmmmuuuummmm IIIImmmmppppaaaacccctttt, on SSSSoooolllliiiidddd IIIImmmmppppaaaacccctttt systems, on OOOO2222 systems, and on
OOOOccccttttaaaannnneeee2222 VVVVPPPPrrrroooo systems, it is not possible to use a context for rendering