joystick sensitivity

Alan Anderson · #9 13-02-2005, 20:38

Quote:

Originally Posted by AIBob

abs(p1_x) can be replaced with (p1_x && 0x7F), because the last bit is the sign,...

Not so. For two reasons, the first of which is very important:

Negative numbers are not stored in sign-magnitude form. They are in "two's-complement" form. The value -1 masked with 0x7F yields a value of 127, a far cry from the expected 1.

(The second reason is that && is a logical operator, giving a true or false result. The arithmetic and is represented by a single &.)

The simplest syntax I know of for an absolute value function uses the ternary if operator. It's cryptic, but effective:

Code:

(value<0?-value:value)

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