Rounds a numeric value to the nearest power of two toward zero.
input value
rounded value
var v = trunc2( 3.141592653589793 ); // returns 2.0
var v = trunc2( 13.0 ); // returns 8.0
var v = trunc2( -0.314 ); // returns -0.25
Rounds a numeric value to the nearest power of two toward zero.