Fix alignment
(Readability) Special effect register
(Readability) Special effect constants
Indentation
Optimize/clarify (x|-x)>>31 expressions
(Readability) Layer masks
Comments
Whitespace
(Readability) Video mode
Refactor mask selection code into an force-inlined function.
Slightly optimize SELECT
(Readability) Layer indices
(Readability) Special effect target layers
(Readability) Special effect target layer tests