Multiplication by 1.0
Have to decide up front when building saturating multiplier what to do for case of 1.0
Two choices:
- Assign a flag bit or detect the case of 255 and simply pass one operand through unchanged.
- Perform internal operations for cases at precision greater than 8 bits (would require fog factor to specified by > 8 bit precision, so use 9 bits to represent 1.0).