For more complex or larger moving objects, you can overlap sprites.
Overlapping simply means that the sprites have the same or relatively
close screen positions. A relatively close screen position can result in
an object that is wider than 16 pixels.
The built-in sprite video priority ensures that one sprite appears to be
behind the other when sprites are overlapped. The priority circuitry gives
the lowest-numbered sprite the highest priority and the highest numbered
sprite the lowest priority. Therefore, when designing displays with
overlapped sprites, make sure the "foreground" sprite has a lower number
than the "background" sprite. In Figure 4-11, for example, the cage should
be generated by a lower-numbered sprite DMA channel than the monkey.
Figure 4-11: Overlapping Sprites (Not Attached)
You can create a wider sprite display by placing two sprites next to each
other. For instance, Figure 4-12 shows the spaceship sprite and how it can
be made twice as large by using two sprites placed next to each other.
(128,65) (128,65) (144,65)
|_ _ _ __ _ _ _ |_ _ _ _ _ _ __|__ _ _ _ _ _ _
| / \ | | / | \ |
__/____\__ / \
| | | | | / | \ |
| | ____/___________\____
| |__________| | | | | | |
\ / | |
|_ _ _\__/_ _ _| | | | | |
| |
| |__________|__________| |
\ /
| \ | / |
\ /
|_ _ _ _ _ _\__|__/_ _ _ _ _ _|
Sprite 0 Sprite 1
Figure 4-12: Placing Sprites Next to Each Other