import { _decorator } from 'cc'

const { ccclass, property } = _decorator

@ccclass('BitUtil')
export default class BitUtil {
  //index是二进制从右到左
  public static isBitSet(value: number, index: number): boolean {
    let str: string = value.toString(2)
    return parseInt(str[str.length - 1 - index]) == 1
  }

  //从右到左计算
  public static setBitValue(value: number, index: number): number {
    let newValue: number = value
    let str: string = value.toString(2)
    let newStr: string = ''
    let maxIndex = Math.max(str.length - 1, index)
    for (let i = 0; i <= maxIndex; i++) {
      if (index == i) {
        newStr = '1' + newStr
      } else {
        if (str[i] == undefined) {
          newStr = '0' + newStr
        } else {
          newStr = str[i] + newStr
        }
      }
    }
    newValue = parseInt(newStr, 2)
    return newValue
  }

  public static clearBitValue(value: number, index: number) {
    let newValue: number = value
    let str: string = value.toString(2)
    let newStr: string = ''
    for (let i = str.length - 1; i >= 0; i--) {
      if (index == str.length - 1 - i) {
        newStr = '0' + newStr
      } else {
        newStr = str[i] + newStr
      }
    }
    newValue = parseInt(newStr, 2)
    return newValue
  }
}