glPushClientAttrib takes one argument,
a mask that indicates which groups of client-state variables
to save on the client attribute stack.
Symbolic constants are used to set bits in the mask.
mask
is typically constructed by OR'ing several of these constants together.
The special mask
GL_CLIENT_ALL_ATTRIB_BITS
can be used to save all stackable client state.
The symbolic mask constants and their associated GL client state are as follows
(the second column lists which attributes are saved):
GL_CLIENT_PIXEL_STORE_BIT Pixel storage modes
GL_CLIENT_VERTEX_ARRAY_BIT Vertex arrays (and enables)
glPopClientAttrib restores the values of the client-state variables
saved with the last glPushClientAttrib .
Those not saved are left unchanged.
It is an error to push attributes onto a full client attribute stack,
or to pop attributes off an empty stack.
In either case, the error flag is set,
and no other change is made to GL state.
Initially, the client attribute stack is empty.