=== SRCH ===
* When searching sx and sy are masked before use. The resulting "found" x position is based on If the unmasked value. i.e. if a matching pixel width is at 30, and you specify x>256, then the match sx is reported to be found at 256+30masked with 255 before use.
* The resulting "found" x position is based on the unmasked value. i.e. if a matching pixel is at 30, and you specify sx>width, then the match is reported to be found at width+30. * When searching in reverse, if no match is found a X coordinate of 0x07ff will be reported. The "match" flag will not be set as expected.
* When searching forwards, if no match is found then a multiple of the width is reported depending on sx. If sx<width then width is reported, if width<sx<width*2 then width*2 is reported etc. The "match" flag will not be set as expected.