void PEXReturnAccumulationBuffer( Display *display, Drawable drawable, float scale_factor )
None.
Invoke PEXReturnAccumulationBuffer to multiply the contents of the accumulation buffer (A) associated with drawable (D) by the scale_factor (w) and then write to the drawable itself.
This function overwrites the existing values in the
drawable.
The operation is as follows:
If underflow or overflow occurs, then the result is implementation-dependent.
See Accumulation Buffers for an overview.