Commodore 128D - Page 324

BUMP
CHR$
COS
—Return sprite collision information
BUMP(N)
To determine which sprites have collided since the last check, use
the BUMP function. BUMP(1) records which sprites have collided
with each other and BUMP(2) records which sprites have collided
with other objects on the screen. COLLISION need not be active to
use BUMP. The bit positions (0-7) in the BUMP value correspond to
sprites 1 through 8 respectively. BUMP(n) is reset to zero after each
call.
The value returned by BUMP is the result of two raised to the power
of the bit position. For example, if BUMP returned a value of 16,
sprite 5 was involved in a collision since 2 raised to the power of 4
(bit position) equals 16. Here's how the sprite numbers and BUMP
values returned correspond:
BUMP Value: 128
Bit Position: 7
Sprite Number: • 8
64
6
7
32
5
6
16
4
5
8
3
4
4
2
3
2
1
2
1
0
1
EXAMPLES:
PRINT BUMP (1)
12 Indicates that sprite 3 and 4 have collided.
PRINT BUMP (2)
32 Indicates that sprite 6 has collided with an
object on the screen.
—Return character for specified CBM ASCII code
CHR$(X)
This is the opposite of ASC and returns the string character whose
CBM ASCII code is X. Refer to Appendix E for a table of CHR$ codes.
EXAMPLES:
PRINT CHR$ (65) Prints the A character.
A
PRINT CHR$ (147) Clears the text screen.
—Return cosine for angle of X radians
COS(X)
This function returns the value of the cosine of X, where X is an angle
measured in radians.
EXAMPLE:
PRINT COS (tt/3)
.5
i I
S i
r i
u
u
LJ
U
U
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BASIC 7.0 ENCYCLOPEDIA—Basic Functions