The collision data register, CLXDAT, is read-only, and its contents are automatically cleared to 0 after it is read. Its bits are as shown in Table 7-3. 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 bitplanes to sprite 6 (or 7) 7 Even bitplanes to sprite 4 (or 5) 6 Even bitplanes to sprite 2 (or 3) 5 Even bitplanes to sprite 0 (or 1) 4 Odd bitplanes to sprite 6 (or 7) 3 Odd bitplanes to sprite 4 (or 5) 2 Odd bitplanes to sprite 2 (or 3) 1 Odd bitplanes to sprite 0 (or 1) 0 Even bitplanes to odd bitplanes About odd-numbered sprites. --------------------------- The numbers 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 bitplanes. The collision control register specifies how to handle the bitplanes during collision detect.
[Back to Amiga Developer Docs]