• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42
• 43
• 44
• 45
• 46
• 47
• 48
• 49
• 50
• 51
• 52
• 53
• 54
• 55
• 56
• 57
• 58

// Taken from the bit-twiddle package

/**
 * Rounds to next power of two.
 * @function nextPow2
 * @memberof PIXI.utils
 * @param {number} v - input value
 * @returns {number} - next rounded power of two
 */
export function nextPow2(v: number): number
{
    v += v === 0 ? 1 : 0;
    --v;
    v |= v >>> 1;
    v |= v >>> 2;
    v |= v >>> 4;
    v |= v >>> 8;
    v |= v >>> 16;

    return v + 1;
}

/**
 * Checks if a number is a power of two.
 * @function isPow2
 * @memberof PIXI.utils
 * @param {number} v - input value
 * @returns {boolean} `true` if value is power of two
 */
export function isPow2(v: number): boolean
{
    return !(v & (v - 1)) && (!!v);
}

/**
 * Computes ceil of log base 2
 * @function log2
 * @memberof PIXI.utils
 * @param {number} v - input value
 * @returns {number} logarithm base 2
 */
export function log2(v: number): number
{
    let r = (v > 0xFFFF ? 1 : 0) << 4;

    v >>>= r;

    let shift = (v > 0xFF ? 1 : 0) << 3;

    v >>>= shift; r |= shift;
    shift = (v > 0xF ? 1 : 0) << 2;
    v >>>= shift; r |= shift;
    shift = (v > 0x3 ? 1 : 0) << 1;
    v >>>= shift; r |= shift;

    return r | (v >> 1);
}