How Collision Detection Is Controlled - Commodore Amiga Hardware Reference Manual

Table 7-3: CLXDAT Bits
Bit
Number Collisions Registered
15 not used
14 Sprite 4 (or 5) to sprite 6 (or 7)
13 Sprite 2 (or 3) to sprite 6 (or 7)
12 Sprite 2 (or 3) to sprite 4 (or 5)
11 Sprite 0 (or 1) to sprite 6 (or 7)
10 Sprite 0 (or 1) to sprite 4 (or 5)
9 Sprite 0 (or 1) to sprite 2 (or 3)
8 Even bit-planes to sprite 6 (or 7)
7 Even bit-planes to sprite 4 (or 5)
6 Even bit-planes to sprite 2 (or 3)
5 Even bit-planes to sprite 0 (or 1)
4 Odd bit-planes to sprite 6 (or 7)
3 Odd bit-planes to sprite 4 (or 5)
2 Odd bit-planes to sprite 2 (or 3)
1 Odd bit-planes to sprite 0 (or 1)
o
Even bit-planes to odd bit-planes
The notes in parentheses in table 7-3 refer to collisions that will register only if you want
them to show up. The collision control register described below lets you either ignore or
include the odd-numbered sprites in the collision detection.
Notice that in this table, collision detection does
not
change when you select either
single- or dual-playfield mode. Collision detection depends only on the actual bits
present in the odd-numbered or even-numbered bit-planes. The collision control register
specifies how to handle the bit-planes during collision detect.
HOW COLLISION DETECTION IS CONTROLLED
The collision control register, CLXCON, contains the bits that define certain characteris-
tics of collision detection. Its bits are shown in table 7-4.
System Control Hardware 203