The MathUtils.isPowerOfTwo() function is a method in the Three.js library that checks whether a given integer is a power of two.
THREE.MathUtils.isPowerOfTwo(value)
value - An integer value to check whether it is a power of two.true if value is a power of two, false otherwise.The isPowerOfTwo() method is used to check whether a given integer is a power of two. This method is useful in situations where you need to perform certain operations only if the number is a power of two.
Internally, the isPowerOfTwo() method is implemented using a bitwise AND operation. A power of two can be represented as a binary number with only one bit set to one. For example, 4 (100 in binary) and 8 (1000 in binary) are powers of two. When we perform a bitwise AND between this number and that number minus one, we get 0. For example, 4 & 3 (011 in binary) is equal to 0. This is true for all powers of two.
MathUtils.isPowerOfTwo = function ( value ) {
return ( value & ( value - 1 ) ) === 0 && value !== 0;
};
let isPowerOfTwo = THREE.MathUtils.isPowerOfTwo;
console.log(isPowerOfTwo(2)); // true
console.log(isPowerOfTwo(3)); // false
console.log(isPowerOfTwo(4)); // true
console.log(isPowerOfTwo(5)); // false
console.log(isPowerOfTwo(8)); // true
console.log(isPowerOfTwo(10)); // false
In conclusion, the MathUtils.isPowerOfTwo() method is a built-in method in the Three.js library. This method checks whether a given integer is a power of two using a bitwise AND operation. This is useful when you need to perform some operations only if the number is a power of two.