static getDataMaskBit(maskPattern /*int*/, x /*int*/, y /*int*/) {
			let intermediate; /*int*/
			let temp; /*int*/
			switch (maskPattern) {
				case 0:
					intermediate = (y + x) & 0x1;
					break;
				case 1:
					intermediate = y & 0x1;
					break;
				case 2:
					intermediate = x % 3;
					break;
				case 3:
					intermediate = (y + x) % 3;
					break;
				case 4:
					intermediate = (Math.floor(y / 2) + Math.floor(x / 3)) & 0x1;
					break;
				case 5:
					temp = y * x;
					intermediate = (temp & 0x1) + (temp % 3);
					break;
				case 6:
					temp = y * x;
					intermediate = ((temp & 0x1) + (temp % 3)) & 0x1;
					break;
				case 7:
					temp = y * x;
					intermediate = ((temp % 3) + ((y + x) & 0x1)) & 0x1;
					break;
				default:
					throw new IllegalArgumentException('Invalid mask pattern: ' + maskPattern);
			}
			return intermediate === 0;
		}
Return the mask bit for "getMaskPattern" at "x" and "y". See 8.8 of JISX0510:2004 for mask
pattern conditions.