How Collision Detection Is Controlled; Table 7-4 Clxcon Bits - Commodore Amiga A1000 Hardware Reference Manual

HOW COLLISION DETECTION IS CONTROLLED

The collision control register, CLXCON, contains the bits that define certain characteristics
of collision detection. Its bits are shown in Table 7-4.
Table 7-4: CLXCON Bits
Bit
Number Name
15 ENSP7
14 ENSPS
13 ENSP3
12 ENSP1
11 ENBP6
10 ENBPS
9 ENBP4
8 ENBP3
7 ENBP2
6 ENBP1
5 MVBP6
4 MVBPS
3 MVBP4
2 MVBP3
1 MVBP2
0 MVBP1
Bits 15-12 let you specify that collisions with a sprite pair are to include the odd-
numbered sprite of a pair of sprites. The even-numbered sprites always are included in
the collision detection. Bits 11-6 let you specify whether to include or exclude specific bit-
planes from the collision detection. Bits 5-0 let you specify the polarity (true-false
condition) of bits that will cause a collision. For example, you may wish to register
collisions only when the object collides with "something green2 or "something blue." This
feature, along with the collision enable bits, allows you to specify the exact bits, and their
polarity, for the collision to be registered.
NOTE
This register is write-only. If all bit-planes are excluded (disabled), then a bit-plane
collision will always be detected.
Function
Enable sprite 7 (OR with sprite 6)
Enable sprite 5 (OR with sprite 4)
Enable sprite 3 (OR with sprite 2)
Enable sprite 1 (OR with sprite 0)
Enable bit-plane 6 (match required for collision)
Enable bit-plane 5 (match required for collision)
Enable bit-plane 4 (match required for collision)
Enable bit-plane 3 (match required for collision)
Enable bit-plane 2 (match required for collision)
Enable bit-plane 1 (match required for collision)
Match value for bit-plane 6 collision
Match value for bit-plane 5 collision
Match value for bit-plane 4 collision
Match value for bit-plane 3 collision
Match value for bit-plane 2 collision
Match value for bit-plane 1 collision
- System Control Hardware 209 -