This patch adjusts the Bokeh Blur node such that it matches between CPU
and GPU. The GPU implementation is followed for the reasons stated
below.
The first difference is a bug in the CPU implementation, where the upper
limit of the blur window is not considered, but the lower limit is.
The second difference is due to an additional weight of 1.0 for blur
size less than 2, which was apparently in place to workaround the
aforementioned bug, since for zero sized blurs, the blur loop will not
run due to the missing upper limit.
The third difference is due to CPU ignoring outside pixels instead of
clamping them to border, which is done until an option is added to the
node to control the boundary condition.
An extra difference existed between Tiled and Full-frame, where the
canvas had different rounding methods, so that was unified.
Pull Request: https://projects.blender.org/blender/blender/pulls/117847
a433adda8e