The sun and moon expand beyond the edges of the day and night sectors if the sectors are small.

[RobertWarrenGilmore]

Possible solutions:

• Shrink them if the sectors are small.
• Mask them so that they are only painted inside of the sector. (The edge of the sector cuts them off.)
• Omit them if the sectors are small. (Perhaps this should only be for extremely small sectors.)

[RobertWarrenGilmore]

Also, what do we do about the arctic?

[RobertWarrenGilmore]

It's possible to do the masking approach!

• Use Paint.setXferMode to paint the sun and moon only within their respective sectors.
• Use this bitmap painting technique to isolate the sector bitmaps to do the masking, then paint the resulting bitmap parts onto the face.

The draw method is starting to do a lot, so maybe everything but the hands should be cached as a bitmap and reapplied in one go on each frame. The watch face service would need to listen to any change that would affect the background or the ticks (settings, properties, ambient mode, location, size change, maybe more) and invalidate the painter.

Also consider that the palette is passed in on draw. Perhaps it should be a field on the painter instead, so that the painter caches an image for each palette and invalidates the cache when either of its palette fields (ambient or interactive) is changed.

[RobertWarrenGilmore]

Canvas.clipPath might be a simpler alternative.