Our SpriteFrameType names refer to the byte channel order rather than
the bit order, meaning that SpriteFrameType.BGRA corresponds to the
standard Color.ToArgb() etc byte order when the (little-endian) integer
is read as 4 individual bytes.
The previous code did not account for the fact that non-indexed Png
uses big-endian storage for its RGBA colours, and that SheetBuilder
had the color channels incorrectly swapped to match and cancel this out.
New SpriteFrameType enums are introduced to distinguish between BGRA
(little-endian) and RGBA (big-endian) formats, and also for 24bit data
without alpha. The channel swizzling / alpha creation is now handled
when copying into the texture atlas, removing the need for non-png
ISpriteLoader implementations to allocate an additional temporary array
and reorder the channels during load.
Do not call SkipDoneActivities method recursively via the
NextActivity property. Rather use the nextActivity member.
Avoiding additional function calls and a recursively
growing stack.
Do not call ChildActivity and NextActivity properties
twice in a row. Once to test for null and after to access
it's value. It will cause the complete list of activities
to be traversed twice looking for non done activities.
Replace Queue method with a version that does not the
NextActivity property causing an extra call to
SkipDoneActivities. Avoid calling Queue recursively.
Similar replace QueueChild with a version that does
not call additional methods.
Note that ActivitiesImplementing returns only non
done activities. The method name does not suggest this.
Please consider making NextActivity a method to cleary indicate it
involves the logic of skipping Done activities. To let
the called know it is 'expensive'.
Please consider renaming the protected property ChildActivity to
FirstChildActivityNotDone to avoid it being used as childActivity.
Please consider maintaining a pointer to the first
non done activity. This avoids the need the each time find it.
