AWTTilePainter simply rounds the scaled double precision clipping rectangle
to receive the integer rectangle.
This leads to uncovered drawing areas, since the integer rectangle position
could be greater - and the size could be smaller than the double precision source.
To get the enclosing rectangle, we need to use
iPos = floor(position)
iSize = ceil(position+size) - floor(position)
.. turns our that the double precision 'Rectangle Rectangle2D.getBounds()'
already performs this math.