void PEXAllocateAccumulationBuffer( Display *display, Drawable drawable )
None.
Invoke PEXAllocateAccumulationBuffer to allocate an accumulation buffer for the specified drawable.
The width and height of the accumulation buffer match that of the drawable. The depth of the buffer is implementation-dependent but must be at least as deep as the drawable. The initial contents of the buffer are undefined. The function PEXLoadAccumulationBuffer initializes the accumulation buffer.
See Accumulation Buffers for an overview.